Lecture 37 (mainly a case study)

Experiments to predict effects of global change

• Many studies focus on “natural experiments”
  - thermal clines
  - Natural disasters
  - areas of notable anthropogenic change

• These are hugely helpful but may have confounding factors
  
  *Manipulative experiments are rare and

  crucial to confirming predictions about

  adaptations to climate change

New Zealand experiment

• Deforestation by humans is a series anthropogenic effect on the landscape

• Stoneflies are relatively common insect with two distinct color morphs

• The black morph mimics a toxic relative and is thought to be protected against predators

Morph frequencies in stone flies

• Data from more than 1200 specimens indicated that the black morph was more common in forested vs. unforested sites

Testing the hypothesis

• To test if bird predation is driving differences in morph frequency, Ni et al. placed models of both morphs into two forested and two deforested sites

• They recorded damage by predators:
  - Birds
  - Rodents
  - insects

Doom and gloom?

• If we keep with current CO2 emission rates, loss of biodiversity is inevitable

• We are getting close to a tipping point, where global climate changes will be irreversible

Where do we go from here, in terms of climate change?

• Reducing Co2 emissions can curtail impacts

• Some species are adapting to the changing climate

• Research is essential to predicting which species will adapt and which need help to avoid extinction

C

case study quesiton

B, no wrong answer but this is what the class chose

There are more case study questions, but its a case study class so watch the video to answer the questions lecture on 4/22