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Biotic Pump
The theory of a biotic pump pertains to the importance of forests in the water cycle, specifically, in determining the levels of rainfall a region will receive. It states that an increased amount of evaporation or transpiration will cause a reduction in atmospheric pressure as clouds form, which will subsequently cause moist air to be drawn to regions where evapotranspiration is at its highest. In a desert this will correspond to the sea whereas in a forest, moist air from the sea will be drawn inland. The theory predicts two different types of coast to contentinental rainfall patterns, first in a forested area one can expect no decrease in rainfall as one moves inland in contrast to a deforested region where one observes an exponential decrease in annual rainfall. While current global climate models fit these patterns well, it is argued this is due to parametrization and not the veracity of the theories. This theory is in contradiction of the more traditional view that surface win ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sensible Heat
Sensible heat is heat exchanged by a body or thermodynamic system in which the exchange of heat changes the temperature of the body or system, and some macroscopic variables of the body or system, but leaves unchanged certain other macroscopic variables of the body or system, such as volume or pressure. Usage The term is used in contrast to a latent heat, which is the amount of heat exchanged that is hidden, meaning it occurs without change of temperature. For example, during a phase change such as the melting of ice, the temperature of the system containing the ice and the liquid is constant until all ice has melted. The terms latent and sensible are correlative. The sensible heat of a thermodynamic process may be calculated as the product of the body's mass (''m'') with its specific heat capacity (''c'') and the change in temperature (\Delta T): : Q_ = m c \Delta T \, . ''Sensible heat'' and ''latent heat'' are not special forms of energy. Rather, they describe exchanges of hea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Pump
The biological pump (or ocean carbon biological pump or marine biological carbon pump) is the ocean's biologically driven sequestration of carbon from the atmosphere and land runoff to the ocean interior and seafloor sediments.Sigman DM & GH Haug. 2006. The biological pump in the past. In: Treatise on Geochemistry; vol. 6, (ed.). Pergamon Press, pp. 491-528 In other words, it is a biologically mediated processes which result in the sequestering of carbon in the deep ocean away from the atmosphere and the land. The biological pump is the biological component of the "marine carbon pump" which contains both a physical and biological component. It is the part of the broader oceanic carbon cycle responsible for the cycling of organic matter formed mainly by phytoplankton during photosynthesis (soft-tissue pump), as well as the cycling of calcium carbonate (CaCO3) formed into shells by certain organisms such as plankton and mollusks (carbonate pump). Budget calculations of the biol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Green Wall (China)
The Great Green Wall, officially known as the Three-North Shelter Forest Program (), also known as the Three-North Shelterbelt Program, is a series of human-planted windbreaking forest strips (shelterbelts) in China, designed to hold back the expansion of the Gobi Desert, and provide timber to the local population. The program started in 1978, and is planned to be completed around 2050, at which point it will be long. The project's name indicates that it is to be carried out in all three of the northern regions: the North, the Northeast and the Northwest. This project has historical precedences dating back to before the Common Era. However, in premodern periods, government sponsored afforestation projects along the historical frontier regions were mostly for military fortification. Effects of the Gobi Desert China has seen of grassland overtaken every year by the Gobi Desert. Each year, dust storms blow off as much as of topsoil, and the storms are increasing in severity each ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Green Wall (Africa)
The Great Green Wall or Great Green Wall of the Sahara and the Sahel (french: Grande Muraille Verte pour le Sahara et le Sahel; ) is a project led by the African Union, initially conceived as a way to combat desertification in the Sahel region and hold back expansion of the Sahara, by planting a wall of trees stretching across the entire Sahel. The modern green wall has since evolved into a program promoting water harvesting techniques, greenery protection and improving indigenous land use techniques, aimed at creating a mosaic of green and productive landscapes across North Africa. The project is a response to the combined effect of natural resources degradation and drought in rural areas. It seeks to help communities mitigate and adapt to climate change as well as improve food security. The population of the Sahel is expected to double by 2039, emphasizing the importance of maintaining food production and environmental protection in the area. History In the 1950s the Briti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rajendra Singh
Rajendra Singh (born 6 August 1959) is an Indian water conservationist and environmentalist from Alwar district, Rajasthan in India. Also known as "waterman of India", he won the Magsaysay Award in 2001 and Stockholm Water Prize in 2015. He runs an NGO called 'Tarun Bharat Sangh' (TBS), which was founded in 1975. The NGO based in village hori-Bhikampura in Thanagazi tehsil, near Sariska Tiger Reserve, has been instrumental in fighting the slow bureaucracy, mining lobby and has helped villagers take charge of water management in their semi-arid area as it lies close to Thar Desert, through the use of johad, rainwater storage tanks, check dams and other time-tested as well as path-breaking techniques. Starting from a single village in 1985, over the years TBS helped build over 8,600 johads and other water conservation structures to collect rainwater for the dry seasons, has brought water back to over 1,000 villages and revived five rivers in Rajasthan, Arvari, Ruparel, Sarsa, Bha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drylands
Drylands are defined by a scarcity of water. Drylands are zones where precipitation is balanced by evaporation from surfaces and by transpiration by plants (evapotranspiration). The United Nations Environment Program defines drylands as tropical and temperate areas with an aridity index of less than 0.65."Millennium Ecosystem Assessment, 2005. Drylands Systems". Chapter 22 in: ''Ecosystems and Human Wellbeing: Current State and Trends'', Volume 1. Island Press. One can classify drylands into four sub-types: * Dry sub-humid lands * Demi-arid lands * Arid lands * Hyper-arid lands Some authorities regard hyper-arid lands as deserts (United Nations Convention to Combat Desertification - UNCCD) although a number of the world's deserts include both hyper-arid and arid climate zones. The UNCCD excludes hyper-arid zones from its definition of drylands. Drylands cover 41.3% of the earth's land surface, including 15% of Latin America, 66% of Africa, 40% of Asia, and 24% of Europe. There ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rainforest
Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainforest, but other types have been described. Estimates vary from 40% to 75% of all biotic species being indigenous to the rainforests. There may be many millions of species of plants, insects and microorganisms still undiscovered in tropical rainforests. Tropical rainforests have been called the "jewels of the Earth" and the " world's largest pharmacy", because over one quarter of natural medicines have been discovered there. Rainforests as well as endemic rainforest species are rapidly disappearing due to deforestation, the resulting habitat loss and pollution of the atmosphere. Definition Rainforest are characterized by a closed and continuous tree canopy, high humidity, the presence of moisture-dependent vegetation, a moist layer of lea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photosynthesis
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in carbohydrate molecules, such as sugars and starches, which are synthesized from carbon dioxide and water – hence the name ''photosynthesis'', from the Greek ''phōs'' (), "light", and ''synthesis'' (), "putting together". Most plants, algae, and cyanobacteria perform photosynthesis; such organisms are called photoautotrophs. Photosynthesis is largely responsible for producing and maintaining the oxygen content of the Earth's atmosphere, and supplies most of the energy necessary for life on Earth. Although photosynthesis is performed differently by different species, the process always begins when energy from light is absorbed by proteins called reaction centers that contain green chlorophyll (and other colored) pigments/chromoph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquifer
An aquifer is an underground layer of water-bearing, permeable rock, rock fractures, or unconsolidated materials (gravel, sand, or silt). Groundwater from aquifers can be extracted using a water well. Aquifers vary greatly in their characteristics. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology. Related terms include aquitard, which is a bed of low permeability along an aquifer, and aquiclude (or ''aquifuge''), which is a solid, impermeable area underlying or overlying an aquifer, the pressure of which could create a confined aquifer. The classification of aquifers is as follows: Saturated versus unsaturated; aquifers versus aquitards; confined versus unconfined; isotropic versus anisotropic; porous, karst, or fractured; transboundary aquifer. Challenges for using groundwater include: overdrafting (extracting groundwater beyond the Dynamic equilibrium, equilibrium yield of the aquifer), groundwater-related subsidence of land, gro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil Carbon
Soil carbon is the solid carbon stored in global soils. This includes both soil organic matter and inorganic carbon as carbonate minerals. Soil carbon is a carbon sink in regard to the global carbon cycle, playing a role in biogeochemistry, climate change mitigation, and constructing global climate models. Overview Soil carbon is present in two forms: inorganic and organic. Soil inorganic carbon consists of mineral forms of carbon, either from weathering of parent material, or from reaction of soil minerals with atmospheric CO2. Carbonate minerals are the dominant form of soil carbon in desert climates. Soil organic carbon is present as soil organic matter. It includes relatively available carbon as fresh plant remains and relatively inert carbon in materials derived from plant remains: humus and charcoal. Global carbon cycle Although exact quantities are difficult to measure, human activities have caused substantial losses of soil organic carbon. Of the 2,700 Gt of carbon st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycorrhizal Network
A Mycorrhizal network (also known as a common mycorrhizal network or CMN) is an underground network found in forests and other plant communities, created by the hyphae of mycorrhizal fungi joining with plant roots. This network connects individual plants together and transfers water, carbon, nitrogen, and other nutrients and minerals between participants. Several studies have demonstrated that mycorrhizal networks can transport carbon, phosphorus, nitrogen, water, defense compounds, and allelochemicals from plant to plant. The flux of nutrients and water through hyphal networks has been proposed to be driven by a source–sink model, where plants growing under conditions of relatively high resource availability (e.g., high-light or high-nitrogen environments) transfer carbon or nutrients to plants located in less favorable conditions. A common example is the transfer of carbon from plants with leaves located in high-light conditions in the forest canopy, to plants located in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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