Es Chapter 6 Part 2 Biomes-1

CHAPTER 6 PART 2 ----------------------------------BIOMES-----------------------------

Defined as climax communities with wide geographic distribution

It is a concept and a generalization and there are variations BUT it is a useful term

In broad terms the general structure of the ecosystem and the kinds of niches and habitats present are similar.

Some of the biomes on earth include: • • • • • • • • • • • •

Desert - very dry, either hot or cold Tundra - cool, treeless, and dry. The permanently frozen soil layer is called permafrost. Scrub - coastal area with hot, dry summers and mild, cool, rainy winters Taiga or Coniferous Forest - cool and dry, with coniferous trees Temperate Deciduous Forest - cool and rainy, with deciduous trees Grassland - Windy, partly dry sea of grass with few trees, including tropical savanna, prairie, steppe, pampas, etc. Mountain Biomes - there are a lot of different mountainous biomes, from grasslands at low altitudes, taiga (coniferous forests) below the treeline, and alpine (the same as tundra) Temperate Rain Forest - cool and wet Tropical Rain Forest - warm and very wet Wetlands - there are many types of wetlands, including swamps, marshes, moors, bogs, fens, sloughs, etc. These have nutrient rich soil. Freshwater Marsh - a wetland located near streams, rivers and lakes Marine (ocean or sea)

7 minute biome video http://www.youtube.com/watch?v=ag5ATGEplbU we will discuss some terrestrial biomes......

The two important non-biological factors are PRECIPITATION AND TEMPERATURE

Precipitation: total amount, form, seasonal distribution

Snow, rain, sleet----even spacing or wet and dry season

Temperature: tropical, polar or even division between hot and cold

Other factors: periodic fires, favor shrubs over woody trees Strong winds—no big trees and very dry soi

Type of soil-- sandy will dry out, wet soil favors certain types of species.

Distribution of terrestrial ecosystems is primary related to temperature and precipitation

Warm near equator and cool toward poles. BUT height above sea level is important because it is related to temperature.

Climb a mountain and pass through biomes. a very handy sampling of biomes

DESERT

primary factor is LACK OF WATER generally less that 10 inches or 25 cm of water per year

When and how is different for different deserts. either in winter months or wet season OR infrequent thundershowers Problems with thundershowers is that rain RUNS OFF and does not sink in. ALSO rate of EVAPORATION is high ---this means that flowering and growth of plants occurs in wet season or time. ALSO desert is WINDY and this leads to drying We think of deserts and hot and dry and devoid of life HOWEVER deserts are full of life and can be cool or cold Sahara and deserts of the southwest of US and Mexico are hot mostly but Gobi desert in Central Asia can be very cold during winter and have cool summers

winter in gobi desert--note snow. ALSO desert TEMPERATURE can very widely in 24 hour period since low precipitation there is low cloud cover and hence sun is not blocked---very hot at night there are no clouds to insulate heat from leaving and radiational cooling leads to very cool temps at night. Species of animals---high diversity low numbers or density. animals and plants have special adaptations to survive desert temps, lack of water and drying examples--small leaves, or lose leaves in winter or like CACTUS will store water in spongy bodies or roots seeds will lie dormant and then grow rapidly during rainy season, reproduce and die and then wait for next rain. could be months perennial plants flower reproduce and during rainy season spiny plant in desert--will keep animals from eating them

] Animals of the desert populations are small small in size hide during day no large groups survive with little water outer skin resists water loss kidneys very efficient at retaining water active in cool parts of day may be underground for most of hotter part of day

GRASSLAND

also call prairies or steppes

25-75 cm or 10-30 inches of rain per year

widely distributed over temperature regions major factor is moisture available windy with hot summers and cold to mild winters FIRE is important is some areas to prevent trees from growing AND to provide nutrients GRASSES are 60-90 % of the vegetation with other flowering plants grasses have extensive root systems with bind soil

trees are rare, need lots of water

found along watercourses

Primary consumers are animals that eat grass grazing animals like bison, wildebeest, sheep, cattle, horses, goats animals function to convert grass to dung and to prevent invasion of woody plants by eating them Grass can be grazed and return healthy

more little animals end 11---27--07 insects, grasshoppers, dung beetles, flies herbivorous mammals like mice and squirrels birds feeding seeds, plants, insects reptiles snakes carnivores like coyotes foxes hawks which eat small mammals Most moist grassland has been converted to agriculture deep rich soil is good for corn (maize) and wheat---these are cultivated grasses dry grassland has been converted to domesticated grazers like cattle sheep goats little natural or undisturbed grassland is left and should be preserved for grassland species that once occupied vast areas of globe

SAVANNA tropical parts of Africa, South America and Australia--extensive grassland spotted with trees.

20 to 60 inches of rain per year

( 50 to 150 cm) not distributed evenly

drought and then rain---season ecosystem plants and animals time reproductive activities to rainy period mostly grass with some drought resistant thorny trees Fire is important and trees are fire resistant (not fire proof) many trees are legumes and nitrogen fixers and provide shade and nesting sites animals--mostly grazing animals wallabies AUS, wildebeests, zebras, elephants, antelope, capybara SA Africa--lion, hyena, leopard eat the grazers rodents, birds, insects, reptiles mound building termites common

Mediterranean Shrubland (Chaparral)

located near an ocean and have wet cool winters and hot dry summers rain is 40 to 100 cm or 15-40 inches typical of Mediterranean and coastal California (southern) southern tip of Africa and west coast of Chile and southern Australia plants--woody shrubs that can withstand hot dry summer, plants may be dormant in summer Fire is common and shrubs are adapted to this animals vary widely, many types of insects birds reptiles mammals In California rattlesnakes, spiders, coyotes, lizards, and rodents are typical TROPICAL DRY FOREST

tropical dry forest seasonal rainfall important a monsoon climate several months of heavy rain followed by extensive dry period which can range from a few to 8 months The rainfall can range from 50cm or 20 inches to 200 cm or 80 inches Plants have adapted to this dry wet cycle, can endure drought, Dry periods are a very hard time so some trees will drop their leaves during the dry period locations: parts of Central and South America, Australia, Africa and Asia (India and Myranmar) Tropical Rain Forest

location: Central South America Africa, Southeast Asia, some islands in Caribbean Sea and Pacific Ocean

temperature: warm and constant, no frost and it rains every day200cm or 80 inches of rain per year to a maximum of 500cm to 200 inches plants grow fast due to warm temp and rainfall BUT SOIL USUALLY POOR. why?---water tends to carry away nutrients that is not immediately taken up by roots Tree-- extensive root networks associated with fungi (micorhizza) near surface of soil to allow capture of nutrients before they are carried away. Most nutrients are tied up in biomass NOT IN SOIL. These area make poor farmland end 12-06-------------------------------------------------------------

Rainfall is a source of nutrients because atmospheric particles and gases dissolve as rain falls. Epiphytic plants (plants that live on surface of others plants) can trap many of these particle before they reach the soil. Understory vines grow toward sun on supporting trees--why? looking for sun, competition for sunlight ferns, mosses and orchids grow on tree surfaces. MOST DIVERSE BIOME--mores species here than in rest of world combined a few square kilometers have hundreds of species of trees (unlike where we live) Same species of tree can be a kilometer or more apart (very different from where we live) Balsa teakwood and ornamental woods are found here Each tree has a community of plants and animals that use it as food shelter and support

THE CANOPY -- a solid wall of leaves between the sun and forest floor. There can be two or three levels here. EMERGENT TREES -- a few three will stick up above the canopy below the canopy are UNDERSTORY TREES below that THE FOREST FLOOR many new organisms live in canopy --new research is showingg Key--most of sunlight is captured by the trees-so only shade tolerant plants Many types of plants, animals animals--insects like--ants, termites, moths, butterflies, beetles---birds are common climbing mammals, tree frogs, lizards---insects are food for many animals Flowers and fruit and available YEAR ROUND mammals

lots of nectar and fruit feeding birds and

very important in pollination and spreading seeds. Very low light levels during the day and difficult to see during the day due to leaves and vines and plants so animals communicate often by sounds. Environmental Pressures logging and agricultural these are often poor countries and try to exploit the rainforest for jobs and money AGRICULTURE IS NOT SUCCESSFUL HERE--cannot take repeated growing seasons of growth Forestry can be sustainable but in many cases is not, too rapid exploitation

TEMPERATE DECIDUOUS FOREST

look familiar? this is where we live. There is a winter summer change here and have trees that lose there leaves in winter and get them back in spring. location: eastern half of US and parts of central and southeastern Canada, southern Africa, and many areas of Europe and Asia

southern africa not shown on this map rainfall: 75 to 100 cm or 30 to 60 inches per year. winter are relatively mild and plants can grow for about half a year each area has certain species of tree that are major producers for the biome unlike tropical rain forest here there are many fewer species and many forests consist of two or three dominant species. common species: maple, birch, aspen , beech, oaks and hickory

tall tree shade the forest floor---here small flower plants grow--these plants have adapted by storing foods in underground structures and in spring before leaves come out on trees the flowers can capture sunlight and reproduce before they are shaded. also smaller shrubs are found animals: many insects which eat leaves and tree wood ants are examples

-- beetles, moth larvae, wasps and

Birds live here but most are MIGRANTS--arrive in spring, reproduce in summer, leave in fall-the food is the large insect population also fruit seeds. year round residents: some birds like woodpeckers, grouse, turkey and some finches amphibians (frogs, toads, salamanders) reptiles (snakes and lizards) prey on insects and other small animals. small and large mammals: mice ,squirrels, deer, shrews, moles and oppossums Predators: foxes, badgers, weasles, coyotes, and birds of prey TAIGA

northern coniferous forest, boreal forest

type of plant: evergreen coniferous forest location: southern half of Canada, parts of northern Europe, and much of Russia climate: short cool summers, long winters with lots of snow, winters are harsh and can last 6 months soils freezes precipitation: 25 to 100 cm or 10 to 40 inches very humid due to snow melt in spring and low temperature combine to reduce evaporation landscape: bogs, lakes and ponds common trees: spruces, firs, and larches adapted to winter and dry?? dry why? moisture fall as snow and stays above soil and melts in spring needle shaped leaves prevent water loss, larch lose needles in fall, branches flexible to shed snow in fall, tree shaped like a pyramid sun is low in sky and photosynthesis is lower animals: temporarily active in summer, most birds are migratory and feed on insect population not around in winter permanent birds: woodpecker, owls, grouse mammals: deer, caribou, moose, wolves few amphibians and reptiles because it is too cold TUNDRA

North of the Taiga is the Tundra description Lacks trees permanently frozen SUBSURFACE soil called PERMAFROST: climate : cold and windy (up to 10 months of winter) precipitation:

less than 25cm or 10 inches like the desert

temperature: short cool summer, summer temperatures and usually less than 50F or 10C hence very low evaporation rate land is waterlogged due to permafrost which does not let water sink into soil many ponds

and pools (shallow) animals: water attracts waterfowl like ducks and geese (migrate there during spring, raise young in summer migrate south in fall) Top few inches will thaw and some plants will grow but be short (less that 8 inches or 20 cm) plants: grasses, dwarf birch, dwarf willow and lichens like reindeer moss insects: lots and serve as food for migratory birds permanent residents: birds like ptarmigan and snowy owl

No reptiles or amphibians can live here Hardy mammals live here: musk oxen, caribou (reindeer), arctic hare, and lemmings---these surivive by eating the vegetation, short grasses and plants Predators: arctic foxes, wolves, and owls. Key point--very short growing season--damage to land will take a long time to heal. ALPINE TUNDRA -- found on some mountaintops around the world. General appearance is similar to Tundra although many species of animals and and plants are different. Also many animals will migrate to alpine tundra in summer and return to lower elevations in winter key point --- tundra due to elevation