Ecology of Rivers & Coasts: Food Webs & Human Impacts

Lecture 2 – Untangling Salt Marsh Food Webs

by Brian R. Silliman, PhD

Search current video

1. Introduction and start of Lecture Two
2. The power and excitement of science
3. Formation of intertidal grasslands
4. Physical characteristics and stresses in a salt marsh
5. Abundance, not diversity, of plants characterizes salt marshes
6. Salt marshes have high densities of animal populations
7. Salt marshes provide beneficial ecosystem services
8. Why are salt marshes so productive?
9. Comparing bottom-up vs. top-down factors that influence food webs
10. Two direct actions lead to a cascading indirect effect
11. The coastal wetland paradigm
12. Design of snail exclusion experiments
13. Are snails farming fungus on salt marsh grass?
14. Snail populations are limited by predators
15. Caged world equals real world
16. Top-down control occurs across diverse ecosystems
17. Re-establishing a trophic cascade with predators may rescue system
18. Top-down forces are important in coastal wetlands
19. Q&A: How do we promote the benefits of salt water marshes?
20. Q&A: How do alligators affect the other populations in the food web?
21. Q&A: How do the snails cultivate fungus on grass?
22. Q&A: What causes sea otter populations to decline?
23. Q&A: Has there been research on the effect of chitin on plants?
24. Q&A: How do grasses respond to fungus and grazing by snails?
25. Q&A: Are the effects of top-down forces greater than bottom-up?

Player Features