2. Illinois LU change 1820-2007
• Prairie: 59% <1%
• Forest: 38% 17%
Hypoxia in the Gulf of Mexico
• 15% N; 10%P comes from Illinois
Jersey County, IL
• Highly forested & highly cultivated regions
Representative of IL LU distributions
• 3 IL natural divisions
http://crystal.isgs.uiuc.edu/nsdihome/webdocs/landcover/nass07.ht
ml
4. Characterize benthic macroinvertebrate community
structure in Jersey County headwater streams
Investigate the effects of upstream agriculture on
macroinvertebrate communities
Assess the effectiveness of macroinvertebrate
community metrics in qualifying regional stream quality
5. Riffles sampled in 15 perennial
streams
• Fall 2013
• Watersheds < 10km2
• 4.6%-80.2% watershed agriculture
Water quality w/YSI probe
Discharge, wetted/channel width,
velocity, habitat quality assessment
(US EPA)
Family level ID
Functional feeding groups (FFGs)
13. Communities differ from those in highly degraded IL
streams (Gorman, 1987; Stone et al., 2005)
• Collector-Filterer vs. Collector-Gatherer dominance
Lack of EPT taxa low stream quality across the region
• Perlodidae indicator taxa for reference quality streams
Multiple community structures?
• Sites 2, 10, 15 > 95% shredders
• Hard-water spring communities (Wetzel and Webb, 2007)
14. Dominance of Hydropsychidae indicates Ag impact
• Hyper-dominance in response to organic/nutrient pollution
H’, Richness, Evenness
• Low H’ for all sites suggests region wide degradation
FBI
• Most streams “good” or “very good” rating.
• Low diversity/evenness decrease effectiveness of FBI
Highly impacted streams may not have been sampled
All sites have intact riparian buffers & <60% cropland
15. Upstream agriculture significantly impacts macroinvertebrate community
structure in JC (Middle Mississippi Border Division) streams
Hilsenhoff’s FBI and other family metrics may not be effective means for
monitoring/comparing stream quality in impacted, low diversity regions
Streams across the MMBD in JC (<80%agriculture) all have similar
functional quality;
• Both pristine and highly degrades streams are rare
Perlodidae at site 14 suggests that higher quality stream communities may
still exist in the regions least degraded watersheds
At least 2 reference quality macroinvertebrate communities may exist in JC
streams
16. Principia College
Advisory support
• Ally Ringhausen
• Mike Rhaesa
• John Lovseth
• Dr. Chrissy McAllister
Field Assistants
• Leah Pyne
• Karlin Krishniswami
• Chelsea Chichester
Editor's Notes
Midwest:one of the most highly altered regions in US
Land Use Change: 1820-present
Runoff from ag fields excess nutrients (N and P-limiting nutrients) -- eutrophication
Eutrophication: process of excess nutrient loading -- increased plant/algal growth -- depleted O2 levels
Hypoxia: low/below adequate O2 levels
Corn and Soybeans: 50% N and 25% P in Gulf.
3 Main Goals of the Study:
Hypothesis:
Diversity metrics would decrease/FBI increase in response to increasing agricultural gradient
15 streams across Jersey County:
searched the whole county
Riffles only were sampled:
to negate community structure differences between different micro-habitats
GIS software – used to make maps, calculate LU distributions
2 radial buffers (50m each side of stream)
20 Total Identified Families
Hydropsyichds and Amphipods = > ½ total invertebrates
Top 5 families=2416 (2560 total)
Many families found at only 1 site—most of these only had 1 individual from that family
Perolodidae found at site 14: only site with Plecoptera (stoneflies)
4% of total community (significant part of community)
CF and Shredders were most dominant across all sites.
Varied from 100% shredders (site 2) to 81.2% CF (site 13)
Sites 2, 10, 15 stand out as uniquely shredder dominated.
All other sites had at least 4 of the 5 functional feeding groups present
Some taxa (gammaridae) can be multiple FFGs (predators)
PCA was used to investigate multivariate patterns in the FFG data.
Multiple Axes—account for different amounts of variance between sample sites
Axis 1 accounted for 55% of the variance;
shredder-CF gradient
Axis 2: 19.2% variance
CG-predators (mostly)
3 Different clusters: Shredder dominance clusters strongly on the right
Ag/Forest Land Use loads strongly on Axis 1.
* p= significant at p=0.01
**p= significant at p=0.05
Gammaridae and Hydropsychidae strongly correlated with Forest and Ag.
Forest 50m buffer was not a strong predictor of any community structure change
Hydropsychidae vs Ag 50m buffer was the strongest relationship.
r=0.653; p=0.008 (99.2% confidence value)—significant at standard p=0.05.
Chironomidae positively correlated with Agriculture in a Spearman, non-parametric correlation test.
Graph: scatter plot of ag 50m vs % Hydropsychidae with line of best fit, equation, and r squared
Average FBI: 4.8. Range: 4.0-6.0.
Average H’: 1.1. Range: 0.07-1.48.
2nd order polynomial relationship between hydropsychidae and H’.
Highest diversity is when hydropsychidae are 40-50% population
Aside from sites with 0 hydropsychidae:
lowest diversity is correlated with hydropsychidae dominance.
More “pool” habitats may make this comparison challenging—severe degradation tends to destroy riffle habitats
EPT: baetidae and hydropsychidae are more tolerant taxa, don’t serve as intolelrant indicators.
Amphipods/Isopods were only shredders
Shredders are key in taking leaves and other organic matter inputs and transforming them into CPOM/FPOM
Shredders excepted to be higher densities in headwater streams (Vannote et al., RCC)
Amphipods also can serve as predators (mixed FFG)—might explain lack of predators in some systems
This may indicate this stream is not severely degraded to that point that this shift occurs
Spring communities dominated by non-insectan taxa (amphipods, isopods, gastrapods, oligochaets etc…)
Sites 3 and 7 also had > 80% Shredders
these sites had most other FFGs as well, however—possible mixing of effects
Dual Effects of more riparian cover/hardwater spring inputs favoring shredders make this inconclusive.
Low family diversity: no EPT. Low evenness (>2/3 of all individuals from 3 families)
Family richness was 20 vs 14 in urban degraded streams study
other study only sampled 1/3 total # insects, also sampled in pools.
inconclusive
Greater diversity in larger streams, larger watersheds
channel width correlated with catchment size
Spearman correlations with wshed size (90% confidence)
stream size > LU for predicting diversity
FBI ratings from 4.0-6.0
Small range
Family index weights scores towards 4
Dominance of H. and A.—both score of 4.
Because of the dominance of 1 or 2 families this index doesn’t pick up on small changes
Suggests decent stream quality/function and that steams aren’t significantly degraded (functionally) along this LU gradient.
Only 3 streams >45% cropland
Cropland may be a better indicator of ag. Impact than total ag
Pasture-hay less fertalized, some just prairie lands or unused lands
Community structure shifts to Hydropsychidae dominance
FBI does not pick up on changes within a 0-80% (60 cropland) gradient
Sangunett: overall degraded quality means BI not fine enough scale to detect changes
Because this is a common method for stream team assessment—this may lead to missing trends
3) Spring communities vs. other: amphipod vs. more dominant
Site 14 and site 2: both very high forest, similar size catchments
4)Uniform stream quality, all somewhat degraded, inspite of land use change
riparian buffers may buffer impact of cropland up.
5) Stoneflies: reference quality streams may have Plecopteran taxa
this taxa can live in area streams—could indicate streams with high stream quality
Be a good indicator in finding most pristine stream communities
