Regulation and function of T helper subtypes

TLS Online TPP Program

#Id: 5985

#Unit 10. Ecological Principles

Strength of mortality factors varies with plant productivity, the rate of production of plant biomass. For very simple systems, where few plants exist, not enough plant material is available to support herbivores, and plants must be resource limited, that is, limited by competition.

 

  

TLS Online TPP Program

#Id: 5986

#Unit 10. Ecological Principles

TLS Online TPP Program

#Id: 5987

#Unit 10. Ecological Principles

Green Earth hypothesis Which stated that since the Earth appears “green,” and plants are common, herbivores must have little impact on plant abundance.

They suggested that herbivores must therefore be limited by their predators.

TLS Online TPP Program

#Id: 5988

#Unit 10. Ecological Principles

Ecosystem exploitation hypothesis

TLS Online TPP Program

#Id: 5989

#Unit 10. Ecological Principles

TLS Online TPP Program

#Id: 5990

#Unit 10. Ecological Principles

Elizabeth Borer and colleagues argued that the ecosystem exploitation hypothesis makes specific predictions about plant and herbivore biomass under certain scenarios: In a community with only plants and herbivores, if nutrients increase, as with fertilization, herbivore biomass should increase, while plant productivity remains unchanged.  n a community with plants, herbivores, and predators, plant biomass should increase with added nutrients, while herbivore biomass should remain unchanged.