3.2 Flashcards
Define ecological succession
Transition in species composition over time.
Define primary succession and give an example.
An almost lifeless area with no soil first gets bacteria, moss, and lichen, which create soil, then grasses and shrubs begin to grow, often taller plants begin to grow next and change the area into a forest. An example would be a volcano erupting with lava flow.
Define secondary succession and give an example.
An existing community is cleared, but the base soil is still intact. It can cause more biodiversity if the entire community of plants and animals is not destroyed. An example would be logging a wooded area.
Define pioneer species
The first living things to come to an area devoid of anything but rock.
Define seral stages
The stage where more, different living things come to an area already inhabited by the pioneer species.
Define climax community
The final stage in primary succession, a community full of plants and animals.
Define species richness
The amount of species in an area.
Define ecological diversity
The variety of communities, ecosystems, and habitats in an area.
Define genetic diversity
The amount of different DNA present in a population.
Define keystone species
A species that is vital to an ecosystem
How do keystone and invasive species affect biodiversity?
Keystone species preserve the biodiversity of an ecosystem, invasive species can destroy it.
Define invasive species
A species that invades a different area where it has no natural predators and it can take over the area.
How are primary succession and secondary succession different?
Primary succession is the slow process of bare rock becoming a thriving ecosystem, secondary succession can take less time and usually has soil already.
Find the Shannon-Weiser index and evenness of a community with 5 species, with amounts in each species of 25, 28, 39, 32, and 14.
Compare this community to one with a richness of 6 species that have 19, 15, 51, 10, 4, and 11.
1st community:
H = 1.56
E = 0.97
2nd community:
H = 1.52
E = 0.85
The first community has less species than the second, but the amounts are more even, the second community has more species, but the species are less even.
