Grab a laptop! Take out your Bubble Lab APES 11/29 Grab a laptop! Take out your Bubble Lab
Bubble Lab Recap- 5 minutes Please compare graphs and analysis answers with your neighbors. Turn it in once you get your questions answered.
Unit 3 Test- Ch. 5, 6, 18 Know these modules at an AP level: 14, 17, 18-21, 60 Just memorize definitions/big ideas for mod 8, 15, 16, 59, 61- these will be multiple choice only and less application-based. Test is on Friday, 12/1!
How do populations respond to change? Succession and Disturbance How do populations respond to change? Modules 8 and 21
Disturbances A disturbance is any event resulting in a change in community composition Not all bad! Ex: Shrubland areas that rely on forest fires for seed germination
Intermediate Disturbance Hypothesis A moderate level of disturbance helps biodiversity
Resistance vs. Resilience Resistance: how much an ecosystem resists being changed by a disturbance. Ex: oceans have high resistance; only now seeing acidification after 200+ years of industry Ex: our lakes have high resistance to acid rain due to natural buffering capacity (limestone base) Resilience: how quickly an ecosystem recovers from a disturbance. Resistance occurs during the disturbance. Resilience occurs after.
Succession Succession is the process of life taking over disrupted ecosystems Primary succession occurs in barren areas with no soil (eruptions, glaciers) Secondary succession occurs where soil is still intact (grazing, logging, etc.)
Primary Succession With no soil, bare ecosystems are very hostile to life Pioneer species are first to colonize Pioneer species need little water, shade Typically small weeds, lichens R-selected and/or type III species
Who lives and who dies? Competition for resources determines who takes over the new land Species that reproduce fast and don’t need many resources survive best, become pioneer species Over time, less weedy species arrive and outcompete the first colonizers
Later Succession As soil appears, larger grasses, shrubs, and shade-intolerant trees appear The species that appear depend on the climate
Results of Succession Primary and secondary succession result in a climax community Maintain species for a long period of time Sustainable (in energy balance) More organism symbioses than a changing community
May 18, 1980
Spirit Lake, before eruption
Spirit Lake, after and now
Windy Ridge Old Growth Forest, above Spirit Lake (before eruption)
Windy Ridge Old Growth Forest, after eruption and now
Case Study: Wolves in Yellowstone How did the removal of a keystone species impact the ecosystem? How can concepts of population and ecosystem disturbance be applied to this case study? Find this in Google classroom. You will also need a textbook to share. Please get as far as possible today- this will help you on your test. This is due Friday at midnight.