Chapter 43: Global Ecology and Conservation Biology Flashcards
What do human activities threaten Earth’s?
biodiversity
What is the human population no longer doing?
growing exponentially, but it is still increasing rapidly
What are the four major threats to biodiversity?
habitat loss, introduced species, over harvesting, global change
What are small populations vulnerable to?
inbreeding and genetic drift
What does MVP stand for
Minimum viable population
What is minimum viable population?
the minimal population size at which a species is able to sustain its number
What has human activities nearly doubled Earth’s supply of?
fixed nitrogen abailable to primary producers
What way has human activites doubled Earth’s supply of fixed nitrogen?
industrial fertilizers
WHat is usable nitrogen?
nitrates
What is a dead zone?
the result of phytoplankton bloom (due to nutrient influx) –> phytoplankton die-off –> resultant decomposition of phytoplankton depletes oxygen levels
What is eutrophication of lakes?
the result of algae and cyanobacteria bloom and die-off; similar to dead zone
What is biomagnification?
humans release an immense variety of toxic chemical into the biosphere with little regard or understanding of their consequence. These chemicals become more concentrated in successive trophic levels (mainly in adipose/fat) of a food web
What is DDT?
a widely used incesticide, this has led to a decrease in pelicans, ospreys, and eagles
Why has the concentration of CO2 in the atmosphere been increasing?
the burning of fossil fuels and deforestation
Over what years have CO2 levels increased fromm 274 ppm to 400 ppm?
150 years
