Chapter 6: Biomes. A. Biomes Are large regions characterized by a specific climate and specific plant and animal communities

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1 Chapter 6: Bimes Sectin 1: What is a Bime? 1. Describe hw plants determine the name f a bime. 2. Explain hw temperature and precipitatin determine which plants grw in an area. 3. Explain hw latitude and altitude affect which plants grw in an area. A. Bimes Are large regins characterized by a specific climate and specific plant and animal cmmunities 1. Climate Is determined by average temperature and precipitatin Varies with and Determines what plants can live in an area 2. Plants Have characteristics, specialized structures, and/r adaptatins that allw them t survive in a particular bime Determine all ther rganisms that can live in an area Sectin 2: Frest Bimes 1. List three characteristics f trpical rain frests. 2. Name and describe the main layers f a trpical rain frest. 3. Describe ne plant in a temperate deciduus frest and an adaptatin that helps the plant survive. 4. Describe ne adaptatin that may help an animal survive in the taiga. 5. Name tw threats t the wrld s frest bimes. A. Trpical Rain Frests Are characterized by High rainfall: cm f rain per year high humidity High temperatures due t year-rund direct sunlight n seasnal variatin Highest bidiversity f all bimes and cntains the mst plant species f all frest bimes Play vital rle in N, O, and C cycles Nutrients are mstly fund in plants NOT sil s run-ff is almst pure H 2 O 1. Layers (Fig. 7, p. 148) (1) Tp layer = 6-1

2 Receives mst sunlight Has the tallest trees: m Has a variety f animals: eagles, bats, mnkeys, and snakes (2) Middle (primary) layer = Receives filtered light Is divided int upper and lwer canpy Has trees with heights 30 m and epiphytes Is where mst animals live (3) Bttm layer = Receives very little light, s plants are adapted t shade Has the shrtest trees: 3.5 m 2. Species Diversity Special adaptatins f plants and animals : plant that uses anther plant fr supprt but nt fr nurishment : a shape r clr that allws an animal t blend int its envirnment Once cvered 20% f Earth s surface, nw nly cver 7% due t Lgging, agriculture, and/r il explratin ~100 acres is clear-cut every minute f every day, destrying habitat and threatening plants, animals, and native peples Trading f extic plants and animals B. Temperate Rain Frests Occur in N. America, Australia, and New Zealand N. America s nly temperate rain frest = Pacific Nrthwest (nrthern CA, OR, and WA) C. Temperate Deciduus Frests Once dminated vast regins f Earth, including parts f N. America, Eurpe, and Asia, but are nw generally limited t between N latitude (map n p. 152) Are characterized by Grwing seasn = 4-6 mnths Grw in layers similar t a rain frest but the frest flr receives mre light, s there is mre plant grwth in the understry Adapted t survive seasnal changes: 6-2

3 Adapted t frest plants fr fd and shelter Adapted t survive seasnal changes: D. Taiga Is lcated just belw the Arctic Circle (map n p. 153) Is characterized by Lng winters (6-10 mnths) with average temperatures f <0-20 C Shrt summers with nearly cnstant daylight and lts f rainfall = shrt grwing seasn (may be as shrt as 50 days nearest the Arctic Circle) Rugh terrain Cniferus frest with a dark, sparsely-vegetated frest flr Few plants because f slw sil frmatin (due t climate) and acidic sil (due t cnifer needles) Adaptatins f cnifers: Are adapted t survive harsh winters: migratin, burrwing/hibernatin, camuflage, etc. Sectin 3: Grassland, Desert, and Tundra Bimes 1. Describe the difference between trpical and temperate grasslands. 2. Describe the climate in a chaparral bime. 3. Describe tw desert animals and the adaptatins that help them survive. 4. Describe ne threat t the tundra bime. A. Savannas (Trpical Grasslands) Are lcated in trpical t subtrpical areas near the equatr and between trpical rain frest and desert bimes (map n p. 155) Must be able t survive lng perids withut H 2 O Adaptatins: large hrizntal rt systems, leaf lss during dry seasn, thrns/sharp leaves Adaptatins: 6-3

4 B. Temperate Grasslands Mst have ht summers and cld winters Average rainfall = cm/year In sme cases, muntains blck rains, which limits rainfall and makes the bime susceptible t fire Dminated by grasses, very few trees and grazing animals Many have been replaced with farms and grazing areas Determined by amunt f rainfall Adaptatins: mst are perennials with dense rt systems, which help them survive fire and drught Grazing Adaptatins: large, flat back teeth fr grinding tugh grasses; thick winter cats; undergrund burrws : grains d nt hld sil as well as native grasses : dmestic animals have replaced native animals C. Chaparral (Temperate Wdland) Occurs in the mid-latitudes, abut 30 N and S f the equatr (map n p. 159) Evergreen shrubs; scattered, lw-grwing, small trees; and herbs Are well-adapted t (1) Mst have il-cntaining, leathery leaves that prevent water lss and prmte fire, which destrys cmpetitin (2) Can resprut frm small bits f surviving plant tissue Mst cmmn adaptatin: : lts f sun, access t the ceans, and a mild year-rund climate 6-4

5 D. Deserts Ht deserts are clser t the equatr (= htter average temperatures) than cld deserts (map n p. 160) Are ften fund near large muntain ranges, which limit r blck rain Adaptatins: (1) : thick and fleshy stems, waxy cating, expansive rt systems near the surface (2) Grazing preventin: sharp spines (3) Drught-resistance: drmancy, require less H 2 O Adaptatins: (1) H 2 O cnservatin: thick, scaly skin (2) (bury themselves undergrund and sleep thrugh the dry seasn) (3) Bdy armr r nest in cacti (4) E. Tundra Shrt summers = permanently frzen sil Tugh grasses, lichens, and herbs Caribu, mse, deer, wlves, fxes, etc. Is ne f the mst fragile bimes n Earth Adaptatins: grw withut sil (msses and lichens); have wide, shallw rt systems; grw clse t the grund Adaptatins: migratin, burrwing, camuflage, Fd chains are simple and easily disrupted Land is easily damaged and slw t recver 6-5