WILDLIFE DIVERSITY AND HABITAT
ASSOCIATED WITH COMMERCIAL CRANBERRY
PRODUCTION IN WISCONSIN
by
Eric Edward Jorgensen
A Thesis submitted in partial fulfillment of the
requirements for the degree
MASTER OF SCIENCE
College of Natural Resources
UNIVERSITY OF WISCONSIN
Stevens Point, Wisconsin
May 1992 APPROVED BY THE GRADUATE COMMITTEE OF:
LyleE.Nauman, Professor of Wildlife and Advisor
James W. Hardin Professor of Wildlife ~'. La~/4 ~'2k> 0rederick A. Copes Professor of Water Resources
ii ABSTRACT
The wildlife diversity and habitat associated with commercial cranberry production in Wisconsin were studied from May 1990 through August 1991. Diversity studies were completed on birds, mammals, fish, reptiles, amphibians and aquatic invertebrates. Habitat studies were completed on the areas near the cranberry beds, associated impoundments, sedge meadows, and sphagnum moss (Sphagnum spp.) communities.
Animals responded to cranberry production in a variety of ways. Avian species diversity was measurably affected by the edge associated with the intersection of cranberry beds and adjacent unmodified habitat. Swallows, savannah sparrows
(Passerculus sandwichensis) and brown-headed cowbirds
(Molothrus ater) used this ecosystem, apparently due to the presence of cranberry beds. Waterfowl used the impoundments for migration and their distribution appeared to be influenced by mollusc abundance or diversity. Mammals selected against the cranberry beds but were evenly distributed outside of them. A range extension for the arctic shrew (Sorex arcticus) was documented in this research. Fishes in the impoundments were characteristic of waters which are susceptible to winterkill. Frogs of the genus Rana spp. are evenly distributed throughout the ecosystem, though spring emergence always occurred away from
iii the cranberry beds and ditches. Mink frogs may have been documented far south of their previously reported range.
The aquatic invertebrates which were most prevalent in the ditches were aeroneustic, indicating an unstable oxygen environment in the ditches.
1
iv ACKNOWLEDGEMENTS
I am grateful to those who have helped see this project through to a timely completion. My major advisor, Dr. Lyle
Nauman has been patient and helpful. He has also been there when I was filled with doubts. The other members of my graduate committee, Dr.'s James Hardin and Fred Copes have also been helpful in hearing out my concerns.
This project would have been impossible without the cooperation and funding from the Wisconsin State Cranberry
Growers Association. I especially thank their secretary, Tom
Lochner and the 5 cooperating growers from Wood, Juneau, and
Portage Counties. I also thank the Natural Resources
Foundation of Wisconsin for their financial support.
Numerous faculty at UWSP have been supportive of the project. I thank Dr. Eric Anderson, Asst. Professor of
Wildlife Ecology, and Dr. Charles Long, Professor of
Mammalogy, for showing a keen interest. I thank Dr. Robert
Freckman, Curator of the herbarium at UWSP, for identifying my plant specimens. Dr. Edward Stern aided in the
invertebrate identification and Dr. William Legrande helped
identify the fish. I thank Dr. Robert Rogers for his help during the statistical analysis. I also thank Dr.'s Charley
White, David Hillier, and Stanley Sczytcko for their guidance and advice.
I am also indebted to my field assistants, Michael and
V Jennifer Lee for their long hours and insect tolerance and
Brian Roberts for identifying my non-insect invertebrates. I
thank my parents Lee and Shirley Jorgensen for their
tolerance and interest. But most especially I thank my wife,
Naomi who put up with the most; who heard about the problems
and gave me courage, who helped in the field every weekend
and who kept supper warm on week nights. In more ways than I
can suggest here, this project was not possible without her.
vi TABLE OF CONTENTS
ABSTRACT------iii
-- ACKNOWLEDGEMENTS------v LIST OF TABLES------ix LIST OF FIGURES------xiv LIST OF APPENDICES------xv INTRODUCTION------1 Justification------1 Background------1 Layout------3 Ecosystems------4 Physiography------~------4 Ecology and Natural History------4
Climate------6 DESCRIPTION OF STUDY AREA------6 Wood County Facilities------7 Juneau County Facility------11
Portage County Facility------15 RESULTS AND DISCUSSION------17
Emergent Vegetation------17 Submerged Vegetation------47 Avian Community------59 Anatinae Migration------90 Mammal Community------102
Herpetofauna ------114 vii Fish------127
Aquatic Invertebrates------137
CONCLUSION------157
LITERATURE CITED------160
APPENDICES------182
viii LIST OF TABLES
Table 1. Relative percent occurrence of plant families in disturbed sedge meadows in south-central Wisconsin, 1990. ------23
Table 2. Correlation coefficients and associated probabilities of importance value of plant species vs. distance from dike in sedge meadow, type 1 sites, south-central Wisconsin, 1990. ------25
Table 3. Correlation coefficients and associated probabilities of importance value of plant families vs. distance from dike in sedge meadow, type 1 and 2 sites, south-central Wisconsin, 1990. ------~- 28 Table 4. Correlation coefficients and associated probabilities of importance value of plant species vs. distance from dike in sedge meadow, type 2 sites, south-central Wisconsin, 1990. ------33 Table 5. Percent occurrence of plant families in disturbed Sphagnum spp. communities in south-central Wisconsin, 1990. ------38
Table 6. Correlation coefficients and associated probabilities of importance value of plant species vs. distance from dike in Sphagnum spp. communities, south-central Wisconsin, 1990. ------40 Table 7. Correlation coefficients and associated probabilities of importance value of plant families vs. distance from dike in Sphagnum spp. communities, south-central Wisconsin, 1990. ------43 Table 8. Water depths recorded in shallow open water and bog mat impoundments associated with commercial cranberry production in south-central Wisconsin, 1990. ------51
ix Table 9. Frequency of occurrence of submerged and emergent vegetation, given as a percentage of the total number of samples taken in a habitat, during the early and late summer of 1990 in shallow qpen water and bog/mat impoundments associated with commercial cranberry production in south-central Wisconsin. ------52 Table 10. Number of submerged and emergent vegetation species recovered in a single sample, given as a percentage of the total number of samples taken in a habitat, during the early and late summer of 1990 in shallow open water and bog/mat impoundments associated with commercial cranberry production in south-central Wisconsin. ----- 55
Table 11. Habitat types associated with transect surveys for birds at commercial cranberry production facilities in south-central Wisconsin, 1990. ------64 Table 12. Index values of birds which seemed to select against the edge associated with cranberry bed matrices on cranberry bed matrix and impoundment transects at commercial cranberry production facilities in south-central Wisconsin, 1990. ------66
Table 13. Index values of birds which seemed to select for the edge associated with cranberry bed matrices on cranberry bed matrix and impoundment transects at commercial cranberry production facilities in south-central Wisconsin, 1990. ------68
Table 14. Index values of birds which did not seem to select for or against any specific habitat on cranberry bed matrix and impoundment transects at commercial cranberry production facilities in south-central Wisconsin, 1990. ------71
Table 15. Index values of birds which seemed to select against the cranberry bed matrix on cranberry bed matrix transects at commercial cranberry production facilities in south-central Wisconsin, 1990. ------74
X Table 16. Index values of birds which seemed to select for the cranberry bed matrix on cranberry bed matrix transects at commercial cranberry production facilities in south~central Wisconsin, 1990. ------78 Table 17. Index values of birds which did not seem to select for or against the cranberry bed matrix on cranberry bed matrix transects at commercial cranberry production facilities in south-central Wisconsin, 1990. ------80 Table 18. Spearman's rank correlation coefficients for the avian community on cranberry bed matrix transect sub-habitats and impoundment transects at commercial cranberry production facilities in south-central Wisconsin, 1990. ------84
Table 19. Observations of migrating ducks on the impoundments at Juneau County no. 1 during 30 March-27 April, 1991. ------94
Table 20. Observations of migrating ducks on the impoundments at Wood County no. 1 during 30 March-27 April, 1991. ------96 Table 21. Mammals snap trapped in and adjacent to commercial cranberry production beds in south-central Wisconsin, 1991. ------106
Table 22. Spatial distribution of small mammals snap trapped in and adjacent to cranberry bed matrices at commercial cranberry production facilities in south-central Wisconsin, 1991. ------107 Table 23. Visitation rates of mammal species to scent stations prepared outside the perimeter of cranberry bed matrices at commercial cranberry production facilities in south-central Wisconsin, 1991. ------108
Table 24. Presence of mammals observed in and near commercial cranberry production facilities in south-central Wisconsin, 1990-1991. ------110
xi Table 25. Percent occurrence of 1451 detected or identified frogs and 37 painted turtles in habitats associated with commercial cranberry production facilities in south-central Wisconsin, summer 1990. ------118
Table 26. Index value of frogs detected in habitats associated with commercial cranberry production facilities in south-central Wisconsin, summer 1990. ------119
Table 27. Average intensity of anuran choruses detected in habitats associated with commercial cranberry production facilities in south-central Wisconsin, spring 1991. --- 121
Table 28. Herpetofauna species observed at commercial cranberry production facilities in south-central Wisconsin during 1990 and 1991. ------123 Table 29. Species and number of fishes trapped with minnow traps in impoundments associated with commercial cranberry production facilities in south-central Wisconsin, 1991. ------130 Table 30. Species and number of fishes trapped with minnow traps in ditches associated with commercial cranberry production facilities in south-central Wisconsin, 1991. ------131 Table 31. Species and number of fishes trapped with windemere traps in impoundments associated with commercial cranberry production facilities in south-central Wisconsin, 1991. ------134 Table 32. Diversity of aquatic insect taxons collected adjacent commercial cranberry bed matrices at commercial cranberry production facilities in Wisconsin, spring and summer 1991. ------141
Table 33. Taxons of aquatic insects collected in the impoundments adjacent cranberry bed matrices at commercial cranberry production facilities in Wisconsin, spring and summer 1991. ------142
xii Table 34. Taxons of aquatic insects collected in water supply ditches adjacent cranberry bed matrices at commercial cranberry production facilities in Wisconsin, spring and summer 1991. ------146 Table 35. Taxons of aquatic insects collected in water removal ditches adjacent cranberry bed matrices at commercial qranberry production facilities in Wisconsin, spring and summer 1991. ------148 Table 36. Taxons of non-insect aquatic invertebrates collected in impoundments adjacent cranberry bed matrices at commercial cranberry production facilities in Wisconsin, spring and summer 1991. ------150
Table 37. Taxons of non-insect aquatic invertebrates collected in water supply ditches adjacent cranberry bed matrices at commercial cranberry production facilities in Wisconsin, spring and summer 1991. ------152
Table 38. Taxons of non-insect aquatic invertebrates collected in water removal ditches · adjacent cranberry bed matrices at commercial cranberry production facilities in Wisconsin, spring and summer 1991. ------154
xiii LIST OF FIGURES
Fig. 1. Location of the 5 commercial cranberry production facilities studied and their location compared to the driftless area, Glacial Lake Wiscon~in, and the tension zone. 5
Fig. 2. study area associated with Wood County no. 1, Township of Babcock (Sec. 32, T22N, R4E), south-central Wisconsin, 1990. ------8
Fig. 3. study area associated with Wood County no. 2, Township of Vesper (Sec. 13, T22N, R4E), south-central Wisconsin, 1990. ------10
Fig. 4. Study area associated with Wood County no. 3, Township of City Point (Sec. 19, T21N, R2E), south-central Wisconsin, 1990. ------12 Fig. 5. Study area associated with Juneau County no. 1, Township of Shennington (Sec. 17, T18N, R2E), south-central Wisconsin, 1990. ------13 Fig. 6. study area associated with Portage County no. 1, Township of Dancy (Sec. 17, T25N, R7E), south-central Wisconsin, 1990. ------16
xiv LIST OF APPENDICES
Appendix A. Definitions. ------183 Appendix B. Species list of all birds observed, and their location, on and near commercial cranberry production facilities in south-central Wisconsin, 1990-1991. ------186 Appendix c. Species list of all reptiles and amphibians observed, and their location, on and near commercial cranberry production facilities in south-central Wisconsin, 1990-1991. ----- 194
Appendix D. Species list of all mammals observed, and their location, on and near commercial cranberry production facilities in south- central Wisconsin, 1990-1991. ------196 Appendix E. Species list of all fish observed, and their location, on and near commercial cranberry production facilities in south-central Wisconsin, 1990-1991. ------198 Appendix F. Reprint; "Handbook Of Wildlife Management Techniques For Commercial Cranberry Growers In Wisconsin, a guide for cranberry growers and land use professionals in Wisconsin". ------200
xv 1
INTRODUCTION
Justification
Because cranberry beds are placed in wetlands, the
commercial cranberry industry is involved in the debate over wetland protection. Nationally, over 50% of the
presettlement wetlands have been lost and palustrine wetlands have been severely depleted (Reid et al. 1989).
Conversion of wetlands to cranberry beds accounts for about
50% of the new wetland losses occurring in Wisconsin
(Kalinich 1991). Because of these issues the Wisconsin State
Cranberry Growers Association wanted to document the status
of wildlife and habitat diversity on the wetlands associated with commercial cranberry production.
It is desirable to manage wildlife on the cranberry
bogs of Wisconsin. The data collected by this research will
help in the development of management techniques which will
have general application in Wisconsin, especially by
cranberry growers.
The research for this project was conducted only in
south-central Wisconsin. Five production facilities were
included. Three facilities were located in Wood County and 1
each in Juneau and Portage counties.
Background
Commercial cranberries are extensively cultivated in
Wisconsin. The cranberry (Vaccnium macrocarpon) is a low 2 growing ericaceous shrub. Under natural conditions it is typically found growing on high points in sphagnum (Sphagnum
-- spp.) bogs near the water's edge. Cranberries grow on high points because they are unable to thrive under moderate periods of root inundation during the growing season.
Because the cranberry is most prevalent close to the advancing edge of a primary hydrosere (the open water-bog edge ecotone) it is apparent that it is a pioneer successional species (Conway 1949) with poor competitive ability (Wilson and Keddy 1986). Reports of extensive beds of cranberries in the wild (Wisconsin State Cranberry
Grower's Association 1989, Eck 1990) probably refer to sites where a rare confluence of circumstances allowed retention of t~e earliest stages of succession.
Two regions of Wisconsin contain relatively dense assemblages of commercial cranberry production facilities.
One of these regions is in northern Wisconsin, including
Washburn, sawyer, Price, Vilas, Oneida, Douglas, Burnett,
Rusk, and Lincoln counties. In 1988 there were 975 ha of production in these counties (Wisconsin State Cranberry
Growers Association 1989). The second major region is in the south-central portion of the state including Jackson,
Monroe, Wood, Juneau, Portage, Eau Claire, Clark, Adams, and
Waushara counties. In 1988 there were 3181 ha of production in this region (Wisconsin state Cranberry Grower's
Association 1989). The growers control vast expanses of land 3 in addition to that which is dedicated to cranberry production. About 11% of a grower's land is in production.
The balance, over 40,469 ha, is available for management. A significant portion of this is wetland.
Layout
Cranberry beds are typically less than 4 ha in size.
Numerous beds are built adjacent to each other, forming a bed matrix. Each bed is bordered by a low dike which serves as an access road. The bed matrix is constructed within a modified wetland. The bed matrix areas are ditched and diked to provide drainage. The native vegetation and soils are removed, exposing peat. A thick layer of sand is laid down over the peat and cranberries are planted in the sand· (U.S.
Army Corps of Engineers 1991). This provides a growing medium which is inhospitable to most species. Even with this extensive modification supplemental chemical inputs are necessary to maintain the beds in productive condition (Mahr et al. 1989).
Extensive modification practices are also responsible for the persistence of cranberry plantings. Unlike most farming practices, cranberry beds are permanent. Beds have been maintained in productive condition for more than a century (Eck 1990). 4
Ecosystems
cranberry growing is water intensive. water is needed for over-winter protection of the cranberry plant, frost protection, harvest, and irrigation. This typically results in placement of the beds near large amounts of water which can be efficiently stored and transported. These areas have been surveyed for wildlife twice in the past. Klingbeil and
Stang (1981) surveyed growers, asking them to list wildlife species they had seen on their properties. IEP (1990) studied 3 facilities over a limited time in the late summer of 1989; too late in the season to have general applicability. Results were inconclusive and thus management techniques were not developed based on this survey.
Physiography
All 5 production facilities studied were in the northern portion of the driftless region of Wisconsin (Fig.
1). This area is marked by extensive zones of sand outwash overlain by peat (Martin 1965). The Wood and Juneau county facilities were located in the bed of Glacial Lake
Wisconsin. Glacial Lake Wisconsin left a contiguous 20,720 ha wetland in south-central Wisconsin (Hamilton 1971).
Ecology and Natural History
The south-central portion of Wisconsin is bisected by a vegetational tension zone (Curtis 1959); a region of 5
I N
~ . •• • • •••• •• •• I \ f'o,t•-~~(o. i I "y i- I i I .....,I I / \ -r---~ w•• .1.C.... l. • \.Joo! Co. 1 41 ...... • Wood C.C.~ ..., I I Legend .---.- Driftless Area ....-.....--... Glacial Lake Wisconsin ···· •· •··· Tension Zone Fig. 1. Location of the 5 commercial cranberry production facilities studied relative to the driftless area, Glacial Lake Wisconsin, and the tension zone. 6 interdigitation of communities of plants and animals. In this case the interdigitation is between the conifer hardwood community and the southern-hardwood community. The Juneau County facility was located south of the tension zone, the Portage County facility was located north of the tension zone and the 3 Wood County facilities were located within the tension zone (Fig. 1). The native wetland left by Glacial Lake Wisconsin included extensive sedge meadows (Catenhusen 1950). They were the result of changing climate (Winkler 1988) and were maintained by fire (Curtis 1959). The bed of Glacial Lake Wisconsin provided a refugium for Atlantic coastal plain plant species into the twentieth century (McLaughlin 1932). The region is of historical interest to wildlife professionals because the Babcock, Wisconsin area is where the last wild passenger pigeon (Ectopistes migratoria) was documented in Wisconsin in 1899 (Hough 1899, Schorger 1955). Climate The region is characterized by extremes of temperature and precipitation in any season (Lange 1990). Average annual precipitation is 81.3 cm and average temperature is 6.6 C (National Oceanic and Atmospheric Administration 1989). DESCRIPTION OF THE STUDY AREAS Five commercial cranberry production facilities were 7 selected as study areas. They were selected based on consultations with interested growers and preliminary field observations (White 1965). Growers had to express an interest in achieving the goals of the study and encouraging wildlife on their facilities. Different habitat types were to be included, habitats with a significant amount of open water, habitat dominated by sedge meadows, and sphagnum communities. All of the commercial cranberry wetlands studied in this research were classified as palustrine (Cowardin et al. 1979). Other habitat descriptions follow Eggers and Reed (1987). Wood County Facilities The first facility (Fig. 2) was located in the Township of Babcock, Wisconsin (Sec. 32, T22N, R4E). The cranberry beds were bordered to the north by an extensive shallow open water impoundment, and a wedge shaped area dominated by sedges (Carex spp.). The matrix was bordered to the east by a ditch and a mat of sedge including sphagnum moss. A shallow open water impoundment bordered the south-east edge. The matrix was bordered to the south by a wet meadow containing sedges, graminoids, and pteridiphytes. Adder's tongue (Ophioglossum vulgatum), was collected in this meadow. The grower's sand supply was also located to the south of the matrix. The matrix was bordered to the west by a lowland forest including maple (Acer spp.), aspen (Populus 8 Lgwland t-orest Wet Meadow Cranberry Bed Matrix .i" ••• I· • . ·. ·1 • • •• ·I ••••••• : •. 1· • • • • Shrub-Carr °I. ••••••••. ·I • • .r. Carex ·. 1- • • -----, ·1 • • • • • • Shrub-Carr I J ...... I I:. -=- :.... ·-· ...! ..!. Carex "'--"-- • · C~rr, Sphagnum - .,,. . a Reservoir -$-N Legend: Ditch I ,.,, G? • Access Road 0 50 100 200 ~w : I SCALE METERS Fig. 1. Study area associated with Wood County no. 1, Township of Babcock {Sec. 32, T22N, R4E). south-central Wisconsin, 1990. 9 tremuloides), and ash (Fraxinus spp.). In the second year of the study new cranberry beds were under construction in this area. Water samples taken on 8 August 1991 in various aquatic habitats indicated a pH of 5.5 to 6.25, alkalinity of 1 to 2 ppm, dissolved oxygen of o to 9 ppm and a temperature of 18 to 23 0 c. The second facility (Fig. 3) was located in the Township of Vesper, Wisconsin (Sec. 13, T22N, R4E). The cranberry beds were bordered to the north by an extensive shallow open water impoundment which was apparently in an advanced state of succession due to the presence of large amounts of water weed (Elodea canadensis) and coontail (Ceratophyllum demersum). Along the north-west edge a lowland forest of maple (Acer spp). and white pine (Pinus strobus) was present. The matrix was bordered to the east by a sedge meadow which was used in the winter as a road to access a sand supply. Adder's-tongue was collected in this meadow. The matrix was bordered to the south by an extensive sedge meadow, which was contiguous with that to the east. A small grove of red maple (Acer rubra) grew in the midst of this meadow. New beds were being constructed along the south-east edge of the existing matrix. The west edge of the matrix was bordered by buildings associated with cranberry production and houses. Lawn and gravel roads were the dominant habitats present. Water samples taken on 8 August 1991 in various aquatic habitats indicated a pH of 5.5 to 10 wav~I," arking I I : I . . . ·. : I Acer. Plnus -1 Carex . . : I I . . . . , I ...... I . . I . . . . . ----- Carex · A~vs Carex . Ace~}-:-:-: Cranberry Bed Matrix lca'r~ .v~~ ~ .A.,A..' ,A Reservoir Ill r Ill 0 I ""v~~~.,,.,,.~~"'-,..___..,.__"-"'__,..__,,__, ... I 1/1 1;,.•------~~ t!) I~,.:~___,.._~.,._ ... ~ f" It,, ...... I.·.\'-: I Reservoir :~::::::::: :~~:~;:>:::::::::: ~~I- t::i:. :u_-;::~:;-,e.,,.....,,...,,~~~~~_.A...... ~!Ii- ...... r-.;::-::-.::-.;::-::-.::-.;::-::::- Legend: 0 50 100 200 HJ : I -$-N ---- Ditch SCALE METERS .. : Eii? •• Access Road Fig. 3. Study area associated with Wood County no. 2, Township of Vesper (Sec. 13, T22N, R4E), south-central Wisconsin. 1990. 11 7.0, alkalinity of 2 to 3 ppm, dissolved oxygen of 5 to 10 ppm and a temperature of 20 to 23 0 c. The third facility (Fig. 4) was located in the Township of City Point, Wisconsin (Sec. 19, T21N, R2E). The cranberry beds were bordered to the north by cranberry beds under construction. Further north an established sphagnum bog and an encroaching coniferous forest of tamarack (Larix laricina) were present along with a bog/mat impoundment to the north-west. The matrix was bordered to the south and east by a mown shrub-carr, dominated by bog birch (Betula pumila) with a ground layer of sphagnum. Further to the south, the extant shrub-carr included bog birch, speckled alder (Alnus rugosa) and a young stand of white pine. The west edge of the matrix was bordered by a bog/mat impoundment. The north-west corner of the bed matrix was occupied by some buildings and a gravel drive. Further to the north-west, a bluff abruptly rose above the landscape. Old growth oak (Quercus spp.) and white pine grew on the bluff. Water samples taken on 9 August 1991 in various aquatic habitats indicated a pH of 4.25 to 5.25, alkalinity of 1 to 2 ppm, dissolved oxygen of 4 to 7 ppm and a temperature of 16 to 22 0 C. Juneau County Facility The Juneau County facility (Fig. 5) was located in the Township of Shennington, Wisconsin (Sec. 17, T18N, R2E). The 12 11 I: 11 I 1 Gravk~I/ 1 Cranberry Bed I : Par ing :1 Matrix I. 1 I: ,L1 ______~_J • . . ·l ·.-.·.-.1. . . I • ·1 • .1 Sptia§pum .11 Sphq8pum. I ··11 . .Ml ••.l ... CJ • · ·1 1• ••••••••••••••.1 (.) ..•••.I I• • • • • • • j I _, _,_ ..,_ .:..J L :_._: ....:.. ..:.. .:_ • ..0 --.-:-:i Cranberry Bed ...::i L ... I Matrix I (/) Sphagnum. ·1 C MCIT • -I 3: . . . . I I 0 _:_·_·_:i ::I!: --:-.7 . . I Sptia§pum."I ------7 · ·I Meadow I ·_:....:....:..0.______J: ------7 Mown Shrub-Carr 1. I ..,...... ~ ~ '"'<""""(' ~""{ I Larix, Betula, Populus Pinus strobus Betula I : Legend: N ---- Ditch -; •·'# G? . Access Road 0 50 100 200 1-LJ I I ~ METERS SCALE Fig. 4. Study area associated with Wood County no. 3, Township of City Point {Sec. 19, T21N, R2E), south-central Wisconsin, 1990. 13 ~----- ~- Reservoir ~ ~ I I I I I I I I Meadow I I I Cranberry Bed I Fraxinus Matrix I I I I 1 I (I· ...... ·. J I A11...... ••.. I I I . . . • . . 1 I I 1• • . • • I I I • • • ~ . • I I Carex ••• l I . . 1 I . . . I 1shallow ::::1 -Marsh . . . . . ; ·:::::J . . . • . I . . . 1 • _. _. j Legend: . . I Ditch . . 1 I,.,, R . Access Road . . . I 0 50 100 200 -----~ HJ : I :::., Fraxinus SCALE METERS • . . . 1 . . . . . I . ·:::1 . . ; • _. J . • I _._.J. 1 . . . I _. _. . . _. . . . . • . . . . 1 - .:_ ·_· _:.:... :__·_: j i------1:::'...J I 1 ; I• ,,:Q •• el, • 6 ,Ii ·"' fo 1, ., ' .... ,. :S • ·I: Fig. 5. Study area associated with Juneau County no. 1, Township of Shennington (Sec. 17, T18N, R2E), south-central Wisconsin, 1990. 14 cranberry beds were bordered to the north by an extensive and diverse shallow open water impoundment. The matrix was bordered to the east by a lowland forest, dominated by ash (Fraxinus spp.). There was also a small shallow marsh along this edge. The south edge of the matrix was substantially developed. There was a narrow planting of lawn grasses, a ditch, some red oak (Ouercus rubra) and then a highway. The west edge of the matrix was bordered by a diverse and unique assemblage of habitats. The habitat was predominately sedge meadow and included golden sedge (Carex aurea), blue-eyed grass (Sisyrinchium albidum), and adder's-tongue (Ophioglossum vulgatum). There were elevated areas within the sedge meadow supporting wild bergamot (Monarda fistulosa) and other plants requiring drier conditions, approximating a tall grass prairie. Near the south-west corner there was a high area with a grove of oak (Quercus spp.). It amounted to a small (4 ha) oak savannah. There also were groundwater seeps present in this sedge meadow. The north-west edge of the matrix had been modified into an airfield. It was seldom used, but was mown. It was often wet, approximating a wet meadow. Blue-eyed grass also grew here. Water samples taken on 9 August 1991 in various aquatic habitats indicated a pH of 5.75 to 7.5, alkalinity of 2 to 4 ppm, dissolved oxygen of 4 to 11 ppm and a temperature of 18 to 23° C. 15 Portage County Facility The Portage County facility (Fig. 6) was located in the Township of Dancy, Wisconsin (Sec. 17, T2~N, R7E). Tbe cranberry beds were bordered to the west and south-west by a bog/mat impoundment. It included sedges but was predominantly sphagnum moss with an encroaching coniferous forest of tamarack (Larix laricina) and black spruce (Picea mariana). The west edge and corner included an impoundment which contained some elements of open shallow water communities. The north-west corner and north east edge included a narrow border of sedge backed by an established forest of red maple (Acer rubra) and hemlock (Tsuga canadensis). The north-east corner was a lawn area including white oak (Ouercus alba) and white pine (Pinus strobus). The south-east edge of the matrix was a mown shrub-carr which was highly disturbed. In the second year of the study, this area was being converted into cranberry beds. The south edge was bordered to the south-east by shrub-carr, in the middle by a forest grove of red maple and to the south-west by a bog/mat impoundment. The mat included sphagnum (Sphagnum spp.), lake sedge (Carex lacustris), cattail (Typha spp.) and a dying grove of tamarack. Water samples taken on 10 August 1991 in various aquatic habitats indicated a pH of 5.0 to 6.25, alkalinity of 2 to 4 ppm, dissolved oxygen of 4 to 12 ppm and a temperature of 20 to 21 0 c. 16 Larix Cranberry Bed Matrix. Alnus Lawn/ ~ Quercus ~ Populus ~ ~ Legend: Ditch I rot# 12 • Access Road 0 50 100 200 LU I I SCALE METERS Fig. 6. Study area associated with Portage County no. 1, Township of Dancy (Sec. 17, T25N, R7E), south-central Wisconsin, 1990. EMERGENT VEGETATION 17 18 INTRODUCTION This research investigated the vegetation gradient formed by the presence of commercial cranberry beds. The hypothesis was that a vegetation gradient would be present and express itself through changes in importance values (Cox 1967) of families and species at various distances from the cranberry beds, with the highest degree of disturbance occurring closest to the cranberry beds. Disturbance, both natural and human induced, strongly •effects wetland plant communities (Auclair et al. 1973, Day et al. 1988, Kantrud et al. 1989). White (1965) found that disturbance was the primary factor affecting vegetation in southeastern Wisconsin shrub-carr. Walker and Wehrhahn (1971) studied 26 environmental factors thought to effect vegetation and identified disturbance as the most important factor. succession is a second phenomena which strongly affects wetland plant communities (Gates 1942, Conway 1949). Sedge Meadows Natural disturbances have maintained sedge meadows in Wisconsin throughout the Holocene (Catenhusen 1950, Curtis 1959). Fire (Curtis 1959), soil drainage (Dix and Smeins 1967), water level fluctuation (Schwintzer and Williams 1974) and exposure to wind and waves (Keddy 1983) are examples of natural disturbances. Incidence of ruderal 19 species (Nilsson et al. 1989) indicates disturbance. Human disturbances have been impacting Wisconsin sedge meadows for over 90 years (Catenhusen 1950). Artif.iclal drainage, inundation, mowing, grazing, burning, soil disturbance and tree/stump removal are human induced disturbances (Frolik 1941, Catenhusen 1950, White 1965). These authors indicated that disturbance is characterized by an increase in ruderal forbs, graminoids, composites and woody shrubs (Frolik 1g41, Catenhusen 1950, White 1965). Bogs Succession is the primary process responsible for plant community segregation in bogs (Gates 1942, Conway 1949). Heinselman (1970) found that water chemistry below the floating mat effected vegetation on the mat. Wiregrass sedge (Carex lasiocarpa) was typically found at the advancing edge of the floating mat (Gates 1942). Disturbance has not been identified as a major process responsible for the makeup of the bog community. However, Gates (1942) suggested that cattail (Typha spp.) and reed (Phragmites spp.) are indicative of disturbance in bog communities while Conway (1949) identified leatherleaf (Chamaedaphne spp.) as an indicator of desiccation. 20 STUDY AREA and METHOD Sampling sites for vegetation analysis were selected which met 2 criteria; 1) they must have appeared homogeneous (White 1965, Dix and Smeins 1967, Auclair et al. 1973) and 2) human induced disturbance (ditches, dikes or roads) lateral to them must have been at least 100 m from its edge. Obvious gradients (elevation, exposure) and the effects of succession (Auclair et al. 1973) were avoided. Each site measured 40X100 m. The 100 maxis extended from the edge of the dike into the wetland matrix. The 40 m axis formed a transect, paralleling the dike at 10 m intervals to a distance of 100 m. Sites were systematically sampled (Frolik 1941, White 1965, Dix and Smeins 1967, Auclair et al. 1973). A floristic curve was generated and new species occurrence was <10% after 7 plots along a transect (Anderson and Ohmart 1986). Plots (0.1 m2 ) (Daubenmire 1968) were sampled at 5 m intervals. A total of 70 plots along 10 transects were sampled per site. Importance values were calculated for each species and family (Cox 1967). A taxonomic group's relationship to disturbance was placed in 1 of 2 classes: 1) "increasers" were taxons which expressed a relatively high importance close to the cranberry beds and, 2) "decreasers" were taxons which expressed a relatively low importance close to the cranberry beds. Taxonomy followed Gleason and Cronquist (1963). 21 Change in importance value was correlated (Pearson's correlation) with distance from the dike. For each taxon, correlations were taken from calculated importance values. Importance values were not normalized between sites because it was assumed that sites with a high importance value gave better estimates of disturbance than sites a with low importance value. Sedge Meadows Eight palustrine (Cowardin et al. 1979) sedge meadows were studied. Three of the sites were from Juneau County no. 1, 4 were from Wood County no. 2 and 1 was from Wood County no. 3. Sites were grouped into 1 of 2 types depending on hydrology. "Type 1 Sites" included 3 sedge meadows which directly abutted a sand dike bordering the cranberry beds. "Type 2 sites" included 5 sedge meadows which were separated from the dike by a drainage ditch. Bogs Seven palustrine (Cowardin et al. 1979) sphagnum (Sphagnum spp.) bogs were studied. Three sites were from Portage County no. 1 and 2 each were from Wood County no.'s 1 and 3. RESULTS The study was conducted during May-July 1990. The 22 results are divided into 3 site types; 2 site types in sedge meadows and 1 in sphagnum bogs. -- On each site 10 records were possible for each taxon. A taxon received a O for a transect if it was absent from the transect but present on at least 1 other transect in a site. Taxons with a sample size of less than 12 were conservatively interpreted because this was the lower limit of sensitivity for the Pearson test (Chatfield and Collins 1980). Sample sizes of 20 or more are generally reliable. The correlation coefficient records the strength of a taxon's importance value vs. distance from a disturbance. High correlation coefficients indicate a strong relationship with distance. The validity of the correlation is given by the probability. Increasers had a negative correlation coefficient and decreasers had a positive correlation coefficient. PLANT COMMUNITIES Sedge meadows Type 1 Sites Forty-five plant species in 19 families (Tables 1-3) were recorded in type 1 sites. Pteridiphytes were the most commonly occurring decreasers (Tables 2-3). The most important increaser, beaked sedge (Carex scoparia), thrives in sandy conditions (Voss 1972). 23 Table 1. Relative percent occurrence of plant families in disturbed sedge meadows in south-central Wisconsin, 1990. % OCCURRENCE IN % OCCURRENCE IN FAMILY TYPE 1 SITES8 TYPE 2 SITESb Alismaceae 0.24 Anacardiaceae 0.03 Balsaminaceae 2.06 1.50 Campanulaceae 4.36 1.19 Caprifoliaceae 0.03 Compositae 24.13 21.25 Convolvulaceae 0.20 Cyperaceae 18.06 20.82 Equisetaceae 0.63 Ericaceae 0.08 0.29 Fabaceae 1.28 Gentianaceae 0.03 Gramineae 4.04 7.11 Iridaceae 0.70 0.05 Juncaceae 0.23 Labiatae 3.01 5.89 Liliaceae 0.55 0.18 Onagraceae 0.26 0.05 Ophioglossaceae 0.16 24 Table 1. Continued. % OCCURRENCE IN % OCCURRENCE IN FAMILY TYPE 1 S ITES8 TYPE 2 SITESb Osmundaceae 8.99 8.93 Oxalidaceae 0.32 Polygonaceae 15.02 5.88 Polypodiaceae 11.43 3.52 Primulaceae 0.99 2.63 Ranunculaceae 0.27 Rosaceae 2.64 11. 80 Rubiaceae 1.07 Salicaceae 1.44 Scrophulariaceae 0.29 Umbelliferae 0.45 1. 53 Verbenaceae 1.96 0.24 Violaceae 1.02 1.14 a Type 1 sites included sedge meadows which were adjacent a cranberry bed matrix. b Type 2 sites included sedge meadows which were adjacent a cranberry bed matrix but separated from it by an open ditch of water. 25 Table 2. Correlation coefficients and associated probabilities of importance value of plant species vs. 8 dist.a.rice from dike in sedge meadow, type 1 sites , south central Wisconsin, 1990. TRANSECTS CORRELATION SPECIES (N) COEFFICIENTb PROBABILITYc Eupatorium maculatum 10 0.70 0.012 Maianthemum canadense 10 0.60 0.032 Osmunda claytoniana 20 0.58 0.004 Aster puniceous 10 0.52 0.061 Rosa palustris 10 0.52 0.061 Trientalis borealis 10 0.52 0.061 Rubus pubesens 20 0.46 0.020 Vaccinium oxycoccos 10 0.41 0.122 Onoclea sensibilis 30 0.40 0.016 Thelypteris palustris 30 0.36 0.024 Phalaris arundinacea 10 0.29 0.208 Dryopteris cristata 30 0.27 0.072 Lysimachia thyrsiflora 10 0.20 0.286 Viola pallens 30 0.18 0.177 Potentilla palustris 10 0.17 0.315 Rubus strigosis 10 0.16 0.330 Sium suave 20 0.13 0.297 Bidens aristosa 30 0.09 0.319 26 Table 2. Continued. TRANSECTS CORRELATION SPECIES (N) COEFFICIENTb PROBABILITYc Polygonum hydropiperoides 20 0.08 0.362 Iris versicolor 20 0.08 0.370 Rubus hispidus 10 0.06 0.437 Aster umbellatus 30 0.05 0.387 Bidens disco idea 20 0.03 0.446 Athyrium angustifolium 30 -0.01 0.478 Impatiens biflora 30 -0.03 0.430 Leersia oryzoides 10 -0.04 0.457 Stachys palustris 20 -0.04 0.432 Sagittaria latifolia 10 -0.06 0.437 Carex rostrata 30 -0.08 0.334 Verbena hastata 10 -0.10 0.396 Polygonum sagittatum 30 -0.10 0.291 Lycopus unifloris 30 -0.16 0.194 Spiraea alba 10 -0.17 0.315 Epilobium angustifolium 20 -0.19 0.213 Solidago gigantea 30 -0.21 0.134 Euthamia graminiflora 10 -0.28 0.214 Osmunda regalis 10 -0.29 0.208 Campanula aparinoides 30 -0.30 0.052 Lycopus americana 20 -0.37 0.054 27 Table 2. Continued. TRANSECTS CORRELATION SPECIES (N) COEFFICIENTb PROBABILITYc Scirpus cyperinus 10 -0.42 0.112 Poa palustris 20 -0.44 0.028 Frageria vesca 20 -0.44 0.025 Eupatorium perfoliatum 20 -0.47 0.019 Calamagrostis canadensis 20 -0.49 0.015 Carex scoparia 20 -0.53 0.008 a Type 1 sites included sedge meadows which were adjacent a cranberry bed matrix. b The correlation coefficient records the strength of a taxon's importance value vs. distance from a disturbance. Increaser's correlation is negative and decreaser's is positive_ .. C The validity of the correlation is given by the probability. 28 Table 3. Correlation coefficients and associated probabilities of importance value of plant families vs. distance ·from dike in sedge meadow, type 1 a and 29 sites, south-central Wisconsin, 1990. TYPE N TRANSECTS CORRELATION FAMILY SITE Spp. (N) COEFFICIENTc PROBABILITYd Liliaceae 1 1 10 0.60 0.032 Osmundaceae 1 2 20 0.57 0.004 Primulaceae 1 2 10 0.57 0.044 Betulaceae 2 1 10 0.56 0.048 Polypodiaceae 1 5 30 0.51 0.002 Osmundaceae 2 2 30 0.48 0.004 Ericaceae 1 1 10 0.41 0.122 Primulaceae 2 2 30 0.39 0.017 Ranunculaceae 2 1 20 0.37 0.055 Convolvulaceae 2 1 30 0.36 0.024 Labiatae 2 5 50 0.27 0.030 Polygonaceae 2 5 50 0.22 0.060 Violaceae 1 1 30 0.18 0.177 Rosaceae 1 8 30 0.14 0.237 Umbelliferae 1 1 20 0.13 0.297 Ericaceae 2 2 20 0.12 0.309 Compositae 2 14 50 0.07 0.320 Gramineae 2 7 40 0.04 0.410 29 Table 3. Continued. TYPE N TRANSECTS CORRELATION FAMILY SITE Spp. (N) COEFFICIENTc PROBABILITYd Rosaceae 2 11 50 0.01 0.466 Iridaceae 1 1 20 0.01 0.491 Polypodiaceae 2 5 50 -0.02 0.458 Umbelliferae 2 1 30 -0.02 0.449 Polygonaceae 1 4 30 -0.03 0.436 Balsaminaceae 1 1 30 -0.03 0.430 Campanulaceae 2 1 40 -0.04 0.404 Alismaceae 1 1 10 -0.06 0.437 Onagraceae 2 1 10 -0.06 0.437 Salicaceae 2 7 40 -0.08 0.304 Verbenaceae 1 1 10 -0.10 0.396 Violaceae 2 3 50 -0.11 0.216 Balsaminaceae 2 1 30 -0.13 0.253 Ophioglossaceae 2 1 20 -0.14 0.277 Campanulaceae 1 30 30 -0.16 0.206 Cyperaceae 2 8 50 -0.16 0.136 Rubiaceae 2 2 40 -0.17 0.149 Onagraceae 1 1 20 -0.19 0.213 Cyperaceae 1 4 30 -0.22 0.117 Labiatae 1 3 30 -0.28 0.068 Scrophulariaceae 2 1 20 -0.29 0.111 30 Table 3. Continued. TYPE N TRANSECTS CORRELATION FAMILY SITE Spp. (N) COEFFICIENTc PROBABILITYd Gramineae 1 5 30 -0.30 0.052 oxalidaceae 2 1 20 -0.32 0.082 Equisetaceae 2 1 30 -0.36 0.025 Juncaceae 2 2 20 -0.37 0.055 Verbenaceae 2 1 20 -0.38 0.047 Anacardiaceae 2 1 10 -0.41 0.122 Caprifoliaceae 2 1 10 -0.41 0.122 Gentianaceae 2 1 10 -0.41 0.122 Iridaceae 2 1 10 -0.41 0.122 Fabaceae 2 2 30 -0.42 0.011 Liliaceae 2 2 20 -0.50 0.012 Compositae 1 10 30 -0.52 0.002 a Type 1 sites included sedge meadows which were adjacent a cranberry bed matrix. b Type 2 sites included sedge meadows which were adjacent a cranberry bed matrix but separated from it by an open ditch of water. C The correlation coefficient records the strength of a taxon's importance value vs. distance from a disturbance. Increaser's correlation is negative and decreaser's is 31 Table 3. Continued. positive. d The validity of the correlation is given by the probability. 32 Type 2 Sites Eighty-four plant species in 31 families were recorded in type 2 sites (Tables 1 and 4). The increasing species prefer dry, sandy or disturbed conditions (Voss 1972, Fassett 1976, Voss 1985). Forty-seven plant species in 25 families were recorded in sphagnum bogs (Tables 5-7). The decreasers, particularly manna grass (Glyceria septentrianalis) (Fassett 1957, Voss 1972), generally preferred wetter conditions. No pattern of disturbance expressed itself through taxonomic importance value changes in bogs. DISCUSSION The sedge meadows sampled during this study (Table 1) most closely corresponded to northern sedge meadows (Curtis 1959). Cyperaceae was present in greater amounts than in any community reported by Curtis (1959). The bogs sampled (Table 5) did not correspond closely to any community identified by Curtis (1959). Cyperaceae and Ericaceae were present in greater amounts than in the communities of Curtis (1959). The data indicate that the disturbance caused by the presence of commercial cranberry beds can extend into the adjacent wetlands. Disturbance was measurable in sedge 33 Table 4. Correlation coefficients and associated probabilities of importance value of plant species vs. 8 distance from dike in sedge meadow, type 2 sites , south central Wisconsin, 1990. TRANSECTS CORRELATION SPECIES (N) COEFFICIENTb PROBABILITYc Polygonum convolvulus 10 0.68 0.014 Betula pumila 10 0.56 0.048 Lysimachia terrestris 10 0.52 0.061 Osmunda claytoniana 30 0.46 0.005 Osmunda regalis 10 0.41 0.122 Polygonum amphibium 30 0.39 0.016 Scutellaria galericulata 20 0.38 0.048 Potentilla palustris 20 0.38 0.050 Caltha palustris 20 0.37 0.055 Vaccinium angustifolium 10 0.34 0.170 Spiraea tomentosa 30 0.33 0.039 Lycopus unifloris 50 0.31 0.014 Eupatorium perfoliatum 10 0.29 0.208 Salix pedicellaris 10 0.28 0.216 Athyrium angustum 30 0.28 0.068 Polygonum sagittatum 50 0.23 0.052 Eupatorium maculatum 40 0.21 0.094 34 Table 4. Continued. TRANSECTS CORRELATION SPECIES (N) COEFFICIENTb PROBABILITYc Scirpus cyperinus 30 0.20 0.149 Aster umbellatus 40 0.18 0.137 Bidens aristosa 40 0.18 0.139 Populus tremuloides 10 0.17 0.315 Viola cucullata 30 0.17 0.190 Phalaris arundinacea 30 0.13 0.253 Viola pallens 30 0.11 0.283 Thelypteris palustris 10 0.11 0.383 Poa palustris 40 0.08 0.305 Calamagrostis canadensis 40 0.06 0.348 Salix pyrifolia 10 0.06 0.437 Lycopus americana 40 0.06 0.367 stachys tenuifolia 40 0.04 0.398 Spiraea alba 20 0.03 0.444 Fragaria vesca 50 0.01 0.467 Galium labradoricum 40 0.01 0.486 Carex rostrata 50 0.00 0.494 Dryopteris cristata 10 -0.02 0.477 Sium suave 40 -0.03 0.438 Achillea rnillefoliurn 30 -0.04 0.425 Carnpanula aparinoides 40 -0.04 0.404 35 Table 4. Continued. TRANSECTS CORRELATION SPECIES (N) COEFFICIENTb PROBABILITYc Epilobium angustifolium 10 -0.06 0.437 Potentilla simplex 20 -0.07 0.387 Rubus pubesens 10 -0.09 0.404 Rubus hispidus 30 -0.09 0.309 Helianthus giganteus 30 -0.11 0.276 Impatiens biflora 30 -0.13 0.253 Ophioglossum vulgatum 20 -0.14 0.277 Rubus strigosis 20 -0.17 0.242 Solidago gigantea 50 -0.17 0.123 Galium boreale 30 -0.27 0.077 Poa pratensis 10 -0.28 0.218 Pedicularis lanceolata 20 -0.29 0.111 Panicum boreale 30 -0.29 0.061 Carex scoparia 30 -0.29 0.058 Eguisetum arvense 40 -0.30 0.030 Rosa palustris 20 -0.31 0.090 Oxalis stricta 20 -0.32 0.082 Salix petiolaris 20 -0.32 0.081 Monarda fistulosa 20 -0.36 0.058 Juncus tenuis 20 -0.37 0.055 Euthamia graminifolia 40 -0.38 0.009 36 Table 4. Continued. TRANSECTS CORRELATION SPECIES (N) COEFFICIENTb PROBABILITYc Onoclea sensibilis 40 -0.38 0.008 Verbena hastata 20 -0.38 0.047 Amphicarpa bracteata 30 -0.40 0.015 Diervilla lonicera 10 -0.41 0.122 Gentiana andrewsii 10 -0.41 0.122 Iris versicolor 10 -0.41 0.122 Toxicodendron radicans 10 -0.41 0.122 Fragaria virginiana 30 -0.42 0.010 Carex stricta 40 -0.43 0.003 Maianthemum canadense 10 -0.44 0.104 Panicum acuminatum 10 -0.45 0.095 Salix humilis 10 -0.47 0.085 Bidens disco idea 10 -0.52 0.061 Carex aurea 10 -0.52 0.061 Carex lasiocarpa 10 -0.52 0.061 Carex ovales 10 -0.52 0.061 Polygonum lapathifolium 10 -0.52 0.061 Salix lucida 10 -0.52 0.061 Salix sericea 10 -0.52 0.061 Vaccinium macrocargon 10 -0.52 0.061 37 Table 4. Continued. TRANSECTS CORRELATION SPECIES (N) COEFFICIENTb PROBABILITYc Hieracium aurantiacum 20 -0.54 0.007 Lilium michiganense 10 -0.57 0.043 Melilotus alba 10 -0.58 0.040 Viola lanceolata 10 -0.73 0.008 a Type 2 sites included sedge meadows which were adjacent a cranberry bed matrix but separated from it by an open ditch of water. b The correlation coefficient records the strength of a taxon's importance value vs. distance from a disturbance. Increaser's correlation is negative and decreaser's is positive. C The validity of the correlation is given by the probability. 38 Table 5. Percent occurrence of plant families in disturbed Sphagnum spp. communities in south-central Wisconsin, 1990. FAMILY % OCCURRENCE Alismaceae 2.46 Betulaceae 2.75 Campanulaceae 0.07 Compositae 1.84 Cyperaceae 33.70 Droseraceae 0.11 Ericaceae 38.18 Gentianaceae 0.34 Gramineae 1. 82 Hypericaceae 1.44 Labiatae 1.50 Lentibulariaceae 0.08 Nymphaeaceae 0.11 onagraceae 0.09 Osmundaceae 1.59 Pinaceae 0.29 Polygonaceae 0.83 Polypodiaceae 0.59 Primulaceae 2.84 39 Table 5. Continued. FAMILY % OCCURRENCE Rosaceae 5.02 Rubiaceae 1.30 Salicaceae 1.39 Sparganiaceae 0.37 Typhaceae 0.92 Violaceae 0.38 40 Table 6. Correlation coefficients and associated probabilities of importance value of plant species vs. ~· distance from dike in Sphagnum spp. communities, south central Wisconsin, 1990. TRANSECTS CORRELATION SPECIES (N) COEFFICIENTa PROBABILITYb Polygonum sagittatum 18 0.4368 0.035 Larix laricina 10 0.4179 0.115 Betula pumila 10 0.4128 0.118 Alnus rugosa 9 0.4108 0.136 Carex rostrata 37 0.3591 0.015 Rumex altissimus 18 0.3567 0.073 Salix pedicellaris 38 0.3292 0.022 Carex oligosperma 20 0.2856 0.111 Galium labradoricum 18 0.2651 0.144 Phalaris arundinaceum 18 0.2394 0.169 Carex lacustris 27 0.1942 0.166 Bidens aristosa 18 0.1936 0.221 Potentilla palustris 27 0.1663 0.204 Chamaedaphne calyculata 38 0.1478 0.188 Erechites hieracifolia 9 0.1338 0.366 Vaccinium Macrocarpon 38 0.0858 0.304 Onoclea sensibilis 18 0.0435 0.432 41 Table 6. Continued. TRANSECTS CORRELATION SPECIES (N) COEFFICIENTa PROBABILITYb Eleocaris elliptica 18 0.0313 0.451 Dulichium arundinaceum 28 0.0246 0.451 Viola pallens 19 0.0205 0.467 Lysimachia terrestris 18 -0.0237 0.463 Scutellaria galericulata 18 -0.0473 0.426 Andromeda glaucophyla 20 -0.0523 0.413 Lysimachia thyrsiflora 37 -0.0700 0.340 Osmunda claytoniana 18 -0.0772 0.380 Calamagrostis canadensis 28 -0.1020 0.303 Scirpus validus 18 -0.1261 0.309 Hypericum boreale 9 -0.1369 0.363 Lycopus unifloris 18 -0.1671 0.254 Epilobium angustifolium 9 -0.2070 0.297 Sagittaria latifolia 27 -0.2397 0.114 Spiraea tomentosa 37 -0.2456 0.071 Typha latifolia 18 -0.3142 0.102 Drosera rotundiflora 9 -0.3729 0.161 Salix pyrifolia 9 -0.4108 0.136 Utricularia intermedia 9 -0.4108 0.136 Carex stricta 18 -0.4636 0.026 42 Table 6. Continued. TRANSECTS CORRELATION SPECIES (N) COEFFICIENT8 PROBABILITYb Eupatorium maculatum 9 -0.5080 0.081 Polygonum lapathifolium 9 -0.5175 0.077 Thelypteris palustris 10 -0.5222 0.061 Campanula aparinoides 9 -0.5477 0.063 Osmunda cinnamomea 9 -0.5477 0.063 Nuphar variegatum 9 -0.5477 0.063 Sparganium eurycarpum 9 -0.5477 0.063 Triadenum fraseri 18 -0.5621 0.008 Menyanthes trifoliatum 10 -0.7129 0.010 Glyceria se12tentrianalis 10 -0.7391 0.007 a The correlation coefficient records the strength of a taxon's importance value vs. distance from a disturbance. Increaser's correlation is negative and decreaser's is positive. b The validity of the correlation is given by the probability. 43 Table 7. Correlation coefficients and associated probabilities of importance value of plant families vs. distance from dike in Sphagnum spp. communities, south central Wisconsin, 1990. N TRANSECTS CORRELATION FAMILY SPP. (N) COEFFICIENTa PROBABILITYb Polygonaceae 3 18 0.50 0.017 Pinaceae 1 19 0.36 0.068 Salicaceae 2 38 0.30 0.033 Rubiaceae 1 18 0.27 0.144 Cyperaceae 7 64 0.16 0.104 Aquifoliaceae 1 9 0.13 0.366 Betulaceae 2 19 0.07 0.380 Violaceae 1 19 0.03 0.467 Polypodiaceae 2 28 -0.01 0.475 Ericaceae 3 64 -0.02 0.446 Compositae 4 18 -0.02 0.466 Primulaceae 2 54 -0.07 0.305 Rosaceae 2 54 -0.13 0.181 Labiatae 2 18 -0.13 0.298 Gramineae 3 28 -0.14 0.245 Osmundaceae 2 27 -0.20 0.162 Onagraceae 1 9 -0.21 0.297 44 Table 7. Continued. N TRANSECTS CORRELATION FAMILY SPP. (N) COEFFICIENTa PROBABILITYb Alismaceae 1 27 -0.24 0.112 Typhaceae 1 18 -0.31 0.102 Hypericaceae 2 27 -0.31 0.058 Droseraceae 1 9 -0.37 0.161 Lentibulariaceae 1 9 -0.41 0.136 Campanulaceae 1 9 -0.55 0.063 Nymphaeaceae 1 9 -0.55 0.063 Sparganiaceae 1 9 -0.55 0.063 Gentianaceae 1 9 -0.71 0.010 a The correlation coefficient records the strength of a taxon's importance value vs. distance from a disturbance. Increaser's correlation is negative and decreaser's is positive. b The validity of the correlation is given by the probability. 45 meadow type 1 and 2 sites. The greatest degree of disturbance was measured in sedge meadow, type 1 sites. Disturbance was not measurable in sphagnum bogs. Bogs are recognized as being stable (Curtis 1959). It is possible that the ditch of water present in sedge meadow, type 2 sites, and the omnipresent water of the bogs was responsible for the reduced degree of disturbance measured in these sites. Water may act as an environmental buffer. There were many factors that may have contributed to the disturbance measured in the sedge meadows. Desiccation due to increased exposure to wind and sand caused the area near the cranberry beds to be drier. Sand eroded and was blown by the wind into the wetland, changing its physical and chemical properties. Herbicides are incorporated in drainage-water (Konrad and Bryans 1974, Tome et al. 1991), chronically exposing the matrix to low concentrations of these compounds. Herbicides are known to change vegetation community relationships (Tomkins and Grant 1977). White (1965) reported that no single species or group of species consistently indicated disturbance. Thus, it was not unusual that sensitive fern (Onoclea sensibilis) acted as both an increaser and decreaser. As an increaser sensitive fern may be reacting to the drier moisture conditions which were generally present in sedge meadow, type 2 sites. Variation is normal. All taxons on a site must be considered together 46 to determine the degree of disturbance. Disturbance affected much more wetland than that which was directly converted to cranberry beds. If the impacts of disturbance extended to 100 m beyond the edge of a bed matrix, which was evident from this study, then for a typical 40.4 ha bed matrix, a circular shape would disturb 26 ha, a square 30 ha and a rectangle (length=2x width) 44 ha of additional wetland habitat. IMPLICATIONS Because disturbance effects the perimeter of cranberry beds, they should be designed as compactly as possible. This can be done at no loss of productive area to the grower. Circular shaped bed matrices are the most compact. Squares are the next most compact (Jorgensen and Nauman 1992). Because water may buffer the effects of disturbance, ditches should separate cranberry beds from the surrounding habitat. To mitigate the effect of desiccation and sand on the wetland matrix, dikes should be vegetated with native grasses. SUBMERGED VEGETATION 47 48 INTRODUCTION Large volumes of water are needed to successfully grow a commercial crop of cranberries (Eck 1990). This water is needed on demand. Therefore, large impoundments are maintained by the growers. In this research, 2 primary types of impoundment were encountered. The first type were the shallow open water impoundments described by Eggers and Reed (1987). It was characterized by a large areal extent of open water bordered by a concentric ring of shallow marsh and may include a limited mat of sphagnum moss (Sphagnum spp.) or sedges (Carex spp.). There were numerous areas with emergent plants interspersed with the open water areas. In those impoundments with a mat edge, small islands of bog, freed by ice action, floated freely in the open water areas. Typically, open water impoundments were formed in instances when a sedge meadow or shrub-carr was flooded. The firm substrates of these habitats allowed formation of open water impoundments. The second type of impoundment was the sphagnum and/or sedge bog impoundment (Eggers and Reed 1987). It was characterized by a small area of open water; usually in the form of a constructed ditch to transport water along the dike edge. This area was usually relatively deep (>3 m). The remainder of the impoundment was overlain by a sphagnum or sedge mat of vegetation. This vegetation predated formation 49 of the impoundment. Essentially an artificial sphagnum bog community was formed or encouraged by construction of these impoundments. small areas of shallow open water marsh became established where the bog became grounded and along the ditch margins. Curtis (1959) reported a need to study impoundments in the south-central region of Wisconsin. The conditions found in the 2 types of impoundments studied significantly affected the submerged vegetation diversity and its frequency of occurrence. The deep, artificial substrate formed by the ditches in the bog impoundments had a higher frequency of unvegetated substrate. METHOD A representative aquatic habitat was sampled at each facility. An initial group of samples was collected from 26 Jun-13 Jul 1990, followed by a second group of samples collected from 23 Aug-30 Aug 1990. Two periods were sampled to account for seasonal variation of vegetation (Andrews 1946). One-hundred samples were taken at each facility during each period. A canoe was used to collect a random sample. A garden rake with 2.3 cm tines was used to collect vegetation (Swindale and Curtis 1957). The rake was placed on the bottom and drawn toward the collector. An area about 0.3 m2 was sampled and all species occurring at a site were recorded. An effort was made to sample a uniform area at 50 each collection site. Fr.~quency of occurrence on a given impoundment was calculated (Swindale and Curtis 1957). With the exception of star duckweed (Lemna trisulca), duckweeds (lemnaceae) were not collected. Taxonomy follows Gleason and Cronquist (1963). Water depth was measured at each collection site. Sampling intensity was divided between 2 impoundments at Wood County no.'s 1-3, and Portage County no. 1. Sampling intensity was generally proportional to the areal extent of open water. RESULTS Table 8 includes impoundment no.'s for easy reference. Water levels remained essentially constant throughout the summer of 1990 (Table 8). South-central Wisconsin has an abundance of water (Hamilton 1971). Shallow open water impoundments were sampled at Wood County no.'s 1 and 2, and Juneau County no. 1. Impoundment no. 's 1-3 and 5 were typical shallow open water impoundments. Impoundment no. 4 was unique in that it contained large floating bog islands. These islands scoured and shaded the bottom, disturbing it and inhibiting plant growth. Vegetation data for impoundment no. 4 are not given because of the effects of these disturbances. The impoundment types given in Tables 8 and 9 refer to what an impoundment would tend toward floristically if it were undisturbed. Thus, impoundment no. 4 (Table 8) was 51 Table 8. Water depths recorded in shallow open water and bog mat impoundments associated with commercial cranberry production in south-central Wisconsin, 1990. IMPOUNDMENT SAMPLES AVERAGE FACILITY (no.) and TYPE DATE (N) DEPTH (m) Wood Co. no. 1 (1) open 5 Jul 50 1.02 Wood Co. no. 1 (1) open 30 Aug 50 1.05 Wood Co. no. 1 (2) open 5 Jul 50 0.97 Wood Co. no. 1 (2) open 30 Aug 50 1.21 Wood Co. no. 2 (3) open 6 Jul 70 1.18 Wood Co. no. 2 (3) open 31 Aug 70 1.17 Wood Co. no. 2 (4) open 6 Jul 30 0.87 Wood Co. no. 2 (4) open 31 Aug 30 0.96 Juneau Co. no. 1 (5) open 12 Jul 100 0.87 Juneau Co. no. 1 (5) open 29 Aug 100 0.96 Wood Co. no. 3 (6) bog 13 Jul 70 1.85 Wood Co. no. 3 (6) bog 22 Aug 70 2.00 Wood Co. no. 3 (7) bog 13 Jul 30 1.37 Wood Co. no. 3 (7) bog 22 Aug 30 1.47 Portage Co. no. 1 (8) bog 26 Jun 60 1.11 Portage Co. no. 1 (8) bog 23 Aug 60 1.03 Portage Co. no. 1 (9) bog 26 Jun 40 1.11 Portage Co. no. 1 (9) bog 23 Aug 40 1.00 52 Table 9. Frequency of occurrence of submerged and emergent vegetation, given as a percentage of the total number of samples taken in a habitat, during the early and late summer of 1990 in shallow open water and bog/mat impoundments associated with commercial cranberry production in south central Wisconsin. OPEN WATER BOG/MAT IMPOUNDMENTS SPECIES/TAXON EARLY LATE EARLY LATE Brasenia schreberi 11. 6 13.4 Ceratophyllum demersum 54.9 43.5 9.4 8.8 Characeae 31.9 33.2 Dulichium arundinaceum 0.4 4.2 3.1 Eleocharis spp. 2.3 1.4 3.6 Elodea canadensis 35.3 44.5 0.6 Glyceria canadensis 0.5 5.8 Glyceria septentrionalis 6.5 Lemna trisulcas 11.0 9.0 Myriophyllum tenellum 3.2 7.8 Najas flexilis 22.9 5.8 0.8 Nuphar variegatum 5.1 7.0 Nymphaea tuberosa 31.8 31.5 Potamogeton amplifolius 2.8 3.0 53 : . -~ - Table 9. Continued. OPEN WATER BOG/MAT IMPOUNDMENTS IMPOUNDMENTS SPECIES/TAXON EARLY LATE EARLY LATE Potamogeton epihydrous 1.5 5.9 14.4 16.0 Potamogeton gramineus 24.3 14.8 Potamogeton natans 12.5 12.1 Potamogeton pectinatus 30.3 31.6 1.0 3.1 Potamogeton pusillus 0.5 3.8 Sagittaria latifolia 0.9 1.7 1.4 3.0 Sparganium eurycarpon 3.9 3.5 10.4 2.3 Scirpus acutus 3.3 3.8 1.0 Scirpus subterminalis 0.3 0.8 Utricularia spp. 11.1 13.1 3.3 2.3 Utricularia vulgaris 20.7 20.6 16.1 24.9 Valisneria americana 36.3 36.8 Zizania aguatica 8.0 Bare - No Vegetation 8.0 6.0 42.9 50.7 54 classified as a shallow open water type. Bog mat impoundments were sampled at Wood County no. 3 and Portage County no. 1. Impoundment no.'s 7, 8 and 9 included modest areas of shallow marsh which were sampled extensively, relative to their areal extent. No submerged vegetation was recovered from the ditches of bog/mat impoundments except infrequent loose groups of bladderwort (Utricularia spp.) (Table 9). Substantial amounts of vegetation were only recovered from bog mat impoundments in areas where the impoundment tended toward a shallow marsh. Impoundment no. 6 consisted of essentially only ditch type open water. Only bladderwort (Utricularia vulgaris) was collected from the middle of the ditch. Some three-way sedge (Dulichium arundinaceum), arrowhead (Sagittaria latifolia), and spikerush (Eleocharis spp.) were collected from the shallow areas along the edge of the ditches. Extensive areas of unvegetated substrate are present in the bog/mat impoundments. A typical sample in the shallow open water impoundments included 4-5 species of aquatic vegetation (Table 10). This was a much more diverse flora than that which was recovered from the bog/mat impoundments, samples of which typically included 0-1 species. DISCUSSION Submerged plant communities are not as diverse as 55 Table 10. Number of submerged and emergent vegetation species recovered in a single sample, given as a percentage of the total number of samples takeri in a habitat, during the early and late summer of 1990 in shallow open water and bog/mat impoundments associated with commercial cranberry production in south-central Wisconsin. NUMBER OF OPEN WATER BOG/MAT SPECIES IMPOUNDMENTS IMPOUNDMENTS RECOVERED EARLY LATE EARLY LATE 0 8.0 6.4 47.4 50.2 1 5.3 7.3 34.0 22.7 2 7.8 7.4 11.9 17.0 3 ..14 .1 19.3 5.7 6.3 4 15.1 13.7 1.0 2.7 5 18.4 15.5 6 11.5 14.5 1.0 7 7.1 8.1 8 7.6 3.4 9 3.6 2.9 10 1.6 0.5 11 1.0 56 emergent or terrestrial floras (Swindale and Curtis 1957). The number of submergent species documented in this research agrees with the literature. swiridaie and Curtis {1957) -also believed that the seasonal variation documented by Andrews (1946) was an expression of increased bulk and stature of community dominants rather than a true shift in frequency. The data generally support this hypothesis. However, naiad (Najas flexilis) and wild rice (Valisneria americana) exhibited frequency shifts (Table 9} which may be attributable to true shifts in frequency. The flora of the shallow open water impoundments were characteristic of eutrophic ecosystems. Soft water was indicated by the growth of chara (characeae) and waterweed (Elodea canadensis) (Curtis 1959). The successional trend appeared to be from an initial community of pondweeds (Potamogeton spp.), naiad and wild rice to an established community of waterweed, coontail (Ceratophyllum demersum), and chara. In the later sampling period, extensive mats of water weed formed in impoundment no.'s 1 and 3 (Wood Co., Table 9). Competition by this plant probably inhibited growth of wild rice and sago.pondweed (Potamogeton pectinatus). These are excellent waterfowl foods (Fassett 1957, Eggers and Reed 1987) which occur frequently where conditions allowed (Table 9). Overly eutrophic shallow open water impoundments did not support these species. 57 The submerged flora of the bog/mat impoundments was poor in diversity and abundance (Tables 9 and 10). This was not surprising, as- the chemical limitations presen~ed by- an extensive community of sphagnum severely limit access to the ecosystem by diverse plant species. In addition to this natural limitation, the open water portions of bog/mat impoundments (ditches) were strictly artificial. They were maintained by dredging. It would be very difficult for a plant community to become established, even if this were a goal the growers desired. The bog/mat which overlaid a great majority of the bog/mat impoundments was set back in succession by impoundment formation. When impoundments of this type are initially flooded, the flora typically include an encroaching growth of tamarack (Larix laricina), black spruce (Picea mariana), bog birch (Betula pumila) or speckled alder (Alnus rugosa). Flooding these impoundments causes the trees and shrubs to drown. Early successional communities of sedges and sphagnum are promoted and maintained by impoundment formation in this specialized situation. Relatively constant levels of water were maintained in the impoundments throughout the summer. This had the positive effect of providing a stable ecosystem for that growing season. Also, in bog/mat impoundments, succession is maintained at an early serial stage throughout the 58 impoundment. In shallow open water impoundments constant water levels have the undesirable effect of maintaining an advanced eutrophic serial stage. Impottndmen-t.s which have advanced in succession to the point where the flora is dominated by a mat of waterweed are of little value to wildlife. Drawdown regimes can be implemented to improve impoundments which are advanced in succession for wildlife. AVIAN COMMUNITY 59 60 INTRODUCTION Wetland avian communities in Wisconsin have not been subject to detailed ecological studies. Bond (1957) studied birds of upland forests applying analogies of Curtis's vegetational studies to birds. Except for a few brief notes and broad compilations, there is no detailed data available on wetland bird communities in Wisconsin. IEP (1990) studied avian communities at 3 cranberry production facilities in Wisconsin. This project was conducted from 16-28 August, 1989, too late in the season to successfully document many species (Connor and Dickson 1980). Birds are less active and substantially less vocal at this time of the year compared to spring and early summer. The data of the IEP (1990) study were not quantified to account for area sampled. Time of year and lack of quantification severely inhibited use of these data. For instance, only 6 red-winged blackbirds (Agelaius phoeniceus) were recorded during 36 hours of observation. The red-winged blackbird is omnipresent in Wisconsin wetlands and its failure to show up in significant numbers brings into question the usefulness of the IEP (1990) data. Sandburg (1968) studied a marsh in Dane County, Wisconsin. Red-winged blackbirds and marsh wrens (Cistoth0rus palustris) were the most prevalent species reported. Mossman and Sample (1990) reported red-winged 61 blackbirds and swamp sparrows {Melospiza georgiana) to be the most prevalent species present on Wisconsin sedge meadows. Common yellowthroat {Geothlypis tricha~T, sedge wren {Cistothorus platensis), bobolink (Dolichonyx oryzivorus), and savannah sparrow (Passerculus sandwichensis) were locally abundant. Mossman and Sample's data are the most complete, but it was not quantified to account for the size of the area which was surveyed. They also listed sharp-tailed sparrow {Ammospiza caudacuta), LeConte's sparrow {Ammospiza leconteii), yellow rail (Coturnicops noveboracensis), and Wilson's phalarope {Steganopus tricolor) as species which were completely dependent on sedge meadows. Hoffman {1990) reported on birds of Wisconsin's marshes. Of the 3 surveys reported, 1 appeared to have been conducted during migration. The remaining 2 included significant numbers of red-winged blackbirds, and yellow headed blackbirds (Xanthocephalus xanthocephalus). Swamp sparrow, tree swallow (Iridoprocne bicolor), wood duck (Aix sponsa), common grackle (Quiscalus guiscula), and mourning dove (Zenaida macroura) were locally abundant. These data were not quantified to account for area surveyed. The most complete studies to date indicate that among prevalent species, red-winged blackbirds and swamp sparrows are the best indicators of wetlands in Wisconsin. The densities at which these and other wetland species are 62 typically found is not known for Wisconsin. STUDY AREA There were 2 categories of habitat which were sampled during this survey. First were the cranberry bed matrices and adjacent habitats. Sub-habitats within this category included the bed matrices (dikes, ditches, and the cranberry beds themselves) and the adjacent semi-natural habitats themselves. The second category included the impoundments and their associated wetlands. METHODS Birds and their associated habitats were surveyed. Habitats were characterized visually, grouped,. and placed into major categories. All habitats within 100 m of the transect were included (Emlen 1971). The bird survey was conducted according to the method of Emlen (1977). Sampling was conducted in the spring and summer of 1990. Sampling was done at dawn and dusk (Connor and Dickson 1980, Shields 1977). Morning sampling was initiated at sunrise and completed within 3 hours (Connor and Dickson 1980). Evening sampling was initiated within 3 hours of sunset and completed by sunset. Transects followed existing dikes along the edge of the cranberry bed matrix. A transect was replicated 3 times within a 1 week period (Ohmart et al. 1985, Franzeb 1976). 63 Adverse weather conditions, including rain and excess wind, were avoided (Connor and Dickson 1980, Emlen 1984). Transect length varied from 1611 to 3134 m. This length adequately sampled most habitats within an area (Connor and Dickson 1980). Visual and auditory detection cues were used. Each cue was linked to habitat (Emlen 1971). Perpendicular distance of detections to the transect line, angle of observation and detection distance were recorded (Eberhardt 1968, Anderson et al. 1979). Spearman's rank correlation was used to compare the similarity of the avian community between in the bed matrix, the semi-natural area adjacent the matrix, and the impoundments. RESULTS Although all detections were recorded, the data presented only account for detections within 100 m of the transect. Very few detections were excluded due to this limitation. Emlen (1977, 1984) even suggested limiting the width of the transect due to decreased detectability at a distance. The Emlen (1977) analysis for determining a population index could not be applied to this ecosystem because it was a high contrast edge (Thomas et al. 1979). Thus the transect types are characterized by their habitats (Table 11). Dikes were included under "beds" and were not separated as a distinct category on the impoundment transects. Index values were calculated (Tables 12-17) based 64 Table 11. Habitat types associated with transect surveys for birds at commercial cranberry production facilities in south-central Wisconsin, 1990. PERCENT OCCURRENCE PERCENT OCCURRENCE ON BED MATRIX ON IMPOUNDMENT HABITAT TRANSECTS 8 TRANSECTSb Cranberry beds 44.0 New cranberry beds 5.2 Ditches 5.3 3.7 Impoundment (open water) 5.8 20.1 Shallow marsh 0.5 10.0 Sedge bog 5.5 8.1 Sphagnum spp. bog 4.5 7.9 Ericaceous shrubs 1.6 1.7 Mature Larix laricina 9.1 Dead Larix laricina 11.2 Sedge meadow 10.0 4.2 Shrub-carr 2.6 8.5 Mown shrub-carr 3.4 Lowland forest 4.8 12.3 Gramineae meadow 6.1 1. 3 Quercus community 0.7 65 Table 11. Continued. PERCENT OCCURRENCE PERCENT OCCURRENCE ON BED MATRIX ON IMPOUNDMENT HABITAT TRANSECTSa TRANSECTSb Sand/ shrub dike 0.9 Gravel/ parking 0.3 0.2 Railroad grade 0.4 a Beds matrix transects were transects which were run adjacent to the cranberry beds. b Impoundment transects were transects which were run near the impoundments and away from the cranberry bed matrix. 66 Table 12. Index values8 of birds which seemed to select against the edge associated with cranberry bed matrices on cranberry bed matrix and impoundment transects at commercial cranberry production facilities in south-central Wisconsin, 1990. INDEX VALUES ADJUSTED BED MATRIX BED MATRIX IMPOUNDMENT SPECIES TRANSECTSb TRANSECTSC TRANSECTSd Bald eagle 0.17 Black-capped chickadee 0.76 1.52 1.55 Blue jay 0.57 1.14 2.46 Great horned owl 0.20 Indigo bunting 0.26 0.52 1. 48 Marsh wren 0.41 0.82 1.86 Osprey 0.18 Song sparrow 4.16 8.32 9.94 Swamp sparrow 2.48 4.96 8.53 Red-breasted nuthatch 0.62 Tree swallow 2.35 4.70 4.72 67 Table 12. Continued. INDEX VALUES ADJUSTED BED MATRIX BED MATRIX IMPOUNDMENT SPECIES TRANSECTSb TRANSECTSc TRANSECTSd Wood duck 0.83 1. 66 2.01 Yellow-throated vireo 0.36 a The index value was the number of individuals of a given species observed per 1000 m of transect surveyed. b Beds matrix transects were transects which were run adjacent to the cranberry beds. C Adjusted bed matrix transects were derived from bed matrix transects. The value is 2x the bed matrix transect value due to the fact that 49.2% of the bed transects includes bed matrices which were used highly selectively by birds. d Impoundment transects were transects which were run near the impoundments and away from the cranberry bed matrix. 68 Table 13. Index values8 of birds which seemed to select for the edge associated with cranberry bed matrices on cranberry bed matrix and impoundment transects at commercial cranberry production facilities in south-central Wisconsin, 1990. INDEX VALUES ADJUSTED BED MATRIX BED MATRIX IMPOUNDMENT SPECIES TRANSECT Sb TRANSECTSc TRANSECTSd American bittern 0.29 0.58 0.28 Bank swallow 0.41 0.82 Barn swallow 3.28 6.56 0.41 Blue-winged teal 3.11 6.22 0.36 Bobolink 1. 20 2.40 Brewer's blackbird 3.38 6.76 1.78 Brown-headed cowbird 5.56 11.12 1.60 Clay-colored sparrow 1.13 2.26 0.79 Cliff swallow 6.07 12.14 1.64 Common crow 0.97 1.94 0.66 Common grackle 0.66 1. 32 Common snipe 0.17 0.34 Eastern meadowlark 1. 32 2.64 European starling 0.21 0.42 Field sparrow 0.16 0.32 69 Table 13. Continued. INDEX VALUES ADJUSTED BED MATRIX BED MATRIX IMPOUNDMENT SPECIES TRANSECTSb TRANSECTSC TRANSECTSd Greater prairie chicken 0.42 0.84 Green-backed heron 0.63 1.26 0.41 Green-winged teal 1. 64 3.28 0.20 House sparrow 0.11 0.22 Kestrel 0.13 0.26 Killdeer 0.90 1.80 0.70 Least flycatcher 0.43 0.86 0.41 Mallard 3.06 6.12 1.92 Northern cardinal 0.14 0.28 Ovenbird 0.14 0.28 Pied-billed grebe 0.16 0.32 Pileated woodpecker 0.25 0.50 0.18 Prothonotary warbler 0.22 0.44 Red-eyed vireo 0.31 0.62 0.18 Red-shouldered hawk 0.13 0.26 Ring-neck duck 0.48 0.96 Rose-breasted grosbeak 0.66 1.32 0.38 Savannah sparrow 6.97 13.94 1.09 Sedge wren 2.11 4.22 1.44 70 Table 13. continued. INDEX VALUES ADJUSTED BED MATRIX BED MATRIX IMPOUNDMENT SPECIES TRANSECTSb TRANSECTSC TRANSECTSd Sharp-shinned Hawk 0.44 0.88 Sora 0.32 0.64 0.18 Veery 0.47 0.94 0.17 White-breasted nuthatch 0.23 0.46 0.18 Yellow-bellied sapsucker 0.14 0.28 Yellow warbler 0.27 0.54 a The index value was the number of individuals of a given species observed per 1000 m of transect surveyed. b Beds matrix transects were transects which were run adjacent to the cranberry beds. C Adjusted bed matrix transects were derived from bed matrix transects. The value is 2x the bed matrix transect value due to the fact that 49.2% of the bed transects includes bed matrices which were used highly selectively by birds. d Impoundment transects were transects which were run near the impoundments and away from the cranberry bed matrix. 71 Table 14. Index valuesa of birds which did not seem to select for or against any specific habitat on cranberry bed matrix and inipoundment trarisec:t.s at commercial cranberry production facilities in south-central Wisconsin, 1990. INDEX VALUES ADJUSTED BED MATRIX BED MATRIX IMPOUNDMENT SPECIES TRANSECTSb TRANSECTSC TRANSECTSd American goldfinch 1.81 3. 62 2.01 American robin 1.07 2.14 1.90 Belted kingfisher 0.36 0.72 0.55 Canada goose 8.04 16.08 12.37 Cedar waxwing 0.60 1.20 0.94 Chipping sparrow 0.66 1.32 0.75 Common loon 0.17 0.34 0.37 Common yellowthroat 3.12 6.24 4.98 Cooper's hawk 0.11 0.22 0.20 Double-crested cormorant 0.66 1. 32 0.79 Eastern bluebird 0.15 0.30 0.19 Eastern kingbird 1.20 2.40 1.46 Eastern pewee 0.37 0.74 0.54 Eastern phoebe 0.42 0.84 0.49 Gray catbird 0.82 1. 64 1. 55 Great blue heron 0.73 1.46 0.92 72 Table 14. Continued. INDEX VALUES ADJUSTED BED MATRIX BED MATRIX IMPOUNDMENT SPECIES TRANSECTSb TRANSECTSc TRANSECTSd Great-crested flycatcher 0.72 1.44 1.02 Hairy woodpecker 0.29 0.58 0.52 House wren 0.11 0.22 0.20 Lincoln's sparrow 0.16 0.32 0.39 Mourning dove 0.38 0.76 0.88 Northern flicker 0.26 0.52 0.59 Northern harrier 0.24 0.48 0.36 Northern oriole 0.15 0.30 0.30 Red-tailed hawk 0.26 0.52 0.39 Red-winged blackbird 9.02 18.04 16.76 Sandhill crane 1.27 2.54 1.55 Spotted sandpiper 0.23 0.46 0. 36 Warbling vireo 0.32 0.64 0.73 White-throated sparrow 0.49 0.98 1.18 a The index value was the number of individuals of a given species observed per 1000 m of transect surveyed. b Beds matrix transects were transects which were run adjacent to the cranberry beds. 73 Table 14. Continued. Adjusted bed matrix transects were derived from bed matrix transects. The value is 2x the bed matrix transect value due to the fact that 49.2% of the bed transects includes bed matrices which were used highly selectively by birds. d Impoundment transects were transects which were run near the impoundments and away from the cranberry bed matrix. 74 Table 15. Index values8 of birds which seemed to select against the cranberry bed matrix on cranberry bed matrix transectsb at commercial cranberry production facilities in south-central Wisconsin, 1990. INDEX VALUES SUB-HABITATc BED MATRIXd SEMI-NATURALe SPECIES BEDS DIKE DITCH American bittern 0.20 American goldfinch 0.07 1. 31 American robin 0.05 0.22 0.02 0.56 Belted kingfisher 0.02 Black-capped chickadee 0.34 Blue jay 0.61 Bobolink 0.02 0.05 1.10 Cedar waxwing 0.05 Chipping sparrow 0.64 Clay-colored sparrow 1.13 Common crow 0.12 0.62 Common loon 0.03 Common snipe 0.09 Common yellowthroat 0.02 3.05 Cooper's hawk 0.11 Double-crested cormorant 0.15 75 Table 15. Continued. INDEX VALUES SUB-HABITATc BED MATRIXd SEMI-NATURALe SPECIES BEDS DIKE DITCH Eastern bluebird 0.15 Eastern kingbird 0.19 0.06 0.84 Eastern pewee 0.37 Eastern phoebe 0.36 European starling 0.21 Field sparrow 0.16 Gray catbird 0.02 0.83 Great-crested flycatcher 0.72 Green-backed heron 0.43 Hairy woodpecker 0.17 House sparrow 0.11 House wren 0.11 Indigo bunting 0.26 Kestrel 0.13 Least flycatcher 0.43 Lincoln's sparrow 0.16 Marsh wren 0.08 0.33 Northern cardinal 0.15 Northern flicker 0.02 0.23 76 Table 15. Continued. INDEX VALUES SUB-HABITATc BED MATRIXd SEMI-NATURALe SPECIES BEDS DIKE DITCH Northern oriole 0.08 ovenbird 0.15 Pied-billed grebe 0.16 Pileated woodpecker 0.25 Prothonotary warbler 0.22 Red-eyed vireo 0.31 Red-shouldered hawk 0.13 Red-tailed hawk 0.26 Red-winged blackbird 0.13 0.77 7.19 Ring-neck duck 0.33 Rose-breasted grosbeak 0.66 Sedge wren 0.04 2.09 Sharp-shinned hawk 0.05 0.28 Song sparrow 0.02 0.34 0.22 3.37 Sora 0.05 0.27 Swamp sparrow 0.24 0.11 2.20 Tree swallow 0.07 Veery 0.47 77 Table 15. Continued. INDEX VALUES SUB-HABITATc BED MATRIXd SEMI-NATURALe SPECIES BEDS DIKE DITCH Warbling vireo 0.32 White-breasted nuthatch 0.23 White-throated sparrow 0.49 Yellow-bellied sapsucker 0.15 Yellow warbler 0.27 a The index value was the number of individuals of a given species observed per 1000 m of transect surveyed. b Beds matrix transects were transects which were run adjacent to the cranberry beds. C Sub-habitats were distinct areas within cranberry matrix transects which exhibited unique avian communities. d A bed matrix sub-habitat included three major components: the cranberry beds, the dikes which enclosed them and ditches which distributed water. These areas were highly modified for the purpose of growing cranberries. e The semi-natural sub-habitat included areas which approximated natural conditions but were highly modified. Flooded areas and mown sedge meadows were examples. 78 Table 16. Index valuesa of birds which seemed to select for the cranberry bed matrix on cranberry bed matrix transectsb at commercial cranberry production facilities in south central Wisconsin, 1990. INDEX VALUES SUB-HABITATc BED MATRIXd SEMI-NATURALe SPECIES BEDS DIKE DITCH Bank swallow 0.09 Brewer's blackbird 2.06 1.02 0.11 Brown-headed cowbird 0.65 2.71 0.07 1.02 Common grackle 0.33 0.16 Great blue heron 0.02 0.02 0.16 0.07 Killdeer 0.11 0.49 0.02 0.03 Savannah sparrow 3.74 1.55 0.38 1.22 a The index value was the number of individuals of a given species observed per 1000 m of transect surveyed. b Beds matrix transects were transects which were run adjacent to the cranberry beds. C Sub-habitats were distinct areas within cranberry matrix transects which exhibited unique avian communities. d A bed matrix sub-habitat included three major components: the cranberry beds, the dikes which enclosed them and 79 Table 16. Continued. ditches which Clistributed water. These areas were highly modified for the purpose of growing cranberries. e The semi-natural sub-habitat included areas which approximated natural conditions but were highly modified. Flooded areas and mown sedge meadows were examples. 80 Table 17. Index values8 of birds which did not seem to select for or against the cranberry bed matrix on cranberry bed mat-rix transectsb at colimferciar cra.nberry production facilities in south-central Wisconsin, 1990. INDEX VALUES SUB-HABITATc BED MATRIXd SEMI-NATURALe SPECIES BEDS DIKE DITCH Blue-winged teal 0.16 0.90 1.03 Canada goose 2.53 1.80 2.38 Cliff swallow 0.03 0.01 0.03 Eastern meadowlark 0.23 0.54 0.54 Greater prairie chicken 0.03 0.12 0.03 0.23 Green-winged teal 0.66 0.72 Mallard 0.13 0.20 0.96 0.51 Mourning dove ·0.17 0.18 Northern harrier 0.06 0.04 Sandhill crane 0.27 0.26 0.07 0.24 Spotted sandpiper 0.03 0.03 0.04 Woodduck 0.33 0.25 a The index value was the number of individuals of a given species observed per 1000 m of transect surveyed. b Beds matrix transects were transects which were run 81 Table 17. Continued. adjacent to the cranberry beds. C Sub-habitats were distinct areas within cranberry matrix transects which exhibited unique avian communities. d A bed matrix sub-habitat included three major components: the cranberry beds, the dikes which enclosed them and ditches which distributed water. These areas were highly modified for the purpose of growing cranberries. e The semi-natural sub-habitat included areas which approximated natural conditions but were highly modified. Flooded areas and mown sedge meadows were examples. 82 on linear distance travelled. Two index values are given for the bed matrix sub habitat on bed matrix transects (Tables 12-14). One was the actual index value and the other was an "adjusted" index value. The "adjusted" index values are twice the index value given for the bed matrix sub-habitat. This was done because 49.2% of the bed matrix transects comprised cranberry beds (Table 11), a habitat which was utilized very selectively. A fair comparison of the impoundment transects with the semi natural sub-habitat of the bed matrix transects needed to incorporate this factor. Species whose "adjusted" index value was less than or equal to the impoundment index value are listed in Table 12. Species whose "adjusted" index value was at least twice the impoundment index value are listed in Table 13. Tables 15-17 present data comparing habitat usage on sub-habitats ~ithin the cranberry matrix transects. Actual index values are utilized. Species whose semi-natural sub habitat index value exceeded any of the matrix sub-habitat index values by 2x are listed in Table 15. Species which had 1 matrix sub-habitat index value at least 2x the semi natural sub-habitat index value are included in Table 16. Species whose index value was less than about 0.3 birds per 1000 m of transect may not have occurred with adequate frequency to allow the categorization implied by Tables 12- 17. Generalizations about such species are made 83 conservatively. On the cranberry bed matrix transects 36 species were observed using the matrix sub~llabitat, 20 species in the cranberry beds, 26 species on the dikes and 18 species in the ditches. This compares to the nearest semi-natural sub habitat which contained 77 species. Transects through the impoundments documented 67 species. Spearman's correlation coefficients for the 6-20 most prevalent species (Table 18) of the semi-natural area indicated that the avian community of the semi-natural sub habitat is significantly related to the community of the impoundments (p < 0.05 for 6-20 most prevalent species). Neither of these communities was significantly related to the avian community of the bed matrix sub-habitat (p > 0.05 for 6-20 most prevalent species, except for the 6 species correlation between the bed matrix sub-habitat and the impoundments). Eight species were not included in the analysis because they were only observed flying over the bed habitat, or using unusual structures near the habitat (ie. power poles and lines). These species were the herring gull (Larus argentatus), black tern (Chlidonias niger), red-headed woodpecker (Melanerpes erythrocephalus), northern rough winged swallow (Stelgidopteryx ruficollis), solitary vireo (Vireo solitarius), yellow-headed blackbird, western meadowlark (Sturnella neglecta), and an unidentified warbler 84 Table 18. Spearman's rank correlation coefficients for the avian community on cranberry bed matrix transecta sub habi'catsb ahd impound:rnent transectsc at commercial cranberry production facilities in south-central Wisconsin, 1990. SPECIES IN SPEARMAN'S RANK CORRELATIONS CORRELATION BETWEEN BED MATRIX AND ... BETWEEN IMPOUNDMENTS CALCULATION SEMI-NATURAL IMPOUNDMENT AND SEMI-NATURAL N SUB-HABITAT TRANSECTS SUB-HABITAT 6 0.29 0.64 0.83 7 0.48 0.74 0.86 8 -0.02 0.15 0.90 9 -0.31 -0.20 0.93 10 -0.03 -0.03 0.94 11 0.15 0.02 0.85 12 0.28 0.11 0.86 13 0.37 0.13 0.74 14 0.17 0.10 0.64 15 0.14 0.07 0.67 16 0.14 0.09 0.62 17 0.22 0.15 0.65 18 0.28 0.20 0.68 19 0.22 0.19 0.62 20 0.27 0.24 0.65 85 Table 18. Continued. a Beds matrix transects were transects which were run adjacent to the cranberry beds. b Sub-habitats were distinct areas within cranberry matrix transects which exhibited unique avian communities. C Impoundment transects were transects which were run near the impoundments and away from the cranberry bed matrix. 86 (parulidae). Species which are primarily aerial were under representea in tlie data .. This included cllff swallow (Petrochelidon pyrrhonota), bank swallow (Riparia riparia), tree swallow, and barn swallow (Hirundo rustica). DISCUSSION The habitat types of the transects were similar but may differ in important aspects (Table 11). Impoundment transects completely lacked cranberry beds, but did include a comparable proportion of ditches. Typically the dikes associated with impoundments were more heavily vegetated. The habitats of the impoundments were more heavily influenced by sphagnum (Sphagnum spp.), on the other hand they also contained a higher proportion of shallow marsh and open water. These differences may or may not be offsetting. The avian community is probably influenced by these differences (Harris et al. 1983). Both transect types included a substantial amount of edge habitat. The edge presented by the presence of the cranberry bed matrix was a high contrast, induced edge. Edges within the impoundments were of lower contrast (Thomas et al. 1979). Bird surveys were conducted on 2 types of habitat for 2 reasons. First was an attempt to document the avian species diversity of each habitat. Second was to attempt to document whether the presence of the cranberry bed matrices 87 affected the composition of the avian community. Swamp sparrows, a prevalent wetland species (Mossman and Sample 1g-g-o, and Hoffman 1990), and the abundant song sparrow (Melospiza melodia) were negatively impacted by the presence of the cranberry bed matrix (Table 12). The edge associated with the presence of the cranberry bed matrix attracted many species (Table 13). Edges typically produce an increase in species diversity (Beecher 1942, Thomas et al. 1979, Weller 1981). This result was expected. In fact this result explains why Emlen's (1977) density index cannot be calculated; birds tend to concentrate their activities at the edge. This would result in a very high density value, using Emlen's (1977) analysis. The data presented in Tables 12-14 indicate how species are distributed throughout the ecosystem. The data presented in Tables 15-17 give a detailed look at species distribution in edge sub-habitats near the cranberry beds. From these data it is apparent that avian use of the cranberry bed matrix is highly selective. Only 7 species (Table 16) seem to select for the bed matrix and an additional 12 species (Table 17) seem to be indifferent to their presence. Fifty eight species (Table 15) seem to select against the bed matrix, though many of these do seem to select for (Table 13), or be indifferent to (Table 14) the semi-natural sub habitat adjacent the beds. The avian community of the bed matrix was dominated by 88 a high proportion of savannah sparrows, brewer's blackbirds (Euphagus cyanocephalus), Canada geese (Branta canadensis), and brown--ileaded cowbirds (Molothrus ater) (Table 15) . Of these, only Canada geese did not seem to select for the bed matrix sub-habitat (Table 17). The avian community of the impoundments was dominated by red-winged blackbird, Canada goose, song sparrow, swamp sparrow, and common yellowthroat. Of these, only the swamp sparrow and song sparrow seemed to select for this habitat (Table 12). The avian communities of the impoundments were distinct from those of the semi-natural sub-habitats when individual species were considered. As a whole the avian community of the impoundments was related to the community of the semi natural sub-habitats though neither of these was related to the highly modified bed matrix sub-habitat. In general, to avians, the bed matrix sub-habitat seemed to be ecologically dry. This is based on the substantial presence of savannah sparrows and brown-headed cowbirds which was documented. Savannah sparrows are typically uncommon or absent in wetlands. When they do occur it is in mesic conditions (Bond 1957, Mossman and Sample 1990). Brown-headed cowbirds are uncommon in wetlands (Mossman and Sample 1990, Hoffman 1990). Both of these are prairie species. 89 IMPLICATIONS There are clearly avian species which respond to the disturbance presentedby oh-going maintenance of commercial cranberry beds. Further research needs to be conducted on Wisconsin wetlands to determine the typical diversity and densities of birds. At some point it may be possible to determine if birds respond to any disturbance or only to specific disturbances. A specific disturbance which may have far reaching implications was identified by Brittingham and Temple (1983); brood parasitism by brown-headed cowbirds may be implicated in the population declines of forest and prairie birds (Johnson and Temple 1990). Can brown-headed cowbirds effect wetland bird communities? Edges, especially high contrast edges, are associated with increased predation (Gates and Gysel 1978, Ratti and Reese 1988) and parasitism (Brittingham and Temple 1983, Johnson and Temple 1990) of birds. Cranberry bed matrices may produce a vector which allows brown-headed cowbirds to subsist in unusually high numbers within a wetland. The effect these cowbirds have on wetland birds needs to be investigated. ANATINAE MIGRATION 90 91 INTRODUCTION The south-central region of Wisconsin contains extensive wetlands (Catenhusen 1950, Hamilton 1971). It would be expected that waterfowl would use this area for breeding and migration. Despite the presence of widespread habitat, south-central Wisconsin has been recognized as a low quality waterfowl production area (Jahn and Hunt 1964, Baldasarre 1978). Baldasarre (1978) concluded that low invertebrate populations, limited by infertile soil and water, were responsible for the low density of breeding waterfowl in the south-central region. The efforts of this research concentrated on documentation of duck diversity during migration. Baldasarre (1978) suggested that invertebrate food supplies held migratory waterfowl, particularly ring-neck ducks (Aythya collaris), in this region during the spring migration. He found that leeches (Hirudinea) were an important food item. Dirschl (1969) and Bartonek and Murdy (1970) also cite leeches as an important food item of diving ducks (Aythyini), particularly lesser scaup (A. affinis). Linde (1969) and Reid et al. (1989) suggested that puddle duck (Anatini) use during migration is related to water depth. They suggested that water depth should not exceed 0.25-0.457 m. 92 METHODS Due to time and material limitations, only the impoundments of Wooa County no. 1 and Juneau County no. 1 were surveyed. These were shallow open water impoundments (Eggers and Reed 1987). The survey was conducted at least every third day between 30 March - 27 April, 1991. The migration census followed the guidelines of Baldasarre (1978). Waterfowl were observed with 7x35 binoculars from a slow moving vehicle because roads on dikes formed the margins of the impoundments. This was an accurate and efficient survey method. The road at Juneau County no. 1 entirely encircled 1 impoundment and provided extensive visual access to a second, very large, impoundment. The road at Wood County no. 1 formed a margin along 50% of each of 2 impoundments and provided visibility of the entire water surface. Censuses were conducted primarily in the morning and evening. Waterfowl were easily observable and could be closely approached. A complete count was attempted. On some dates the numbers of rafted ducks were so great that estimates were made. A census required 30-50 minutes to complete. RESULTS By the date of the first census, ice had been partially melted for about 1 week. Only the deepest water areas were open at Wood County no. 1 on 30 March. Substantial areas of 93 open water were available to waterfowl at Juneau County no. 1 by 30 March. Peak mallard (Anas platyrynchos) migration was underway or had passed by 30 March. Peak migration was temporally divided between 1 and 5 April for ring-necked duck, and 13 and 15 April for scaup, both lesser and greater (Aythya marila), canvasback (A. valisneria), and redhead (A. americana). American wigeon (Anas americana) accompany the scaup, canvasbacks, and redheads on migration (Bellrose 1976). Because of this behavior "other" in Table 19 includes primarily lesser scaup, greater scaup, canvasback, redhead, as well as a few American wigeon which were rafted at distances too great to be identified accurately with binoculars. It is possible that some ring-neck ducks were included in Table 19 as "other". However, ring-neck ducks typically formed their own rafts which were clearly identifiable. These observations are included in "ring-neck ducks" in Table 19. All anatinae which were close enough to be identified to species were listed independently in Table 19. There was a distinctly different pattern of use documented at the 2 facilities (Tables 19 and 20). Common goldeneye (Bucephala clangula), scaup, bufflehead (Bucephala albeola), and common merganser (Mergus merganser) were present at both facilities and exhibited a unique and similar pattern of usage across species. Each appeared in substantial numbers at Wood County no. 1 for 1 day and then 94 Table 19. Observations of migrating ducks on the impoundments at Juneau County no. la during 30 March-27 April, 1991. DATES OF % OF PEAK SUBSTANTIAL OBSERVED NUMBER MIGRATION MIGRATION SPECIES ANATINAE OBSERVED PEAK ACTIVITY Mallard 5.8 100 30 Mar 30 Mar-1 Apr American black duck 0.1 2 30 Mar 30 Mar Northern shoveler 0.2 4 27 Apr 27 Apr Blue-winged teal 0.9 8 3 Apr 3 Apr-7 Apr Wood duck 0.2 2 Ruddy duck 1 3 Apr 3 Apr Common merganser 3.9 26 5 Apr 30 Mar-15 Apr Red-breasted merganser 0.1 2 13 Apr 13 Apr Common goldeneye 0.4 9 3 Apr 1 Apr-3 Apr Bufflehead 1.1 15 1 Apr 30 Mar-5 Apr Ring-neck duck 48.5 500 1 Apr 1 Apr-7 Apr Scaup 19.2 280 15 Apr 13 Apr-18 Apr 95 Table 19. Continued. DATES OF % OF PEAK SUBSTANTIAL OBSERVED NUMBER MIGRATION MIGRATION SPECIES ANATINAE OBSERVED PEAK ACTIVITY Canvasback 2.7 80 15 Apr 13 Apr-18 Apr Redhead 0.5 20 15 Apr 13 Apr-18 Apr American wigeon 5.7 140 15 Apr 13 Apr-18 Apr 19.9 300 13 Apr 13 Apr-18 Apr a Located in Sec. 17, T18N, R2E. b "Other" included primarily lesser scaup, greater scaup, canyasback, redhead, as well as a few American wigeon which were rafted at distances too great to be identified accurately. A few ring-neck ducks may also be included. / 96 Table 20. Observations of migrating ducks on the impoundments at Wood County no. 18 during 30 March-27 April, ET91. DATES OF % OF PEAK SUBSTANTIAL OBSERVED NUMBER MIGRATION MIGRATION SPECIES ANATINAE OBSERVED PEAK ACTIVITY Mallard 22.9 16 10 Apr 30 Mar-27 Apr Blue-winged teal 34.9 30 5 Ap:r:; 5 Apr-27 Apr Wood duck 1.0 2 Common merganser 5.4 23 1 Apr 1 Apr Common goldeneye 5.2 31 30 Mar 30 Mar Bufflehead 2.7 7 1 Apr 1 Apr Ring-neck duck 14.2 22 13 Apr 30 Mar-13 Apr Scaup 13.6 30 1 Apr 1 Apr a Located in Sec. 32, T22N, R4E. 97 moved elsewhere. This compares to Juneau County no. 1 where these species appeared in substantial numbers and stayed for an extended period of time. Migratory activity at Juneau County no. 1 included mostly Aythyini and American wigeon (Table 19). This activity was transient, lasting for about 1 week. Migratory activity at Wood County no. 1 included mostly Anatini (Table 20). After 5 April, most of the activity was due to mallards and blue-winged teal (Anas discors) which appeared to be resident on the impoundments. In addition to the waterfowl listed in the tables, other incidental sightings were made. At Wood County no. 1, 3 bald eagles (Haliaeetus leucocephalus) were present on 30 March. on the same date 1 was observed at Juneau County no. 1. At Juneau County no. 1 notable migrants besides anatinae were also observed. On 30 March, 6 tundra swans , I (Olar columbianus), (2 adults and 4 juveniles), were observed as were pied-billed grebes (Podilymbus podiceps). several hundred American coots (Fulica americana) were first observed on 13 April. They were resident through April. On 15 April a few horned grebes (Podiceps auritus) and 1 red necked grebe (Podiceps grisegena) were present. The horned grebes remained on the impoundment for a few days. 98 DISCUSSION Impoundments used for commercial cranberry production can be important for migrating waterfowl. Aythyini were present in much greater numbers than anatini. Thus, as migratory habitat, these impoundments were best suited to aythyini. Common mergansers, common goldeneyes, buffleheads and scaup clearly preferred the habitat available at Juneau County no. 1. Understanding why these species preferred one impoundment over another will suggest what characteristics of habitat are important for migrating aythyini. The impoundment present at Juneau County no. 1 was larger than the impoundment present at Wood County no. 1. size may be a factor contributing to use by migratory anatinae. Large size would decrease the amount of disturbance. Disturbance by humans affects waterfowl habitat selection (Cronan 1957, Thornburg 1973, Reid et al. 1989). However, the fact that the species appeared at Wood County no. 1 and then departed indicates that something other than size is involved. If size alone were involved, it might be expected that the species would never appear at all. There was no boating observed. The only disturbances which were observed occurred on the shoreline. Such disturbances are not as intrusive to waterfowl as water activities. The waterfowl were approachable by car throughout the study period. Biota sampling conducted in conjunction with this project may help to shed light on other factors which may 99 contribute to the distribution of species observed in this research. Fish trapping was conducted on these impoundments concurrent with waterfowl observation. There was a much greater diversity of fish available at Juneau County no. 1 (see Fish, this document). Hundreds of yellow perch (Perea flavescens) were trapped. At Wood County no. 1 only a few central mudminnows (Umbra limi), and tadpole madtoms (Notorus gyrinus) were trapped early in the spring. Salyer and Lagler (1940) found yellow perch to be a preferred food item for common mergansers. It is likely that common mergansers were present at Juneau County no. 1 due to yellow perch. Submerged vegetation was sampled on these impoundments in 1990. The vegetation present at Juneau County no. 1 was more evenly distributed between taxons. Additionally, there were many types of substrate present in the impoundment. Sand, vegetated, muck, and detritus substrates were present at Juneau County no. 1. Of 100 samples taken, 17% indicated a bare substrate. At Wood County no. 1, 80% of the samples taken included waterweed (Elodea canadensis). This evergreen submergent grew in extensive mats. The substrate of this impoundment was almost completely vegetated. Only 2% of the samples indicated a bare substrate. However, the submerged plants found in all impoundments are known to provide excellent habitat for aquatic insects (Krull 1970). 100 Invertebrates were observed concurrent with the migration during fish trapping concurrent with this research (see Fish and Invertebrates, this paper). Substantial numbers of leeches and aquatic insects were present in both impoundments. Dragonfly nymphs (Stylurus sp. (gomphidae), Epitheca sp. (corduliidae), and libellulidae) were abundant. Substantial numbers of snails (gastropoda) and clams (bivalvia) were present in both impoundments. Invertebrates were the primary food of common goldeneye, bufflehead and scaup (Martin et al. 1951, Bellrose 1976). Among the invertebrates, molluscs are of primary importance. Anderson (1959), Rogers and Korschgen (1966), and Thompson (1973) studied food habits of migrating lesser scaup at Keokuk, Iowa. Each found that molluscs comprised about 90% of the diet. Fingernail clams (Sphaeridae) were of particular importance (Thompson 1973). Therefore, differences of molluscs, between impoundments, may be expected to influence anatinae distribution. Although not quantified, sizeable populations of aquatic insects and molluscs appeared to be present in both impoundments. Thus, it appeared that the amount of food available did not limit the distribution of migrating aythyini. Diversity, particularly of molluscs, or the presence of key mollusc species, appear to be the features which may influence aythyini distribution during migration. The greater diversity of fish, vegetation and bottom 101 types present at Juneau County no. 1 probably supports a greater diversity of molluscs than the monotypic community of Wood County no. 1 (Harman 1972, Salmon and Green 1983, stern 1983, Lodge et al. 1987, Way et al. 1990). Cronan, Jr. (1957), Mills et al. (1966), Gale (1969), and Thornburg (1973) have all linked aythyini distribution during migration to mollusc populations. Fingernail clams, found in conjunction with this research (see Invertebrates, this paper) are of particular importance. This research suggests · that diversity of molluscs, or dependence on key mollusc species, need to be investigated as a mechanisms affecting migrational distribution of aythyini. My observations suggest that amount of food available is not the only factor controlling anatinae, particularly aythyini, distribution during migration. I believe that migrating aythyini and common mergansers were distributed according to either mollusc and fish diversity or to the distribution of other key prey species. MAMMAL COMMUNITY 102 103 INTRODUCTION Ma:nunals were sampled usTng 3 methods. Incidental sightings were used but were of relatively limited importance. During summer 1991 snap traps were set in and around the cranberry beds. Also in summer 1991, scent stations were placed in the habitat outside of the cranberry beds. STUDY AREA Th~ study area included commercial cranberry beds and the adjacent wetlands. The adjacent wetlands were composed of sedge meadows and mats, sphagnum (Sphagnum spp.) communities, wet meadows, and lowland forest. METHODS Snap Traps Each of the 5 facilities was sampled over 2 periods of 2 days each from May through August, 1991. Each day, 100 snap traps were placed in 25 identical clusters of 4 traps each (Call 1986). Clusters were located using a stratified random sampling method. Clusters were placed in 3 distance classes, relative to the cranberry bed matrix: clusters were placed in the cranberry beds, within 50 m of the cranberry bed matrix and, >100 m from the cranberry bed matrix. The test statistic was the clustei:- night. Only if one or more 104 traps in a cluster caught an animal was the cluster credited with a capture. Clusters containing traps which had been sprung but were empty were not credited. A Kruskal-Wallis one way AOV was completed. It compared the catches of the clusters in the 3 distance classes to each other. All animals caught were identified and the location recorded. Scent Stations Each facility was sampled over 2 periods of 2 days each from June through August 1991. Five scent stations were prepared and monitored for 2 nights (Roughton and Sweeny 1982). They were located on dikes which were not used regularly by the growers. The dikes were constructed of sand and provided a suitable and accessible substrate for the scent stations (Roughton 1980). Animal tracks were frequently observed on the dikes which were apparently being used as travel lanes by mammals. Thus, scent stations on the dikes would likely be encountered with a high frequency. Commercial combination lure was used with red fox (Vulpes vulpes) urine. The lure was placed on a Q-tip in the middle of a 1 m diameter circle of raked sand and the urine was sprayed in the sand around the lure. Five scent stations were used because of the limited areal extent of the habitat being sampled. A 5x2 line was considered an alternative to Roughton's l0xl line. 105 RESULTS Snap Traps - Eight species were trapped (Tables 21 and 22) including 1 eastern chipmunk (Eutamias striatus). Eastern chipmunks were omnipresent but typically were not captured because the traps were too small to hold them. Open areas were trapped extensively. Typical eastern chipmunk habitat was avoided and it did not appear that traps which had been sprung, but were empty, overly influenced the results for catchable species. Arctic shrews (Sorex arcticus) were caught at Juneau County no. 1 and Wood co. no. 3. These records are slightly outside of the previously documented range for the arctic shrew in Wisconsin (C. A. Long, pers. commun.). The meadow vole (Microtus pennsylvanicus) was the most frequently caught and observed small mammal. At Wood co. no. 2 the prairie deer mice (Peromyscus maniculatus) which were caught were of the subspecies E-m-bairdii. Statistical analysis indicated that the small mammal populations of the cranberry beds were significantly less (p < 0.0042) than the populations in the adjacent semi-natural habitat (Table 22). Scent Stations Of the 100 station nights which were sampled, 7 stations were obliterated by animal activity and 1 was disturbed by a vehicle. Seven identifiable species responded to the scent stations (Table 23). White-tailed deer 106 Table 21. Mammals snap trapped in and adjacent to commercial cranberry production beds in south-central Wisconsin, 1991. a Wood Wood Wood Juneau Portage County County County County County SPECIES no. 1 b no . 2 c no. 3 d no. 1 e no. 1 f Microtus pennsylvanicus 22 31 1 9 6 Zapus hudsonius 3 5 2 3 Peromyscus leucopus 4 1 4 Peromyscus maniculatus 10 Blarina brevicauda 7 1 Sorex arcticus 1 5 Sorex cinereus 1 2 1 Eutamias striatus 1 a Total numbers caught in 1000 trap nights (250 cluster nights) are given. b Located in Sec. 32, T22N, R4E. C Located in Sec. 13, T22N, R4E. d Located in Sec. 19, T21N, R2E. e Located in Sec. 17, Tl8N, R2E. f Located in Sec. 17, T25N, R7E. 107 Table 22. Spatial distribution of small mammals snap trapped in and adjacent to cranberry bed matrices at commercial cranberry production facilities in south-central Wisconsin, 1991. SIGNIFICANCE OF DIFFERENCE BETWEEN DISTANCE CLASSES % CLUSTERS OF% CLUSTERS WITH A DISTANCE CLUSTERS WITH A CAPTURE COMPARED TO ... b CLASS 8 N CAPTURE BEDS <50 m >100 m Cranberry Beds 75 6.0 0.0006 0.0042 <50 m Distant 100 26.5 0.0006 0.6003 >100 m Distant 75 24.0 0.0042 0.6003 a Distance class refers to where traps were placed relative to the cranberry bed matrix. Traps were placed in the cranberry beds, within 50 m of the beds and further than 100 m from the beds. b Kruskal-Wallis one way AOV comparing number of trap clusters with a capture between the 3 distance classes. 108 Table 23. Visitation rates8 of mammal species to scent stations prepared outside the perimeter of cranberry bed matrices a"t commercial cranberry production facilities in south-central Wisconsin, 1991. VISITATION VISITATION RATE PER RATE PER STATION NIGHTb FACILITY NIGHTc White-tailed deer 42.3 90 Striped skunk 17.4 55 Raccoon 16.3 50 Red fox 12.0 40 Coyote 4.3 20 River otter 1.1 5 Mink 1.1 5 a Visitation rate is the percent of scent stations visited or the percent of facilities which a visitation occurred at on a given night. b N=92, a station night was 1 night of activity recorded at each of 5 scent stations at 1 facility. Eight stations were disturbed, thus there were 92 station nights possible instead of 100. C N=20, a facility night was 1 night of activity recorded at any of 5 scent stations at 1 facility. 109 (Odocoileus virginianus) were the most frequent visitor. Striped skunk (Mephitis mephitis), raccoon (Procyon lotor), and red fox were frequent visitors. These carnivores are the primary target of scent stations. Coyotes (Canis latrans) were also expected and were documented. There were 92 station nights (100 possible - 7 obliterated - 1 disturbed). There were 20 facility nights. A facility night was recorded if an animal visited any of the 5 stations present. Incidentals Opossums (Didelphis virginianus) were not documented by scent-stations and are not easily detected with them (Conner et al. 1983). Road-killed opossums were frequently observed in the area. River otter (Lutra canadensis) were observed on a regular basis and are also relatively undetectable using scent-stations (Robson and Humphrey 1985). Four gray fox (Urocyon cinereoargenteus) were observed in the area on 1 occasion, but not near the cranberry beds. A listing of mammalian species observed during the study as well as those observed enroute, within 2 km of a study site is provided (Table 24). Bats (chiroptera), hares (leporidae), and rabbits (leporidae) are not included. 110 Table 24. Presence of mammals observed in and near commercial cranberry production facilities in south-central Wisconsin, 1990-1991. Wood Wood Wood Juneau Portage County County County County county SPECIES no. 1 a no. 2 b no. 3 c no. 1 d no. 1 e Didelphis virginiana * Sorex cinereus * * * Sorex arcticus * * Blarina brevicauda * * Condylua cristata * * * Marmota monax * Spermophilus tridecemlineatus * * * * Eutamias striatus * * * * * Sciurus carolinensis * * Sciurus niger * Castor canadensis * * * Peromyscus maniculatus * Peromyscus leucopus * * * Microtus pennsylvanicus * * * * * Ondatra zibethicus * * * * * Zapus hudsonius * * * * * 111 Table 24. Continued. Wood Wood Wood Juneau Portage County County County County County SPECIES no. 1 a no. 2 b no. 3 c no. 1 d no. 1 e Canis latrans * * * * Vulpes vulpes * * * Urocyon cinereoargenteus * Procyon lotor * * * * * Mustella vison * Mephitis mephitis * * * * * Lutra canadensis * * * * Odocoileus virginianus * * * * * a Located in Sec. 32, T22N, R4E. b Located in Sec. 13, T22N, R4E. C Located in Sec. 19, T21N, R2E. d Located in Sec. 17, Tl8N, R2E. e Located in Sec. 17, T25N, R7E. 112 DISCUSSION Snap Traps The snap trap data (Table 22) show that small mammals are present in significantly (p < 0.0042) greater numbers in the semi-natural habitat outside of the cranberry beds. There are 3 factors which could contribute to this. The first factor is the continual disturbance which is present in the beds. Disturbance included various human intrusions and pesticide applications. The second factor may be a relative lack of cover (Wrigley et al. 1979, Reich 1981). There appeared to be less vertical cover in the beds than in the adjacent habitat. Harriers (Circus cyaneus) hunt over the beds. A lack of cover may contribute to increased predation, or otherwise contribute to a lack of habitat suitability. The third factor may be a lack of diversity within the beds. The vegetation is essentially monotypic and the insect populations, when they are not being controlled, are probably monotypic also and present in low numbers. Interspecific competition has been implicated as a factor affecting small mammal distribution (Buckner 1966). This study was not designed to detect this type of interaction. Scent Stations Scent stations detected relative abundance within a species (Roughton 1980). It cannot be said that raccoons are more abundant than coyotes because different species are not 113 equally attracted to scent stations (Roughton 1980). A small line such as the one used in this study is only useful for detecting abundant species (Roughton and Sweeny 1982, Connor et al. 1983). The visitation rates documented in this study correspond to the rates recorded in the literature for other habitats. Nottingham et al. (1989) found a raccoon visitation rate of 17.2%. Linhart and Knowlton (1~75), and Roughton and Sweeny (1982) reported coyote visitation rates of about 10% in western North America. The present state of knowledge does not allow population estimates to be made from scent station indices (Roughton 1980, Clark and Andrews 1982) . HERPETOFAUNA 114 115 INTRODUCTION Reptiles and amphibia-ns were sampled by 2 methods, plus recording incidental sightings. During the summer of 1990 strip censuses were run along the margin of appropriate habitat (Warren and Schwalbe 1985). During completion of this survey it became apparent that the strip census was only adequately detecting frogs of the genus Rana and painted turtles (Chrysemys picta). Therefore, in the spring of 1991, an auditory anuran survey was completed at each site. Besides documenting additional species, this survey indicated early spring habitat use and built on the findings of 1990. The data are presented as a pair of frog surveys. Other herpetofauna data are presented as incidental information. METHODS Strip Census Survey Margins of habitat were strip censused during the summer of 1990. The strip was as wide as can be detected by an observer carrying a D-net, capturing, and identifying frogs. In practice this amounted to about a 3-4 m radius from the observer. Three groups of censuses were made on each property. Six habitats were sampled. These included impoundment shores, exterior ditches (those bordered by semi-natural habitat and the cranberry bed matrix), interior 116 ditches (those bordered on each side by a cranberry bed matrix), the cranberry bed edges adjacent each of these hafiitats, and interior beds (those which were bordered only by other cranberry beds). A Kruskal-Wallis one way AOV was completed. It compared the frog populations encountered between the different habitats. As frogs were encountered they were captured, identified when possible, and tallied. Auditory Anuran Survey Each site was sampled 3 times in spring 1991. A sample included data collection at 6 listening stations. Listening stations were monitored for 5-10 minutes each after sunset. All listening stations were within auditory range of the cranberry beds. All anuran species heard were recorded (Vogt and Hine 1982). The intensity of the chorus of that species at each station was recorded on a scale of 0-3. A 11 0 11 indicated that the species was not calling. A 11 1 11 indicated that the species was present, but so few individuals were represented that they could be picked out of the chorus. Typically this meant that fewer than 5 individuals were calling. A 11 2 11 indicated that individuals were not separable from the chorus but that it was also less than full. A 11 3 11 indicated that the species was in full chorus. Incidentals Incidental sightings are an important component of a 117 complete herpetofauna diversity survey (Jones 1986). Incidental sightings made throughout the 2 year study are listed in this report. RESULTS Strip Census Strip censuses were found to be only appropriate for detection of frogs in the genus Rana and painted turtles. American toads (Bufo americanus) and garter snakes (Thamnophis sirtalis) also were detected during the strip census. Table 25 indicates the habitat distribution of 1451 detected (all frogs seen) and 497 identified frogs (all frogs identified to species from among those that were seen), and 37 painted turtles. All frogs were counted and 34 percent were identified. Transect length varied according to the dimensions of the habitat being surveyed. An attempt was made to survey a representative (both in type and amount) portion of habitat. The shortest transect was 154 m while the longest was 1158 m. The average transect was 486 m. A frog population index (Table 26) is presented. The Kruskal-Wallis one way AOV indicated that frogs of the genus Rana were evenly distributed throughout the habitats surveyed during the strip census. Three groups of data were excluded from the analysis. One group was excluded because it was collected late in the season and although frogs were 118 Table 25. Percent occurrence of 1451 detected8 or identifiedb frogs and 37 painted turtles in habitats associat~d with commercial cranberry production facilities in south-central Wisconsin, summer 1990. Species Reservoir Ditch Beds Leopard frog 23.2 18.2 9.2 Mink frog 10.4 11.4 17.5 Green frog 5.8 3.9 2.6 Wood frog 0.6 0.3 0.9 Bull frog 0.6 o.o 0.0 Unidentified 59.4 66.2 69.8 Painted turtle 70.3 27.0 2.7 a Detected frogs were all frogs seen during the strip censuses. b Identified frogs were frogs which were identified to species from among those which were detected during the strip censuses. 119 Table 26. Index value of frogs detecteda in habitats associated with commercial cranberry production facilities - in south--central Wisconsin, slimmer 1990. Habitat Period lb Period 2c Period 3d Cumulative Impoundments 2.40 2.19 1.56 2.17 Exterior Ditch 2.22 4.00 4.32 3.31 Beds Adj. Ext. 1.40 2.29 1.00 l. 61 Interior Ditch 0.90 2.38 0.63 1.47 Beds Adj. Int. 2.72 3.79 4.39 3.71 Interior Beds 2.43 1.14 0.16 1.46 Impoundments 2.40 2.19 1.56 2.17 All Ditches 1.62 3.19 2.84 2.46 All Beds 1.88 2.66 1.51 2.15 a Number of frogs detected per 100 m of transect sampled. b Period 1 ran from 26 June-16 July. C Period 2 ran from 25 July-30 July. d Period 3 ran from 15 August-2 September. 120 present it was evident that they were not active. Two groups were excluded because they were collected during major tadpole 1neta:morphbses. Tnese metamorphoses resulted in an index of 25 frogs per 100 m. These unusual events were outside of the typical situation. All species were combined in the analysis. This was because it was not always possible to capture and identify each individual. Anuran Survey The anuran survey succeeded in detecting frogs of diverse genera. All anuran activity in the early spring occurs outside of the cranberry bed and ditch systems. No calling occurred within the beds or ditches except after a few leopard frogs (Rana pipiens) had begun dispersing. The periods in Table 27 corresponded to the visits made to each site. Activity periods varied between species. Gray tree frogs (Hyla versiclor) were active throughout the study, while the closely related Cope's gray tree frog (Hyla chrysoscelis) became active only after 25 April. Western chorus frogs (Pseudacris triseriata) also became active after 25 April. Wood frogs (Rana sylvatica) were active only before 16 April. Green frogs (Rana clamitans) became active after 14 May. 121 Table 27. Average intensity8 of anuran choruses detected in habitats associated with commercial cranberry production facilities in south-ce-ritral Wisconsin, spring 1991 • Species Perie. d 1 b Period 2c Period 3d Spring peeper 2 > 2 > 1 Gray tree frog > 1 > 0 > 1 Leopard frog > 0 > 0 > 2 American toad > 0 > 1 > 1 Wood frog > 0 0 0 Cape's gray tree frog 0 > 0 > 1 Western chorus frog 0 > 0 > 0 Green frog 0 0 > 0 a Intensity was measured according to the audibility of the chorus. A "O" indicated that the species was not calling. A "1" indicated that a few individuals of the species were present and their individual calls could be distinguished. A "2" indicated that the calls of individuals were not separable from the chorus. A "3" indicated that the species was in full chorus. b Period 1 ran from 5 April-16 April. C Period 2 ran from 25 April-10 May. d Period 3 ran from 14 May-23 May. 122 Incidentals Incidental sightings and their locations are listed in - Table 28~ Many species of reptiles and amphibians are poorly detectable with systematic survey techniques. Fox snakes (Elaphe vulpina) were observed twice and growers reported observing them in the beds. One red-bellied snake (Storeria occipitomaculata) was found. Snapping turtles (Chelydra serpentina) were commonly observed in impoundments and crossing the dikes which surround them. They were not observed in ditches. Blanding's turtles (Emydoidea blandingi) , a Wisconsin threatened species (Wisconsin Bu_reau of Endangered Resources 1989), were observed on 4 facilities and near the fifth. They were seen in the impoundments, on the dikes, and in isolated pools of standing water in the wetlands next to the cranberry beds. They were observed somewhat frequently crossing highways throughout the area in May and early June. I frequently observed turtle eggs dug up on the dikes. It is presumed that Blanding's turtles lay their eggs in the dikes as they are frequently observed near them during the egg laying period. DISCUSSION Strip census results indicate that leopard frogs were the most abundant species. Anuran survey results indicate that spring peepers (Hyla crucifer) and gray tree frogs were 123 Table 28. Herpetofauna species observed at commercial cranberry production facilities in south-central Wisconsin during 1~90 and 1991. Wood Wood Wood Juneau Portage County County County County County Species no . 1 a no. 2 b no . 3 c no. 1 d no. 1 e Leopard frog * * * * * Mink frog * * * * * Green frog * * * * * Wood frog * * * * * Bull frog * * Pickerel frog * * Spring peeper * * * * * Gray tree frog * * * * * Cope's gray tree frog * * Western chorus frog * * American toad * * * * * Garter snake * * * * * Fox snake * * Red-bellied snake * Painted turtle * * * * * Snapping turtle * * * * * Blanding's turtle * * * * 124 Table 28. Continued. a Located in Sec. 32, T22N, R4E. b Located in Sec. 13, T22N, R4E. C Located in Sec. 19, T21N, R2E. d Located in Sec. 17, T18N, R2E. e Located in Sec. 17, T25N, R7E. 125 also relatively abundant. Mink frogs (Rana septentrionalis) were captured at each - -stady -site. Vogt (1~81) did not record mink frogs this far south in Wisconsin. Pope and Dickinson (1928) noted their presence and examined samples from Adams and Clark counties. The auditory survey failed to verify their presence, but it was completed before mink frogs typically begin calling. Vogt (1981) indicated that mink frogs begin calling in early June in the northern third of Wisconsin. Phenology would suggest that a southern population of mink frogs would begin calling earlier. It is possible that immature green frogs were being mistaken for mink frogs (Vogt 1981). No pickerel frogs (Rana palustris) and few bull frogs (Rana catesbeiana) were captured. Neither species was recorded in the anuran survey which was complete before bull frogs became active (Vogt 1981). Bull frogs were heard sporadically throughout the study period at Wood County no. 3 and Juneau County no. 1. Pickerel frogs were audibly detected on 1 occasion at 2 of the facilities in June. Pickerel frogs are the rarest frog in Wisconsin (Vogt 1981) and would not be expected to occur in high numbers. He stated that they are sensitive to pollution and changes in water quality. Both circumstances occur in conjunction with commercial cranberry growing due to pesticide applications. Strip census results indicated that habitat usage was essentially uniform throughout the areas adjacent to the 126 cranberry beds. Emerging frogs did not occur in the cranberry beds or ditches. It is presumed that this is explainei:t by tlre continuar liabitat disruption which occurred in the beds.due to harvesting and winter protection activities. During the spring, water conditions in the ditches varies significantly between no flow and high flow events. This lack of stability also contributes to the unsuitability of ditch habitat during the spring. Apparently these conditions are only met by unmodified habitats. Unpredictable water levels in the spring may be expected to adversely effect late emerging species, such as the bullfrog, to a greater extent than early emergers. Painted turtles were commonly observed.and collected in the reservoirs. The strip census was probably moderately effective at detecting painted turtle habitat usage. According to the data (Table 25) painted turtles are frequent users of the impoundments compared to the beds and ditches. FISH 127 128 INTRODUCTION Fish were samp1ed using 2 methods in the impoundments and 1 method in the ditches. Ten minnow traps were rotated throughout the facilities. They were placed in the impoundments and the ditches. Two windemere traps were used in the impoundments on each of 2 facilities. METHODS Minnow Traps Minnows were sampled over 3 time periods with minnow traps baited with bread. Two periods were conducted in impoundments and 1 period in ditches. During the first impoundment period (March 30-May 5) 6-8 nights of trapping were conducted at each facility. During the ditch period and the second impoundment period, 3 nights of trapping were conducted at each facility. Due to pesticide application the ditch period and the second impoundment period were conducted concurrently. The traps were maintained at the same location within a trapping period. They were placed in different locations during different periods. Windemere Traps Two windemere traps, baited with bread, were placed in the impoundments of each of 2 facilities from April 1-May 29, 1991. The opening to the traps had a 12.5 cm diameter 129 circular opening. The wire enclosing them was 3.5 cm stretch mesh. The impoundments chosen were those which were believed likely to produce the most diverse results. This judgement was based on the bottom and vegetation types which were observed during the submerged vegetation study of 1990. Traps were maintained at a location for a few days or were moved intermittently to different locations. The results were quantified on a catch per unit effort basis (Cuplin 1986) . RESULTS Minnow Traps Eight species of fish were caught in the impoundments (Table 29) and 20 species were ,caught in the ditches (Table 30). Three species were present in the impoundments which were not present in the ditches. These were largemouth bass (Micropterus salmoides), northern pike (Esox lucius), and a single pirate perch (Aphredoderus sayanus). Generally the numbers of fish caught in the ditches exceeded the catch in the impoundments. This is true even if the large figures for the northern red-bellied dace (Phoxinus eos) were ignored. No single species occurred in all 5 of the impoundments sampled. Only the central mudminnow (Umbra limi), tadpole madtom (Noturus gyrinus), brook stickleback (Culaea inconstans), and pumpkinseed (Lepomis gibbosus) occurred in more than 1 impoundment. several species occurred in the 130 Table 29. Species and number of fishes trapped with minnow traps in impoundments associated with commercial cranberry production facilities in south-cen~ral Wisc-onsin, 1991. SPECIES OCCURRENCE 8 NUMBER CAUGHTb Yellow perch 1 18.2 Central mudminnow 4 12.0 Tadpole madtom 2 2.5 Brook stickleback 2 1.0 Pumpkinseed 2 0.6 Largemouth bass 1 0.5 Northern pike 1 0.2 Pirate perch 1 0.1 a Occurrence was the number of facilities on which the species was trapped. b Number caught was the number of fishes of a specific species caught per 10 trap nights. A trap night occurred when 1 trap was in place for 1 night. There were 510 minnow trap nights in the impoundments. 131 Table 30. Species and number of fishes trapped with minnow traps in ditches associated with commercial cranberry ~· production facilities iffoOUth-centi:al Wisconsin,~~991. SPECIES OCCURRENCE 8 NUMBER CAUGHTb Northern red-bellied dace 2 104.3 Brook stickleback 3 10.4 Central mudminnow 5 8.7 Common shiner 1 5.0 Pumpkinseed 2 4.2 Brown bullhead 4 4.0 Finescale dace 1 3.7 stonecat 1 3.3 Tadpole madtom 4 1. 6 Mimic shiner 1 1.0 Yellow perch 3 0.8 Iowa darter 1 0.7 Pugnose minnow 1 0.7 Golden shiner 2 0.7 Central stoneroller 1 0.3 Black bullhead 1 0.3 Green sunfish 1 0.3 132 Table 30. Continued. S)?ECtES OCCURRENCEa NUMBER CAUGHTb Large scale stoneroller 1 0.3 Goldfish 1 0.3 Weed shiner 1 0.3 a Occurrence was the number of facilities on which the species was trapped. b Number caught was the number of fishes of a specific species caught per 10 trap nights. A trap night occurred when 1 trap was in place for·1 night. There were 147 minnow trap nights in the ditches. 133 ditches of more than 1 facility. ~· Winde:rnere ·Traps Ten species were caught in windemere traps (Table 31). Three of these species were also caught in minnow traps: pumpkinseed, northern pike, and largemouth bass. cumulative Results Fifteen species were caught in impoundments using windemere or minnow traps. Eight of these were only caught at Juneau County no. 1. The yellow perch (Perea flavescens), central mudminnow, pumpkinseed, and brown bullhead (Ictalurus nebulosus) were the most prevalent species. Pumpkinseed and yellow perch were unevenly distributed with most captures occurring at Juneau Co. no. 1. DISCUSSION The results indicate that in most instances the impoundments supported only a very limited number of fish comprising a few species. The most prevalent species in the impoundments, except for the unevenly distributed pumpkinseed and yellow perch, are indicative of low dissolved oxygen conditions (Becker 1983). This was probably due to winterkill. Such over-winter water conditions were predictable based on the amount of vegetation which grows in the impoundments and their shallow depth. The ditches freeze 134 Table 31. Species and number of fishes trapped with windemere traps in impoundments associated with commercial cranberry proauctton-facilities in south-central Wisconsin, 1991. NUMBER CAUGHT 8 LOCATION WOOD COUNTY JUNEAU COUNTY SPECIES no. 1 b no. le Brown bullhead 3.8 28.8 Black crappie 1.8 5.3 Pumpkinseed 1.5 19.3 Northern pike 0.7 White crappie 0.2 0.3 Common carp 0.2 Yellow bullhead 5.8 Black bullhead 1.5 Green sunfish 1.0 Largemouth bass 0.7 a Number caught was the number of fishes of a specific species caught per 10 trap nights. A trap night occurred when 1 trap was in place for 1 night. There were 60 windemere trap nights at Wood County no. 1 and 44 windemere trap nights at Juneau County no. 1 in the impoundments. 135 Table 31. Continued. b Located in Sec. 32, T22N, R4E. C Located in Sec. 17, T18N, R2E. 136 solid in winter and overwintering is unlikely. Although the impoundments generally do not support an overwintering population of fish, they are hydrologically connected to other water bodies where fish can survive through the winter. Therefore, in the spring the impoundments can serve as migration and potential spawning sites. The weedy conditions may be favorable spawning habitat for northern pike (Becker 1983). Migration will only occur when the ditches are maintained with an adequate supply of water. A migration of northern red-bellied dace was occurring during one of the trapping periods and I captured nearly 500 individuals in 2 traps at this time. AQUATIC INVERTEBRATES 137 138 STUDY AREA All aquatic habitats hydrologically connected to the cranberry bed matrix were sampled at each facility. The aquatic system included an impoundment of water which was connected to ditches supplying the cranberry beds with water. The beds in turn were drained by a continuation of these ditches; the removal ditches. Four important aquatic invertebrate habitat types were formed by this system: the cranberry beds, the impoundment, the supply ditches and the removal ditches. Except for the cranberry beds all aquatic habitats were sampled. The supply ditches were within the bed matrix and the removal ditches were downstream of it. Of these habitats the impoundment was least affected by human activity. Both ditch types were effected by human activity to a substantial but unmeasured degree. Effects included: flow control, digging, dirt and dust deposition, and pesticide application and runoff. Such disturbances have profound effects on invertebrate communities (McAuliffe 1984) . METHODS An invertebrate survey was made at each facility. Invertebrates were collected on 6 different days at each of the 5 properties. Different locations within a given habitat type were sampled. In all, 16 reservoir sites, 9 supply 139 ditch sites and 5 removal ditch sites were sampled. Additionally, invertebrates were caught in fish traps concurrent with fish collecting. Fourteen collections were made this way. The collecting method was qualitative, employing a D net (Merritt and Cummins 1984). A habitat was sampled until new families failed to occur. This required 1 to 4 hours of sampling per habitat. Collections were identified to genus whenever possible. The few invertebrates collected during fish trapping were considered incidental because a dedicated sampling for invertebrates was not conducted at that time. All habitats sampled with fish traps were also D-netted. Insect taxonomy followed Hilsenhoff (1981), non-insect invertebrate taxonomy followed Pennak (1989) except for the leeches (hirudinea) which followed Klemm (1985) and crayfish (decapoda) which followed Hobbs and Jass (1988). Some bugs (corixidae), flies (culicidae, chironomidae) and dragonflies (gomphidae) could only be identified to family. Non-insect invertebrates were identified to the lowest taxonomic level possible. RESULTS The qualitative nature of the sampling prevented all but the most general data characterization. The data for insects are more complete in that a more diverse array of taxons was available for collection, compared to the non- 140 insect invertebrates. Greater insect diversity was documented in the reservoirs compared to all other habitats (Table 32). One end ditch sample included 12 families and 19 genera. Excluding this sample, the removal ditches averaged 2.5 families and 3.0 genera. The insect taxons which occurred most frequently in either ditch type are aeroneustonic. Very few hydroneustic families were caught in ditches. Beetles (haliplidae) were very common in these habitats. This stands juxtaposed to the impoundment habitats which contained a wide variety of invertebrates including many hydroneustic taxons. Damselflies (coenigrionidae) and dragonflies (libellulidae and corduliidae) were common. Collections made concurrent with fish trapping revealed no unique taxons. These collections did provide information on how widespread the distribution of various taxons were within the reservoir habitat. Dragonflies ((Stylurus spp.), (gomphidae), (Somatochlora spp.), (corduliidae), and (Epitheca spp.), (corduliidae)) were very prevalent in the impoundments during the early spring ice out period. Complete lists of the insect taxa caught in each habitat are given in Tables 33-35. Tables 36-38 record the non-insect invertebrates which were collected. These data are of less value than the insect data due to difficulties in collection and identification. Certain taxons were easily collected, such as side-swimmers 141 Table 32. Diversity of aquatic insect taxons collected adjacent cranberry bed matrices at commercial cranberry production facilities in Wisconsin, spring and summer 1991. Average Average no. of no. of Habitat n sites Families Genera Families Genera Impoundment 16 29 64 10.6 13.5 Supply Ditch 9 15 28 6.5 7.8 Removal Ditch 5 13 22 4.4 6.2 142 Table 33. Taxons of aquatic insects collected in the impoundments8 adjacent cranberry bed matrices at commercial cranberry production facilities in Wisconsin, spring and summer 1991. Order Family Genus Ephemeroptera Caenidae Caenis Baetidae Cloeon Siphlonouridae Parameletus Odonata Aeshnidae Anax Boyeria Gomphidae Stylurus Arigomphus Libellulidae Libellula Plathemis Sympetrum Leucorrhinia Ladona Perithemus Corduliidae Cordulia Sgmatochlora Epitheca Dorocordulia Lestidae Lestes 143 Table 33. Continued. Order Family Genus Odonata Coenigrionidae Enallagma or Ischnura Coenigrion Argia Hemiptera Nepidae Ranatra Notonectidae Notonecta Buenoa Corixidae Callicorixa Rhamphocorixa Sigara Hespercorixa Palmacorixa Pleidae Plea Gerridae Gerris Belostomatidae Belostoma Tricoptera Ryacophilidae Ryacophilia Polycentropidae Polycentro12us 144 Table 33. Continued. Order Family Genus Tricoptera Phryganeidae Banksiola Fabria Oligostoma Leptoceridae Ceraclea Ocetis Nectopsyche Mystacides Triaenodes Lepidoptera Pyralidae Paraponyx Coleoptera Hydrophilidae Tropisternus Hydrochara Berosus Haliplidae Haliplus Peltodytes Gyrinidae Dineutus Gyrinus 145 Table 33. Continued. Order Family Genus Coleoptera Dytiscidae Hydaticus Deronectes Laccophilus Agabus Matus Rhantus Hydroporus Captotomus Ilybius Elmidae Dubriaphia Curculionidae Lissorhoptrus Diptera Tabanidae Chrysops Culicidae Coguillettidia Chaoboridae Chaoborus Chironomidae a Impoundments were water bodies upstream of the cranberry bed matrices. 146 Table 34. Taxons of aquatic insects collected in water supply ditches8 adjacent cranberry bed matrices at commercial cranberry production facilities in Wisconsin, spring and summer 1991. Order Family Genus Ephemeroptera Caenidae Caenis Odonata Aeshnidae Anax Aeschna Libellulidae Plathemis Libellula Coenigrionidae Enallagma or Ischnura Hemiptera Pleidae Plea Notonectidae Buenoa Notonecta Corixidae Sigara Callicorixa Rhamphocorixa Hespercorixa Nepidae Ranatra Tricoptera Leptoceridae Ocetis Triaenodes My:stacides 147 Table 34. Continued . Order . Family Genus Coleoptera Gyrinidae Gyrinus Dineutus Haliplidae Haliplus Peltodytes Hydrophilidae Tropisternus Berosus Elmidae Dubriaphia Optioservus Dytiscidae Laccophilus Hydaticus Dytiscus Diptera Chironomidae a Water supply ditches were ditches which were located within the cranberry bed matrix. They contained a mixture of water draining from the beds and water draining from the impoundments. 148 Table 35. Taxons of aquatic insects collected in water removal ditches8 adjacent cranberry bed matrices at commercial cranberry production facilities in Wisconsin, spring and summer 1991. Order Family Genus Odonata Lestidae Lestes Coenigrionidae Enallagma or Ischnura Hemiptera Pleidae Plea Notonectidae Notonecta Corixidae Hespercorixa Sigara Callicorixa Gerridae Gerris Tricoptera Lepidostomatidae Lepidostoma Limnephilidae Asynarchus Coleoptera Dytiscidae Laccophilus Coptotomus Hydaticus Agabus Oreodytes Gyrinidae Gyrinus Dineutus 149 Table 35. Continued. Order Family Genus Coleoptera Haliplidae Haliplus Peltodytes Brychius Hydrophilidae Berosus Diptera Chironomidae a Water removal ditches were located downstream of the cranberry bed matrices. They contained the highest proportion of water which had drained from the cranberry beds. 150 Table 36. Taxons of non-insect aquatic invertebrates collected in impoundmentsa adjacent cranberry bed matrices at commercial cranberry production facilities in Wisconsin, spring and summer 1991. Order Family Genus Species Tricladida Planariidae Amphipoda Talitridae Hylalla azteca Gammaridae Gammarus Gastropoda Planorbidae Planorbella Helisoma Physidae Aplexa elongata Hydrobiidae Cochliopina riograndensis Lymnaeidae Pseudosuccinea colurnnella Viviparidae Viviparus Carnpelorna Pelecypoda Unionidae Potarnilus alatus Anodontoides ferussacianus Sphaeriidae Sphaeriurn Isopoda Asellidae Caecidotea Hydracarina Hydracarinadae Cladocera 151 Table 36. Continued. Order Family Genus Species Rynchobdellida Glossiphoniidae Placobdella ornata papillifera parasitica Helobdella Decapoda Cambaridae Orconectes immunis Cambarus a Impoundments were water bodies upstream of the cranberry bed matrices. 152 Table 37. Taxons of non-insect aquatic invertebrates collected in water supply ditchesa adjacent cranberry bed matrices at commercial cranberry production facilities in Wisconsin, spring and summer 1991. Order Family Genus Species Amphipoda Talitridae Hyalella azteca Gastropoda Planorbidae Helisoma Planorbella Phycidae Physa Aplexa elongata Hydrobiidae Cochliopina riograndensis Lymnaeidae Pseudosuccinea columella Viviparidae Viviparus Pelecypoda Sphaeridae Sphaerium Unionidae Isopoda Asellidae Caecidotea Hydrocarina Hydracarinadae Cladocera Gnathobdellida Hirudinidae Haemopsis plumbea Mooreobdella Oligochaeta Decapoda Cambaridae Fallicambarus fodiens Orconectes virilis 153 Table 37. Continued. a Water supply ditches were ditches which were located within the cranberry bed matrix. They contained a mixture of water draining from the beds and water draining from the impoundments. 154 Table 38. Taxons of non-insect aquatic invertebrates collected in water removal ditches8 adjacent cranberry bed matrices at commercial cranberry production facilities in Wisconsin, spring and summer 1991. Order Family Genus Species Amphipoda Talitridae Hyalella azteca Gastropoda Planorbidae Helisoma Planorbella Phycidae Aplexa elongata Lymnaeidae Pseudosuccinea columnella Viviparidae Viviparus Pelecypoda Sphaeridae Sphaerium Isopoda Asellidae Caecidotea Hydracarina Hydracarinadae Cladocera Pharyngobdellida Erpobdellidae Erpobdella punctata Mooreobdella melanostoma Gnathobdellida Hirudinidae Macrobdella Oligochaeta a Water removal ditches were located downstream of the cranberry bed matrices. They contained the highest proportion of water which had drained from the cranberry beds. 155 (amphipoda) and snails (gastropoda). Other taxons were collected only with difficulty, such as clams (pelecypoda), and I was not confident that the survey for these taxons was complete. Other taxons were easily collected but are identifiable by only a few individuals in the whole country. Water fleas (cladocera) are such a taxon. With the caveat of these substantial limitations, the data appeared to show equal diversity in the various aquatic habitats for non insect invertebrates. DISCUSSION The data show greater diversity of aquatic insect fauna in the impoundments relative to the ditches. This was the least disturbed habitat. It was also the only habitat which does not receive a substantial input of pesticides. Insecticides which are known to have been applied in 1991 include the organophosphate parathion, the carbamates sevin and lorsban, and the acephate orthene. Other pesticides are used as conditions warrant (Meyer 1988, Mahr et al. 1989). Mayer and Ellersieck (1986) reported toxicity of parathion to aquatic invertebrates. Other available compounds are also very toxic to freshwater invertebrates (Coats et al. 1989, Day 1989). Most of the insect fauna of the ditches was aeroneustic. Many of the taxons which are not aeroneustic were tolerant of low levels of dissolved oxygen. Mayflies 156 in the family caenidae and flies (chironomidae) typify low oxygen environments (Hilsenhoff 1991) and low oxygen levels can effect the diversity of the insect community (Anderson and Wallace 1984). The findings indicate that there was an unstable level of dissolved oxygen in the ditches. Stable oxygen levels would be indicated by a higher prevalence of hydroneustic fauna. One of the oxygen measurements I made in the ditches indicated that essentially no dissolved oxygen was present. In this same ditch I caught only beetles (coleoptera, haliplidae). Herbicides can reduce oxygen levels in water. The runoff of these chemicals may be partially responsible for the fauna that was observed. casoron, evital, devrinol and roundup are known to have been used in 1991. In the impoundments there was a diverse fauna which appeared to be largely unaffected by human activities. Although pesticide drift and deposition does occur (Tome et al. 1991), apparently the amounts were diluted in the environment. The fauna of the impoundments indicate a detritivore community in a depositional environment (Edmunds 1984, Westfall 1984, Polhemus 1984, White et al. 1984, Hilsenhoff 1991). A mix of lentic and lotic taxons are present. Those lotic taxons which were present are probably better described as habitat generalists based on this research. CONCLUSION 157 158 CONCLUSION The wildlife diversity associated with commercial cranberry production was documented in this study. It would be a pointless exercise to say "it is high" or "it is low". The diversity, and its distribution, were unique to the specific ecological circumstances which were found near commercial cranberry production facilities. There were aspects of the diversity which appeared to be unique to the wetlands associated with commercial cranberry production. The avian community near the cranberry beds contained a high proportion of mesic species, including savannah sparrows and brown-headed cowbirds, and aerial species such as swallows. The presence of cowbirds is of concern to wildlife professionals. The bed matrix/adjacent wetland interface expressed a strong edge effect. This accounts for much of the perception that cranberry beds are wildlife habitat. There was a measurable degree of disturbance in the area near cranberry beds. Disturbance was observable and measurable in the avian community, the amphibian community, the invertebrate community, and the vegetation. The typical impoundment was susceptible to winterkills of fish. This inhibited the fish diversity. However, the impoundments supported a substantially more diverse animal community than the cranberry bed matrices. The abundance, 159 distribution, and diversity of species within the impoundments could be affected through application of appropriate management techniques. A handbook was prepared concurrent with this research which suggests some appropriate techniques (Jorgensen and Nauman 1992). It has been distributed to the Board of the Wisconsin State cranberry Grower's Association. A reprint of this handbook is provided in the appendices of this document. 160 LITERATURE CITED Anderson, B. W., and R. D. Ohmart. 1986. Vegetation. Pages 639-660 in A. Y. Cooperrider, J. J. Boyd, and H. R. Stuart, eds. Inventory and monitoring of wildlife habitat. USDI, BLM. Anderson, D.R., J. L. Laake, B. R. Crain, and K. P. Burnham. 1979. Guidelines for line transect sampling of biological populations. J. Wildl. Manage. 43:70-78. Anderson, H. G. 1959. 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Cultural. structures and landscape features which are constructed by and for humans. Decreaser. A plant, or family of plants, which had higher importance far away from the cranberry bed matrix than close to the matrix. Driftless area. An unglaciated area. Edge. An area where 2 ecological communities come together. Facility. A property, analogous to a farm, including the cranberry bed matrices, supporting lands and cultural features needed by commercial cranberry growers. Facility night. A facility night refers to the mammalian scent post survey. A "facility night" is a measure of the frequency of visitation to scent posts by 1 species. A "facility night" occurred when a species visited any of the scent posts placed on a property during a given night. 184 High contrast edge. An habitat formed where 2 very different habitats come together. Importance. Wh~_11 ref~_!"_rin_g to plants_, see importance value. Importance value. A measure for plant communities. It incorporates the frequency of occurrence of taxonomic groups in plots and the amount of plot covered by the taxonomic group. Impoundment. A reservoir of water stored for use by the growers. It was located upstream of the cranberry bed matrix but often received drainage water from upstream growers. Impoundment transect. Avian transects which were conducted primarily near the impoundments. No portion of the cranberry bed matrix was included in these transects. Increaser. A plant, or family of plants, which had a higher importance close to the cranberry bed matrix than far from the matrix. Induced edge. An edge which has been formed due to human activities. Removal ditch. See water removal ditch. Scent Post. A raked area of sand with a scent attractant in the center. The scent attracts primarily carnivores which leave their tracks in the sand when they investigate the scent. Semi-natural. Habitat adjacent the cranberry bed matrix. Essentially it was natural habitat except that it had been created due to the actions of humans. 185 station night. A station night refers to the mammalian scent post survey. A "station night" is a measure of the frequency of visitation to scehtposts Ey i species. A "station night" occurred when a species visited a scent post placed on a property during a given night. Sub-habitat. Refers to avian bed matrix transects. The avian community of the bed matrix was distinctly different and separable from that of the adjacent semi-natural habitat. These were the 2 sub habitats. Supply ditch. See water supply ditch. Tension zone. Defined by Curtis (1959). The tension zone is a region of interdigitation between plant communities. Type 1 site. Refers to vegetation sampling. Type 1 sites were sedge meadows which directly abutted the cranberry bed matrix. Type 2 site. Refers to vegetation sampling. Type 2 sites were sedge meadows which were separated from the cranberry bed matrix by a ditch of water which was 10 to 15 m wide. Water removal ditch. Water removal ditches were located downstream of the cranberry bed matrix. They contained the highest proportion of drainage water from the cranberry beds. Water supply ditch. Water supply ditches were located within the cranberry bed matrix. They contained varying proportions of cranberry bed drainage water depending on location along the drainage gradient. 186 Appendix B. Species list of all birds observed, and their location, on and near commercial cranberry production facilities in south-central Wisconsin, 1990-1991. Wood Wood Wood Juneau Portage County County County County County SPECIES no. 1 8 no. 2b no. 3c. no. ld no. le American bittern * * * American blackduck * American coot * American goldfinch * * * * * American robin * * * * * American wigeon * * American woodcock * * Bald eagle * * * Bank swallow * * * * Barn swallow * * * Barred owl * Belted kingfisher * * * * * Black tern * * * * Black-capped chickadee * * * * * Blue jay * * * * * Blue-winged teal * * * Bobolink * * * * 187 Appendix B. Continued. Wood Wood Wood Juneau Portage County County County County County SPECIES no. 1 8 no. 2b no. 3c no. ld no. le Bobwhite quail * Brewer's blackbird * * Brown-headed cowbird * * * * Brown thrasher * * Bufflehead * * Canada goose * * * * * Canvasback * Cedar waxwing * * * * Chipping sparrow * * * * * Clay-colored sparrow * * * * * Cliff swallow * * * * * Common crow * * * * * Common goldeneye * * * Common grackle * * Common loon * * * * Common merganser * * Common nighthawk * * Common snipe * * * * Common yellowthroat * * * * * 188 Appendix B. Continued. Wood Wood Wood Juneau Portage County County County county county SPECIES no . 1 a no • 2 b no . 3 c no . 1 d no . 1 e Dark-eyed junco * * Double-crested cormorant * * * * * Downy woodpecker * Eastern bluebird * * * * * Eastern kingbird * * * * * Eastern meadowlark * Eastern phoebe * * * * * Eastern pewee * * * * * European starling * * * Field sparrow * * Gray catbird * * * * * Gray-cheeked thrush * Great-blue heron * * * * Great-crested flycatcher * * * Great egret * Great horned owl * Greater prairie chicken * * Green-backed heron * * * * 189 Appendix B. Continued. Wood Wood Wood Juneau Portage County County County County County SPECIES no. 1 8 no. 2b no. 3c no. ld no. le Green-winged teal * * Hairy woodpecker * * * * Herring gull * * Horned grebe * Horned lark * * House sparrow * House wren * * Indigo bunting * * * Kestrel * Killdeer * * * * * Lark sparrow * Least flycatcher * * Lesser yellowlegs * Lincoln's sparrow * * * Mallard * * * * * Marsh wren * Mourning dove * * * * * Northern cardinal * Northern flicker * * * * * 190 Appendix B. Continued. wood Wood Wood Juneau Portage County County county County County SPECIES no. 1 6 no. 2b no. 3c no. ld no. le Northern harrier * * * Northern oriole * * * Northern parula * Northern rough-winged swallow * Northern shoveller * Olive-sided flycatcher * Osprey * ovenbird * * Palm warbler * Pied-billed grebe * * Pileated woodpecker * * * * Pine warbler * Prothonotary warbler * * Purple martin * Red-bellied woodpecker * Red-breasted merganser * Red-breasted nuthatch * Red-eyed vireo * * * 191 Appendix B. Continued. Wood Wood Wood Juneau Portage County County County County County SPECIES no. 18 no. 2b no. 3c no. ld no. le Red-headed woodpecker * * Red-necked grebe * Red-shouldered hawk * Redhead * * Red-tailed hawk * * * * * Red-winged blackbird * * * * * Ring-neck duck * * Ring-necked pheasant * Rose-breasted grosbeak * * Ruddy duck * Ruffed grouse * * Sandhill crane * * * * * Savannah sparrow * * * * * Scaup * * Sedge wren * * * * Semi-palmated sandpiper * Sharp-shinned hawk * * * Snow goose * Song sparrow * * * * * 192 Appendix B. Continued. Wood Wood Wood Juneau Portage County County County County County SPECIES no. 1 8 no. 2b no. 3c no. ld no. le Solitary vireo * * Sora * * Spotted sandpiper * * * Swamp sparrow * * * * * Tree swallow * * * * Tundra swan * Turkey vulture * Veery * * * Warbling vireo * * * * Western meadowlark * Whip-poor-will * White-breasted nuthatch* * * White-throated sparrow * * * * Wood duck * * * * * Wood thrush * Yellow-bellied sapsucker * Yellow-billed cuckoo * Yellow-headed blackbird * 193 Appendix B. Continued. Wood Wood Wood Juneau Portage County County County County County SPECIES no. 18 no. 2b no. 3c no. 1d no. le Yellow-rumped warbler * Yellow warbler * * a Located in Sec. 32, T22N, R4E. b Located in Sec. 13, T22N, R4E. C Located in Sec. 19, T21N, R2E. d Located in Sec. 17, T18N, R2E. e Located in Sec. 17, T25N, R7E. 194 Appendix C. Species list of all reptiles and amphibians observed, and their location, on and near commercial cranberry production facilities in south-central Wisconsin, 1990-1991. Wood Wood Wood Juneau Portage County County County County County SPECIES no. 1 8 no. 2b no. 3c no. ld no. le American toad * * * * * Blanding's turtle * * * * Bull frog * * * Cope's gray tree frog * * Fox snake * * Garter snake * * * * * Gray treefrog * * * * * Green frog * * * * * Leopard frog * * * * * Mink frog * * * * * Painted turtle * * * * * Pickerel frog * * Red-bellied snake * Snapping turtle * * * * * Spring peeper * * * * * 195 Appendix c. Continued. Wood Wood Wood Juneau Portage County County County County County SPECIES no. 18 no. 2b no. 3c no. ld no. le Western chorus frog * * Wood frog * * * * * a Located in Sec. 32, T22N, R4E. b Located in Sec. 13, T22N, R4E. C Located in Sec. 19, T21N, R2E. d Located in Sec. 17, T18N, R2E. e Located in Sec. 17, T25N, R7E. 196 Appendix D. Species list of all mammals observed, and their location, on and near commercial cranberry production facilities in south-central Wisconsin, 1990-1991. Wood Wood Wood Juneau Portage County County County County County SPECIES no. 18 no. 2b no. 3c no. ld no. le Arctic shrew * * Beaver * * * Cinereous shrew * * * * Coyote * * * * Eastern chipmunk * * * * * Fox squirrel * Gray fox * Gray squirrel * * * * Meadow jumping mouse * * * * * Meadow vole * * * * * Mink * Muskrat * * * * * Prairie deer mouse * Raccoon * * * * * Red fox * * * River otter * * * * Short-tailed shrew * * 197 Appendix D. Continued. Wood Wood Wood Juneau Portage County County County County County SPECIES no. 1 8 no. 2b no. 3c no. ld no. le Star-nosed mole * * * striped skunk * * * * * Thirteen-lined ground squirrel * * * * Virginia opossum * White-footed mouse * * * White-tailed deer * * * * * Wood chuck * a Located in Sec. 32, T22N, R4E. b Located in Sec. 13, T22N, R4E. C Located in Sec. 19, T21N, R2E. d Located in Sec. 17, T18N, R2E. e Located in Sec. 17, T25N, R7E. 198 Appendix E. Species list of all fish observed, and their location, on and near commercial cranberry production facilities in south-central Wisconsin, 1990-1991. Wood Wood Wood Juneau Portage County County County County County SPECIES no. la no. 2b no. 3c no. ld no. le Black bullhead * Brook stickleback * * * * Brown bullhead * * * * Central mudminnow * * * * * Central stoneroller * Common carp * Common shiner * Finescale dace * Golden shiner * * * Goldfish * Green sunfish * Iowa darter * Largemouth bass * Large scale stoneroller * Mimic shiner * Northern pike * 199 Appendix E. Continued. Wood Wood Wood Juneau Portage County County County County County SPECIES no. 1 a no. 2b no. 3c no. 1 d no. 1 e Northern Red-bellied dace * * Pirate perch * Pugnose minnow * Pumpkinseed * * Stonecat * Tadpole madtom * * * * Weed shiner * Yellow perch * * * a Located in Sec. 32, T22N, R4E. b Located.in Sec. 13, T22N, R4E. C Located in Sec. 19, T21N, R2E. d Located in Sec. 17, T18N, R2E. e Located in Sec. 17~ T25N, R7E. 200 Appendix F. Reprint; "Handbook Of Wildlife Management Techniques For Commercial Cranberry Growers In Wisconsin, a guide for cranberry growers and land use professionals in Wisconsin". See following page. 201 HANDBOOK OF WILDLIFE MANAGEMENT TECHNIQUES FOR COMMERCIAL CRANBERRY GROWERS IN WISCONSIN A Guide For Cranberry Growers And Land Use Professionals In Wisconsin Eric E. Jorgensen and Lyle E. Nauman March 1992 202 CONTENTS INTRODUCTION------204 ACKNOWLEDGMENTS------204 SECTION 1. Land Use Practices------205 Formation of a Conservation District------205 Land Trust------205 Private Conservation Organization------206 Habitat Fragmentation------206 Roads------207 Fences------207 Consolidation of Operations------207 Expansion------208 Impoundment Management------209 Dust Control------210 Dike Design and Construction------211 Succession Control------211 Controlled Burning------211 SECTION 2. Management of Specific Species------214 Canada Goqse ------214 Provide A Buffer------214 A Goose Fence------215 Promote Competing Species------215 Intensive Hazing------216 Lure Crops------216 Swallows------216 Bank Swallows------217 Northern Rough-Winged Swallow------217 Barn Swallow------218 Cliff Swallow------218 Tree Swallow------219 Plan For Cliff Swallow Nest Structure -- 220 203 Waterfowl------222 Display and Nesting Structure::.------222 impoundment Management------222 Wood Ducks------223 Hunting and Refuges------223 General Bird Conservation Practices------223 Sources of Information and Materials --- 223 Turtles------224 Muskrats------224 White-Tailed Deer------225 Appendix A. Definitions------226 Appendix B. Bibliography of Wildlife Management Techniques---- 227 Appendix c. Bibliography of Selected Natural History Readings - 228 204 INTRODUCTION This handbook provides suggestions for management technigy_~~ -whj.c::::h are apg_l icg~_Jg to commerc::::_i&1 c::::ra_nberry production areas. It is designed to provide interested individual or groups of growers with a source of wildlife management information which they can apply to their situation. It deals with species which are likely to be present on their properties. Although the research was limited to south-central Wisconsin, the techniques suggested may be applied throughout the midwest. Some of the proposals in this handbook are easily implemented. Others will require site specific information which can be found through a county extension agent or state wildlife professional. This handbook was developed in conjunction with research conducted during 1990 and 1991. The data collected during the research are available at the library of The University of Wisconsin-Stevens Point in a MS Thesis titled "Wildlife Diversity and Habitat Associated With Commercial Cranberry Production In Wisconsin". There are two sections to this handbook. The first suggests land use management techniques which will benefit whole ecosystems and groups of species. The second suggests management techniques which can be employed to benefit or control certain targeted species. Some of these techniques are generally known, such as woodduck nest boxes, and they are mentioned for the sake of completeness. I acknowledge the past efforts of the many technicians and researchers who developed these techniques. ACKNOWLEDGMENTS The research upon which the suggestions of this handbook are based was funded primarily by The Wisconsin State Cranberry Grower's Association. Supplemental support was provided by The Natural Resources Foundation of Wisconsin and The University of Wisconsin-Stevens Point student research fund. Work-study support was provided through The University of Wisconsin-Stevens Point. DEFINITIONS Specialized terms are avoided as much as possible. Exceptions which I am aware of are listed in the appendices. 205 SECTION 1. LAND USE PRACTICES 1 . 1 Formation Of A Conservation District Substantial quantities of land are controlled by cranberry growers. Much of this is in excess to that required for cranberry beds and impoundments. This land is needed to assure a dependable source and catchment for water. Individual or adjacent groups of growers may not want to carry the property taxes for this land. They do so to assure a dependable water supply. Two avenues of action are proposed which will decrease the property taxes of the growers. Additionally, income tax reductions may be available if the proposals are properly implemented. In addition to direct tax savings, wildlife and wetland ecosystems will benefit from implementation of these proposals. The primary benefit will be a cessation of habitat fragmentation and human disturbance on substantial tracts of wetlands. Implementation of these proposals will result in excellent public relations for cranberry growers. conservation groups will appreciate the permanent wetland· protection which would result from these proposals. Avenue 1 - Land Trust I propose that groups of growers, perhaps even the entire state organization, combine to form a land trust, perhaps under the banner of 'The Glacial Lake Wisconsin Cranberry Conservation District• or another appropriate moniker. The land trust would be a non-profit organization. Growers would contribute land or appropriate conservation easements and development rights to the land trust. These "gifts" would probably be deductible from income taxes. Obviously the property tax burden would be relieved. The board of the proposed 'Conservation District• would be independent of the growers and their associations. Such independence would be an important credibility issue. There are alternatives available which may allow growers to maintain a modicum of control over their gifted land or rights. Obviously, tax advantages may be lost in these instances. If the trust were formed by a group of growers it would be empathetic to growers concerns. 206 Avenue 2 - Private Conservation Organizations Under this proposal, growers would contribute land or appropriate conservation easements and development rights to a private third party conservation organization. The Nature Conservancy is an example of such an organization. Income and property tax savings would be available. Gifts to a third party conservation organization would be excellent for public relations. The grower would be relieved of concerns about future liabilities. This avenue is limited by the caveat that the third party conservation organization accept the gift under the conditions proposed by the grower. Summary The advantages to the growers and wildlife of implementation of either of these proposals are extensive and manifest. Growers would be assured of a dependable water supply and would not be responsible for the expense of its maintenance. Wildlife would be assured an unfragmented, undisturbed ecosystem in which to thrive. 1 .2 Habitat Fragmentation Habitat fragmentation is an important concern of wildlife managers. Fragmentation occurs when contiguous tracts of land in the same successional stage are segmented into smaller tracts by an invading, or imposed new stage of succession. In nature, a fire or a tornado may cause fragmentation. At this time, human induced fragmentation is seriously degrading native communities of plants and wildlife. Examples of fragmentation which are observable in conjunction with cranberry growing include road building, road use, diking, ditching, fencing and quarrying. A property of fragmentation is that it effects an area much greater than that which is observable at first glance (Analogous to the 'edge effect'). For instance, the effects of road noise adjacent to a highway extends far beyond the edge of the concrete. Fragmentation should be avoided, especially in sensitive plant communities such as sedge meadows. There are many actions which can be undertaken to reduce fragmentation. It is a daily issue and practiced observers easily recognize it and become sensitive to it. I cannot enumerate every instance in this handbook. Examples 207 and suggestions are provided. Roads Road building should be minimized. I observed multiple accesses, apparently for convenience, to many locations associated with the cultural needs of cranberry growing. Road building for convenience needs to be avoided. The impact of roads on the ecosystem is widely unrecognized. Road building can be further minimized by centrally locating the growing operation and the resources needed for its continuance. For instance, supplies of sand should be located close to the beds, where it is needed. Roads which are not absolutely necessary should be blocked to vehicular access. Disturbance will be reduced and the intensity of the fragmentation will be decreased. This is especially true of roads through wetland areas which are distant from the growing operations. Fences Fences effect animal movement and concentrate predator behavior. They are usually placed along edge areas, though if they are not, edge areas often result from their presence. Fences are used to control white-tailed deer activities on cranberry production facilities. I do not regard fencing as an acceptable solution to wildlife depredation problems. As applied they provide little effect because they are not maintained and gates are not closed. Other options for controlling deer are suggested in this guide. No control method will be 100% effective, and fences are not either. I think that they are an expensive and aesthetically degrading response to a problem which is better dealt with through other means. Consolidation of Operations Fragmentation can be minimized through central location of the cultural features of the growing operation. Central location would have the immediate benefit of lowering the level of road usage on distant portions of the facility. Further, the effect of the cultural features would be concentrated in one area of intensive development. This is preferable to dispersing them throughout the facility. For instance, a 40 acre tract around the garages and fruit processing facilities would also contain the sand supply and waste disposal areas. These in turn would be located next to the bed matrix. such situations already exist at-many facilities. 208 Expansion Expansion should take place only next to established beds .. Existing dikes and access roctds cap be used. Not only will this minimize fragmentation, it is economical. Because fragmentation is expressed over an area greater than is evident at first glance it is desirable to maximize the use of already developed areas and concurrently minimize their effect on the surrounding ecosystem. This is accomplished very easily. The geometric shape of a cranberry bed matrix can be controlled to limit its impact on the surrounding wetlands. Long narrow geometries are highly disruptive, compact circular geometries are less disruptive. The following table provides an example for a hypothetical 100 acre bed complex and a 100 yard disturbance radius. Bed Matrix Disturbed Shape Area Rectangular 109 acres Square 74 Acres Circle 64 acres The rectangular example assumes a rectangle having a length = 2x width. Rectangular geometries which are longer on one side will express their fragmenting and disturbing influences over a significantly greater area. Such bed matrix geometries are not uncommon. Additions to existing bed matrices should be planned so that the shape of the resulting matrix tends to form a circular or square shape. This assumes that there are no other features which are inhibiting. summary Fragmentation is a prevalent cultural feature of cranberry production. Although there are natural processes which cause fragmentation, the results are not permanent. Fragmentation should be considered undesirable in most instances. There is a need to decrease the existing level of fragmentation. This can be accomplished by closing vehicular access to dispensable roadways and consolidation of the cultural components of the growing operation. There is also a need to decrease the expression of fragmentation through increased use of existing indispensable structures (roads, ditches, dikes) and adoption of consolidated circular or square bed matrix geometries. 209 1 . 3 Impoundment Management There are two general types of impoundments present in conjunction with commercial cranberry production in Wisconsin. There are flooded sedge meadow/lowland forest and flooded sphagnum moss communities. Flooded sedge meadows are typically open water communities while flooded sphagnum communities are typified by a floating sphagnum mat, often with tamarack and black spruce. Flooded sphagnum communities are probably maintained in a desirable condition by the action of flooding. Woody vegetation is suppressed and the open areas preferred by wildlife, particularly sandhill cranes, are maintained. Also, sphagnum communities tend to succeed through a group of specialized sedges which are relatively uncommon in south-central Wisconsin. In south-central Wisconsin this community is of interest in its own right. Its maintenance is desirable. Flooded sedge meadow/lowland forest matures into an unproductive open water community which is of little value to wildlife. This mature community is composed of common plants and is not of particular interest as a community in its own right. The productivity can be enhanced through management. The balance of this section refers to such flooded sedge meadow/lowland forest. The impoundments associated with commercial cranberry production are managed for water availability and security. Many of these impoundments are long past their prime as forage areas for wildlife. Mature impoundments are usually shallow open water areas dominated by 1-3 monotypic plant species. Few of the impoundments are fishery resources, except to the extent they are migration areas for fish. Winterkill appears to be prevalent, though many fish are apparently able to migrate to secure areas. It is well established that the value of impoundments to wildlife can be greatly improved through management. Management includes periodic drainage of mature impoundments for varying periods of time; typically a growing season. This is called a "drawdown". Each impoundment varies and no absolute prescription is available. There are many wetland professionals, particularly at The Mead Wildlife Area, Marathon County, Wisconsin, The Sandhill Wildlife Area, Wood County, Wisconsin, and The University of Wisconsin-Stevens Point who are practiced and familiar with drawdown techniques in 210 central Wisconsin. Implementation of this management is suggested and can be expected to substantially benefit wildlife. Ooviously, such management is only available to cranberry growers if an adequate supply of water can be maintained. Some growers already have a more than adequate supply of water. They may begin implementing a trial drawdown schedule at any time. Other growers may need to impound more areas or divide existing impoundments into a group of smaller areas which can be independently managed. The Grower should plan and prepare for removal of all surface waters in the impoundment for a growing season. The water this impoundment held will not be available for that year. 1 . 4 Dust Control There is a substantial amount of dust produced in the bed matrix and near the sand supply. The texture of the dust varies from sand to much finer dried and decomposing organic mucks. Dust is more than a nuisance. Most significantly, pesticides adhere to the particles and are transported with them. These pesticides are deposited in the adjacent wetlands where they undoubtedly effect the native ecosystem. Perhaps more importantly, these residues are breathed by the growers and their employees, particularly on windy days. Besides this apparent synergistic effect between dust and pesticides, blowing dust itself adversely effects plant communities. Dust clogs the respiration system of plants, inhibiting growth. Blowing sand may abrade and desiccate plant tissues. Where it occurs, dust production within the bed matrix needs to be eliminated or greatly reduced. This is because the bed matrix probably contains the highest concentrations of pesticide residue. Dust production can be minimized by growing vegetation on bare dikes. Vegetated dikes will not be maintained in heavy traffic areas. Minimization and localization of road use will reduce dust production, even if the dikes are bare. It will be nearly impossible to establish vegetation on a sand dike. The dike will need to be top dressed with soil and seeded with an appropriate mix. Specific information is available through county extension agents. Reed canary grass should be avoided because it aggressively invades wetlands. 211 1 . 5 Dike Design and Construction The dikes which abut the impoundments are typically narrow and have a sharp slope. It is not uncommon for dikes to be unvegetated. Narrow dikes are susceptible to damage by muskrats and beaver. The potential for damage is increased when the face of the dike is sharply sloped. Muskrat damage can be controlled by building dikes which are 16 feet wide at the water line. Potential damage can be eliminated by combining this with a dike slope of 5 to 1. Dikes should be vege~9ted to prevent water damage from rain and waves. 1 . 6 Succession Control Sedge meadows are a disappearing ecosystem in south central Wisconsin. In south-central Wisconsin there are two types of sedge meadow: those dominated by sphagnum and those which are not. Growers control a lot of sedge meadow habitat. Subsequently, they need to take steps to maintain sedge meadows on their lands. The method of maintenance depends upon the type of land. There are three techniques which can be employed to maintain sedge meadows. There are natural means, mowing and herbicides used in conjunction with burning. Natural Means The natural means which are used depends on the type of land which is to be managed. The two types of sedge meadow communities require two primary strategies. Sphagnum Based Sedge Meadows Besides the presence of sphagnum, these sedge meadows can be identified by the presence tamarack and black spruce. Impoundment of water causes the peat mat to float, drowning the woody vegetation and maintaining the meadow. In this unique case, impounded water actually helps to maintain a desirable community. Non-Sphagnum Communities Succession control in non-sphagnum communities is a never ending proposition. Impounded water can be used but where the peat mat will not float, the sedge community is 212 destroyed by water impoundment. Controlled burning is the best method which can be used to maintain these sedge meadows. Woody vegetation will encroach slowly, and the encroachment may be accelerated by qertain Q~rning practices. Fast~ cool burns will top kill woody vegetation (alder, willow, etc.) and accelerated root growth and shoot multiplication will result. When woody vegetation becomes too extensive it is necessary to use a slow hot burn which will kill the woody vegetation. I presume that such a hot burn will need to be employed every 5-10 years. Ideally the hot burn would be completed toward the end of July or into the first two weeks of August. This is not the usual time for burning in Wisconsin. Spring is the usual time but control of woody vegetation is only marginally achieved through spring burning. Mowing Mowing can be used to control woody vegetation in sedge meadows. It is not a permanent solution. Mowing will top kill woody shrubs, causing an increase in the number of shoots. Mowing is labor intensive. Tractor tires can permanently scar landscapes in peat soils. For these reasons mowing is not suggested as a habitat maintenance technique in wetlands, though in specific local circumstances it may be an acceptable practice. Herbicides Herbicides have been used on state wetlands as a method of last resort. They should not be used in any situation where burning promises to achieve the desired result. If herbicides are used the land will recover quicker if they are followed with a fire after the dead vegetation has dried. Dense stands of alder or willow may only be controllable with herbicides, particularly if the grower is unwilling or unable to complete a hot late summer burn. 1.6 Controlled Burning Besides controlling undesirable vegetation, burning has other desirable effects, such as making nutrients available. Spring burns will momentarily set back succession. Spring 213 burns must not be used after April 20 in Wisconsin. After this date too many birds, particularly waterfowl, are nesting and the disruption caused by the burn is unacceptable. When spring burns are employed, blocks of burnt acreage (approximately 20-40 acres) should be juxtaposed with blocks of unburnt acreage. The unburned area will provide cover. The following year they will be burned. Such a scheme will maintain a checkerboard of diverse ages and structures of vegetation. 214 SECTION 2. MANAGEMENT OF SPECIFIC SPECIES 2.1 Canada Goose Canada geese are prevalent where open reservoirs occur. They typically nest in the native wetland and bring their goslings to the bed matrix shortly after they hatch. They use the dikes for grazing and loafing. This is a safe area with a readily available food supply. They are only disturbed by humans which they can see coming from a long distance. Once the geese become habituated to the matrix they will enter the beds. Growers perceive that damage is being done at this point. Canada geese appear to use the beds primarily for loafing. I believe that Canada geese are more of a perceived problem than a real problem. A certain amount of wildlife damage is inherent in any agricultural activity. The question becomes, how much is too much? Canada goose control is an area of extensive research. No sure control methods have been found. To the extent that growers would like to control goose activities near the bed matrix, methods are suggested which may alleviate the problem. The key to discouraging goose usage of the beu matrix lies in preventing their habituation to this area. This means that they must be prevented or discouraged from bringing their broods to the dike after the broods are hatched. Method 1 - Provide A Buffer This solution cannot be implemented on existing marshes. However, future plans can employ this system and future marsh designs can incorporate it. The dikes are used because of their close proximity to water, their supply of food, and good visibility. If a buffer strip of trees or shrubs (cover for predators) is left between the impoundments and the bed matrices the parents may judge the journey too dangerous, and would not attempt it. The goslings will never habituate to the matrix and damage within the beds will be avoided. 215 Method 2 - A Goose Fence At locations where the impoundment and the bed matrices are alrea_c!Y_ adj ac_~nt a f en_c::~ cou_l.cl be c::Qnstructed which would.prevent access to the dike by the goslings. A fence would be a barrier which would prevent the goslings from swimming to the dike. Ideally the fence would be constructed in the water and would penetrate to the bottom of the impoundment. This too would prevent habituation of the goslings to the matrix area. It may be acceptable to locate the fence at the edge of the dike. This technique could possibly cause significant mortality. The adult geese can fly over the fence and they may not figure out that the goslings cannot. Such a scenario may end in the death of the goslings due to dehydration and/or exhaustion. The fence has additional drawbacks which need to be considered. It would be expensive to install and would be a high maintenance item. It may need to be removed each fall to prevent ice damage. It would block growers access to the impoundment. Method 3 - Promote Competing Species At some sites it may be possible to discourage geese by increasing the activity of competing species. Preliminary techniques employed during the research which led to this handbook appeared to be somewhat successful in this regard. At one site a bald eagle nesting platform was erected in the top of a white pine on an island in the impoundment. Eagles and ospreys used this platform, though not for nesting in the first year. I observed eagles chasing waterfowl at this location and the grower believed that they were having an effect on the noticeably reduced goose population during the second year of the study. If geese can be discouraged from nesting in the first place, due to a perception of danger, there will be no goslings to deal with. To implement this method a population of eagles or ospreys should already be present nearby. These could serve as a source population for colonialization of the new nesting area. A nesting area would include constructed platforms in tall trees or on posts over open water. Personnel from state wildlife areas are familiar with the construction of these platforms and directions are available through a publication of the Minnesota Department Of Natural Resources, titled "Woodworking For Wildlife". Proper location may be crucial to success of this method. Consultations should be made with wildlife professionals. 216 In addition to large raptors, a rookery of colonial waterbirds may help produce enough commotion to discourage nesting by a majority of the Canada geese. Manmade rookeries 'for great blue heron and double-crested cormorant can be found o:ri several state lands .. and their personnel are familiar with rookery construction. I believe that this method, promoting competing species, is the best long term, low maintenance solution to lowering the level of goose activity. The method recommends itself on the basis that it promotes other desirable species for the enjoyment of the growers and their families. Method 4 - Intensive Hazing Hazing is much maligned and has been primarily applied against migrating geese. Its effectiveness on nesting resident geese is unknown. In any event, a hazing program will not work if persistence is not maintained at the critical time when goslings are being brought to the dikes. A hazing program will only work if persistence is maintained. Constantly chasing the geese off the dikes is probably the only effective, dependable hazing option. Use of dogs and cracker shells can enhance and complement a persistent hazing program. Radio controlled aircraft may be used. Mylar streamers are effective in some instances, as are noisemakers. Method 5 - Lure Crops Growers can provide geese with a feeding area which is preferable to the bed matrix. The safety of the dike can be duplicated on dikes which go through the impoundments. If food is provided in open areas on these impoundment dikes it is probable that some geese will use this area as a feeding and loafing area. Food can be provided by planting crops like smartweed or clover on the dike. In many instances it may be easier to provide a supplemental food like cracked corn. Corn can be spread regularly by hand or a commercially available, timed, corn dispenser could be used. Dispensers are available through mail order houses such as Cabella's. 2.2 Swallows Of all of the species observed, swallows appear to be the best adapted to the area near the bed matrices. This is fortunate because they may reduce local insect populations to an extent which is beneficial to the grower. I do not 217 believe that it was an accident that the facility with the fewest swallows also had the most biting insects. The beneficial effects of swallows ought to be encouraged by the growers. There are five species of swallow which nest in Wiscons-tn. All nest in areas assoclafi~-a with commercial cranberry production and all have different nesting needs. Some of these needs can be met by manmade structures. Although swallows seem to be present in appreciable numbers, there is cause for concern. There are modifications taking place which will impact the availability of swallow nesting structures. One of these impacts is the use of prefabricated underground water control structures. They are used exclusively in new developments and are slowly replacing existing concrete structures. The concrete structures were used as nesting areas by ciiff swallows. When the concrete structures are removed it is expected that the cliff swallows will cease nesting in the area. With them will go their beneficial effects to the grower. Bank Swallows Bank swallows nest in sand quarries, which are used by growers in their operations. Bank swallows are colonial nesters and are easily identified by the large group of holes they create in the sand. Nesting sites are few and far between. Growers who are fortunate enough to have a colony of bank swallows on their properties need to take steps to protect the nesting area. If the nesting area is left undisturbed, the swallows will return each year. If the nesting area is disturbed and the nesting holes destroyed there is a chance that the swallows will not re-establish the colony. One grower's strategy was to take sand from half the colony, leaving the remainder. New habitat can be created by exposing new sand banks. A vertical drop off needs to be created to protect nesting swallows from predation. Northern Rough-Winged swallow The northern rough-winged swallow is Wisconsin's least abundant swallow. It is not a colonial nester. They nest in holes like bank swallows. I observed rough-winged swallows nesting in vertical dike banks on dikes which bounded open water impoundments. I also observed these dikes being filled at the water's edge. This covered up the nest holes. In order to maintain a population of rough-winged swallows, fillings activities must be delayed until late in the summer. This will allow the swallows to successfully rear their young. Filling activities should not be conducted from April 20 - July 31. 218 Barn Swallow Barn swallows are present in limited numbers at most growing operations. They nest in pumphouses which are typically-Tocate-cr close 1:0 the bed -matrix. The clOse proximity of the pumphouses to the beds inherently exposes the swallows to some level of pesticide drift and the pumphouses are a noisy place to bring up a family! The pumphouses should be enclosed to prevent access to the swallows. Enclosure would only have to be maintained during the nesting season. An enclosure may include something as simple as blocking the windows and doors of the pumphouse with a tarp. The second management practice complements the first. By enclosing the pumphouse the swallows will be denied a nesting location. Nesting structures will need to be provided for. A barn swallow nesting structure would essentially be a pumphouse with no pump in it. The structure could be used for storage. It is important that several crossing rafters be included for the swallows to cement their nests to. I believe that a structure dedicated to swallow nesting would not need to be completely enclosed. Perhaps sides on the west and south sides would be adequate. Maybe no sides are needed. I am aware that some building centers have plans for nesting structures which measure about lOxlO. In very wet locations these structures would be built at wide areas on dikes, preferably dikes that are closed or subject to limited traffic. They should be placed away from the bed matrix, but close enough to allow the swallows to forage there, for this is their beneficial effect. I suggest locating the structure at least 50 yards from the bed matrix. It may take one or more years for the swallows to colonize the structure. Two structures were built at a facility during this research and neither of them were used in the first year. Colonization will be enhanced where there is an existing population of barn swallows. Cliff Swallows Cliff swallows appear to be well adapted to the area close to the cranberry bed matrix. They are colonial nesters. They nest under overhanging ledges of concrete. These ledges are found under bridges and on some older water control structures. These are both structures which are being replaced by prefabricated steel structures. As the older structures are replaced, nesting structure is lost. This structure needs to be replaced if a population of cliff swallows is to be maintained. 219 I have developed a structure which could be used to replace these cliff swallow nesting areas. A drawing of it and a bill of materials appears on pages 17 and 18. This structure measures about 10x2 and could be constructed on - most dikes~- due to its narrow profile. Existing structures (concrete bridges and water control structures) should be conserved as long as they are able to maintain their function to the grower. Cliff swallows will benefit by this conservation. Tree Swallows Tree swallows are found at most cranberry production facilities. They are not colonial nesters, but they do·nest very close together. They nest in cavities and will use nesting boxes, like bluebird nest boxes. Their numbers can be increased at any facility by the provision of nest boxes. Tree swallows prefer open areas and nest boxes can be placed on 4x4 poles, on the side of trees or on power poles. Two boxes can be placed on opposite sides of each pole. They also should be placed at different elevations, ie. one facing east and 5 ft off the ground and one facing west and 8 ft off the ground. Tree swallows are not the only cavity nesting birds which will use artificial nest boxes. House sparrows and starlings also use them. These species are aggressive and are not native to The Americas. If house sparrows and/or starlings are allowed to colonize the nesting boxes in a short time all of the desirable tree swallows will be displaced. Therefore, growers need to vigilantly watch the nest boxes during the nesting season. If house sparrows or starlings are nesting, their nests and eggs should be destroyed. There may be other desirable species which use nest boxes. Bluebirds and flying squirrels are examples of such species. 220 9'-10" ~1 4" Cone. Blocks 1't Cone. Blocks 1't Cone. Blocks 4" Cone. Blocks 4 x 8 x 16 Cone. Block PLAN VIEW 2x6 Face Board 2-2x8 Beam / 4x6 Beam 4x4 Posts 4x4 Posts- Grade 3'-4" Solid Cone. Block rtg. 6'-4" \ END VIEW SIDE VIEW BILL OF MATERIAL (4) 4 x 8 x 16 Solid Cone. Blocks (1) 2 x 8 x 10 ft. Continuous (26) 4 x 8 x 16 Concrete Blocks (5) 2 x 4 x 10 ft. Continuous (26) 12 x 8 x 16 Concrete Blocks (2) 2 x 2 x 10 ft. Continuous (2) 4 x 6 x 10 ft. Beams (5) 2 x 4 x 2 ft. 6 in. Supports ( 4) 2 x 8 x 6 ft. Beams (4) 2 x 4 x 4 ft. Braces (4) 4 x 4 x 10 ft. Posts (4) 2 x 4 x 3 ft. Braces (2) 2 x 6 x 10 ft. Face Boards (4) 5/8 in. x 8 in. Bolts (2) 2 x 6 x 5 ft. Face Boards 16d & Bd Nails CLIFF SWALLOW NEST STRUCTURE 221 12 x 8 x 16 Cone. Block L 2-2x8 2x4 Cont. 4x4 Posts Solid Cone. Block Ftg. CUFF SWALLOW NEST STRUCTURE CROSS SECTION DETAIL 222 2.3 Waterfowl waterfowl, except for Canada geese, are present in low numbers on the impoundments. To an extent this may be due to an inherent infertility in the south-central Wisconsin area. I also believe that the high level of Canada goose activity may be adversely impacting other waterfowl through interspecific competition. Even so, I believe that steps can be taken which will increase waterfowl use of the impoundments, at least during migration. Display and Nesting Structures I observed a general lack of structures available for display during pairing. The impoundments are very clean. Logs have been removed, or were never present. I believe that logs should be introduced to impoundments where they are lacking. They should be placed about 20-30 ft from shore. These logs would be secured by a cable which would be anchored to the bottom. Anchored logs would have the additional benefit of increasing the visibility of turtles. Another structure which will increase the available display areas is a haybale. Not the small rectangular ones but the large round ones. Haybales will also serve as nesting structures for waterfowl and songbirds, such as the song sparrow. The bales should be placed where there is a secure bottom. This is so they do not wash away before the broods are hatched. Bales should not be placed right next to the dike because predators use the dikes as travel and hunting lanes. If the bales are right next to the dikes the nests will be predated and destroyed at a very high rate. An ideal placement would be within a stand of emergent vegetation, such as bulrush, within the impoundment. The vegetation will help anchor the bales. The bales can be placed on the ice over winter and should be staked to set flat on the bottom of the impoundment. Impoundment Management A diverse impoundment of varying water depth, fauna and vegetation will provide for the needs of more waterfowl, in terms of both numbers and species, than a mature, monotypic impoundment. Thus, implementation of a drawdown management regime should greatly increase the level of waterfowl activity on mature impoundments. 223 Wood Ducks Wood duck nesting boxes can be erected, and can be useful in sphagnum impoundments as well as open water impoundments. The boxes should be placed over water next to shore. Boxes which are placed over land are not used as frequently. If trees are not available a 2" steel pole will be needed for attachment of the nest box. Trees which overhang the impoundment are very good locations for wood duck boxes. Hunting and Refuges Waterfowl hunting is frequently practiced on the impoundments. At some facilities it is recommended that refuge areas be established. This is a good conservation practice and is encouraged. 2.4 General Bird Conservation Practices Electric fences are being erected at many facilities to prevent white-tailed deer depredation. The fence borders the matrix which is often also bordered by a ditch. This ditch is used by waterfowl and prairie chickens. Several times I scared waterfowl and prairie chickens out of these ditches and they flew into the fence. These fences need to flagged to increase their visibility to birds. This is a very simple, inexpensive technique which will prevent needless mortality. Electric fences also contain insulators. In the past ~hite insulators were used exclusively. Recently, colored insulators have come into use. These colored insulators attract hummingbirds, which are electrocuted. Thus, colored insulators should not be used and where they have been used they should be replaced with white insulators. Sources of Information and Materials Appendix A. lists several general information sources. Detailed information regarding specific species is available through The Wisconsin Society For Ornithology, 115 Meadow Wood Dr., Randolph, WI 53956. Finished nesting boxes for many cavity nesting birds are available for $2.10 each through a senior citizen program operated by Mr. Don Kopff, N7426 Edgewater Drive, Beaver Dam, WI 53916-9535, phone (414) 885-4220. 224 2.5 Turtles Turtles, particularly painted turtles, are very prevalent in the impoundments. Their presence is largely unappreciated because of limited visibility. They often bask on the edge of the impoundment, obscured in the vegetation. Provision of basking structures is an easily implemented management technique which will provide growers with visual enjoyment and confirmation of their efforts. A basking area can be provided simply by anchoring logs with a cement block to the bottom of the-impoundments. The logs can be secured by cables to the bottom of the impoundment. Anchored logs have the additional benefit of providing waterfowl display and loafing areas. The logs should be placed within 30 ft of shore. Optimally, they would also be placed where they can be observed with binoculars. 2.6 Muskrats Muskrats are identified by growers as a nuisance animal. This is because they burrow into dikes, causing leakage and eventual dike failure. Trapping is the best method of control for muskrats. Local support can be encouraged by using a local trapper. New dike construction can be planned to reduce the effects of muskrat burrows. Narrow dikes can be armored with chain-link fence buried in the soil. Narrow dikes can also be cored with rock or fence. Fence material will eventually decompose. The best proactive control method is construction of wide, gently sloped dikes. Because a typical muskrat burrow may extend 8 ft it is necessary to construct dikes which are at least 16 ft wide at the waterline. Further, dike slopes of 5 to 1 will tend to prevent muskrats from starting burrows in the first place. 225 2.7 White-tailed Deer White-tailed deer are identified by growers as a nuisance animal. They run through the beds, knocking off berries and cause processing problems. Electric fences are becoming popular control devices for deer. I do not support this. Fences disrupt the landscape and contribute to fragmentation. They are aesthetically obnoxious. Most importantly, the fences generally do not work. Deer can jump over the fence and can they can get around it. The fences cross roads and dikes, necessitating gates, and deer preferentially travel these lanes. I have observed that the gates are seldom closed. Because dikes/roads are preferred travel lanes the fence is completely useless if the gates are not kept closed. Some growers feel that if they keep trees and shrubs from encroaching on the areas adjacent to the bed matrix, the deer do not use the matrix as much. This is a good natural strategy which has the collateral benefit of maintaining early succession vegetation communities. White-tailed deer are omnipresent in great numbers in Wisconsin. Present policy is that their depredations are largely a cost of doing business for agriculturists. I do not agree with this policy but it is a reality that many farmers have to deal with. Rather than building fences to decrease depredation I think that the growers should work with the Department of Natural Resources deer damage program to secure shooting permits for excess animals. 226 APPENDIX A. Definitions Bed(s). See Cranberry Bed. Bed Matrix. An entire group of cranberry beds, their encompassing dikes and associated ditches. Cranberry Bed Matrix. See Bed Matrix. Cranberry Bed(s). A relatively small area surrounded by, but not including a dike. Many beds together form a bed matrix. Cultural. Created by, and often for, humans. Wood Duck nest boxes are cultural improvements to wildlife habitat. Edge Effect. The tendency of species and individuals to congregate where two habitats meet. Habitat. Habitat is where an animal lives. Habitat requires the presence of an animal. Matrix. See Bed Matrix. 227 APPENDIX B. Bibliography of Wildlife Management Tecilnigues Henderson, c. L. 1987. Landscaping for wildlife. Minnesota's Bookstore, 117 University Ave., st. Paul, MN 55155. Phone 1-800-652-9747. 144pp. Henderson, C. _L. Woodworking for wildlife, homes for birds and mammals. Minnesota Department of Natural Resources, Non-game Wildlife Program, Box 7. 500 Lafayette Road, St. Paul, MN 55155-4007. Linde, A. F. 1969. Techniques for wetland management. Wisc. Dept. Nat. Res. Research Rept. 45. 159pp. Timm, R. M. ed. 1983. Prevention and control of wildlife damage. Great Plains Ag. council Wildlife Resources Committee and Nebraska Coop. Ext. Serv., Univ. of Nebr., Lincoln. 228 APPENDIX C. Bibliography of Selected Natural History .. Readings. This bibliography is provided to give interested growers ideas for sources of information which go beyond readily available field-guides. In general, familiarity with the terminology of the wildlife or natural history professions would be very helpful in the appreciation of these works. Many of these references are available at libraries or through inter-library loan. Suggested Resource Books For Wisconsin Becker, G. C. 1983. Fishes of Wisconsin. Univ. of Wisconsin Pr., Madison. 1052 pp. Curtis, J. T. 1959. Vegetation of Wisconsin. Univ. of Wisc. Pr., Madison. 657pp. Fassett, N. c. 1957. A manual of aquatic plants. Univ. of Wisc. Pr., Madison. 405pp. Fassett, N. c. 1976. Spring flora of Wisconsin. Univ. of Wisc. Pr., Madison. 413pp. Jackson, H. H. T. 1961. Mammals of Wisconsin. Univ. of Wisc. Pr., Madison. 504pp. Martin, L. 1965. The physical geography of Wisconsin. Univ. of Wis. Pr., Madison. 608pp. Robbins, s. D., Jr. 1991. Wisconsin birdlife, population and distribution, past and present. Univ. of Wisc. Pr., Madison. 702 pp. Vogt, R. c. 1981. Natural history of amphibians and reptiles of Wisconsin. The Public Museum of Milwaukee. 205pp. 229 Suggested General Resource Books. Bellrose, F. C. 1976. Ducks, geese and swans of North America. The Wildlife Management Institute, washington, n.c., Stackpole Books, Harrisburg, PA. 540pp. Eck, P. 1990. The american cranberry. Rutgers Univ. Pr. 420pp. Gleason, H. A., and A. Cronquist .. _1963. Manual of vascular plants of northeastern United States and adjacent Canada. Willard Grant Pr., Boston, MA. 810pp. Leopold, A. 1933. Game management. Univ. of Wisc. Pr., Madison. 48lpp. Martin, A. c., H. S. Zim, and A. L. Nelson. 1951. American wildlife and plants a guide to wildlife food habits. Dover Publ., Inc. New York, NY. 500pp. Newcomb, L. 1977. Newcomb's wildflower guide. Little, Brown and Co., Boston, Toronto, London. 490pp. Reid, F. A., J. R. Kelley, Jr., T. S. Taylor, and L. H. Fredrickson. 1989. Upper mississippi valley wetlands-refuges and moist-soil impoundments. Pages 181-202 in L. M. Smith, R. L. Pederson, and R. M. Kaminski, eds. Habitat management for migrating and wintering waterfowl in North America. Texas Tech Univ. Pr. 560pp. Voss, E.G. 1972. Michigan flora part 1: gymnosperms and monocots. Cranbrook Inst. of Sci., Bloomfield Hills, MI. 488pp. Voss, E.G. 1985. Michigan flora part 2: dicots. cranbrook Inst. of Sci., Bloomfield Hills, MI. 724pp. Weller, M. W. 1981. Freshwater marshes ecology and wildlife management. Univ. Minn. Pr., Minneapolis. 150pp. 230 Suggested Articles From Professional Societies. catenhusen, J. 1950. Secondary successions on the peat lands of Glacial Lake Wisconsin. Trans. Wis. Acad. Sc1. 40:29-48. Hoffman, R. M. 1990. Birds of Wisconsin's deep marshes and shallow open water communities. Passenger Pigeon 52:259-272. Kalinich, J. c. 1991. Cranberry growing and Wisconsin's bird diversity. Passenger Pigeon 53:126-136. McLaughlin, w. T. 1932. Atlantic coastal plain plants in the sand barrens of northwestern Wisconsin. Ecol. Mono. 2:335-383. Mossman, M. J., and D. W. Sample. 1990. Birds of Wisconsin sedge meadows. Passenger Pigeon 52:39- 56. White, K. L. 1965. Shrub-carrs of southeastern Wisconsin. Ecol. 46:286-304. 231 Suggested Resources From Governmental Agencies and Universities. Cowardin, L. M., V. Carter, F. Golet, and E.T. LaRue. 1979. ClassificaEion of wetlands aria deepwater habitats of the United States. USFWS, USDI. 131pp. Eggers, s. D., and D. M. Reed. 1987. Wetland plants and plant communities of Minnesota and Wisconsin. US Army Corps of Engineers, St. Paul District. 20lpp. Hamilton, L. J. 1971. Water for cranberry culture in the Cranmoor area of central Wisconsin. Geological Survey Water Supply Paper 1999-I. USGS. 20pp. Hilsenhoff, W. L. 1981 Aquatic insects of Wisconsin. Natural History Council, Univ. Wisc. Madison. 60pp. Lange, K. L. 1990. A postglacial vegetational history of Sauk County and Caledonia Township, Columbia County, south central Wisconsin. Wisconsin Department of Natural Resources Tech. Bull. No. 186, Madison. 40pp. Meyer, M. W. 1988. Pesticide use and wildlife in Wisconsin cranberry marshes. Wisconsin Department of Natural Resources. 9pp. U.S. Army Corps of Engineers. 1991. Draft; St. Paul district analysis regarding section 404 review of commercial cranberry operations. USACE. st. Paul, MN. 34pp. 232 Suggested Resources From Private Resources. IEP. 1990. Wildlife utilization and ecological functions of commercial cranberry wetland ecosystems. IEP, Inc. New Hampshire. 23pp. Klingbeil, G. C., and E. J. Stang. 1981. Wisconsin cranberries, wetlands and wildlife preserving and nurturing Wisconsin's heritage: a 1981 resource survey. 16pp. Suggested Masters Theses. Baldasarre, G. A. 1978. Ecological factors affecting waterfowl production on three man-made flowages in central Wisconsin. MS Thesis, Univ. of Wisc. Stevens Point. 124pp. Jorgensen, E. E. 1992. Wildlife diversity and habitat associated with commercial cranberry production in Wisconsin. MS Thesis, Univ. of Wisc •. Stevens Point. In Print.