ii ABSTRACT
Karen V. Root, Advisor
Oak savannas of the Midwestern U.S. are among the most imperiled North American plant communities. The 478-km2 Oak Openings region of Northwestern Ohio is one of the few landscape-scale savanna systems remaining in the Midwest. Despite conversion of large portions of the Oak Openings for human land uses, the region still supports high levels of floristic diversity. However, regional patterns of Oak Openings plant diversity within the modern landscape are not well understood. My research objectives were 1) to determine the current extent and distribution of Oak Openings plant communities, 2) to quantify multiscale patterns of plant species richness within the context of the surrounding landscape, and 3) to build predictive species distribution models of rare plants to evaluate regional patterns in habitat suitability.
First, using multi-seasonal Landsat images, I determined that <3% of the Oak Openings remains covered by native savannas, prairies, and barrens, while three-fourths of the region has been converted for urban, residential, and agricultural uses. Second, using measures of spatial heterogeneity derived from field data and remote sensing, I develop models of native and exotic plant species richness at two spatial extents and at four ecological levels for the Oak Openings.
These models consistently explained more variation in exotic richness (better explained at the larger spatial extent) than in native richness (better explained at the smaller spatial extent). At all ecological levels, percentage of human-modified land cover in the surrounding landscape
(negatively correlated with native richness, positively correlated with exotic richness) was a strong predictor of species richness. Finally, I developed species distribution models for nine rare plant species within the Oak Openings region using the Maxent modeling algorithm.
Proportional land cover surrounding species occurrences accounted for a large proportion of the iii predictive power of all models. As percentage of human development increased in the surrounding landscape, the relative habitat suitability for modeled species decreased. From these collective results, I conclude that human-caused disturbances exert a strong influence on
Oak Openings species richness patterns. It is therefore important for resource managers to consider landscape context when implementing conservation actions for the Oak Openings region.
Natural Areas Journal
Environmental Management
ABSTRACT
INTRODUCTION
STUDY AREA
Lycaeides melissa samuelis
METHODS
Classification system
Landsat image selection
Supervised image classification
n + n
Training site selection
Accuracy assessment
Absolutely Wrong
Understandable but Wrong (Not Right)
Reasonable or Acceptable Answer
Good Answer
Absolutely Right
Regional assessment
RESULTS
Map accuracy assessment
Status of Oak Openings region
Rhamnus frangula
DISCUSSION
Map Evaluation
refer to
Implications for Midwest Oak Savannas
ACKNOWLEDGMENTS
Table 1. Oak Openings region land cover classification. Class descriptions are based on field observations by the authors in September 2007 and September - December 2009. Quercus palustris Quercus bicolor . with Acer rubrum Populus deltoides Platanus occidentalis Fraxinus Acer saccharinum Populus Fraxinus Quercus Quercus velutina Quercus alba Quercus rubra Sassafras albidum , Prunus serotina , Acer rubrum Vaccinium Carex pensylvanica Pinus Quercus velutina Quercus alba Quercus palustris Quercus coccinea Andropogon gerardii Sorghastrum nutans Rhamnus frangula Salix Cornus Cephalanthus occidentalis , Physocarpus opulifolius Carex
continued
Table 1. Continued. Carex Calamagrostis Schizachrium scoparium, Andropogon virginicus , Aristida Rubus Festuca Poa Bromus Rosa multiflora Eleaegnus umbellata
______
Table 2. Error matrix and accuracy for the 15-class Oak Openings region land cover map. The RIGHT function evaluates whether the mapped class is acceptable for a given reference site using the linguistic scale of Gopal and Woodcock (1994). 28 38 66 56 27 43 36 7 6 39 79 61 175 41 129 1392 Overall 60% 69% Kappa = 0.56
Table 3. Error matrix and accuracy for the Oak Openings region land cover map using seven classes. The RIGHT function evaluates whether the mapped class is acceptable for a given reference site using the linguistic scale of Gopal and Woodcock (1994). 275 27 43 128 79 272 183 1392 Overall 72% 79% Kappa = 0.65
Table 4. Summary of land cover map results for the entire Oak Openings region and lands permanently protected as parks and preserves.
Table 4. Continued.
LITERATURE CITED
in
.
ABSTRACT
INTRODUCTION
STUDY AREA
METHODS
Site selection and field sampling
Cyperaceae
GIS data collection
see
Landscape pattern analysis
see
see
Statistical analyses
P
n
x y F P
P
P P
RESULTS
Plant species richness among Oak Openings communities
R P
P
t P t P t
P t P
t P t P
t P t P
Physical and landscape attributes among Oak Openings communities
Relationships between spatial heterogeneity and species richness
P
Best explanatory models of native and exotic richness
DISCUSSION
R P
Management Implications for Midwest Oak Savannas
Landscape Composition as a Rapid Assessment Tool
ACKNOWLEDGEMENTS
54
n
F P R P
FPR ` ` ` ` ` `` `` `` ``
FPR ` `` `` `` `` `` `` `
FPR ` ` ` ` ` ` `
FPR `` ` ` ` ` ` `
R FP no variables significant at p<0.05 F P
R FP F P
61
P R ` no variables significant at p<0.05
no variables significant at p<0.05
`` Clay soil (%) 0.018 <0.0001 0.56 -44.21 0 Oak Openings land cover (%) 0.006
`` Human-modified land cover (%) -0.007 0.007 0.50 -26.12 0
n ` `` 62
P R ` Total ground litter (%) 0.002 <0.0001 0.62 6.59 0.68 Upland prairies / barrens land cover (%) 0.010 Human-modified land cover (%) 0.017 `` Total foliar cover (%) -0.323 <0.0001 0.69 3.32 0.70 Distance from roads -0.001 Savanna land cover (%) -0.009 ``
Soil Na (ppm) 0.132 <0.0001 0.77 -4.35 0.00 Soil S (ppm) -0.016 Savanna land cover (%) -0.011
n ` `` 63
Oak Openings land cover forested land cover human-modified land cover 0105 ¯ Kilometers
Lake Erie
r OHIO ive R ee um Ma
Figure . Current extent of Oak Openings land cover (adapted from Schetter and Root 2011). Oak Openings land cover includes wet prairies, dry prairies, mesic prairies, sand barrens, and oak savannas. 64
Region Oak Openings Region Level (all communities) N=39
Intermediate Upland Communities (Prairies, Barrens, Savannas) N = 30 Level I
Intermediate Upland Prairies & Level II Barrens N=21
Sand Barrens N =7 Community
Level Wet Prairies Dry Prairies N =8 Oak Savannas N =9 N =9
Mesic Prairies N =6
65
` R P
no variables significant at P<0.05
Slope Ground R R R P P P
native species richness Total foliar cover (%) Bare ground (%) Slope (%) Upland forest land cover 60-m (%)
` R R R R P P P P
ecies richnes
p R R P P
exotic s Total litter (%) Oak openings land cover (%) Proximity to water (m) Upland prairie land cover 120m (%) Human-mod. land cover 120m (%) *log10 (n+1) Figure 3. Relationship between native / exotic species richness and individual predictor variables for four Oak Openings community types. For mesix prairies, no variables were significant at P = 0.05.
LITERATURE CITED
̄
Phragmites australis
,
P
r P
X
N N
Salix petiolaris
A. purpurascens
S. triglomerata
P
S.
petiolaris J. greenei
S. triglomerata S. petiolaris
L. perennis A. purpurascens
A. purpurascens
S. petiolaris
A. purpurascens
pers. comm
A. purpurascens
S. petiolaris
90
Aristida purpurascens Desmodium sessilifolium Euthamia remota Helianthemum canadense Juncus greenei Lupinus perennis Polygala polygama Salix petiolaris Scleria triglomerata 91
Aristida Desmodium Euthamia Helianthemum Juncus Lupinus Polygala Salix Scleria purpurascens sessilifolium remota canadense greenei perennis polygama petiolaris triglomerata 0.02 ` 0.04 ` 0.09 ``` ` 0.04 `` 0.07 `` 0.11 ``` 0.08 ``` ``` 0.12 ``` `` 0.11 `` `` 0.03 ` 0.03 ` 0.03 ` 0.04 ` 0.18 ``` 0.22 ``` 0.12 ``` 0.25 ``` 0.24 ``` ``` ` ``` `` ` `` 0.49 ``` `` `` 0.12 ``` `` ``` `` `` ``` 0.09 ``` 0.20 ``` 0.26 ``` 0.30 ``` 0.30 ``` 0.37 ``` 0.37 ``` 0.33 ``` 0.23 ``` 0.41 ``` ` ``` ``` ``` 0.53 ``` ``` 0.70 ``` ``` ``` 0.55 ``` 0.69 ``` ``` 0.48 ``` ``` 0.44 ``` ``` 0.60 ``` 0.37 ``` ` ``` `` ``` ` 0.03 ` 0.04 ` 0.04 ` 0.05 `` `` 0.04 ` ``` R ` P `` P ``` P 92
Aristida Desmodium Euthamia Helianthemum Juncus Lupinus Polygala Salix Scleria purpurascens sessilifolium remota canadense greenei perennis polygama petiolaris triglomerata 93
Aristida Desmodium Euthamia Helianthemum Juncus Lupinus Polygala Salix Scleria purpurascens sessilifolium remota canadense greenei perennis polygama petiolaris triglomerata 1% ` `` `` ``` ``` ``` ``` 5% ` `` ``` ``` ``` ``` ``` ` ``` 10% ` ``` ``` ``` ``` ``` ``` `` ``` MSS threshold 18% 29% 15% 19% 13% 10% 15% 32% 31% ``` ``` ``` ``` ``` ``` ``` ``` ``` ` `` ``` 94
95
96
Aristida purpurascens High : 0.97 !H
!H Low : 0 !H !H!H!H!H!H!H !H !H
!H !H !H !H!H !H !H!H !H !H
!H
!H !H
!H
Desmodium sessilifolium !H High : 0.98 !H!H!H
Low : 0 !H !H!H !H !H
!H
!H!H !H !H !H!H !H !H
!H
Euthamia remota !H High : 0.98 !H
!H!H Low : 0 !H !H !H!H !H !H!H !H!H !H!H
!H !H ¯ !H
!H !H !H !H !H !H!H Species Record
!H 10
Kilometers Figure 1. Maxent habitat suitability models for nine Oak Openings plant species. Logistic output shows relative suitability from low (blue) to high (red). Red circles show locations of species occurance records. 97
Helianthemum canadense !H !H!H High : 0.97 !H !H
Low : 0 !H !H !H!H !H !H !H!H!H !H !H!H !H !H !H!H !H !H !H !H!H!H
Juncus greenei High : 0.94
Low : 0 !H !H!H!H!H !H !H
!H !H !H !H !H !H!H !H!H!H !H !H!H!H!H
Lupinus perennis High : 0.94 !H !H
Low : 0 !H!H !H !H!H !H !H!H!H ¯ !H !H !H !H!H !H!H!H !H !H !H !H !H!H!H!H Species Record
10
Kilometers Figure 1. (continued) 98
Polygala polygama !H !H!H High : 0.96 !H!H!H
Low : 0 !H !H !H!H
!H
!H !H !H !H !H !H !H !H!H !H!H !H !H !H !H !H !H!H!H!H !H
Salix petiolaris High : 0.99
!H!H!H Low : 0
!H
!H
!H !H
Scleria triglomerata !H High : 0.97 !H
Low : 0
!H !H!H!H !H !H
!H!H ¯ !H
!H !H !H !H!H Species Record
10
Kilometers Figure 1. (continued) 99
a)
b) 100
Canacomyrica monticola
)
.
Centrocercus urophasianus
Coefficient of Conservatism Acer rubrum Acer saccharinum Achillea millefolium Actaea rubra Agalinis gattingeri Agalinis purpurea purpurea Agalinis tenuifolia Agrimonia parviflora ` AGROSTIS GIGANTEA Agrostis hyemalis Agrostis perennans ` AILANTHUS ALTISSIMA Aletris farinosa Alisma subcordatum Ambrosia artemisiifolia Amelanchier arborea Amelanchier spicata Amphicarpaea bracteata Andropogon gerardii Andropogon virginicus Anemone cylindrica Anemone virginiana
Antennaria neglecta Antennaria parlinii Apios americana Apocynum androsaemifolium Apocynum cannabinum ` ARABIDOPSIS THALIANA Aralia nudicaulis ` ARENARIA SERPYLLIFOLIA Aristida longespica longespica Aristida purpurascens Aronia melanocarpa Asclepias hirtella Asclepias incarnata Asclepias syriaca Asclepias tuberosa Aster laevis Aster lanceolatus Aster macrophyllus Aster novae-angliae Aster pilosus Aster praealtus Aster sagittifolius Aster umbellatus Aureolaria pedicularia ambigens Baptisia tinctoria Bartonia virginica ` BERTEROA INCANA ` BETULA PENDULA Betula populifolia Bidens frondosa Botrychium dissectum ` BROMUS INERMIS
Calamagrostis C. canadensis and C. stricta ` BROMUS TECTORUM Bulbostylis capillaris Calamagrostis canadensis Calamagrostis stricta Calamagrostis (see note above) Calystegia sepium Calystegia spithamaea Carex alata Carex albicans emmonsii Carex atherodes Carex aurea Carex bebbii Carex bicknellii Carex blanda Carex buxbaumii Carex conoidea Carex cristatella Carex cryptolepis Carex gracillima Carex granularis Carex interior Carex lacustris Carex lasiocarpa Carex muhlenbergii Carex pellita Carex pensylvanica Carex sartwellii Carex scoparia Carex stipata Carex stricta Carex swanii Carex tenera tenera
Carex tetanica Carex tonsa Carex tribuloides Carex vulpinoidea Ceanothus americanus ` CELASTRUS ORBICULATUS Celastrus scandens Celtis occidentalis Cenchrus longispinus Cephalanthus occidentalis ` CERASTIUM VULGATUM Chamaecrista fasciculata ` CHRYSANTHEMUM LEUCANTHEMUM Cicuta bulbifera Cicuta maculata Circaea lutetiana Cirsium discolor Cirsium muticum Cladium mariscoides Comandra umbellata Comptonia peregrina Conopholis americana Conyza canadensis ` COREOPSIS TINCTORIA Coreopsis tripteris Cornus amomum Cornus drummondii Cornus racemosa Corylus americana Crataegus mollis Crataegus punctata Cuscuta gronovii
` CYCLOLOMA ATRIPLICIFOLIUM Cyperus lupulinus Cyperus strigosus Danthonia spicata ` DAUCUS CAROTA Desmodium canadense Desmodium marilandicum Desmodium nudiflorum Desmodium sessilifolium ` DIANTHUS ARMERIA ` DIGITARIA ISCHAEMUM ` DIGITARIA SANGUINALIS Dioscorea villosa Dulichium arundinaceum ` ELAEAGNUS UMBELLATA Eleocharis elliptica ` ELYTRIGIA REPENS Equisetum arvense Equisetum laevigatum Eragrostis spectabilis Erechtites hieracifolia Erigeron annuus Erigeron strigosus Eupatorium altissimum Eupatorium maculatum Eupatorium perfoliatum Euphorbia corollata ` EUPHORBIA CYPARISSIAS ` EUPHORBIA DENTATA Euphorbia maculata Euthamia graminifolia Euthamia remota
` FESTUCA PRATENSIS Fragaria virginiana Fraxinus pennsylvanica Galium aparine Galium circaezans Galium pilosum Galium tinctorium Galium triflorum Gaultheria procumbens Gaylussacia baccata Gentiana andrewsii Gentianopsis crinita Geranium maculatum Gleditsia triacanthos Glyceria acutiflora Glyceria striata Gnaphalium obtusifolium Hackelia virginiana Hamamelis virginiana Hedeoma hispida ` HELENIUM FLEXUOSUM Helianthemum bicknellii Helianthemum canadense Helianthus divaricatus Helianthus giganteus Helianthus occidentalis ` HIERACIUM CAESPITOSUM Hieracium gronovii Hieracium scabrum Hypericum gentianoides Hypericum kalmianum Hypericum majus
Hypericum mutilum ` HYPERICUM PERFORATUM Hypericum prolificum Ilex verticillata Iris virginica Juncus anthelatus Juncus articulatus Juncus brachycarpus Juncus canadensis Juncus dudleyi Juncus effusus Juncus greenei Juncus marginatus Juncus nodosus Juncus tenuis Juncus torreyi Juniperus virginiana Koeleria pyramidata Krigia biflora Krigia virginica Lactuca canadensis Lechea intermedia Lechea mucronata Lechea pulchella Leersia oryzoides Lepidium virginicum Leptoloma cognatum Lespedeza capitata Lespedeza hirta Leucospora multifida Liatris aspera Liatris spicata
Liatris squarrosa ` LIGUSTRUM VULGARE Lilium philadelphicum Linaria canadensis Linum medium Liparis loeselii Lipocarpha micrantha Liriodendron tulipifera Lithospermum caroliniense Lobelia spicata ` LONICERA JAPONICA ` LONICERA MORROWII Ludwigia alternifolia Ludwigia palustris Lupinus perennis Luzula echinata Lycopus americanus Lycopus uniflorus Lycopus virginicus Lysimachia ciliata Lysimachia lanceolata Lysimachia quadrifolia Lysimachia terrestris Lysimachia thyrsiflora Lythrum alatum ` LYTHRUM SALICARIA Maianthemum canadense Maianthemum racemosum Maianthemum stellatum Medeola virginiana ` MEDICAGO LUPULINA ` MELILOTUS ALBA
Monarda fistulosa Monarda punctata Muhlenbergia mexicana Muhlenbergia schreberi Nyssa sylvatica Oenothera biennis Oenothera clelandii Oenothera laciniata Onoclea sensibilis Opuntia humifusa Osmunda cinnamomea Osmunda regalis Oxalis dillenii Panicum acuminatum Panicum boreale Panicum clandestinum Panicum columbianum Panicum depauperatum Panicum dichotomiflorum Panicum implicatum Panicum latifolium Panicum meridionale Panicum oligosanthes Panicum rigidulum Panicum spretum Parthenocissus quinquefolia Paspalum setaceum Pedicularis canadensis Penstemon digitalis ` PHLEUM PRATENSE ` Phragmites australis Physalis heterophylla
Physocarpus opulifolius ` PINUS STROBUS ` PINUS SYLVESTRIS ` PLANTAGO LANCEOLATA ` PLANTAGO MAJOR Platanthera lacera Platanus occidentalis ` POA COMPRESSA ` POA PRATENSIS Polygala polygama Polygala sanguinea Polygala verticillata Polygonatum biflorum Polygonum amphibium Polygonum pensylvanicum ` POLYGONUM PERSICARIA Polygonum scandens Polygonum tenue Populus deltoides Populus grandidentata Populus tremuloides Potentilla simplex Prenanthes alba Prenanthes racemosa Proserpinaca palustris Prunella vulgaris Prunus pensylvanica Prunus pumila Prunus serotina Prunus virginiana Pteridium aquilinum Pycnanthemum virginianum
Pyrola elliptica Quercus alba Quercus coccinea Quercus palustris Quercus rubra Quercus velutina Rhamnus alnifolia ` RHAMNUS CATHARTICA ` RHAMNUS FRANGULA Rhus copallinum Rhus typhina Rhynchospora capitellata Rhynchospora recognita ` ROBINIA HISPIDA Robinia pseudoacacia Rosa carolina ` ROSA MULTIFLORA Rosa palustris Rosa setigera Rubus allegheniensis Rubus flagellaris Rubus hispidus Rubus idaeus strigosus Rubus occidentalis Rubus pubescens Rudbeckia hirta ` RUMEX ACETOSELLA ` RUMEX CRISPUS Salix bebbiana Salix discolor Salix eriocephala Salix exigua
Salix humilis Salix petiolaris ` SAPONARIA OFFICINALIS Sassafras albidum Schizachyrium scoparium Schoenoplectus acutus Schoenoplectus tabernaemontani Scirpus atrovirens Scirpus cyperinus Scirpus hattorianus Scirpus pendulus Scleria triglomerata Scutellaria lateriflora Senecio aureus ` SETARIA FABERI ` SILENE LATIFOLIA Sisyrinchium albidum Sisyrinchium angustifolium Sium suave Smilax glauca Smilax hispida ` SOLANUM CAROLINENSE Solidago canadensis Solidago gigantea Solidago juncea Solidago nemoralis Solidago patula Solidago riddellii Solidago rugosa Solidago speciosa Sorghastrum nutans Sphenopholis obtusata obtusata
Spiraea alba Spiraea tomentosa Sporobolus cryptandrus Stachys tenuifolia Stellaria longifolia ` TARAXACUM OFFICINALE Tephrosia virginiana Thalictrum dasycarpum Thelypteris palustris Toxicodendron radicans ` TRAGOPOGON DUBIUS Trichostema dichotomum Tridens flavus ` TRIFOLIUM PRATENSE Triplasis purpurea ` TYPHA ANGUSTIFOLIA ` ULMUS PUMILA Uvularia sessilifolia Vaccinium angustifolium Vaccinium pallidum ` VERBASCUM THAPSUS Verbena hastata Verbena urticifolia Vernonia gigantea Viola lanceolata Viola sagittata Vitis aestivalis Vitis riparia Vulpia octoflora ` XANTHIUM STRUMARIUM Xyris torta Zanthoxylum americanum
P
P
P
floristic quality assessment index
126
75 70 Total Species Richness
65 60 P 55 50 45 40 35 30 25 20 15 10 5 0
75 70 Native Species Richness 65 60 P 55 50 45 40 35 30
number of species 25 20 15 10 5 0
13 Exotic Species Richness 12
11 P 10 9 8 7 6 5 4 3 2 1 0 1 10 100 1000 area (m2) Figure 1. Species area curves for five Oak Openings plant communities based on 39 1000-m2 modified- Whittaker, multi-scale plots. Statistical relationships are based on log10 transformed data for both area and number of species. 127
0.6 0.6 0.5 0.5
0.4 0.4
0.3 0.3
0.2 n 0.2 n r r 0.1 P 0.1 P 0 0 2 2.5 3 3.5 4 4.5 2 2.5 3 3.5 4 4.5
0.6 0.6 0.5 0.5
0.4 0.4
0.3 0.3
0.2 n 0.2 n Jaccard's Coefficient r r 0.1 P 0.1 P 0 0 2 2.5 3 3.5 4 4.5 2 2.5 3 3.5 4 4.5
0.6 0.6 0.5 0.5
0.4 0.4
0.3 0.3
0.2 n 0.2 n r r 0.1 P 0.1 P 0 0 2 2.5 3 3.5 4 4.5 2 2.5 3 3.5 4 4.5
Log10(Distance)
Figure 2. Relationship between species composition overlap (Jaccard’s Coefficient) and proximity of sampling plots for five Oak Openings plant communities. Distance units are in meters.
Aristida purpurascens
Aristida purpurascens
Desmodium sessilifolium
Euthamia remota
Helianthemum canadense
Juncus greenei
Lupinus perennis
Polygala polygama
Salix petiolaris
Scleria triglomerata