Chapter 3 Flashcards
ecosystems are dynamic
evolution
formation of new species over a long period of time due to diverging natural selection
ecological succession
replacement of a group of species by another as env changes over time: change in species structure
primary succession
is the colonization of unvegetated areas: no soil
when glaciers retreate
1)herbaceous, grasses, weeds: cover a wide range: created env that allows other species to establish
2)sand dune, withstand high varibility in temperature
secondary succession
soil already exists;
abandoned fields; no soil-forming stage
climatic climax
when the ecosystem has reached a steady-state; after ecological succession
eutrophication
nutrence supply increasing in a water environment
intermediate disturbance hypothesis
moderately disturbances in ecosystems maintain higher levels of diversity
mature ecosystem
a higher level of community organization
Human effect on succession
1) more herbaceous plants (weeds)
2) species most effected are specialized in high trophic levels
Dynamic equilibrium of ecosystems
they are subject to change and do change over time
Gaia hypothesis
the ecosphere is a self-regulating homeostatic system
inertia-ecosystem
ability to withstand change
resilience- ecosystem
ability to recover to original state
invasive species
species that are not in their range and harm the area it is in
fast-growing generalist: bad
allelopathic
can inhibit growth of species by putting chemicals into the soil
