Fundamentals of Ecology- week 2

community biomes

between extremes conditions on planet lie many other types of complex communities each well suited to particular conditions of climate prevailing

microbiomes

The communities of bacteria and archaea that inhabit our bodies

biomes represent

large regions like forests, deserts, grasslands, characterized by distinct climate and specific species (especially vegetation) adapted to it

aquatic life zones

include freshwater and ocean/marine zones.

each biome has...

plant component, responsible trapping energy from sun & making it available to other members. each has grazing animals (large & small)

all living things form....

complicated network of feeding interactions and at base of system. microbes in soil are ready to consume the energy rich plant litter on dead animal flesh that remains

biome is then...

integrated within each species which it plays its particular role

different communities lead...

different communities of organisms, especially vegetation, mostly by difference in average temperature due to global air & water circulation

why is it difficult to divide the world into a few ecological zones?

b/c small scale variations exist everywhere and b/c gradual changeover from biomes

deserts

area where evaporation exceeds precipitation. annual precipitation is low and often scattered

vegetation in deserts

sparse, widely spread. mostly low vegetation

what percentage of earth's land surface is found in tropical and subtropical regions?

30%

where are the largest deserts found?

interiors of continents. far from moist sea air & moisture bearing winds.

rain shadow desert

a desert found on the leeward side of a mountain range, formed when moist marine air produces precipitation on the windward side of a mountain, causing the air on the leeward side to be much warmer and drier

how are deserts classified?

hot and dry. semiarid. coastal. cold

tropical deserts are...

hot and dry most of the year. few plants and hard windblown surface strewn w/rocks and some sand

temperate deserts

daytime temps are high & low in winter and more precipitation than tropical deserts. sparse vegetation= widely dispersed drought resistant shrubs/cacti

cold deserts

winters are cold, summers are warm/hot and precipitation is low

semidesert

found in semiarid zones between deserts and grasslands. biome is dominated by thorn trees and shrubs to long dry spells followed by brief, sometimes heavy rains

grasslands

enough precipitation to support grasses but not enough support large amount of trees. found in tropical, temperate, and polar regions.

what regions are grasslands found in?

tropical. temperate. polar.

where are grassland typically found at?

found in interior part of continents

how do grasslands persist?

persist b/c combination seasonal drought, grazing large herbivores and occasional fire. all keep large numbers of shrubs and trees from growing.

what are the polar grasslands also known as?

tundra

what is the savanna?

type of tropical grassland. warm temperature year round. 2 prolonged dry season and abundant rain res of year.

african tropical savannas

enormous herds of grazing (grass & herb eating) and browsing (twig & leaf nibbling) hoofed animals. feed variety of savanna plants

temperate grasslands

have cold & hot/dry summers. have deep & fertile soils making them widely used for growing crops and grazing cattle

where do temperate grasslands cover?

cover vast expanses of plains & gently rolling hills in interiors of North and South America, Europe, and Asia

weather in temperate grasslands

winters bitterly cold. summers hot/dry. annual precipitation fairly sparse. fall evenly throughout the year

temperate grasslands in North America

tall grass and short grass prairies. many disappeared b/c great places to grow crops

polar grasslands

covered w/ice and snow except during brief summer. occur just South of artic polar ice cap

what are polar grasslands also known as?

freezing desert

vegetation in polar grasslands

carpeted w/thick, spongy mat of low growing plants, primarily grasses, mosses, and dwarf woody shrubs