Ecosystem Diversity

Ecosystem

interacting system composed of a biological community plus associated physical and chemical environment 

Biological community

all the species that live in a particular location

Ecosystem Diversity

• variation in ecosystems

• variety of ecological processes

• relates to ecosystem functionality and stability

functionality 

processes normally associated with ecosystem are functioning well

stability

ecosystem is relatively constant over time despite disturbances

resistant

tending to be not harmed or affected by something

resilient

tending to recover quickly after being harmed or affected by something

higher species diversity

higher genetic diversity and levels of ecosystem function

ecosystems with high levels of disturbance

lower ecosystem, species, and genetic diversity

• lower functionality

• lower stability, resilience, and resistence

ecosystem biodiversity

important concepts for understanding ecosystem diversity

Food web

diagram showing who eats who

bottom up control

population level and activity of primary producers regulate the overall activity of the ecosystem above

• traditional

top down control

population level and activity of top predators regulate the overall activity of the ecosystem below

density mediated control

predators directly reduce the numbers of prey by consuming them

trait mediated control

predators indirectly reduce the numbers of prey

Hypotheses about how species diversity relates to ecosystem stability

• 1: increased species diversity leads to increased ecosystem stability 

• 2: increased species diversity doesn’t lead to increasing ecosystem stability

#1 is correct

Insurance hypothesis

high biodiversity is insurance against ecosystem collapse