Aquatic Macroinvertebrate Use of Rootmat Habitat Created By

AQUATIC MACROINVERTEBRATE USE OF ROOTMAT HABITAT CREATED BY

EIGHT WOODY RIPARIAN SPECIES

Thesis

Presented in Partial Fulfillment of the Requirements for the Degree of Master of Science

in the Graduate School of The Ohio State University

Sonia Nicole Bingham, B.A

Environmental Science Graduate Program

The Ohio State University

2009

Thesis Committee:

Dr. Virginie Bouchard, Advisor

Dr. Peter C. Smiley, Jr.

Dr. Charles Goebel Copyright by:

Sonia Nicole Bingham

2009

Abstract

Rootmats are an instream habitat type created by fine roots of riparian vegetation that are exposed through natural erosion at the stream bank. Previous research indicated that rootmats may be important habitats for aquatic invertebrates and may have a distinct invertebrate composition compared to other instream habitat types. The objective of this study was to examine the invertebrate communities inhabiting rootmats of eight common woody riparian species in Cuyahoga Valley National Park, Ohio (CVNP). I collected 47 rootmat samples from pools across 10 CVNP streams. Coarse particulate organic matter, root morphology, and physiochemical variables were measured to characterize the local habitat at each location. Invertebrate community indices, multivariate techniques and univariate techniques were used to investigate the role of rootmats as habitat and determine whether any associations existed between invertebrate communities and eight woody riparian species. Additionally, invertebrate communities of rootmats were compared to adjacent riffles for eight sites.

A total of 138 taxa were collected from rootmats across all woody species. Most (59%) of the taxa were gathering collectors and this suggests that fine particulate organic matter may be a dominant food source within or near rootmats. Additionally, 15% of the captures were predators, while scrapers, shredders and filtering collectors were present in

similar proportions (8-9% each). Paratanytarsus dissimilis was the most abundant organism across the samples at nearly 250 organisms m-2. Other abundant taxa were

Chironomidae (midges), Calopteryx maculata (damselfly), Caecidotea communis

(isopod), Stenelmis sp. and Dubiraphia bivittata (riffle beetles). Invertebrate diversity,

species composition and functional feeding guilds differed among certain tree species.

Specifically, rootmats of two willow species (Salix interior and Salix nigra) were

consistently similar to each other, and different from rootmats of Carpinus caroliniana,

Fraxinus pennsylvanica, and Acer saccharum. Additionally, invertebrate species

composition was different in adjacent rootmat and riffle habitats, but the habitats were

similar in terms of diversity and abundance.

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Dedication

This thesis is dedicated to those who have always believed in me, particularly my grandfather, Charles Gordon Moot, who had a strong influence on my interest in biology and motivation to pursue an advanced degree because of his belief that I could make a difference.

Acknowledgements

This research was supported by the National Research Initiative of the USDA CSREES,

and was completed during my tenure as a SCEP employee for the Heartland Inventory

and Monitoring Network within the National Park Service, which provided the

opportunity to work within Cuyahoga Valley National Park with many exceptional and supportive colleagues. The members of my thesis committee (Virginie Bouchard,

Charles Goebel and Rocky Smiley) provided invaluable insight and advice as necessary.

My advisor, Virginie Bouchard, provided financial support that made it possible for me to focus on my academic and professional progress simultaneously. Rocky Smiley provided a tremendous amount of statistical advice. Many field & lab assistants (Rhonda

Mendel, Joel Bingham, Pat Geraghty, Steven Wise, Amy Barrett, Matt Lane, Sarah

Boley, Beth Wallace) pushed the project through very tedious phases and without their help, certain parts of the research may not have been possible. Additionally, the graduate students in the Aquatic Systems Ecology Lab at OSU provided guidance and advice.

Dennis Taylor (Hiram College) graciously permitted my use of his field equipment, Ola

Ahlqvist and Bob Gates (OSU) provided software assistance and support. I am also very grateful for the support and patience of my husband, Joel, who is also a willing partner in field work, and for the support of my beautiful family. Finally it is through the grace of

God that I had the guidance, strength, and support of those listed, to achieve this goal.

Vita

B.A. Biology, Hiram College ...... 2000

EnviroScience, Inc., Aquatic & Wetland Biologist ...... 1999 – 2006

Oxbow River & Stream Restoration, Inc., Aquatic & Wetland Biologist...... 2006 - 2007

Graduate Research and Teaching Assistant, The Ohio State University...... 2007-2009

National Park Service, Wetland Biologist ...... 2007 – Present

Fields of Study

Major Field: Environmental Science

Specializations: Wetland and stream ecology, floodplain restoration

Table of Contents

ABSTRACT...... II

DEDICATION...... IV

ACKNOWLEDGEMENTS...... V

VITA...... VI

LIST OF TABLES...... XI

LIST OF FIGURES ...... XIII

CHAPTER 1: INTRODUCTION...... 1

CHAPTER 2: METHODS...... 8

2.1 SITE SELECTION...... 8

2.2 FIELD SAMPLING ...... 13

2.2.1 Rootmat sampling ...... 13

2.2.2 Stream measurements ...... 14

2.2.3 Riffle sampling...... 15

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2.3 SAMPLE PROCESSING...... 16

2.3.1 Root structure- ...... 16

2.3.2 Root biomass...... 16

2.3.3 Invertebrates...... 16

2.3.4 Coarse particulate organic matter ...... 17

2.3.5 Nutrient analysis ...... 18

2.4 STATISTICAL ANALYSES...... 18

2.4.1 Research question 1 ...... 18

2.4.2 Research question 2 ...... 19

2.4.3 Research question 3 ...... 21

2.4.4 Research question 4 ...... 22

CHAPTER 3: RESULTS...... 24

3. 1RESEARCH QUESTION 1: ROOTMAT TAXA ...... 24

3.2 RESEARCH QUESTION 2: ASSOCIATION BETWEEN INVERTEBRATES AND SPECIFIC

WOODY RIPARIAN SPECIES...... 26

3.2.1 Invertebrate community indices...... 26

3.2.2 Invertebrate species composition...... 28

3.2.3 Functional feeding guild composition ...... 30

3.2.4 Associations between woody species and selected environmental variables

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...... 32

3.3 RESEARCH QUESTION 3: INFLUENCE OF ENVIRONMENTAL VARIABLES...... 33

3.4 RESEARCH QUESTION 4: ROOTMAT HABITAT COMPARED TO RIFFLE HABITAT ...... 36

3.4.1 Invertebrate community indices...... 36

3.4.2 Invertebrate species composition...... 37

3.4.3 Functional feeding guild composition ...... 38

CHAPTER 4: DISCUSSION...... 40

REFERENCES ...... 46

APPENDIX A: SPECIES LISTS SHOWING FEEDING GUILDS AS WELL AS

AVERAGE ABUNDANCE AND FREQUENCY ACROSS SITES ...... 52

List of Tables

Table 1. Distribution of the rootmats of each riparian species among the ten streams. ...12

Table 2. Methods for processing nutrient ions and detections limits associated with the

Lachat QuikChem...... 18

Table 3. Environmental variables used as parameters in the canonical correspondence

analysis (CCA)...... 22

Table 4. ANOVA results for invertebrate community indices. Woody species are the

categorical explanatory variable...... 24

Table 5. Multiple comparisons between woody species treatments using species scores

from NMS Axis 1 as the response variable...... 28

Table 6. MRPP results showing significantly different FFG compositions among woody

species...... 32

Table 7. Summary statistics for the four CCA axes...... 34

Table 9. ANOVA results comparing riffles and rootmats for five community variables.36

Table 10. MRPP results indicating significant differences in the functional feeding guild

proportions of rootmat and riffle habitats...... 39

Table 11. List of species collected across all rootmat samples, showing feeding guild as well as the average abundance, count and frequency of occurrences across sites...... 53

Table 12. Species list for the eight rootmat and eight riffle samples that were compared in question 4...... 57

List of Figures

Figure 1. Map of rootmat locations sampled within Cuyahoga Valley National Park in northeast, Ohio, USA...... 10

Figure 2. Top ten most abundant (A) and top ten most common (B) taxa across all rootmats...... 25

Figure 3. Means and standard errors (± 1) associated with each woody riparian species for density (A), richness (B) and evenness (C)...... 27

Figure 4. NMS ordination diagram for species composition...... 29

Figure 5. Invertebrate taxa strongly associated with woody species groups depicted on

NMS Axis 1...... 30

Figure 6. Stacked bar chart illustrating differences in FFG composition across woody species treatments...... 31

Figure 7. Environmental variables shown in ordination space using a canonical correspondence analysis...... 35

Figure 8. NMS ordination diagram illustrating the difference in species composition among roots and riffle samples...... 38

Figure 9. Functional feeding guild proportions for riffle and rootmat samples...... 39

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Chapter 1: Introduction

Undercut banks, overhanging vegetation, root wads, and rootmats are important instream habitat features associated with vegetation growing on stream banks. Of these features, the role of rootmats as habitat is poorly understood, although previous studies have indicated that the faunal composition in these environments is unique compared to other instream habitats (Brunke et al. 2001, Phillips 2003). Riparian zones have high rates of below ground production dominated by fine fibrous roots (< 2 mm diameter) (Kiley and

Schneider 2005). These fine roots may become exposed beneath the water surface following the natural process of stream bank erosion, and create rootmat habitat. The utilization of many organic habitat types (e.g., aquatic macrophytes, root wads, woody debris and rootmats) by aquatic invertebrates is recognized by many aquatic biologists

(Percival and Whitehead 1929, Hynes 1970, McCafferty 1981, Benke et al. 1984, Flory and Milner 1999, Kaenel and Uehlinger 1999, Rabeni 2000, Glotzhober and McShaffrey

2002, Phillips 2003, Sudduth and Meyer 2006, Rocha-Ramirez et al. 2007, Merrit and

Cumins 2008) and these habitats are often sampled in biological assessment programs

(Rankin 1989, Rabeni 2000). However, there is an overall lack of available literature and specific knowledge related to rootmats which has resulted in limited formal acknowledgement regarding their importance within stream ecosystems. By realizing the

importance of rootmats within the invertebrate community, biologists could more

effectively communicate to the public the extent to which the loss of these habitat

features will impact stream communities. Furthermore, if these habitats are indeed of

importance for aquatic life, special attention should be placed on re-establishing them in

restoration projects.

Previous research has indicated that submersed roots from riparian vegetation will often

have more surface area than inorganic sediments and substrates (e.g., cobble, gravel,

boulder) within pools and riffles (Sudduth and Meyer 2006) and their position near the

stream bank provides refugia from the active channel during flood events (Hynes 1970,

McCafferty 1981, Thorp and Covich 1991, Rempel et al. 1999). Some macroinvertebrate

taxa (such as several genera of Ephemeroptera) may simply use roots to grow and/or

emerge after pupating in higher velocities, and others (e.g., Trichoptera and Megaloptera)

may use them for oviposition (Hynes 1970).

Roots consume large quantities of carbohydrates through biomass production, respiration,

and exudation, and thus have a rapid turnover of carbon (Leuschner et al. 2004). These

carbon-rich organs may provide a key source of carbon to the aquatic community directly

from the turnover of rootlets or in the form of dissolved exudates. Since all plants

produce and respire oxygen, roots in wetland and terrestrial environments have been

shown to improve the oxygen availability in their local surroundings (Thorp and Covich

1991). This would also be true for aquatic systems, and invertebrate taxa with higher oxygen demands may take advantage of this oxygen source as an alternative to pool

bottoms, where oxygen may be limited by low velocities and decaying substrates (Hynes

1970).

The rate of plant growth and the presence of certain ions in the soil and water may also have an indirect effect on rootmat quality by modifying root structure. Fine roots function primarily in resource acquisition and the structure of the root systems is largely influenced by a plant’s necessity to obtain these resources under different environmental conditions (Fitter 1987). Consequently, root structure is highly influenced by the availability of water and certain nutrients (Eissenstat et al. 2000, Bouma et al. 2001;

Comas et al. 2002; Leuschner et al. 2004, Hishi 2007). Nitrate, phosphate, sulfate, and iron are expected to play a key role in root architecture (Lopez-Bucio et al. 2003) by acting as signals for hormones (auxins and cytokinins) that regulate the characteristics of root systems. Growth rate may also influence root structure since faster growing tree species generally have finer roots, larger specific root length, greater root tip frequencies, lower quantities of phenolic compounds, and higher root nitrogen concentrations than slower growing species (Espeleta and Donovan 2002, Comas and Eissenstat 2004).

These characteristics may also increase root density, roots surface area, and perhaps the palatability of the roots, and in turn, increase the benefits as a habitat type for aquatic organisms.

Furthermore, some invertebrates are known to be associated with specific vegetation types and even plant species (Hynes 1970). The species traits of riparian vegetation may play a role in defining the function and quality of roots as habitat. Riparian species that

are better adapted to the fluvial pressures associated with the stream bank will likely

provide the discussed benefits (e.g., oxygen, refuge, carbon) in greater abundance. Also, vegetation types that produce roots with greater densities are likely to provide more

surface area and favorable habitat. Roots with greater densities may also be more

efficient at trapping and retaining detrital material from the water column and serve as

sites of depositional carbon in streams.

Besides the attributes of the roots themselves, the quality of the instream environment

may also influence the structure of aquatic communities (Hynes 1970) and the function of

roots as habitat. The quality of dissolved substances and water temperature may limit the

types of invertebrates locally present within a reach. Dominant food sources (i.e.,

allochthonous vs. authochthonous sources, dissolved organic carbon) will influence

feeding guild proportions (Vannote et al. 1980). Water velocity influences feeding and/or

respiratory requirements which may alter the types of invertebrates that can permanently

inhabit lower oxygen conditions often associated with pools where rootmats are common.

Finally, available substrate types within a stream reach may also change the utilization of

roots by aquatic life. Invertebrate density and diversity may increase on rootmats when

homogenous or embedded substrates are dominant, or decrease in the presence of

heterogenous substrate types. Many of these environmental variables are influenced by

stream discharge (Thorp and Covich 1991).

Based on this information, it seems evident that rootmats may be a dynamic habitat that is

different from other microhabitat types in stream ecosystems and may provide unique

services for the invertebrate community. While these rootmat functions and services are suggested, they have yet to be quantified. Further characterizing the role of rootmats as a habitat for aquatic invertebrates is the primary focus of this research and four specific research questions were developed to achieve this goal. The research questions and their associated hypotheses follow.

Research question 1: What aquatic invertebrate taxa utilize rootmats as a habitat type?

I expected the functional feeding groups of macroinvertebrates to be consistent among most rootmat samples and to be comprised of mostly shredders, collectors, and predators.

Based on literature (Hynes 1970, McCafferty 1981), I expected to document use of rootmats by numerous taxa, including

1. Climbers, such as larvae of many dragonflies (Anisoptera) and damselflies

(Zygoptera);

2. Small square gilled mayflies (Caenidae);

3. Riffle beetle adults (Elmidae);

4. Endophytic breathers that pierce vascular plants to use atmospheric oxygen

such as larvae of aquatic leaf beetles (Chrysomelidae);

5. Larvae and pupae of mosquitos (Culicidae) and shore flies (Ephydridae); and

6. Predators that use the roots to stalk prey such as broad-winged damselflies

(Calopterygidae) narrow-winged damselflies (Coenagrionidae), garners

(Aeshnidae) and greeneyed skimmers (Corduliidae).

Research question 2: Are there unique associations between individual woody riparian species and aquatic invertebrate communities?

I suspected that certain plant species would provide higher quality habitat that would be linked with increased invertebrate diversity. Higher habitat quality was expected to be associated with greater root density since dense rootmats would provide greater surface area, enhance flood protection, and trap more coarse particulate organic matter (CPOM) from the water column. I predicted that woody species with higher inundation tolerances would be better adapted to the fluvial pressures associated with the stream bank and produce rootmats with higher root densities.

Research question 3: What physical or chemical characteristics exert notable influence on the macroinvertebrate community?

In addition to root density and carbon, water velocity and dominant benthic substrate types (e.g., cobble, gravel, boulder) within the vicinity of the rootmat were suspected to be the most influential environmental variables affecting invertebrate species composition in rootmats. Water velocity is important since is affects the respiratory requirements of invertebrates, the abundance of particulate organic matter in the water column, and the use of stable substrate types as refugia (Thorp and Covich 1991, Rempel et al. 1999). Physical habitat is considered one of the most important variables within a stream that influences biological potential (Rankin 1989, Ohio EPA 2002), and many aquatic species specialize on certain substrate types (Hynes 1970, Gorman and Karr

1978).

Research question 4: How do invertebrate communities compare between rootmat and riffle habitat types?

Riffles are often considered one of the most diverse and productive instream habitats

(Plafkin et al. 1989, Barbour et al. 1996), yet some of the earliest invertebrate studies indicated that invertebrates are often more abundant on moss, rooted plants, and filamentous algae than on stone (Percival and Whitehead 1929). More recently, several studies have indicated that invertebrate abundance and richness in rootmats tend to rank intermediately when compared to other instream habitats (Brunke et al. 2001, Phillips

2003). However, based on observations from a preliminary survey, I expected to find that rootmats and riffles are similarly diverse habitats. Invertebrate species composition should be different in rootmats and riffles since both habitats may have important and distinct functions in the stream ecosystem (Hynes 1970).

Chapter 2: Methods

2.1 Site selection

This study was located in northeast Ohio, USA within the Cuyahoga Valley National

Park (CVNP, 41°15’N and 81°32’W). Available literature on the existing physical habitat (Qualitative Habitat Evaluation Index, QHEI) and biological habitat integrity

(Invertebrate Community Index (ICI) or Headwater Macroinvertebrate Field Evaluation

Index (HMFEI)) of CVNP streams was reviewed to determine which streams were comparable to reference streams within the ecoregion, as documented by the Ohio

Environmental Protection Agency (Ohio EPA). These indices were developed by the

Ohio EPA and are used for regulatory purposes (Ohio EPA 1989, 2002).

Site selection was structured to minimize variation in state controls (i.e., climate, topography, biology, time, anthropogenic influences, and parent material) and facilitate site comparability (Amundson and Jenny 1997). Drainage area ranged between 1.09 to

80.29 km2, and was the most difficult to standardize because of the scattered distribution of the rootmats. Ten tributaries of the Cuyahoga River were selected for the study

(Figure 1). Most selected stream reaches were located at elevations between 213

meters to 229 meters above mean sea level, in the Erie Gorges subregion of the Erie-

Ontario Lake Plain (Woods et al. 1998). The intensity of agricultural and urban land use

varies within the sub-watersheds, and may influence hydrology, water chemistry,

substrate characteristics, and the biota. However, all sampling occurred within the

confines of the national park in areas that are documented as reference (least impacted)

conditions within Ohio (Holmes 2008). Base flow is largely groundwater driven, which

should provide fairly consistent water levels, temperatures, and dissolved oxygen.

Field reconnaissance

Field reconnaissance was completed from April to June 2007 to locate all rootmats

present within selected stream reaches and to determine which woody species were

appropriate for the study. A total of 67 rootmats were identified along the ten streams within a two week period. The location of each rootmat was recorded using a Global

Positioning System (GPS). Additionally, stream microhabitats (riffle, pool, run), rootmat quality (e.g., poor, fair, good, very good) based on visual estimates of root density, tree species, and dominant substrate types (visual examination) were recorded for each location.

Figure 1. Map of rootmat locations sampled within Cuyahoga Valley National Park in northeast, Ohio, USA.

The rootmats were almost exclusively found in stream pools, and rootmats not located in pools were removed from the experiment to simplify the design and the effect of many other stream variables. Low quality rootmats (i.e., only a few roots present) were also excluded. A total of ten tree species were affiliated with the rootmats, but only eight of them were found in four or more locations. These eight tree species were selected for the study. Platanus occidentalis L. (sycamore) was the only tree with rootmats present in more than ten locations. In this case, only ten of the rootmats were randomly selected.

The elimination of rootmats based on these criteria resulted in a total of 47 rootmats included in the study (Table 1 and Figure 1). The selected riparian species represent the spectrum of inundation tolerance as indicated by their wetland indicator status ranging from facultative upland (FACU) to obligate wetland (OBL) (USFWS 1988, 1993). Of these eight woody species, several species, such as Acer saccharum Marsh (sugar maple),

Carpinus caroliniana Walter (ironwood), Platanus occidentalis L. (sycamore), and Salix interior Rowlee (sandbar willow), are commonly planted in local riparian restoration projects. Salix nigra Marsh (black willow) and Populus deltoides Bartram ex Marsh

(cottonwood) are less commonly planted because of their tendency to colonize disturbed sites quickly. Ulmus americana L. (American elm) is avoided in plantings because of dutch elm disease and more recently, the use of Fraxinus pennsylvanica Marsh (green ash) in plantings is undesirable because of the recent emerald ash borer threat.

Table 1. Distribution of the rootmats of each riparian species among the ten streams. BR = Boston Run, C = Columbia Run, D = Dickerson Run, FR = Furnace Run, L = Langes Run, Perk = Perkins Trail, RR = Riding Run, RC = Rock Creek, Y = Yellow Creek. OBL = obligate wetland species, FACW = facultative wetland species, FAC= facultative species, FACU = facultative upland species. The + and – signs indicate that the species weights toward the upper or lower end of the probability range. Woody riparian species Wetland Indicator BR C D FR L Perk PT RR RC Y Total

Scientific Name Common Name

Acer saccharum sugar maple FACU- 2 0 0 1 0 2 0 1 0 0 6

Carpinus caroliniana ironwood FAC 0 0 0 0 4 0 0 0 0 0 4

Populus deltoides cottonwood FAC 0 0 1 1 0 0 0 1 2 0 5

Platanus occidentalis sycamore FACW- 1 2 1 3 1 0 0 1 0 1 10 12 Ulmus americana american elm FACW- 0 0 1 3 3 0 0 0 2 0 9

Fraxinus pennsylvanica green ash FACW 0 1 0 0 1 0 1 0 1 0 4

Salix nigra black willow FACW+ 0 0 0 2 0 0 0 0 0 2 4

Salix interior sandbar willow OBL 0 0 0 5 0 0 0 0 0 0 5

Total 3 3 3 15 9 2 1 3 5 3 47

2.2 Field sampling

Forty-seven sites were sampled from early July to mid-October 2007 at low flow

conditions. A random number table was used to select the sampling order of sites to

control the effects of temporal variation. Each site consisted of the rootmat and the

surrounding stream pool. Upon arrival at the site, care was taken not to disturb the

rootmats or substrate in the vicinity of the pools until sampling.

2.2.1 Rootmat sampling

All rootmats were variable in their length and size and most were 1 - 2 m in length and

less than 0.3 m in width and depth. Certain woody species, such as Platanus

occidentalis, Salix nigra and Ulmus Americana, occasionally had very well developed, thick rootmats that spanned 5-10 m in length with widths and depths over 0.5 m. Acer saccharum, Carpinus caroliniana and Populus deltoides typically had poorly developed roots that were sparse in distribution. Because of this variability in size, rootmats were consistently sampled near the center of the rootmat. Samples were cut with pruners at the water surface, starting from the roots closest to the channel and working inward toward the stream bank. The length and width of the samples were confined by the mouth of a standard D-frame dip net (305 mm x 254 mm). However the entire submersed depth

(different for each sample) was collected. The net was constructed of 800 x 900 µm nylon mesh, which is a type used in many rapid bioassessment protocols. Initially, I considered collecting a fixed sample size (length, width and depth), but decided to collect the entire submersed depth because: 1) a standard sample size would have over-

represented root tips in many cases; 2) species found in the rootmat core (i.e., Tipula sp. and Nigronia sp.) may have been overlooked without sampling the entire submersed depth; and 3) the depth of the submersed root may be an important attribute for differentiating between tree species that produce high or low quality rootmat habitat.

Root surface area was calculated to enable standardization based on surface area of root.

Cut roots were submerged into a clean pan of water and agitated to dislodge as many organisms and debris as possible. All clinging organisms were removed from the rootmats before the rootmats were transferred to moist sample bags and frozen until processing. Invertebrates and detritus collected from the rootmat were preserved together in labeled sample containers with a 70% ethanol solution.

2.2.2 Stream measurements

A grab sample of stream water was taken for nutrient analyses (i.e., orthophosphate, total phosphorus, total nitrogen, ammonia nitrogen, and nitrate). A number of in-situ water chemistry measurements (i.e., pH, D.O., conductivity, temperature) were recorded at three predetermined locations (upstream riffle, rootmat pool, downstream riffle) using a calibrated multiparameter YSI meter. Velocity was also recorded upstream from the rootmat, at the side of the rootmat, downstream of the rootmat, and at riffle locations upstream and downstream of the pool using a USGS Type AA current meter (Model

6200).

A generic cross section and longitudinal profile were surveyed using procedures described in Harrelson et al. (1994) to determine bankfull width in the vicinity of the roots and measure other potentially important morphological variables (e.g., water depth in the deepest part of the pool, length of pool, total length and width of the rootmat, length to the closest riffle). A cross section tape was stretched perpendicular to the water flow. The tape was placed at the top of the bank behind the tree trunk of the rootmat site and stretched to the opposite bank using a line level to ensure readings would be taken at a consistent elevation. A longitudinal profile was set up that stretched 3 times the bankfull width, upstream and downstream of the cross section. The location and elevation of all major changes and important features were measured using a standard survey rod. Pebble counts combined with a visual assessment of the substrate were used to estimate dominant substrate types within the pool and the diameter of the tree at breast height was also measured.

2.2.3 Riffle sampling

Eight riffle samples were also collected at locations immediately upstream (within 10 m) from eight of the rootmat samples to allow paired comparisons between riffles and rootmats. The same D-frame dip net was used to collect the riffle samples. The mouth opening was positioned so that all disturbed organisms and coarse debris within an area approximately 305 mm x 305 mm x 102 mm deep (0.009 m3) in front of the net was collected. The collection of benthic invertebrates was the goal and the water above the net was not included in this volume measurement. The invertebrate / detritus sample was preserved in ethanol until processing.

2.3 Sample processing

2.3.1 Root structure

Frozen root samples were thawed in the lab prior to analysis. All 47 rootmat samples were scanned using WinRHIZOTM 2005 (Regent Instruments, Inc.). Roots were spread out in water with as little overlap as possible and scanned at grey scale at 400 dpi using a setting effective for scanning darker roots on a lighter background. Scanned images of roots were analyzed to document total length (cm), average diameter (cm), surface area

(cm2), and root volume (cm3). Root tissue density (g cm-3) was estimated by dividing the dry mass of the root by root volume. Specific root length (SRL m g-1) was calculated by dividing the total root length by root dry mass.

2.3.2 Root biomass and root organic matter

All rootmats were dried at 55°C for 24 to 36 hours. A subsample of each rootmat was burned in a muffle furnace at 450° C for 8 hours then re-weighed. Based on these measurements, root biomass (expressed in g Ash Free Dry Mass or g AFDM) and percentage of organic content was estimated for each rootmat sampled.

2.3.3 Invertebrates

Initially, the intent was to sort the entire sample into four separate components (broken roots, detritus, midges, and other invertebrates). However, this process proved to be an extensive effort as there was a high density of broken root tips mixed in with the coarse

particulate organic matter (CPOM), and a compound microscope was required to separate

them. Twenty-six samples, which included all the riffle samples, were sorted entirely and

sub-sampling was used for the remaining root and detritus samples (29 samples). Most invertebrates (70 – 100%) were removed prior to sub-sampling. Samples were then split into quarters for sub-sampling roots and detritus. All invertebrates found in the root / detritus sub-samples were also counted, identified, and numbers corrected to account for the other 75% of the sample, then added to the initial invertebrate data for each site.

Invertebrates were typically identified to genus or species and selected groups were identified to class (Oligochaeta, Platyhelminthes) or family (some Diptera, Collembola).

This level of taxonomy follows that used by Ohio EPA (2008). Members of the family

Chironomidae were cleared using a 10 % KOH solution for 6-8 hours and mounted on

slides using CMCP 10 mounting media for identification.

For research questions 1, 2, and 3, invertebrate counts were divided by the total root

surface area of the rootmat to calculate density (organisms m-2). For research question 4,

invertebrate counts for each of the eight paired riffle and rootmat samples were divided

by the sample volume to calculate density (m-3).

2.3.4 Coarse particulate organic matter

Detrital material collected for each rootmat sample was dried at 55°C for 24-36 hours and

weighed. The samples were transferred to a muffle furnace where they were combusted

at 450°C for 8 hours and re-weighed to calculate ash-free dry mass (AFDM) and total

organic carbon.

2.3.5 Nutrient analysis

Orthophosphate, total phosphorus, total nitrogen, ammonia nitrogen and nitrate were

analyzed in the lab using a Lachat QuikChem® flow injection analysis system. The

accuracy level and detection limits of the Lachat are specified for each of these ions in

Table 2.

Table 2. Methods for processing nutrient ions and detections limits associated with the Lachat QuikChem. Values below these limits were replaced with a zero. Ion Method Detection limit (mg L-1) + NH4 10-107-06-1-J 0.002 - NO3 10-107-04-1-J 0.012 3+ PO4 10-115-01-1-A 0.01 Total P 10-115-01-1-A & persulfate digestion 0.015 Total N 10-107-01-1-J & persulfate digestion 0.093

2.4 Statistical analyses

2.4.1 Research question 1

No statistical methods were necessary to answer research question 1. Average

invertebrate density, total counts, and frequency of occurrence were calculated at all sites.

Invertebrate taxa were assigned to their respective functional feeding guilds (FFG)

following Merritt and Cummins (2008). For many damaged organisms or early instars, a positive identification could not be made to genus / species and the taxon was assigned to a class-level or family-level feeding guild. In few cases, NA (not-applicable) was

assigned to organisms when a class-level or family-level guild was not available. The

proportion of organisms within each of the functional feeding guilds for all 47 rootmats

was examined. In addition, invertebrate taxa that ranked in the top ten most abundant

and most frequently occurring were noted.

2.4.2 Research question 2

Univariate and multivariate statistical methods were used to examine differences in the

invertebrate community structure among woody species. Five invertebrate community

indices were calculated and compared between woody species treatments using one-way

ANOVA. The multi-response permutation procedure (MRPP) was used to test

differences in the invertebrate functional feeding guilds. Non-metric multidimensional

scaling (NMS) was combined with analysis of variance (ANOVA) to test differences in

the invertebrate species composition.

The five community indices included: invertebrate density, richness, evenness, Shannon diversity, and Simpson diversity. Density was calculated using invertebrate abundance per m2 of root. Species richness (S) was simply the number of taxa per sample and any

questionable identifications (early instar, damaged) that could not be verified as new taxa

were not included in the total. Evenness, Shannon diversity and Simpson diversity were

calculated using PC-ORD version 5.0 (McCune & Mefford 1999). The Shannon

Diversity index (H’) is the Sum (Pi*ln(Pi)), where pi is the proportion of individuals

found in the ith species and ln in the natural log ( Shannon and Weaver 1949). Evenness

(E) = H’ / ln(S) compares actual diversity values from Shannon’s Index to the maximum

possible diversity (Pielou 1969). Simpson`s diversity index (1/D) represents the

likelihood that two individuals picked randomly from the population would be different

species. For an infinite population, Simpson’s Index equals 1 / sum (Pi*Pi), where Pi =

importance probability in element i (element I relativized by row total).

Using R statistical software, the values from each community metric was compared among the woody species with a one-way analysis of variance (ANOVA) followed by a

Tukey test when significant effects among treatments were found. Species and environmental data were tested for normality and homogeneity of variance. Tests for normality (Shapiro-Wilk, histograms), skewness (D’Agostino), kurtosis (Anscombe-

Glynn) and homogeneity of variance (box plots, Bartlett, Levene tests) were used to

determine whether log transformations were necessary to meet ANOVA assumptions.

Invertebrate density and richness was log transformed.

Non-metric multidimensional scaling (NMS) was used to identify patterns in the invertebrate composition among the woody species using PC-ORD. NMS is

recommended for use with community data because of its flexibility with non-normal

data and its ability to eliminate the truncation produced by many ordination techniques

(McCune and Grace 2002). Invertebrate density data were log transformed and

Sorenson’s distance measure was used (McCune and Grace 2002). A Monte Carlo test

was completed with randomized data to verify that the NMS was not creating stronger axes than expected by chance. The site scores for each NMS axis were used as response variables in a multivariate ANOVA test with woody species as the explanatory variable,

and one-way ANOVAs were conducted for axes with significant effects. A Tukey test was used to distinguish differences among woody species.

Finally, the MRPP was used to examine differences in functional feeding guild composition across the eight woody species (Table 1). MRPP was used because it is a robust non-parametric test that does not require multivariate normality or homogeneity of variance (McCune and Grace 2002). Sorensen’s distance measure (Bray-Curtis) was used to be consistent with the NMS distance measure.

2.4.3 Research question 3

A canonical correspondence analysis (CCA) was used to examine which measured stream and root variables had stronger relationships (primary gradients) with the rootmat invertebrate communities using Canoco for Windows 4.5 (ter Braak and Smilauer 2002).

Invertebrate density was used for the species matrix. Dominant substrates, watershed variables, water chemistry parameters, organic matter parameters, and root structure features were the environmental variables used (Table 3). A correlation matrix of the environmental variables was examined and variables with correlations close to 0.6 were selectively eliminated to avoid redundancy. Bankfull was eliminated because it had a strong correlation with drainage area (0.592), and pH was eliminated because it had a strong correlation (0.746) with dissolved oxygen. Root density and specific root length were also correlated (-0.674) but were kept in the model due to their importance for evaluating my hypothesis. A focus on inter-species differences was used with Hill’s

scaling and rare species were down weighted. A Monte Carlo permutation test was used to determine the significance of the axes.

Table 3. Environmental variables used as parameters in the canonical correspondence analysis (CCA). Type Parameter Unit Substrates clay/hardpan NA organic NA sand NA gravel NA cobble/boulder NA bedrock NA Watershed drainage area mi2 average velocity m sec-1 Water chemistry dissolved oxygen mg L-1 conductivity mS cm-1 nitrate mg L-1 orthophosphate mg L-1 ammonium mg L-1 total phosphorus mg L-1 total nitrogen mg L-1 Organic matter coarse organic matter g root biomass (organic) g Root structure root surface area cm3 specific root length m/g root density g/cm3

2.4.4 Research question 4

The statistical methods used to examine differences in the invertebrate community

structure between rootmat and riffle habitat types were similar to methods used in section

2.4.2 for research question 2. The same five invertebrate community indices

(invertebrate density, richness, evenness, Shannon diversity and Simpson diversity) were

calculated and compared between rootmats and riffles using one-way ANOVAs. Density

was calculated using invertebrate abundance per m3 of water and required a log transformation to improve normality. NMS using PC-ORD was combined with ANOVA

tests, conducted using R statistical software, to determine differences in the invertebrate species composition between habitat types. Invertebrate density was again log transformed and Sorenson’s distance was used. MRPP was also used to test for differences in the invertebrate functional feeding guild composition between rootmats and riffles.

Chapter 3: Results

3. 1 Research Question 1: Rootmat taxa

A total of 138 macroinvertebrate taxa were collected in the 47 rootmat samples

(Appendix A, Table 11). Approximately 59% of the organisms were gathering

collectors, 15% were predators, while scrapers, shredders and filtering collectors were

present in similar proportions (8-9% each). Paratanytarsus dissimilis, a midge within the

Tanytarsini tribe, was by far the most abundant organism across the samples at nearly

250 organisms m-2 (Figure 2a). The density of the remaining top nine taxa decreased

from approximately 55 organisms m-2 to less than 20 organisms m-2 (Figure 2a) Many

abundant taxa belonged to the family Chironomidae, and Calopteryx maculata

(damselfly), Caecidotea communis (isopod), Stenelmis sp., and Dubiraphia bivittata

(riffle beetle) were also abundant in most samples. These taxa, as well as Physa sp. (lung snails) and Oligochaeta (aquatic worms), were also common among sites (Figure 2b).

275 250 225 A 200 ) 2 175 150 125

100

Density (orgs / m 75 50 25

sp. bivittata maculata

communis Calopteryx Dubiraphia Caecidotea dissimilis Polypedilum neomodestus Stenelmis sp. Stenelmis Dicrotendipes Tanytarsus illinoense grp.illinoense exiguus grp. Conchapelopia Paratanytarsus Rheotanytarsus grp. glabrescens 10 most abundant taxa

100

80 B 70

60 50 40

Percent frequency Percent 30

grp. sp. bivittata Physa sp. Physa maculata Calopteryx Dubiraphia Tanytarsus glabrescens dissimilis neomodestus Stenelmis sp. Dicrotendipes Conchapelopia OLIGOCHAETA Paratanytarsus Helopelopia sp. 10 most common species

Figure 2. Top ten most abundant (A) and top ten most common (B) taxa across all rootmats.

3.2 Research Question 2: Association between invertebrates and specific woody riparian species

3.2.1 Invertebrate community indices

Invertebrate density, richness, and evenness were different among the woody species (P <

0.05), and the Shannon diversity index and Simpson diversity index were similar among the woody species (ANOVA, Table 4). The multiple comparison tests (Tukey) indicated that differences in invertebrate density and richness occurred consistently between certain woody species (Figure 3, A & B). Invertebrate density was significantly greater for rootmats of Salix interior than rootmats of Carpinus caroliniana and Fraxinus pennsylvanica. Taxa richness was significantly greater for roots of Salix interior and

Salix nigra than Carpinus caroliniana. Evenness did not differ among most woody species, but Fraxinus pennsylvanica had a greater evenness than Platanus occidentalis rootmats (Figure 3 C).

Table 4. ANOVA results for invertebrate community indices. Woody species are the categorical explanatory variable. Density and richness values were log transformed. Df F-value P-value Density Tree 7 3.099 0.011 Richness Tree 7 3.572 0.005 Evenness Tree 7 2.279 0.048 Shannon Diversity Tree 7 1.355 0.252 Simpson Diversity Tree 7 0.925 0.498

2500 A A ) 2 2000

1500 AB AB AB 1000 AB AB B 500 B Abundance (orgs / (orgs Abundance m

40 B 35 A A 30 AB 25 AB AB 20 AB AB Richness 15 B

1 A AB AB C 0.9 AB AB 0.8 AB AB B 0.7 0.6 0.5 0.4

Evenness 0.3 0.2 0.1 0 Acer Ulmus Populus deltoides Carpinus Platanus americana Salix nigra saccharum caroliniana Fraxinus occidentalis Salix interior pennsylvanica

Figure 3. Means and standard errors (± 1) associated with each woody riparian species for density (A), richness (B) and evenness (C). Different letters above bars indicate a significant difference between treatments. 27

3.2.2 Invertebrate species composition

The non-metric multidimensional scaling (NMS) test resulted in a three dimensional solution with a final stress of 16.039 after 109 iterations. The fit of the NMS axes was better than expected by chance (p = 0.020), therefore the NMS axes should provide a useful representation of the dimensionality of the species composition. The ordination diagram shows the similarity in invertebrate species composition between some woody species (represented by AB), and differences between others (represented by an A or B)

(Figure 4). Axis 1 was the only axis with effects significantly associated with the woody species (MANOVA, F = 6.690, p < 0.00001). Axis 2 (F = 2.218, p = 0.054) and Axis 3

(F = 1.373, p = 0.244) were not significantly associated with the woody species. The cumulative variance explained by all 3 axes was 78.2%, with a total variance of 31.6% explained by Axis 1 and 25.9% explained by Axis 2. The species composition gradient represented by NMS Axis 1 was characterized by two main groups (Table 5, A & B).

Table 5. Multiple comparisons between woody species treatments using species scores from NMS Axis 1 as the response variable. N = # of replicates, S.D. = Standard Deviation. N Mean S.D. Ulmus americanaA 9 0.1954 0.4490 Salix nigraA 4 0.5468 0.1498 Populus deltoidesAB 5 0.0137 0.3166 Fraxinus pennsylvanicaB 4 -0.8196 0.8370 Carpinus carolinianaB 4 -0.7470 0.3694 Salix interiorA 5 0.6582 0.2522 Acer saccharumB 6 -0.2736 0.4433 Platanus occidentalisAC 10 0.0602 0.4426

Platanus occidentalis created another group (AC) since the composition of invertebrates inhabiting its rootmats was similar to Group A, but different than Fraxinus pennsylvanica in Group B. Populus deltoides does not appear to separate into any group.

A A AC

AB B B

Fraxinus pennsylvanica Salix nigra Populus deltoides Ulmus americana Carpinus caroliniana Salix interior Acer saccharum Platanus occidentalis

Figure 4. NMS ordination diagram for species composition. Woody species groups that were dissimilar (Tukey test) are defined as A and B on the axis. Platanus occidentalis (AC) is not different in composition to Group A, but is different than Fraxinus pennsylvanica (part of Group B). Populus deltoides (AB) is similar in composition to both Groups A and B.

NMS also indicated which of the 138 invertebrate taxa collected were associated with different groups along NMS Axis 1 (Figure 5). Specifically, Group A was associated with increasing abundance of Hydroptilidae, Orconectes sp., Nilotanypus sp., Simulium sp., Cricotopus spp., Tvetenia spp., Parachironomous sp., Sublettea coffmani, Dicanota sp., Baetis intercalaris, and Agraylea sp. Conversely, Group B was associated with increasing abundance of Pilaria sp., Eurylophella sp., Paraphaeonocladius sp., Pseudoorthocladius sp., Limnephilidae, Neurocordulia sp., Collembolla, and Tropisternus sp (Figure 5).

A A AC NMS Axis 1 AB B Pilaria sp. Natarsia sp. B Hydroptilidae Eurylophella sp. Calopteryx maculata Orconectes sp. Paraphaenocladius sp. Polycentropodidae Nilotanypus sp. Psuedoorthocladius sp. Dubiraphia bivittata Simulium sp. Limnephilidae Microvelia sp. Cricotopus trifascia Neurocordulia sp. Neophlax sp. Tvetenia bivarica grp. Collembola Tanytarsus curticornus Tvetenia vitracies Tropisternus sp. Ferrissia sp. Cricotopus absurdus Parachironomus sp. Sublettea coffmani Dicranota sp. Baetis intercalaris Agraylea sp.

Figure 5. Invertebrate taxa strongly associated with woody species groups depicted on NMS Axis 1. Woody species groups that were dissimilar (Tukey test) are defined as A and B on the axis. Platanus occidentalis (AC) is not different in composition to Group A, but is different than Fraxinus pennsylvanica (part of Group B). Populus deltoides (AB) is similar in composition to both Groups A and B.

3.2.3 Functional feeding guild composition

Similar to trends noted for the 47 rootmats collectively, organisms within the gathering collectors guild were also dominant within the rootmats of each woody species (Figure

6), typically followed by organisms within the predator guild. However, rootmats of

Salix nigra (black willow) and Ulmus americana (american elm) had less gatherers and

more scrapers and shredders than the other tree species, and filterers were present in

much higher proportions on Platanus occidentalis (sycamore) rootmats than the others.

A A B B BCC D

100%

80%

NA 60% FC SH SC 40% PR GC FFG compositionFFG

20%

0% Ulmus Populus deltoides Carpinus Platanus americana Salix nigra caroliniana Fraxinus occidentalis Salix interior pennsylvanica Acer saccharum

Figure 6. Stacked bar chart illustrating differences in FFG composition across woody species treatments. Different letters above bars indicate significant differences (MRPP). NA = no applicable guild, FC = filtering collectors, SH = shredders, SC = scrapers, PR = predators, GC = gathering collectors.

Furthermore, the multi-response permutation procedure (MRPP) indicated significant

differences in functional feeding guild composition across woody species (T = -2.43, p =

0.017). Three main groups were generally distinguished from each other (Figure 6 and

Table 6). Feeding guild composition was different for Groups A and B (Figure 6).

Ulmus americana and Platanus occidentalis (Group C) feeding guilds were different than some but not all of the woody species in both, Groups A and B (Figure 6). Populus deltoides differed from some of the species in all three groups (Figure 6).

Table 6. MRPP results showing significantly different FFG compositions among woody species. Samples sizes were different for each woody species. Comparisons T A p Fraxinus pennsylvanica vs. Salix interior -2.7579 0.1638 0.0169 Fraxinus pennsylvanica vs. Salix nigra -2.5668 0.1804 0.0203 Acer saccharum vs. Salix nigra -2.0658 0.0773 0.0331 Platanus occidentalis vs. Salix nigra -1.9992 0.0591 0.0446 Carpinus caroliniana vs. Salix interior -2.1931 0.1182 0.0373 Carpinus caroliniana vs. Salix nigra -2.5522 0.1511 0.0224 Populus deltoides vs. Salix nigra -2.1191 0.1144 0.0354 Populus deltoides vs. Salix interior -2.6671 0.1203 0.0179 Populus deltoides vs. Fraxinus pennsylvanica -2.4084 0.1434 0.0261 Populus deltoides vs. Ulmus americana -2.0622 0.0795 0.0435 Salix interior vs. Ulmus americana -2.5180 0.0862 0.0226

3.2.4 Associations between woody species and selected environmental variables

A one way analysis of variance indicated significant differences in rootmat density (F =

2.836, p = 0.017), specific root length (F = 7.499, p < 0.0001) and drainage area (F =

3.453, p < 0.01) for some woody species. The Tukey tests depicted that Salix interior

and Ulmus americana were the only two woody species with different root densities. 32

Specific root length was different for Salix interior then all other woody species, and

Salix nigra rootmats were located in stream reaches with larger drainage areas than all other woody species treatments.

3.3 Research question 3: Influence of environmental variables

The influence of root attributes and other environmental variables were examined with the canonical correspondence analysis. The CCA resulted in four canonical axes representing invertebrate community structure (Table 7). All axes were significantly associated with the measured environmental variables (F = 1.634, p = 0.004). The first two axes shown on the CCA diagram explained 21.6% of the variance in species composition. Axis 1 explained the most variance (12%, F = 3.536, p = 0.022) and was positively correlated with drainage area, average velocity, and root organic carbon

(Figure 7). These variables also had a strong positive relationship with each other (Table

8). Several substrate types (sand, bedrock, cobble/gravel), water chemistry variables

(total nitrogen, dissolved oxygen) and some other root attributes (coarse particulate organic matter and specific root length) showed a weak relationship with Axis 2, which explained another 9.6% of the variance in the species data.

Table 7. Summary statistics for the four CCA axes. Axes 1 and 2 explain nearly 21.6% of the variance in the invertebrate data. Axis 1 Axis 2 Axis 3 Axis 4 Eigenvalues: 0.553 0.445 0.237 0.211 Species-environment correlations: 0.95 0.946 0.902 0.904 Cumulative percentage variance explained of species data: 12 21.6 26.7 31.3 Cumulative percentage variance explained of species- 21.5 38.8 48 56.1 environment relation: Sum of all eigenvalues (total inertia) 4.619

Table 8. Multiple regression results (regression of sites in species space on environmental variables) showing the relationship between ordination Axes 1 - 4 and the measured environmental variables. The variables with the highest correlations are in bold. SPEC AX1 SPEC AX2 SPEC AX3 SPEC AX4 clay / hardpan -0.1166 -0.11 -0.0468 0.4984 organic -0.1981 -0.1232 -0.1754 0.0428 sand -0.0132 0.3555 -0.027 0.1034 gravel 0.2089 -0.0082 0.1147 -0.4218 cobble / boulder 0.0353 -0.2322 -0.1543 -0.1936 bedrock 0.0634 0.293 0.4024 0.1501 drainage area 0.8092 0.0836 -0.1105 0.0089 dissolved oxygen 0.1193 -0.3551 -0.3712 0.0591 conductivity -0.0778 0.1721 0.1664 0.1586 average velocity 0.7164 -0.1186 -0.0562 -0.1489 nitrate -0.2506 0.2192 -0.1459 -0.2736 orthophosphate 0.0968 0.1577 0.1087 0.1123 ammonium -0.1676 -0.1406 0.0052 -0.0499 total phosphorus 0.043 -0.0041 0.151 0.1879 total nitrogen -0.1751 0.3072 0.2899 0.0102 coarse particulate organic matter -0.0772 0.2517 -0.4757 0.1901 root organic carbon 0.7422 0.1593 -0.0488 0.1912 total root surface area 0.5992 0.5458 -0.2193 0.1289 specific root length -0.1313 0.2336 -0.279 -0.6235 root density 0.0433 -0.014 0.5158 0.5107

bedrock

sand Root SA

TN CPOM NO3 SRL

Cond OrthoP Root OC

DrainArea

gravel

organic AveVel NH4 clay/hrd cobble / boulder

DO -0.6 1.0 -0.4 1.0

Figure 7. Environmental variables shown in ordination space using a canonical correspondence analysis. Drainage area (DrainArea), velocity (AveVel), root ash-free dry mass (Root OC) and root surface are (Root SA) show the strongest effect on species composition (12% of the variance) for the two axes shown.

3.4 Research question 4: Rootmat habitat compared to riffle habitat

3.4.1 Invertebrate community indices

Ninety-three taxa were collected between riffles and rootmats, and only 40% (37 taxa) were common to both habitat types even though they were collected within 10 m of each other (Appendix A, Table 12). Seventy-three taxa were collected within the eight rootmats, compared to 57 taxa in the eight riffle samples. The average density of invertebrates was also higher for rootmats and nearly 25,573 organisms were estimated per m-3 in comparison to approximately 15,018 organisms per m-3 for riffle samples.

However, according to the ANOVA, there were no significant differences in density, richness, evenness, the Shannon diversity index or the Simpson index between the two habitat types (Table 9, P values > 0.05).

Table 9. ANOVA results comparing riffles and rootmats for five community variables. F-Value P-Value Density 0.0127 0.9117 Richness 1.3319 0.2678 Evenness 1.9718 0.1821 Shannon Diversity 0.0018 0.9668 Simpson 1/D 0.653 0.4326

3.4.2 Invertebrate species composition

The NMS documented a two dimensional solution with a final stress of 16.334 after 50 iterations. The fit of the NMS axes was better than expected by chance (p = 0.020), which indicates the NMS axes should provide a useful representation of the dimensionality of the species composition. The cumulative variance explained by the

NMS axes was 98.9 %, and both axes had significant associations with habitat type

(MANOVA, F = 12.097, p = 0.001), which confirmed that invertebrate species composition of rootmats was different then riffles. The two habitat types grouped in distinctly different clusters on the ordination diagram (Figure 8).

Axis 2 Axis Riffle Rootmat

Axis 1

Figure 8. NMS ordination diagram illustrating the difference in species composition among roots and riffle samples.

3.4.3 Functional feeding guild composition

The dominant functional feeding guilds were also different between rootmats and riffles

(Figure 9). Gathering collectors were the most abundant feeding guild among rootmat samples and filtering collectors were dominant among riffle samples. The MRPP

determined that the difference in guilds between the two types was greater than expected

by chance (Table 10, p < 0.001).

A B 100% 12078 31632 90% 7522

80% 16209 38663 70% Total NA 18010 60% Total SH 39474 Total SC 50% Total PR 40% FFG Composition FFG Total GC

30% Total FC 65791 87980 20%

10%

0% 5700 Riffle Root Habitat Type

Figure 9. Functional feeding guild proportions for riffle and rootmat samples. Numbers inside bars represent the total number of invertebrates within each guild for that habitat type. Different letters above bars indicate significant differences.

Table 10. MRPP results indicating significant differences in the functional feeding guild proportions of rootmat and riffle habitats. Eight samples were used for each habitat type. Average Distance (Riffle) 0.585 Average Distance (Rootmat) 0.692 Test statistic (T) -3.937 Observed delta 0.638 Expected delta 0.701 Variance of delta 0.0003 Skewness of delta -0.852 Chance-corrected within-group agreement (A) 0.089 Probability of a smaller or equal delta (p) 0.002

Chapter 4: Discussion

Rootmats were used by all of the predicted Anisoptera and Zygoptera predator families

(Calopterygidae, Coenagrionidae, Aeshnidae, and Corduliidae), and taxa within many of

the other predicted families (Caenidae, Elmidae, Culicidae, and Ephydridae). Endophytic breathers that pierce vascular plants to use atmospheric oxygen (Chrysomelidae) were not found in rootmats within this study. The majority (59%) of invertebrates inhabiting rootmats of all eight woody riparian species were gathering collectors. The prevalence of organisms within this guild suggests that depositional fine particulate organic matter

(FPOM < 1mm) may be one of the most abundant food sources within the rootmats.

Because many gathering collectors re-locate as necessary in search of FPOM (Merritt and

Cummins 2008), it is also possible that rootmats are used as a substrate surface or refugia

while gathering FPOM from nearby depositional areas such as pool bottoms. The dominant gathering collectors across all rootmats included two midges within the

Tanytarsini tribe (Paratanytarsus dissimilis and Tanytarsus glabrescens grp) and a riffle beetle (Dubiraphia bivittata). Gathering collectors were also the most abundant organisms collected in a study that examined invertebrates within bank habitat at bioengineered sites in Georgia (Sudduth and Meyer 2006).

Although the gathering collectors were more abundant, invertebrates representing four other feeding guilds (i.e., predators, shredders, scrapers, filtering collectors) were 40

consistently present throughout the sites, indicating that the rootmats create an environment with multiple benefits to the stream ecosystem.. Abundant invertebrate taxa found within the other guilds included another riffle beetle (Stenelmis sp.), a pulmonate

snail (Physa sp.) within the scraper guild, the isopod shredder (Caecitodea communis), and two predator species, (a damselfly, Calopteryx maculata, and a midge from the

Tanypodinae tribe, Conchapelopia sp.).

Another study (Phillips 2003) compared invertebrates on rootmats with other habitat types (i.e. aquatic macrophytes, coarse woody debris, leaf packs, submersed roots, submerged macrophytes, and sand) in a stream in eastern Texas, and observed significantly greater densities of odonate and coleopteran taxa on rootmats than most other habitat types. Argia spp., Helichus sp. and Dubiraphia sp. were the most abundant taxa in the Texas stream (Phillips 2003) and are also common in rootmat samples across this study. Dominant Chironomidae tribes were different between the two studies. The

Tanypodinae midge, Thienemannimyia sp. was dominant and Tanytarsini midges were not as common in rootmats of the Texas stream (Phillips 2003).

There were some consistent differences in diversity, species composition, and functional feeding guilds among some of the eight woody species. The two willow species, Salix interior and Salix nigra had the greatest invertebrate abundance and richness while

Fraxinus pennsylvanica and Carpinus caroliniana had the lowest. Platanus occidentalis,

Ulmus Americana, Populus deltoides, and Acer saccharum ranked intermediate in richness and abundance than these two groups. Platanus occidentalis ranked among the

highest in invertebrate density and richness after the Salix spp. but its evenness value was the lowest. This could be partly due to the prevalence of the Chironomidae species,

Paratanytarsus dissimilis, within its roots.

The species composition of all hydrophilic riparian species (Salix spp. Platanus occidentalis and Ulmus americana) was similar. The functional feeding guild composition was also similar between the two Salix spp. However, functional feeding groups differed between the two Salix spp. and Platanus occidentalis and Ulmus

Americana. Upland affiliated riparian species and Fraxinus pennsylvanica were similar in species composition and functional feeding guild composition. These similarities suggest that some of the variation in species composition may partially explained by the differences in feeding guilds. Also, based on these findings it could be inferred that the woody species within these groups may have similar traits based on their inundation tolerances and provide similar functions for the invertebrate community. However, the presence of Fraxinus pennsylvanica (a water tolerant species) within Group B in both cases is not necessarily supportive of this idea. I originally hypothesized that species with higher inundation tolerances, such as those associated with the A group, would provide higher quality rootmats associated with increased root density. It was thought that the increase in density would provide more surface area and perhaps trap more coarse particulate organic matter. The results of the canonical correspondence analysis suggest that aquatic invertebrates are indeed influenced by root surface area. Yet the

ANOVA results did not depict differences in root surface area or CPOM across the eight woody species, and the only significant difference in root density was between Salix

interior and Ulmus americana. Therefore, little evidence was provided in support of the hypothesis that water tolerant species have higher density rootmats or that density is the root attribute that determines rootmat quality.

This research also indicates that different woody riparian species often provide different habitat types, and the quality of habitat is also likely influenced by other environmental variables such as drainage area, velocity, and water chemistry as indicated by the canonical correspondence analysis, or by other species traits of the riparian vegetation that were not examined in this research. Water chemistry and dominant substrate types appeared to have less influence on the invertebrate assemblages than originally hypothesized. However, bedrock substrates had a stronger association with species composition than other substrates did. The homogenous nature of bedrock may increase the utilization of rootmats within a reach.

By comparing invertebrate species composition, diversity, and feeding guilds between rootmat and adjacent riffle samples, the significance of rootmat habitat was substantiated.

Riffles are generally considered to be the most productive instream habitat types in terms of abundance and diversity (Plafkin et al. 1989, Barbour et al. 1996). However, no differences were depicted for the five invertebrate community metrics used to compare diversity and abundance of the invertebrate community between rootmats and riffles.

Although diversity between riffles and rootmats is similar, the species composition and the composition of functional feeding guilds were significantly different between habitat types. Unlike the rootmats, invertebrate taxa within the filtering collector guild

dominated the community in riffles, while predators, gatherers, shredders and scrapers

were less abundant. Shredders and predators were also more abundant on organic

habitats (e.g., rootmats) than inorganic habitats (e.g., benthic substrates) in a Georgia

stream (Sudduth and Meyer 2006). There also appeared to be more rheophilic taxa that

are typically associated with higher velocity habitats, in the riffles sampled for this study

than in rootmats. However, some overlap in these taxa occurred at rootmat sites with higher velocities. The CCA results distinguished this relationship between velocity and species composition in rootmats. The observations in this study confirm the hypothesis that rootmats and riffles provide distinctly different functions in stream ecosystems, while

having similar invertebrate diversity and abundance. Rootmats tend to be less common

than riffles so their relative importance within the stream ecosystem should be considered

very high.

Other studies also demonstrated that rootmats had unique species composition when

compared with other substrate types (Brunke et al. 2001, Phillips 2003). In these studies,

rootmats ranked intermediately in taxa richness among other habitats (Dreissena-bank,

unionid mussel bed, rip-rap, alder roots, coarse woody debris, sand, mud, leaf packs,

aquatic macrophytes). Roots, coarse woody debris, and leaf packs were more similar in

species composition to each other than to the other habitat types in these studies (Brunke

et al. 2001, Phillips 2003).

The persistence of native, locally adapted vegetation on the stream bank is an important

component of a healthy riparian zone. The root systems of riparian vegetation play a key

role in stream bank stability (Lawler 1992, Abernethy and Rutherford 1998, 2000, Wynn

et al. 2004,). Where riparian vegetation is present, roots enhance soil shear strength and

can create bank conditions up to 20,000 times more resistant to erosion from fluvial

entrainment and freeze-thaw cycles (Abernethy and Rutherford 1998) than banks without

vegetation (Smith 1976). Bioengineering projects attempt to mimic these naturally

stabilizing effects of vegetation. Also, newly exposed floodplain soils are very

susceptible to invasion by undesirable, aggressive plant species making re-establishment of native riparian vegetation an important goal. Unfortunately, obtaining locally adapted genotypes of riparian trees and shrubs for these purposes can be challenging and little guidance is available on the benefits of planting certain species for specific goals.

Rootmats are a unique habitat that can provide immediate benefits for macroinvertebrate community recovery after restoration (Sudduth and Meyer 2006), and little attention has so far been given to this potential benefit. This research suggests that special attention should be given to re-establishing them in restoration projects.

This research also provides evidence that not all species provide the same benefits for invertebrate communities and certain woody riparian species may be better candidates for restoration of these stream bank associated habitat features than others. Further research examining what constitutes high quality habitat and why certain species have more diverse communities would be useful. Research comparing the invertebrate species composition of rootmats to pool bottom substrates would also be beneficial to more clearly demonstrate rootmat function.

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Appendix A: Species lists showing feeding guilds as well as average abundance and frequency across sites

Table 11. List of species collected across all rootmat samples, showing feeding guild as well as the average abundance, count and frequency of occurrences across sites. Feeding Not No. Taxa Code Taxa Guild Average Count %Freq counted 1 HYDRA Hydridae PR 2.15 1 2.08 2 PLSP Planariidae GC 6.095 13 27.08 3 OLISP OLIGOCHAETA GC 16.846 24 50 4 CACO Caecidotea communis SH 38.073 14 29.17 5 CRASP Crangonyx sp. GC 17.212 15 31.25 6 CASP Cambarus sp. GC 0.357 3 6.25 7 ORCSP Orconectes sp. GC 0.401 3 6.25 8 EPHM EPHEMEROPTERA NA 1.103 5 10.42 x 9 BAET Baetidae GC 0.146 1 2.08 x 10 BAFL Baetis flavistriga GC 0.122 3 6.25 11 BAIN Baetis intercalaris GC 0.172 1 2.08 12 STFE Stenonema femoratum SC 0.118 2 4.17 13 EPEU Eurylophella sp. GC 0.524 1 2.08 14 CAESP Caenis sp. GC 1.919 11 22.92 15 CAMA Calopteryx maculata PR 41.757 41 85.42 16 HETSP Hetaerina sp. PR 0.327 1 2.08 17 ARSP Argia sp. PR 5.674 18 37.5 18 ENASP Enallagma sp. PR 10.388 16 33.33 19 AESP Aeshna sp. PR 0.295 3 6.25 20 BOYSP Boyeria sp. PR 1.522 6 12.5 x 21 BOVI Boyeria vinosa PR 2.437 11 22.92 22 GOMPH Gomphidae PR 0.086 1 2.08 x 23 GOMSP Gomphus sp. PR 0.124 2 4.17 24 NERSP Neurocordulia sp. PR 0.068 1 2.08 25 EPISP Epitheca sp. PR 0.193 3 6.25 26 LESP Leuctra sp. SH 0.701 4 8.33 27 COLL Entomobryidae NA 0.265 2 4.17 28 MISP Microvelia sp. NA 0.293 3 6.25 29 RHASP Rhagovelia sp. NA 0.38 4 8.33 30 BESP2 Belostoma sp. PR 0.119 1 2.08 31 SISP Sialis sp. PR 3.556 16 33.33 32 NISE Nigronia serricornis PR 0.362 5 10.42 33 TRICH TRICHOPTERA NA 0.405 3 6.25 x 34 CHOB Chimarra obscura FC 0.136 2 4.17 35 LYSP Lype diversa SC 0.186 2 4.17 36 POLSP Polycentropodidae FC 0.207 3 6.25 x 37 NESP Neureclipsis sp. FC 2.263 11 22.92 38 NYSP Nyctiophylax sp. FC 0.786 6 12.5 39 HYDF Hydropsychidae FC 1.578 3 6.25 x 40 CHESP Cheumatopsyche sp. FC 2.716 9 18.75 Continued

Table 11 continued Feeding Not No. Taxa Code Taxa Guild Average Count %Freq counted 41 HYDSP Hydropsyche sp. FC 0.022 1 2.08 42 HYMO Hydropsyche morosa grp. FC 0.581 4 8.33 43 HYSP Hydropsyche sparna FC 0.66 4 8.33 44 HYDE Hydropsyche depravata grp. FC 0.022 1 2.08 45 HYDRP Hydroptilidae SH 0.221 1 2.08 x 46 AGRSP Agraylea sp. SH 0.049 1 2.08 47 HPTSP Hydroptila sp. SH 0.025 1 2.08 48 PHRY Phryganeidae SH 0.161 2 4.17 x 49 PTSP Ptilostomis sp. SH 0.912 3 6.25 50 LIMN Limnephilidae NA 1.034 3 6.25 x 51 NEOSP Neophylax sp. SC 0.323 1 2.08 52 PYCSP Pycnopsyche sp. SH 1.665 6 12.5 53 OESP Oecetis sp. PR 0.091 2 4.17 54 TRISP Triaenodes sp. SH 0.399 7 14.58 55 OCHSP Ochrotrichia sp. GC 0.109 1 2.08 56 NOCT Noctuidae SH 0.358 1 2.08 57 HETR Heteroceridae NA 0.143 1 2.08 58 HALSP Haliplus sp. SH 0.056 1 2.08 59 PESP Peltodytes sp. SH 0.149 3 6.25 60 HYPSP Hydroporus sp. PR 0.704 4 8.33 61 HPHSP Hydrophilidae GC 0.079 2 4.17 x 62 BESP Berosus sp. SH 0.58 7 14.58 63 HYDBSP Hydrobius sp. GC 0.289 2 4.17 64 TROP Tropisternus sp. GC 1.376 4 8.33 65 HELSP Helichus sp. SC 1.329 9 18.75 66 ANVA Ancyronyx variegata GC 0.494 8 16.67 67 DUBI Dubiraphia bivittata GC 28.041 35 72.92 68 MAGL Macronychus glabratus GC 2.107 6 12.5 69 STESP Stenelmis sp. SC 37.873 30 62.5 70 WEEV Curculionidae SH 0.072 1 2.08 71 TIDAE Tipulidae NA 0.054 1 2.08 x 72 ANTSP Antocha sp. GC 0.264 2 4.17 73 DICSP Dicranota sp. PR 0.025 1 2.08 74 LIMON Limonia sp. SH 0.025 1 2.08 75 PILSP Pilaria sp. PR 0.262 1 2.08 76 PSESP Pseudolimnophila sp. GC 0.319 4 8.33 77 TISP Tipula sp. SH 0.832 10 20.83 78 PERSP Pericoma sp. GC 0.413 3 6.25 79 DIXSP Dixella sp. GC 0.143 1 2.08 80 ANOSP Anopheles sp. FC 1.07 5 10.42 81 SIMSP Simulium sp. FC 0.278 3 6.25 82 CERAT Ceratopogonidae PR 1.546 10 20.83 x Continued

Table 11 continued Feeding Not No. Taxa Code Taxa Guild Average Count %Freq counted 83 ATRSP Atrichopogon sp. GC 0.022 1 2.08 84 TANY Chironomidae PR 1.736 7 14.58 x 85 ABMA Ablabesmyia mallochi PR 1.446 8 16.67 86 ABRA Ablabesmyia ramphe grp. PR 0.172 1 2.08 87 CONSP Conchapelopia sp. PR 17.841 37 77.08 88 HESP Helopelopia sp. PR 12.029 25 52.08 89 LASP Labrundinia sp. PR 0.38 3 6.25 90 MOSP Monopelopia sp. PR 0.167 2 4.17 91 NASP Natarsia sp. PR 0.984 7 14.58 92 NABA Natarsia baltmoreus PR 0.536 4 8.33 93 NISP Nilotanypus sp. PR 0.315 3 6.25 94 BRFL Brillia flavifrons SH 0.565 3 6.25 95 CORSP Corynoneura sp. GC 0.645 4 8.33 96 CRSP Cricotopus sp. SH 2.233 7 14.58 x 97 CRAB Crictopus absurdus SH 0.025 1 2.08 98 CRBI Cricotopus bicinctus SH 15.717 15 31.25 99 CRTR Crictopus trifascia SH 0.074 1 2.08 100 CRORSP Cricotopus/Orthocladius GC 0.221 1 2.08 x 101 DICU Diplocladius cultriger GC 0.88 3 6.25 102 HYSO Hydrobaenus sp. O GC 0.102 2 4.17 103 LISP Limnophyes sp. GC 0.307 2 4.17 104 NANO Nanocladius sp. GC 0.351 3 6.25 105 ORSP Orthocladius sp. GC 1.195 1 2.08 x 106 ORAN Orthocladius annectens NA 0.239 1 2.08 107 OROB Orthocladius obumbratus NA 2.271 4 8.33 108 TVVI Tvetenia vitracies NA 0.172 1 2.08 109 PAMSP Parametriocnemus sp. GC 1.388 7 14.58 110 PAPSP Paraphaenocladius sp. GC 0.708 3 6.25 111 PSSP Pseudorthocladius sp. GC 0.521 3 6.25 112 THAT Thienemanniella taurocapita GC 0.086 1 2.08 113 THXE Thienemanniella xena GC 0.887 3 6.25 114 TVBA Tvetenia bavarica grp. GC 0.025 1 2.08 115 XYSP Xylotopus sp. SH 0.358 1 2.08 116 CHIR Chironomidae GC 1.959 9 18.75 x 117 CHSP Chironomus sp. GC 0.61 5 10.42 118 CRNSP Cryptochironomus sp. PR 0.063 2 4.17 119 DISP Dicrotendipes sp. GC 5.39 6 12.5 x 120 DIFU Dicrotendipes fumidas GC 2.92 3 6.25 121 DINE Dicrotendipes neomodestus GC 20.889 24 50 122 MIPE Microtendipes pedellus grp. GC 0.985 8 16.67 123 PASP Parachironomus sp. GC 0.025 1 2.08 Continued

Table 11 continued Taxa Feeding Not No. Code Taxa Guild Average Count %Freq counted 124 PACL Paracladopelma sp. GC 0.025 1 2.08 125 PAAL Paratendipes albimanus GC 4.624 12 25 126 PHAEN Phaenopsectra sp. GC 0.178 2 4.17 x 127 PHOB Phaenopsectra obediens grp. GC 0.82 4 8.33 128 PHPU Phaenopsectra punctipes grp. GC 6.468 18 37.5 129 POSP Polypedilum sp. GC 1.204 3 6.25 x 130 POTR Polypedilum tritum GC 0.701 3 6.25 131 POFL Polypedilum flavum GC 3.74 9 18.75 132 POFA Polypedilum fallax grp. GC 0.426 2 4.17 133 POIL Polypedilum illinoense grp. GC 19.492 16 33.33 134 POSC Polypedilum scalaenum grp GC 0.381 2 4.17 135 STNSP Stenochironomus sp. SH 0.523 7 14.58 136 STISP Stictochironomus sp. GC 0.019 1 2.08 137 PSCH Psuedochironomus sp. GC 0.024 1 2.08 138 TASI Tanytarsini GC 0.094 2 4.17 x 139 CLSP Cladotanytarsus sp. GC 0.9 7 14.58 140 MIDI Micropsectra dives/germinata GC 1.041 1 2.08 141 MIPO Micropsectra polita GC 4.074 9 18.75 142 MICRO Micropsectra sp. GC 0.1 1 2.08 x 143 PADI Paratanytarsus dissimilis GC 250.893 45 93.75 144 RHEX Rheotanytarsus exiguus grp. FC 55.924 12 25 145 RHSP Rheotanytarsus sp. FC 0.108 2 4.17 x 146 STMPSP Stempellinella sp. GC 0.048 1 2.08 147 SUCO Sublettea coffmani GC 0.025 1 2.08 148 TACU Tanytarsus curticornis GC 0.882 4 8.33 149 TAGL Tanytarsus glabrescens grp. GC 37.452 33 68.75 150 CHRSP Chrysops sp. GC 0.48 5 10.42 151 ALLSP Allognosta sp. GC 0.163 1 2.08 152 STRSP Stratiomys sp. GC 0.349 2 4.17 153 EMPID Empididae PR 0.146 1 2.08 x 154 HEMSP Hemerodromia sp. PR 4.848 14 29.17 155 EPHSP Ephydridae GC 0.047 2 4.17 156 LIMSP Limnophora sp. PR 0.072 1 2.08 157 GAST GASTROPODA SC 0.411 1 2.08 x 158 LYMSP Fossaria sp. SC 0.273 2 4.17 159 PHYSP Physa sp. SC 15.857 30 62.5 160 PLAN Planorbidae SC 0.711 3 6.25 x 161 GRYSP Gyraulus sp. SC 0.072 2 4.17 162 HELAN Helisoma anceps SC 0.356 4 8.33 163 MEDI Menetus dilatatus SC 0.441 4 8.33 164 FESP Ferrissia sp. SC 2.535 11 22.92 165 SPHAE Sphaeridae FC 0.056 1 2.08 x 166 SPSP Sphaerium sp. FC 0.401 4 8.33

Table 12. Species list for the eight rootmat and eight riffle samples that were compared in question 4. Average abundance, count and frequency of occurrence are also included across sites, and the taxa that were common to both habitats are shown. Invertebrate taxa marked within the column labeled “Not Counted” were not included in the total taxa count. Riffle Rootmat Average % Average % Common Not Number Taxa Code Taxa Abundance Count Frequency Abundance Count Frequency Taxa Counted 95 TAGL Tanytarsus glabrescens grp. 344.318 7 87.5 1288.789 8 100 x 90 PADI Paratanytarsus dissimilis 132.43 3 37.5 3349.465 8 100 x 57 HESP Helopelopia sp. 92.701 4 50 1000.464 7 87.5 x 56 CONSP Conchapelopia sp. 66.215 1 12.5 1146.297 7 87.5 x 101 PHYSP Physa sp. 13.243 1 12.5 410.173 6 75 x 44 STESP Stenelmis sp. 754.851 5 62.5 4130.442 5 62.5 x 24 SISP Sialis sp. 66.215 3 37.5 217.82 5 62.5 x 57 50 TISP Tipula sp. 79.458 3 37.5 83.118 4 50 x 16 BOVI Boyeria vinosa 39.729 1 12.5 107.066 4 50 x 91 RHEX Rheotanytarsus exiguus grp. 529.72 4 50 35.456 3 37.5 x 98 HEMSP Hemerodromia sp. 463.505 4 50 95.697 3 37.5 x 80 MIPE Microtendipes pedellus grp. 39.729 3 37.5 92.516 3 37.5 x 71 PAMSP Parametriocnemus sp. 79.458 2 25 193.695 3 37.5 x 3 CACO Caecidotea communis 39.729 1 12.5 3507.072 3 37.5 x 81 PAAL Paratendipes albimanus 13.243 1 12.5 113.868 3 37.5 x 65 CRBI Cricotopus bicinctus 648.907 5 62.5 120.715 2 25 x 25 NISE Nigronia serricornis 79.458 3 37.5 123.395 2 25 x 85 POIL Polypedilum illinoense grp. 238.374 3 37.5 6.601 2 25 x 7 BAFL Baetis flavistriga 79.458 2 25 39.188 2 25 x 88 CLSP Cladotanytarsus sp. 13.243 1 12.5 64.286 2 25 x 96 CHRSP Chrysops sp. 13.243 1 12.5 58.796 2 25 x 103 FESP Ferrissia sp. 13.243 1 12.5 29.819 2 25 x Continued

Table 12 continued

Riffle Rootmat Taxa Average % Average % Common Not Number Code Taxa Abundance Count Frequency Abundance Count Frequency Taxa Counted 29 CHESP Cheumatopsyche sp. 3363.722 7 87.5 471.698 1 12.5 x 31 HYMO Hydropsyche morosa grp. 2661.843 6 75 11.792 1 12.5 x 34 HYDE Hydropsyche depravata grp. 291.346 5 62.5 11.792 1 12.5 x 19 LESP Leuctra sp. 238.374 4 50 120.482 1 12.5 x 30 HYDSP Hydropsyche sp. 701.879 4 50 11.792 1 12.5 x x 26 CHOB Chimarra obscura 251.617 3 37.5 47.17 1 12.5 x 51 SIMSP Simulium sp. 172.159 3 37.5 3.811 1 12.5 x 63 CORSP Corynoneura sp. 79.458 2 25 30.12 1 12.5 x 72 THAT Thienemanniella taurocapita 145.673 2 25 47.17 1 12.5 x 84 POFL Polypedilum flavum 79.458 2 25 11.792 1 12.5 x

58 1 PLSP Planariidae 13.243 1 12.5 22.866 1 12.5 x 9 STFE Stenonema femoratum 66.215 1 12.5 8.091 1 12.5 x 22 MISP Microvelia sp. 13.243 1 12.5 17.606 1 12.5 x 54 TANY Tanypodinae 13.243 1 12.5 15.06 1 12.5 x x 68 DICU Diplocladius cultriger 13.243 1 12.5 11.792 1 12.5 x 70 OROB Orthocladius obumbratus 39.729 1 12.5 12.887 1 12.5 x 86 POSC Polypedilum scalaenum grp. 13.243 1 12.5 17.606 1 12.5 x 11 CAMA Calopteryx maculata 0 0 0 1290.249 7 87.5 42 DUBI Dubiraphia bivittata 0 0 0 2556.94 6 75 79 DINE Dicrotendipes neomodestus 0 0 0 125.607 5 62.5 2 OLISP OLIGOCHAETA 0 0 0 660.111 4 50 14 ENASP Enallagma sp. 0 0 0 265.559 4 50 4 CRASP Crangonyx sp. 0 0 0 1515.322 3 37.5 Continued

Table 12 continued

Riffle Rootmat Taxa Average % Average % Common Not Number Code Taxa Abundance Count Frequency Abundance Count Frequency Taxa Counted 10 CAESP Caenis sp. 0 0 0 60.673 3 37.5 13 ARSP Argia sp. 0 0 0 530.866 3 37.5 23 RHASP Rhagovelia sp. 0 0 0 37.083 3 37.5 28 NESP Neureclipsis sp. 0 0 0 59.531 3 37.5 37 TRISP Triaenodes sp. 0 0 0 54.263 3 37.5 40 HELSP Helichus sp. 0 0 0 212.85 3 37.5 43 MAGL Macronychus glabratus 0 0 0 416.351 3 37.5 60 NABA Natarsia baltmoreus 0 0 0 59.763 3 37.5 87 STNSP Stenochironomus sp. 0 0 0 53.326 3 37.5 41 ANVA Ancyronyx variegata 0 0 0 96.528 2 25 59 49 PSESP Pseudolimnophila sp. 0 0 0 29.398 2 25 52 CERAT Ceratopogonidae 0 0 0 26.853 2 25 76 CHSP Chironomus sp. 0 0 0 6.601 2 25 82 PHPU Phaenopsectra punctipes grp. 0 0 0 10.412 2 25 94 TACU Tanytarsus curticornis 0 0 0 100.543 2 25 102 MEDI Menetus dilatatus 0 0 0 41.45 2 25 6 EPHM EPHEMEROPTERA 0 0 0 75.301 1 12.5 x 15 AESP Aeshna sp. 0 0 0 3.811 1 12.5 17 EPISP Epitheca sp. 0 0 0 11.792 1 12.5 27 POLSP Polycentropodidae 0 0 0 11.792 1 12.5 36 PYCSP Pycnopsyche sp. 0 0 0 15.06 1 12.5 39 BESP Berosus sp. 0 0 0 23.585 1 12.5 53 ATRSP Atrichopogon sp. 0 0 0 11.792 1 12.5 Continued

Table 12 continued

Riffle Rootmat Average % Average % Common Not Number Taxa Code Taxa Abundance Count Frequency Abundance Count Frequency Taxa Counted 55 ABMA Ablabesmyia mallochi 0 0 0 8.091 1 12.5 58 LASP Labrundinia sp. 0 0 0 4.045 1 12.5 59 NASP Natarsia sp. 0 0 0 3.811 1 12.5 x 77 DISP Dicrotendipes sp. 0 0 0 12.136 1 12.5 x 78 DIFU Dicrotendipes fumidas 0 0 0 4.045 1 12.5 89 MIPO Micropsectra polita 0 0 0 11.792 1 12.5 92 RHSP Rheotanytarsus sp. 0 0 0 17.606 1 12.5 x 93 STMPSP Stempellinella sp. 0 0 0 15.06 1 12.5 97 STRSP Stratiomys sp. 0 0 0 3.811 1 12.5

60 99 EPHSP Ephydridae 0 0 0 11.792 1 12.5 104 SPSP Sphaerium sp. 0 0 0 30.12 1 12.5 33 HYSP Hydropsyche sparna 675.393 6 75 0 0 0 8 BAIN Baetis intercalaris 198.645 4 50 0 0 0 32 HYSL Hydropsyche slossonae 251.617 4 50 0 0 0 46 ANTSP Antocha sp. 92.701 4 50 0 0 0 35 HPTSP Hydroptila sp. 437.019 3 37.5 0 0 0 45 PSHE Psephenus herricki 79.458 3 37.5 0 0 0 47 DICSP Dicranota sp. 437.019 3 37.5 0 0 0 67 CRORSP Cricotopus/Orthocladius sp. 119.187 3 37.5 0 0 0 x 83 POAV Polypedilum aviceps 145.673 3 37.5 0 0 0 48 HEXSP Hexatoma sp. 26.486 2 25 0 0 0 73 THXE Thienemanniella xena 291.346 2 25 0 0 0 74 TVBA Tvetenia bavarica grp. 39.729 2 25 0 0 0 Continued

Table 12 continued

Riffle Rootmat Taxa Average % Average % Common Not Number Code Taxa Abundance Count Frequency Abundance Count Frequency Taxa Counted 5 CASP Cambarus sp. 13.243 1 12.5 0 0 0 12 HETSP Hetaerina sp. 26.486 1 12.5 0 0 0 18 PLESP PLECOPTERA 13.243 1 12.5 0 0 0 x 20 ACRSP Acroneuria sp. 13.243 1 12.5 0 0 0 21 PERLO Perlodidae 13.243 1 12.5 0 0 0 38 OCHSP Ochrotrichia sp. 13.243 1 12.5 0 0 0 61 NISP Nilotanypus sp. 13.243 1 12.5 0 0 0 62 ORTHO Chironomidae 13.243 1 12.5 0 0 0 x 64 CRSP Cricotopus sp. 13.243 1 12.5 0 0 0 x

61 66 CRTR Crictopus trifascia 52.972 1 12.5 0 0 0 69 EUDE Eukiefferiella devonica grp. 13.243 1 12.5 0 0 0 75 CHIR Chironomidae 13.243 1 12.5 0 0 0 x 100 LYMSP Fossaria sp. 13.243 1 12.5 0 0 0 Total Taxa 57 73