Investigating Earth's Desert, Grassland, and Rainforest Biomes
INTRODUCTION Any amount of traveling around the world reveals a constantly changing landscape alive with abundant and diverse plants animals climates and landforms Biomes are major ecological communities large areas of Earth in which particular animals and plants and environ mental conditions are found Deserts grasslands and rainforests are three biomes that cover a sig nificant part of our lively and varied planet This volume investigates this varied trio offering a broad overview of some of the most fascinating regions on Earth About 20 percent of the Earth's surface is covered by deserts Although deserts are typically thought of as hot they may also be cold Most of the world's hot deserts are between 20° and 35° north and south of the equator The main temperate cold deserts are found in the middle latitudes Desert landscapes range from bare rock to boulders to sand Such arid areas receive scanty precipitation and vegetation is meager Yet little of the desert is entirely desolate Desert dwelling plants and ani mals are expressly adapted to the severe conditions of this biome Following a good rain plants and flow ers bloom with vibrant colors Most deserts sport grasses North America's Sonoran Desert is spot ted with the distinctive saguaro cactus Carnegiea
INTRODUCTION Torrey's Yucca Yucca Torreyi blooms in the Chisos Mountains of the Chihuanbuan Desert in Texas David Ponton Design Pics Getty Images
INVESTIGATING EARTH's DESERT GRASSLAND AND RAINFOREST BIOMES gigantea while the cooler Mojave Desert is home to the Joshua tree Yucca brevifolia Deserts are home to reptiles marsupials and mammals Perhaps the camel is the iconic desert animal well suited to the climate with its ability to travel many miles without water People also inhabit deserts and even grow crops there though only in areas known as oases where water is available Grasslands occupy another 20 percent of Earth's land These grass dominated areas extend between forests and deserts The grasses vary as soil and climate conditions change For example more arid areas closer to deserts grow short or bunch grasses Tropical grasslands called savannas have a marked dry season and yield coarse stiff grasses In the middle latitudes or prairies temperatures are less extreme and taller grasses grow alongside flowering plants in the fertile soil Steppe grasses tend to be rather short with shallow root systems making for a less varied landscape Many animals inhabit savannas such as herbivorous plant eating animals which in turn attract carnivores or meat eaters Tropical grasslands teem with zebras lions and kangaroos More temperate grasslands are home to hawks horses and prairie dogs
INTRODUCTION The verdant rainforest features broad leaved evergreen trees and abundant rainfall In many areas the upper layer of trees creates a canopy so thick that sunlight rarely shines through to lower foliage An incredible diversity of plants and animals is found in rainforests such as orchids lia nas orangutans bats birds of paradise and many frog species Although some rainforests occur in more temperate areas most are found in warm trop ical climes around the equator Subtropical rainforests lie beyond the equatorial region temperatures in these forests generally only fluctuate a little though rainfall may be unevenly distributed Montane and tropical seasonal rainforests diverge some from the classical definition of rainforest but they do have periods of intense rain and moisture Deserts grasslands and rainforests cer tainly cover an ample portion of the globe On the following pages you will find a sweep ing look at these captivating areas each with its own distinctive flora and fauna
