L13 - what controls community dynamics

Question 1

what are the three causes of abundance- diversity patterns covered in class

Answer 1

1. Niche dynamics
2. Neutral Dynamics
3. Multiple Filter Model

Question 2

describe Niche Dynamics

Answer 2

species characteristics, tolerances, and interactions lead to Niche partitioning within an ecosystem.
difference between generalists and specialists

Question 3

What is the Neutral Theory of biodiversity

Answer 3

patterns of diversity/abundance can be explained by random extinction and dispersal processes.
- all species function equally and dominant ones occur due to random selection.

Question 4

what is the Filter model of community assembly?

Answer 4

Relative species abundance is the product of multiple successive filters.
EX. Dispersal, Environmental Filtering, Species interactions, fine scale variation.

Question 5

what is a flaw with Niche dynamics, neutral dynamics, and the filter model?

Answer 5

Independently none of the theories work in properly. real ecosystems have aspects of all to varying degrees.

Question 6

what is an invasive species

Answer 6

species that has established in a new range where it is not historically persistent and its spread is causing degrading the Environment.

Question 7

what are the key mechanisms of invasive species

Answer 7

predation, and competition

Question 8

why is number of invasive and exotic species increasing?

Answer 8

human interaction and transport movies species all across the globe. Climate change also plays an important role

Question 9

what are the 5 components of invasion ecology

Answer 9

Transport, introduction, establishment, spread, impact.

Question 10

what are some attributes of a successful invader?

Answer 10

• number of propagules
• residence time
• previous history
• fecundity
• short generation time
• rate of population expansion

Question 11

what makes an ecosystem vulnerable to invasion?

Answer 11

• extreme environments resistant
• island are vulnerable
  
  • low diversity = empty niches
• human activity and disturbance level

Question 12

what are novel ecosystems

Answer 12

ecosystems with species that has no precedent in that biome

Question 13

What is succession?

Answer 13

Cumulative directional change in community composition in a given area through time.

Question 14

what is a Seral stage?

Answer 14

distinct communities through the successional sequence.

Question 15

what is a sere?

Answer 15

The sequence of communities through the process of succession

Question 16

what is primary succession?

Answer 16

community development on surfaces not ‘recently’ occupied by organisms.

Question 17

what is secondary succession?

Answer 17

succession that occurs on previously vegetated site where the previous community is damaged or killed due to disturbance.