NATR 320 Lecture Notes - Lecture 7: Spatial Ecology, Metapopulation, Biome
22 May 2020
School
Department
Course
Professor
Michael Le
Arc
NATR 320
Principles of Ecology
● Collecting data for life tables
○ Cohort approach: follow a group of same-aged individuals (a cohort) throughout lives
■ Easy to apply to organisms that are sessile or easily tracked throughout lives
● Results can be confounded with environmental change
○ Static approach: all individuals at a particular point in time
■ Can be applied to more mobile individuals but requires a way to identify age
■ Age is not confounded with time, but …year selected may not be representative
● Unusual environmental conditions
● Unusual age distribution
● Multiple years advise
● Human Population Growth
● Easter Island
○ Famous for statues made by local populations
○ Colonized around 500 AD by Polynesians
○ 1400 AD Easter Island palm went extinct from overharvesting
■ Rats ate palms
■ Only 1 out of 22 native species still left
■ Seed species died because birds went extinct
○ 1722 - population of 2000 people, civil war, signs of cannibalism
○ How could such a group of people build such massive statues?
● Human population growth
○ Has been growing exponentially - cannot continue indefinitely
○ What is out K? Will we overshoot K? Have we already? If so, what will be the
consequences?
● Spatial Population Structure
● Spatial ecology
○ The concept of scaling
■ The spatial extent of ecological processes and the spatial interpretation of the data
■ Response of an organism to the environment is particular to a specific scale
○ Spatial scaling: global - continental - biome - region - landscape - local community
○ Populations have a spatial structure
■ Global range - metapopulation in a region - population - social groups - individual
■ Mountain Boomer Lizard
● Found in southwestern US and Mexico - dry, rocky, open mountains,
glades, isolated in pockets - which gland does it choose and why?
● Population distribution attributes and estimation
○ Niche and distributions
Document Summary
Cohort approach: follow a group of same-aged individuals (a cohort) throughout lives. Easy to apply to organisms that are sessile or easily tracked throughout lives. Results can be confounded with environmental change. Static approach: all individuals at a particular point in time. Can be applied to more mobile individuals but requires a way to identify age. Age is not confounded with time, but year selected may not be representative. Famous for statues made by local populations. Only 1 out of 22 native species still left. Seed species died because birds went extinct. 1722 - population of 2000 people, civil war, signs of cannibalism. Has been growing exponentially - cannot continue indefinitely. The spatial extent of ecological processes and the spatial interpretation of the data. Response of an organism to the environment is particular to a specific scale. Spatial scaling: global - continental - biome - region - landscape - local community.
