Terrestrial Biomes

Assignment on Management Strategies of World Biomes Submitted by: Sonia Nazneen Roll: 875 Submission date: 15/07/2012 Department of Geography & Environment JAHANGIRNAGAR UNIVERSITy Introduction Today, Forests occupy approximately one-third of Earth’s land area, account for over two-thirds of the leaf area of land plants, and contain about 70% of carbon present in living things. However, forests are becoming major casualties of civilization as human populations have increased over the past several thousand years, bringing deforestation, pollution, and industrial usage problems to this important biome. Biomes Biomes are the major regional groupings of plants and animals discernible at a global scale. Their distribution patterns are strongly correlated with regional climate patterns and identified according to the climax vegetation type. However, a biome is composed not only of the climax vegetation, but also of associated successional communities, persistent sub climax communities, fauna, and soils. Types of Biomes Present-day forest biomes, biological communities that are dominated by trees and animals, can be classified according to numerous characteristics, with seasonality being the most widely used. They are Terrestrial Biomes Deserts Grassland: Prairies & Savannas Tundra Conifer Forests Broad-Leaved Deciduous and Evergreen Forests Mediterranean/Chaparral/Thorn Shrub Tropical Moist Forests Tropical Seasonal Forests Estuaries and Wetlands: Transitional Communities Figure: World Biomes Forest Name Figure Tropical Forests Savannas Deserts Chaparral Temperate Grasslands Temperate Deciduous Forests Coniferous Forests Tundra  Terrestrial Biomes Biomes are broad types of biological communities with similar climatic and topographic conditions with comparable communities. Temperature and precipitation are the two most important factors influencing the type of biome found in a location. Deserts Desert biomes are characterized by low moisture levels and infrequent, unpredictable precipitation. Desert plants have adapted to prevent water loss (leaf adaptations, water-storage tissues, thick epidermal layers) and to discourage predation (thorns and spines). Desert animals also have adapted to fight the heat and conserve water. Many have adopted burrowing behaviors to escape the sun, and many produce highly concentrated urine and feces in order to conserve water. Grasslands: Prairies and Savannas Grasslands are moderately dry areas of abundant grasses, herbaceous flowering plants, and open savannas. Seasonal cycles for precipitation and temperature contribute to the rich growth. Grasslands have few trees due to inadequate rainfall and frequent grassfires. In some parts of the world, native people use fire to create grasslands for grazing while in other parts, fire suppression has greatly reduced the amount of native grasslands. Tundra Climates in high mountain areas or at far northern or southern latitudes are often too harsh for trees. This treeless landscape, called tundra, is characterized by a very short growing season, harsh winters, and the potential for frost any month of the year. Although the tundra may swarm with life during the brief growing season, few species are able to survive the harsh winter. Dominant tundra plants are mosses, lichens, grasses, sedges, and dwarf shrubs. Flocks of migratory birds and bloodsucking insects reside in the arctic wetlands. Larger animals (musk ox, caribou, mountain goats) must be specially adapted to deal with the climate and sparse food supply. Damage to the tundra is slow to heal because of the short growing season. For example, truck tire ruts and bulldozer tracks from the oil and natural gas industries may take centuries to repair. Conifer Forests Coniferous forests are characterized by limited moisture which has caused the vegetation to develop thin, needlelike evergreen leaves with a thick waxy coating. The boreal (northern coniferous forest) stretches in a broad band of mixed coniferous and deciduous trees around the world between 45o and 60o north latitude. Among the dominant conifers are spruce, pine, hemlock, cedar, and fir. Mosses and lichens form most of the ground cover. Broad-Leaved Deciduous and Evergreen Forests Forests of broad leaved trees where rainfall is plentiful are called deciduous forests. Trees found here are able to produce summer leaves and shed them at the end of the growing season. These include oak, maple, birch, ash, and elm trees. Mediterranean/Chaparral/Thorn Shrub Mediterranean climates are characterized by warm, dry summers and cool, moist winters. Evergreen shrubs, scrub oaks, and pines dominate this landscape. Fires play an important role in plant succession here. This biome is considered to be a hotspot for biological diversity. Tropical Moist Forests Tropical moist forests are characterized by ample rainfall and uniform temperatures. Cool cloud forests are found high in mountains and cannot resist erosion from the abundant rains. Tropical Seasonal Forests Tropical regions characterized by distinct wet-dry seasons with hot temperatures all year round give rise to tropical seasonal forests. These areas are dominated by semi-evergreen or partly deciduous forests tending toward open woodland or grassy savannas. Tropical rainforests occur where rainfall is abundant (>200 cm per year) and temperatures are hot year round. Estuaries and Wetlands: Transitional Communities Estuaries are bays of brackish water that form where rivers enter the ocean. They contain rich sediments that support a multitude of aquatic life and are important as "nurseries" to a variety of species. A fan shaped sediment deposit at the mouth of a river is called a delta. Wetlands are ecosystems in which the land surface is covered by standing water at least part of the year. There are three types of wetlands; swamps (contain trees), marshes (no trees), and bogs and fens (may or may not have trees, tend to accumulate peat, low productivity). Wetland areas are being destroyed or degraded by human processes at an alarming rate. Human Disturbance Figure: A world map of Human Disturbance Humans have become the dominant organisms over most of the earth and have damaged or disturbed more than half the world's ecosystems. Conversion of natural habitat to human use is the largest single cause of loss of biodiversity. Temperate broad-leaved forests are the most completely human-dominated of any major biome. Mediterranean climates are also generally desirable for human habitation, leading to conflict between human preferences and biological values. Tundra and arctic deserts are among the least disturbed biomes in the world. That is changing, however, with the discovery of large reserves of oil and natural gas. Tundra and arctic deserts are among the least disturbed biomes in the world. That is changing, however, with the discovery of large reserves of oil and natural gas. Human disturbance Biome Total Area (106 Km2) % Undisturbed Habitat % Human Dominated Temperate broadleaved forests 9.5 6.1 81.9 Chaparral and thorn scrubs 6.6 6.4 67.8 Temperate grasslands 12.1 27.6 40.4 Temperate rainforests 4.2 33.0 46.1 Tropical dry forests 19.5 30.5 45.9 Mixed mountain systems 12.1 29.3 25.6 Mixed island systems 3.2 46.6 41.8 Cold deserts/semi-deserts 10.9 45.4 8.5 Warm deserts/semi-deserts 29.2 55.8 12.2 Moist tropical forests 11.8 63.2 24.9 Tropical grasslands 4.8 74.0 4.7 Temperate conifer forests 18.8 81.7 11.8 Tundra and arctic desert 20.6 99.3 0.3 Landscape Ecology Landscape ecology is the study of reciprocal effects of spatial pattern on ecological processes. Reciprocal effects refers to the fact that complex spatial patterns shape, and are in turn shaped by, the ecological processes that occur in them. Landscape ecology considers humans important elements of most landscapes and take them into account in their studies. Landscape Dynamics Time and space are of special concern in landscape ecology. The boundaries between habitat patches are considered especially significant by landscape ecologists. Edges can induce, inhibit, or regulate movement of materials, energy, or organisms across a landscape. There are many similarities between landscape ecology and conservation biology. Restoration Ecology Restoration ecology seeks to repair or reconstruct ecosystems damaged by humans or natural forces. Defining Some Terms Restoration involves active manipulation of nature to re-create species composition and ecosystem processes as close as possible to the state that existed before human disturbance. Rehabilitation refers to an attempt to rebuild elements of structure or function in an ecological system without necessarily achieving complete restoration to its original condition. Remediation is a process of cleaning chemical contaminants from a polluted area by physical or biological methods. Reclamation is used to describe chemical or physical manipulations carried out in severely degraded sites, such as open pit mines or large-scale construction. Re-creation attempts to construct a new biological community on a site so severely disturbed that there is virtually nothing left to restore. Conflicting Views of Restoration There are conflicting views over the effectiveness and ideology of different approaches to protecting nature. Two of the different camps are preservationists and restorationists. Preservationists argue that the best strategy is to avoid destructive projects in the first place. Restorationists counter that we are unlikely to preserve more than small areas in pristine form. They believe that we should use science to repair damage done by destructive projects. Tools of Restoration There are many different ways to approach restoration. Curtis Prairie at the University of Wisconsin-Madison was restored through intensive horticultural and animal control methods. Sometimes, an alien species must be removed before native species may take hold again. For example, in Hawaii, feral pigs that root out native plants and eat native birds are being hunted and removed. Successional restoration uses fire to discourage invasion of exotic species. In southern Kansas, fire and native bison have been introduced to restore a 16,000 ha tall grass prairie. Letting Nature Heal Itself Sometimes to reestablish a healthy ecosystem, all we have to do is walk away and leave it alone. The DMZ between North and South Korea is a perfect example. An area shattered by war that has been left alone for almost 50 years has become a thriving wildlife refuge.And in Bangladesh, after SIDR - Sundarban recover itself very successfully. Creating Artificial Ecosystems Sometimes artificial ecosystems may be created to solve human problems. For example, Arcata, California, created a wetland to deal with it sewage waste from the city. The wetland allowed for detoxification of the water and for a beautiful nature preserve. Ecosystem Management Ecosystem management is a relatively new discipline in environmental science that attempts to integrate ecological, economic, and social goals in a unified systems approach to make environmental management decisions. Principles of ecosystem management Managing across whole landscapes, watersheds, or regions over an ecological time scale. Considering human needs and promoting sustainable economic development and communities. Maintaining biological diversity and essential ecosystem processes. Utilizing cooperative institutional arrangements. Integrating science and management. Generating meaningful stakeholder and public involvement and facilitating collective decision-making. Adapting management over time, based on conscious experimentation and routine monitoring.   Principles and Goals of Ecosystem Management There are several important differences between the current integrated approach to ecosystem management and traditional policies of the past. Hierarchical context: A focus on any one level of the biodiversity hierarchy is insufficient. Ecosystem managers must see interconnections between all levels. Ecological boundaries: Rather than divide administrative units by political boundaries, natural units should be managed in an integrated fashion. Data collection and routine monitoring: To function correctly, ecosystem management requires ongoing research and data collection so that successes and failures may be recognized and evaluated. Adaptive management: Ecosystem management assumes that scientific knowledge is provisional and regards management plans as learning processes or continuous experiments where incorporating the results of previous actions allows managers to remain flexible and adapt to uncertainty. Organizational change: Implementing ecosystem management requires changes in agency structure and ways of doing business. Humans in nature: People cannot be separated from nature. Values: Regardless of the role of scientific knowledge, human values play a dominant role in ecosystem management goals. Ecosystem management goals Maintain viable populations of native species in situ. Represent, within protected areas, all native ecosystem types across their natural range of variation. Protect essential ecological processes such as nutrient cycles, succession, hydrologic processes, etc. Manage over long enough time periods to sustain the evolutionary potential of species and ecosystems. Accommodate human use and occupancy within these constraints.   Critiques of Ecosystem Management There are many criticisms of ecosystem management. Many ecologists say that due to their chaotic, unpredictable nature, we will never understand ecosystems and developing policies to manage them is a waste of time. Many people also fear that effective ecosystem management will allow humans to believe we can do damage to nature and that at may be repaired. Conclusion To achieve the objective of sustainable development much will depend upon official commitment, investment and strategic planning and further technical assistance. An early policy decision by the Government on the recommended reforms would provide a tangible indication of the way forward for implementing integrated management systems for the World. It is therefore recommended that the feasibility studies to augment policy decisions be implemented as soon as possible according to the targets of the investment programme. References www.blueplanetbiomes.org.htm www.managingwholes.com.htm www.eco-pros.com.htm www.wikipedia.com www.wcmc.org.uk