1. Mechanisms driving nonnative plant-mediated change in small mammal populations and communities Dan Bachen

2. Approach and Methods http://www.stolaf.edu/depts/environmental-studies/courses/es-399%20home/ es-399-05/Projects/Jared's%20Senior%20Seminar%20Research%20Page/htt.htm

3. Question 1 Do invasive species alter the structure of the vegetation and the food resources within the ecosystem? Answering question will provide: – What factors change native vs. invasive dominated – Quantifications of these changes To answer: – Literature Review – Focused Research at Site

4. Types of factors: Vegetation Food resources – Granivorous – Insectivorous – Herbivorous

5. Vegetation analysis Horizontal vs vertical

6. Measurement Techniques: Vegetation Horizontal Structure: Techniques: – Quadrat % cover – Stem/area

7. Measurement Techniques: Vegetation Vertical Structure Techniques: – Sidelook

8. Measurement Techniques: Food Resources Grain Techniques: – Count -> Density Biomass http://www.nouriche.com/NutriorWheatProtein.html

9. Measurement Techniques: Food Resources Arthropods Techniques: – Pitfall – biomass

10. Measurement Techniques: Food Resources Edible Vegetation Techniques: – % cover – Clip-> dry weight – Biomass

11. Question 2 Is there evidence that small mammal communities and species abundance are influenced by the structure of their habitat’s vegetation and by the available food resources? Answering question will provide: – Basis for asking future questions To answer: – Literature review Established correlation

12. Question 3 Can native plant communities be manipulated in such a way that the alterations mimic those induced by the presence of non-native plants? Answering question will provide: – Tested treatments of isolated factors To answer: – Use previous knowledge to ID important potential factors – Test treatments for factors – Confirm

13. Question 3 Use previous knowledge to ID important potential factors – Question 1: All potential factors – Question 2: Factors previously correlated – Combination

14. Question 3 Test – 10x10 m test plot(s) – Control – Quantify Measurement methods used in Question 1 – Success of treatment based on ability to mimic characteristic of invasion

15. Question 4 Can the consequences of manipulating the physiognomy of the vegetation and the available food resources be quantified in small mammal community structure and species abundance? If so what are the effects? Answering question will provide: To answer: – Treat plots – Assess: small mammal population demography species abundance Species richness Vegetation

16. Experimental Design Sample Plots – 1ha (100m x 100m) Selection – Random sampling – Randomization of treatments Treatment plots Control plots Grid numbers sampled – Replicate plots per treatment – Paired with 4 “control” plots

17. Experiment Design – Trapping Each plot trapped 5 nights 10x10 grid of Sherman live traps http://www.depauw.edu/univ/naturepark/classes/sma ll%20mammals.asp

18. Capture Mark Recapture Marks – Ear tag – Sharpie marker Processing – Species – Age-class – Sex – Reproductive status – Weight http://www.flickr.com/photos/captainschlumpy/3961667069/

19. Analysis of Data Species Abundance: estimate of number of animals per plot – Ideally by age class Account for age-class heterogeneity – CMR Data – Model in Program Mark – Results expected

20. Analysis of Data Species richness: Measure of number of species on each plot – Similar to CMR for species but uses species as “individuals” Accounts for species heterogeneity – Analyzed in MARK – Expected Results

21. Analysis of Data Species demographics: The proportion of animals in a given age class in a population – Data from CMR – Analyzed in MARK – Expected results – Important Why?

22. Analysis of Data Method of comparison – Treatment vs Control – Two sample t-test – Significance level

23. Vegetation confirmation Re-sample vegetation – Confirmation of isolation of factor – If different provide opportunity to reassess statistical methods

24. Question 4 Can the consequences of manipulating the physiognomy of the vegetation and the available food resources be quantified in small mammal community structure and species abundance? If so what are the effects?

25. Question 5 Is there a plausible explanation for how the treatments affected (or didn’t affect) the community structure and species abundance of the small mammals? Answering question will provide: – Confidence in results To answer: – Explore logical explanations

26. Summary Do invasive species affect habitat? Does habitat affect small mammals? Can I mimic the habitat alterations caused by invasive plants? What are the effects of the application of these treatments on small mammals? Do the effects seen make logical sense?

27. Questions?