Environmental Problems, Their Causes, and Sustainability 1

Broad-wingedhawkGraysquirrelHairywoodpeckerFigure 6-31 Natural capital:some components and interactionsin a temperate deciduousforest ecosystem. When theseorganisms die, decomposersbreak down their organic matterinto minerals that plants use.Colored arrows indicate transfersof matter and energy betweenproducers, primary consumers(herbivores), secondary,or higher-level, consumers (carnivores),and decomposers. Organismsare not drawn to scale.White oakWhite-taileddeerMetallicwood-boringbeetle andlarvaeWhite-footedmouseShagbark hickoryMountainwinterberryFungiLong-tailedweaselMay beetleRacerBacteriaWood frogProducerto primaryconsumerPrimaryto secondaryconsumerSecondary tohigher-levelconsumerAll producers andconsumers todecomposersof slowly decaying leaf litter that is a storehouse of nutrients(Figure 4-27, bottom middle, p. 75).The temperate deciduous forests of the easternUnited States were once home for such large predatorsas bears, wolves, foxes, wildcats, and mountain lions(pumas). Today most of the predators have been killedor displaced, and the dominant mammal species oftenis the white-tailed deer, along with smaller mammalssuch as squirrels, rabbits, opossums, raccoons, andmice. Some of these diverse forests have been clearedand replaced with tree plantations consisting of onlyone tree species (see photo on p. vi).Warblers, robins, and other bird species migrate tothese forests during the summer to feed and breed.Many of these species are declining in numbers becauseof loss or fragmentation of their summer andwinter habitats.What Are Evergreen Coniferous Forests?Green and ColdThese forests in cold climates consist mostly ofcone-bearing evergreen trees that keep their needlesyear-round to help the trees survive long and coldwinters.Evergreen coniferous forests, also called boreal forests andtaigas (“TIE-guhs”), are found just south of the arctictundra in northern regions across North America,Asia, and Europe (Figure 6-16). In this subarcticclimate, winters are long, dry, and extremely cold,http://biology.brookscole.com/miller14123