Lesson 3.2 Flashcards
What is biodiversity?
the population heterogeneity of a community
What makes up biodiversity?
species richness, species evenness
What is genetic diversity?
the range of different inherited traits within a species
Why is it important for there to be genetic variation in a community?
Genetic variation reduce the communicableness of diseases and parasites so the production of successfulness is higher between biodiversity.
What does ecosystem diversity mean?
the range or variation within ecosystems
What happens when there is a greater diversity?
Greater stability is achieved which leads to more food resources, more habitats, and more resilience in the face of environmental change.
Define species richness
the number of species (R)
Define species evenness
the abundance/proportion of species (E)
How do you calculate evenness?
E = H/ln(R)
What is the Shannon- Wiener Index value?
the uncertainty of predicting the species (H)
What are keystone species?
organisms that help hold the ecosystem together
What are invasive species?
organisms that aren’t native to an area and usually cause harm
How do keystone species affect biodiversity?
They help maintain biodiversity and influence the abundance and types of other species in a habitat.
How do invasive species affect biodiversity?
They reduce biodiversity and can cause the extinction or endangerment of native species.
What is ecological succession?
Transition in species composition over time
What is primary succession?
Newly formed rock/land is colonized by living things for the first time
What is secondary succession?
When a climax community is impacted by a disturbance and regrows.
What is the main difference between primary and secondary succession?
Primary succession starts off where no life has ever been however secondary succession starts with an already established climax community.
What are pioneer species?
species (mosses, lichens,fungi,etc.) that grow fast and provide soil with nutrients for the faster growing plants and trees
What are seral stages?
the stages where a community is progressively advancing to its climax community
What is a climax community?
the endpoint of succession where a community is stable and unchanging
(taiga, temperate deciduous forest)
What happens to the pioneer species after the seral stages occur?
They are over shaded and outgrown by the fast growing trees and plants.
What are some human activities that cause disturbances in secondary succession?
Deforestation, Building Infrastructure, Logging, Farming
What drives succession?
Tolerance - a higher r value means the community is tolerant of harsh conditions.
Examples of primary and secondary succession?
Primary - volcanic eruption that causes barren land
Secondary - major flooding of a creek bed
