1152 Chapters
Medium 9781607321934


Don Hunter University Press of Colorado ePub

G E O R G E   B.   S C H A L L E R

PAKISTAN A renowned biologist vividly describes his first encounter with a snow leopard and the lofty world it inhabits.

Whenever I walk through the Bronx Zoo, I like to halt in front of the snow leopards. Their luxuriant smoke-gray coats sprinkled with black rosettes convey an image of snowy wastes, and their pale, frosty eyes remind me of immense solitudes. For a moment the city vanishes and I am back in the Hindu Kush, the home of these magnificent cats.

The December cold gripped the valley as soon as the feeble sun disappeared behind the ridge. The slopes and peaks above an altitude of 11,000 feet were snow-covered, and a bank of clouds along the distant summits suggested that soon so would be the valleys. I hurried down the trail along the edge of a boulder-strewn stream until the valley widened. There I stopped and with my binoculars scanned the steep slope ahead, moving upward past the scree and outcrops, past scattered oak trees and stands of pine, to a cliff over a thousand feet above me. A female snow leopard lay on the crest of a spur, her chin resting on a forepaw, her pelage blending into the rocks so well that she seemed almost a part of them. Several jungle crows sat in a nearby tree, and a Himalayan griffon vulture wheeled overhead, intent, I knew, on the carcass of a domestic goat the leopard was guarding.

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Medium 9781603447652

7. Ecosystem-Based Management in the Laguna Madre, Western Gulf of Mexico

John W Day Texas A&M University Press ePub

Elizabeth H. Smith, Alfonso Banda, John W. Tunnell Jr., and Kim Withers

The unique geomorphic setting of the Laguna Madre ecosystem was first described by Enriquez Barroto when, on 8 March 1867, he sailed into the Río de las Palmas (now Soto La Marina, Tamaulipas). Three days later, he rowed into a water body he named Laguna de Ysmuth and described it as a river that paralleled the coast. He continued to refer to this “river” as he traveled northward along Padre Island, Texas (Bartlett 2002). In actuality, he had documented one of the most distinctive features along the northwestern Gulf of Mexico, the hypersaline lagoon system created and protected by Gulf barrier islands. In turn, Laguna Madre of Texas and Tamaulipas provides a protective buffer for the mainland as well as productive resources for its people. Human alterations have cumulatively impaired certain ecological functions of this Tamaulipan thornscrub, Gulf coastal plain, and hypersaline estuarine system. In this chapter we describe the physical, chemical, and biological features of the Laguna Madre ecosystem; review alterations applied to the system; and provide recommendations for future conservation and management.

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Medium 9780253353139

The Geography of Somewhere

Scott Russell Sanders Indiana University Press ePub

for Dan Shilling

If we are to build up a civilization
around ourselves in these United States,
we must learn to keep our beautiful things and
to look at them more than once.


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Medium 9781623490386

3. Beach Materials, Structures, and Sources

Richard A. Davis Texas A&M University Press ePub

Beach Materials, Structures, and Sources

THE most common term associated with the beach is sand. True, most beaches are predominantly sand, but there are many other kinds of materials that can also be present in large amounts at some locations. In fact, the term sand denotes only grain size; it tells us nothing about the composition of the particles. Sand can be composed of a wide range of minerals. This chapter discusses the range of materials that constitute beaches: their textures, composition, and origins. This information will give us a much more comprehensive appreciation of the beach environment.

Beach Textures

Sand is a particle that is between 0.0625 mm and 2.00 mm, or about 1/16 inch. This range of particle size is part of a comprehensive size classification called the Wentworth Grain Size Scale (table 3.1). Some of the terms for grain-size categories in this classification are quite recognizable, but they also have specific quantitative definitions. For example, the term boulder has a specific definition: any particle between 256 mm and 1048 mm or about 10 inches and larger. The terms cobble, pebble, silt, clay, and mud also have specific quantitative size ranges. Beaches can be composed of boulders, cobbles, or sand (figure 3.1).

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Medium 9780253006820

5. Climate-Agriculture Vulnerability Assessment for the Midwestern United States

Sara C Pryor Indiana University Press ePub


The Midwest is a breadbasket for the United States and one of the major contributors of corn and soybean production globally. Current corn yields in the Midwest are around 150 bushels per acre with a total production of about 10 billion bushels, while soybean yields in the Midwest are 45 bushels per acre with production of about 3 billion bushels. Agriculture is a major enterprise requiring investments in terms of water, landscape, energy, and human/economic resources. Projected climate and land use changes can affect the dynamics and availability of soil, water, and land resources leading to food insecurity (Lobell et al. 2008). Thus the water and land required for agricultural production are vital components of the natural resources of the Midwest. Agricultural land comprises 89 percent of the land use in the Midwest, and as documented in chapter 2 of this volume, agriculture continues to play a major role in the economy of the region.

Agriculture is both a source and sink of greenhouse gas (GHG) emissions. Photosynthesis is a significant seasonal sink, while the emissions from the soil surfaces for nitrous oxide and other gases from animal waste and fertilizers are a source term. Agriculture accounted for about 17 percent of the global GHG emissions and 7 percent of the emissions across the United States (Pryor and Takle 2009). Additionally, as documented in several chapters to follow, the agricultural sector is perhaps uniquely sensitive to climate variability and change.

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