Lab 4: What is a niche? Flashcards
What is fundamental niche when applied to habitats?
total area potentially occupied by a species in absence of any competitors, predators, parasites
What is realized niche when applied to habitats?
actual area in which the species exists in the presence of competitors, predators, parasites,e t
What is the competitive exclusion principle?
no two species may occupy the same space indefinitely if their niches overlap completely
What is direct or interference competition?
one species prevents access to a resource needed by another species
What is indirect or resource competition?
one species more efficiently utilized resources in comparison to another species
Why is there the cypress swamp?
“natural” experiement resulting from the introduction of bald-cypress trees to the Big Dry Creek/Victory Lake area by Martha Berry
What are Bald Cypress and what have they done?
native exotics that have competitively excluded native floodplain species from the area where they were once introduced
What is Bald Cypress’ primary mechanism of competitive superiority?
pneumatophores that allow for oxygen exchange during flooded condition (indirect or resource competition)
What can Bald Cypress’ fast heigh growth allow them to do?
to overtop and thus shade out native tree species (direct or interference competition)
What community does the Bald Cypress invade?
Calcareous flatwoods
What non-native plants did we see?
Nepal brown top, silverleaf, periwinkle, chinese privet, tree-of-heaven
What did the beaver feeding area show evidence of?
intermediate herbivory promoting local biodiversity by reducing fast growing competitive species
What could come to dominate the site if beavers continue selective foraging?
muckernut hickory
How do beavers modify habitat?
felling or girdling large trees, thus opening up habitat
