Final Pt.2- Ecosystems and Populations

ecosystem

a COMMUNITY of organisms and the PHYSICAL ENVIRONMENT in which they live

population

group of individuals of the same species that occupy the same geographical area

community

populations of all species that occupy the same geographic area and interact with eachother

biosphere

all ecosystems on earth

ecosystem includes both ___ and ________ components

living, nonliving

biomass

total living COMPONENT of an ecosystem

nonliving components of ecosystem include…

chemical elements, energy supply

energy flow

Sun ——> producers ——> consumers

producers

CAPTURE and CONVERT energy, make their own organic molecules

consumers

AQUIRE organic molecules and energy by CONSUMING OTHER ORGANISMS

producers ___ and _____ energy, consumers ___ on ____ _____

capture and convert, rely on stored energy

Producers are…

autotrophs—“self-nutritive”—-most producers are capable of photosynthesis

terrestrial autotrophs

plants

aquatic autotrophs

algae

consumers are…

heterotrophs—-must consume foods that already contain stored forms energy ex. animals, fungi, most bacteria

four types of heterotrophs:

herbivores, carnivores, omnivores, decomposers

herbivores

primary consumers—use green plants as energy source

carnivores

secondary/tertiary consumers—use other animals as energy source

omnivores

use either plants or animals as energy source

decomposers

use dead organisms as energy source

Food Web

interactions among producers and consumers—often depicted as a chain

Humans are primary consumers OF

plants

humans are secondary consumers of

eating meat

Most of human history

stable pop, not exceeding 10 mil

4000 ago in human history

slow increase of population development of agriculture decreased environmental resistance and increased carrying capacity

carrying capacity

population size that the environment can support indefinitely

300 years ago human history

industrial revolution, rapid growth of human population

factors that reduced environmental resistance

agricultural development, improved medical care, improved transportation/housing

How high is the carrying capacity of earth?

<1 bil

can the carrying capacity be raised by future scientific discoveries

Do humans have the capacity to limit population growth before carrying capacity is met?