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Chelse Prather, PhD

•  Grew up in Northern Kentucky •  BS, biology, University of Kentucky •  PhD, biology, University of Notre Dame, research in the rainforest in Puerto Rico •  Previous Postdoc, biology/history/philosophy, Florida State University •  Now Research Faculty at University of Houston


Prairie restoration and management •  Focus on restoring and managing for diverse native plant communities or creating habitat for game, migratory and threatened species. •  What about the smaller animals—the invertebrates? •  Butterflies, the “pretty” invertebrates have been mentioned. •  What about all the others?


Outline 1.  Why care about invertebrates? Invertebrates and humans 2.  Research question: What determines invertebrate herbivore community structure in coastal tallgrass prairies? 3.  Other projects 4.  How to use this information?


Outline 1.  Why care about invertebrates? Invertebrates and humans 2.  Research question: What determines invertebrate herbivore community structure in coastal tallgrass prairies? 3.  Other projects 4.  How to use this information?


Invertebrates: •  Represent over 80% of all known eukaryotic species •  Fill a vast array of ecological niches • Attain high biomass in most ecosystems.


Do insects affect humans? Ecosystem services: Benefits from ecosystems that support human life and wellbeing


Some%invertebrates%cause% problema2c%disservices%


The little things that run the world E. O. Wilson

Invertebrates, ecosystem services, climate change Chelse M. Prather, Shannon Pelini, Angela Laws, Emily Rivest, Megan Woltz, Christopher P. Bloch, Izzy Del Torro, Chuan-Kai Ho, John Kominoski, T. A. Scott Newbold, Sheena Parsons. 2012. Biological Reviews, in press.

“…If invertebrates were to disappear, I doubt that the human species would last more than a few months.”%

Goal: Evaluate invertebrate influences on ecosystem services and how these influences may be altered by climate change


Invertebrate effects on ecosystem services -On the National Bison range, it’s estimated that grasshoppers eat more vegetation than all the large vertebrates combined (Belovsky 2002). - Can eat 0-100% of plant biomass in an ecosystem

- 11,000 species of myrmechores

-3/4 of all plants and 1/3 of all crops by volume are pollinatordependent


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!Dung&beetles&that&decompose&feces&are&worth& es6mated&at&$454&million&in&the&US&


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!Emerging&insect&cause& !Invertebrate&frass&can& huge&changes&in& increase&or&decrease& available&nutrients% nutrients&to&plants%


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Invertebrate effects on ecosystem services%

Food web stability


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In summary: •  Invertebrates provide or indirectly influence all ecosystem services. •  They are the major providers of a few services, and influence most of the others to a great degree. •  BUT: the basic science has not been done to evaluate their relative importance.


Outline 1.  Why care about invertebrates? Invertebrates and humans 2.  Research question: What determines invertebrate herbivore community structure in coastal tallgrass prairies? 3.  Other projects 4.  How to use this information?


Fundamental question in ecology: What is the relative importance of factors that affect the abundance and diversity of organisms?


Why grasshoppers?

•  One of the major herbivores in most prairies across the US •  Can eat more than ungulate herbivores combined •  Relatively easy to sample


Top down controls Predator pressure & Parasite load Herbivore community characteristics Herbivore abundance

Herbivore diversity

Plant community characteristics

Plant biomass

Plant diversity

X

Plant micronutrients

Plant macronutrients

P L A N T

Q U A L I T Y

Site characteristics

Precipitation & temperature

CLIMATE

Soil macronutrients

X

Soil micronutrients

GEOLOGY

Land use & management

Fragment size

HUMAN

Time since restoration

INFLUENCES


Top down controls Predator pressure & Parasite load Herbivore community characteristics Herbivore abundance

Herbivore diversity

Plant community characteristics

Plant biomass

Plant diversity

X

Plant micronutrients

Plant macronutrients

P L A N T

Q U A L I T Y

Site characteristics

Precipitation & temperature

CLIMATE

Soil macronutrients

X

Soil micronutrients

GEOLOGY

Land use & management

Fragment size

HUMAN

Time since restoration

INFLUENCES


Pristine prairie

Restored prairie

Measured grasshopper diversity and density, and possible predictors across 3 habitats (n=12). Plant community  Biomass  Diversity  Water  Plant height  Macro-nutrients (N, P)  Micro-nutrients (Ca, Cu, Fe, K, Mg, Mn, Na, S, Zn)  Root biomass  Root moisture

Shell-rich area

Predators  Wolf spider density Soil  Moisture  Oyster shell content  pH

Invasive forest


Density of food web members Number of individuals per m2

0.16% 0.08%

Shell-rich areas

Predators%(wolf%spiders)%

0% 1% 2%

2%

df%=%22% t%=%5.79% P%=%<%0.001%%%

Herbivores%(orthopterans)%

0% 5%

df%=%22% t%=%=6.92% P%=%%0.496%%%

Omnivores%(crayďŹ sh)%

1% 0% 2%

Pristine prairie

1%

df%=%22% t%=%=2.54% P%=%<%0.019%%%

2%

Detri2vores%(isopods)%

0% 1%

df%=%22% t%=%=2.00% P%=%<%0.058%%%

2%


Results

Top down controls

Single-factor, bivariate relationships; build up to multiple factors.

Predator pressure & Parasite load

Soil moisture

Herbivore community characteristics Herbivore abundance

Herbivore diversity

Significant drought event in 2011 Plant community characteristics

Plant biomass

Plant diversity

X

Plant micronutrients

Plant macronutrients

Site characteristics

Precipitation & temperature

CLIMATE

Soil macronutrients

X

Soil micronutrients

GEOLOGY

Land use & management

Fragment size

HUMAN

Time since restoration

INFLUENCES


Results

Top down controls Predator Predator pressure pressure & & Parasite Parasite load load Herbivore community characteristics Herbivore abundance

Herbivore diversity

Plant community characteristics

Plant biomass

Plant diversity

X

Plant micronutrients

Plant macronutrients

Site characteristics

Precipitation & temperature

CLIMATE

Soil macronutrients

X

Soil micronutrients

GEOLOGY

Land use & management

Fragment size

HUMAN

Time since restoration

INFLUENCES


Results

Top down controls Predator pressure & Parasite load

Herbivore community characteristics Herbivore abundance

Herbivore diversity

Plant community characteristics

Plant biomass biomass Plant

Plant diversity

X

Plant micronutrients

Plant macronutrients

Site characteristics

Precipitation & temperature

CLIMATE

Soil macronutrients

X

Soil micronutrients

GEOLOGY

Land use & management

Fragment size

HUMAN

Time since restoration

INFLUENCES


Results

Top down controls Predator pressure & Parasite load

Herbivore community characteristics Herbivore abundance

Herbivore diversity

Plant community characteristics Plant biomass

Plant diversity diversity Plant

X

Plant micronutrients

Plant macronutrients

Site characteristics

Precipitation & temperature

CLIMATE

Soil macronutrients

X

Soil micronutrients

GEOLOGY

Land use & management

Fragment size

HUMAN

Time since restoration

INFLUENCES


Results

Top down controls Predator pressure & Parasite load

Phosphorus Nitrogen

Herbivore community characteristics Herbivore abundance

Herbivore diversity

Plant community characteristics Plant biomass

Plant diversity

X

Plant micronutrients

Plant macronurients nutrients

Site characteristics

Precipitation & temperature

CLIMATE

Soil macronutrients

X

Soil micronutrients

GEOLOGY

Land use & management

Fragment size

HUMAN

Time since restoration

INFLUENCES


Results

Top down controls Predator pressure & Parasite load

Calcium Potassium Sodium Sulfur

Herbivore community characteristics Herbivore abundance

Herbivore diversity

Plant community characteristics Plant biomass

Plant diversity

Plant macronutrients

X

Plant Plant micromicronutrients nutrients

Site characteristics

Precipitation & temperature

CLIMATE

Soil macronutrients

X

Soil micronutrients

GEOLOGY

Land use & management

Fragment size

HUMAN

Time since restoration

INFLUENCES


Results

Top down controls Predator pressure & Parasite load

Herbivore community characteristics Herbivore abundance

Herbivore diversity

Plant community characteristics Plant biomass

Plant diversity

Plant macronutrients

Plant micronutrients

Site characteristics

Precipitation & temperature

CLIMATE

Soil macronutrients

X

Soil micronutrients

GEOLOGY

Land use & management

Fragment size

HUMAN

Time since restoration

INFLUENCES


Results

Top down controls Predator pressure & Parasite load

Herbivore community characteristics Herbivore abundance

Herbivore diversity

Plant community characteristics Plant biomass

Precipitation & temperature CLIMATE

Soil macronutrients

Plant diversity

Soil micronutrients

GEOLOGY

Plant macronutrients

Land use & management

Plant micronutrients

Fragment size

HUMAN

Time since restoration

INFLUENCES


Results

Top down controls Predator pressure & Parasite load

Herbivore community characteristics Herbivore abundance

Herbivore diversity

Plant community characteristics Plant biomass

Precipitation & temperature CLIMATE

Soil macronutrients

Plant diversity

Soil micronutrients

GEOLOGY

Plant macronutrients

Land use & management

Plant micronutrients

Fragment size

HUMAN

Time since restoration

INFLUENCES


Results

Top down controls

Dependent variable Dependent variable Density Grass-feeder density Mixed-feeder densityPlant biomass

Predator pressure & Parasite load

Predictors (coefficent)

R2

F

P

F

Herbivore community characteristics Herbivore Predictors Herbivore R2 abundance (coefficent) P (0.456) diversity0.48

Soil moisture (-0.866) 0.221 N:P Fe (-0.564) N (-0.649) Plant community characteristics Veg height (-0.219) Ca diversity (0.014) (0.501) 0.732 Plant Plant Plant macroRoots (-0.229) Ca (0.478)nutrients diversity Zn (0.734)

Richness K(0.920) 0.35 S (-0.687) Forb-feeder Ca (1.453) 0.791 density P (-0.561) Soil Precipitation Na Soil (0.475) Land use & & macro- Znmicromanage(-0.322) temperature nutrients nutrients ment CLIMATE

P

GEOLOGY

<0.001

11.59

0.006

5.105

<0.001 30.755 Plant micronutrients <0.001 <0.001 Fragment size

HUMAN

7.653 4.763 Time since restoration

INFLUENCES


CONCLUSION: What is the relative importance of factors that affect the abundance and distribution of prairie herbivores? Top down controls Predator pressure & Parasite load

Herbivore community characteristics Herbivore abundance

Herbivore diversity

Plant community characteristics

Plant biomass

Precipitation & temperature CLIMATE

Soil macronutrients

Plant diversity

Soil micronutrients

GEOLOGY

Plant macronutrients

Land use & management H U M A N

Plant micronutrients

Fragment size

Time since restoration

I N F L U E N C E S


Conclusions: If you build it, will they come?


Katydid: Orchelimum vulgaris

Grasshopper: Melanoplus femurrubrum

Grasshopper: Metataplea brevicornis

Katydid: Concephalus strictus


Species%specific%effects%

100%

Mixed%feeders%

Grass%feeders%

50% 0% =50% =100% 100% 50% 0% =50% =100%

2%Grass%

Both%

2%Mixed%


Grasshopper%diversity%conclusions% •  The%number%of%species%doesn’t%necessarily% maSer,%but%the%iden2ty%of%the%species%you% have%maSers.% •  Next—bigger%experiment%at%more%sites.%


**Disclaimer: understanding of what controls communities, not to be used to manage insects with current results**


Are Plants Enough: The Relative Importance of Plants and Nutrients to Insect Communities  

By Chelsea Prather