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Evapotranspiration Rates
Evapotranspiration (ET) refers to the combined processes which move water from the Earth's surface (open water and ice surfaces, bare soil and vegetation) into the atmosphere. It covers both water evaporation (movement of water to the air directly from soil, canopies, and water bodies) and transpiration (evaporation that occurs through the stomata, or openings, in plant leaves). Evapotranspiration is an important part of the local water cycle and climate, and measurement of it plays a key role in water resource management agricultural irrigation. Definition ''Evapotranspiration'' is defined as: "The combined processes through which water is transferred to the atmosphere from open water and ice surfaces, bare soil and vegetation that make up the Earth’s surface." Evapotranspiration is a combination of evaporation and transpiration, measured in order to better understand crop water requirements, irrigation scheduling, and watershed management. The two key components of evap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Water Cycle
A surface, as the term is most generally used, is the outermost or uppermost layer of a physical object or space. It is the portion or region of the object that can first be perceived by an observer using the senses of Visual perception, sight and Somatosensory system, touch, and is the portion with which other materials first interact. The surface of an object is more than "a mere geometric solid", but is "filled with, spread over by, or suffused with perceivable qualities such as color and warmth". The concept of surface has been abstracted and formalized in mathematics, specifically in geometry. Depending on the properties on which the emphasis is given, there are several inequivalent such formalizations that are all called ''surface'', sometimes with a qualifier such as algebraic surface, smooth surface or fractal surface. The concept of surface and its mathematical abstractions are both widely used in physics, engineering, computer graphics, and many other disciplines, pri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instrumental Temperature Record
Global surface temperature (GST) is the average temperature of Earth's surface. More precisely, it is the weighted average of the temperatures over the ocean and land. The former is also called sea surface temperature and the latter is called surface air temperature. Temperature data comes mainly from weather stations and satellites. To estimate data in the distant past, proxy data can be used for example from tree rings, corals, and ice cores. Observing the rising GST over time is one of the many lines of evidence supporting the scientific consensus on climate change, which is that human activities are causing climate change. Alternative terms for the same thing are global mean surface temperature (GMST) or global average surface temperature. Series of reliable temperature measurements in some regions began in the 1850—1880 time frame (this is called the ''instrumental temperature record''). The longest-running temperature record is the Central England temperature d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precipitation (meteorology)
In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwealth usage), snow, ice pellets, graupel and hail. Precipitation occurs when a portion of the atmosphere becomes saturated with water vapor (reaching 100% relative humidity), so that the water condenses and "precipitates" or falls. Thus, fog and mist are not precipitation; their water vapor does not condense sufficiently to precipitate, so fog and mist do not fall. (Such a non-precipitating combination is a colloid.) Two processes, possibly acting together, can lead to air becoming saturated with water vapor: cooling the air or adding water vapor to the air. Precipitation forms as smaller droplets coalesce via collision with other rain drops or ice crystals within a cloud. Short, intense periods of rain in scattered locations are called shower (p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desertification
Desertification is a type of gradual land degradation of Soil fertility, fertile land into arid desert due to a combination of natural processes and human activities. The immediate cause of desertification is the loss of most vegetation. This is driven by a number of factors, alone or in combination, such as drought, climatic shifts, tillage for agriculture, overgrazing and deforestation for fuel or construction materials. Though vegetation plays a major role in determining the Soil biology, biological composition of the soil, studies have shown that, in many environments, the rate of erosion and runoff decreases exponentially with increased vegetation cover. Unprotected, dry soil surfaces blow away with the wind or are washed away by flash floods, leaving infertile lower soil layers that bake in the sun and become an unproductive hardpan. At least 90% of the inhabitants of drylands live in Developing country, developing countries, where they also suffer from poor economic and s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Table
The water table is the upper surface of the phreatic zone or zone of saturation. The zone of saturation is where the pores and fractures of the ground are saturated with groundwater, which may be fresh, saline, or brackish, depending on the locality. It can also be simply explained as the depth below which the ground is saturated. The portion above the water table is the vadose zone. It may be visualized as the "surface" of the subsurface materials that are saturated with groundwater in a given vicinity. In coarse soils, the water table settles at the surface where the water Hydraulic head, pressure head is equal to the atmospheric pressure (where gauge pressure = 0). In soils where capillary action is strong, the water table is pulled upward, forming a capillary fringe. The groundwater may be from precipitation or from more distant groundwater flowing into the aquifer. In areas with sufficient precipitation, water infiltrates through pore spaces in the soil, passing through t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rainforest
Rainforests are forests characterized by a closed and continuous tree Canopy (biology), canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforests can be generally classified as tropical rainforests or temperate rainforests, but other types have been described. Estimates vary from 40% to 75% of all biotic community, biotic species being Indigenous (ecology), 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 "medicine chest (idiom), 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, deforestation, the resulting habitat loss and air pollution, pollution of the atmosphere. Definition Rainforests are cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cloud Forest
A cloud forest, also called a water forest, primas forest, or tropical montane cloud forest, is a generally tropical or subtropical, evergreen, Montane forest, montane, Tropical and subtropical moist broadleaf forests, moist forest characterized by a persistent, frequent or seasonal low-level cloud cover, usually at the canopy level, formally described in the ''International Cloud Atlas'' (2017) as silvagenitus. Cloud forests often exhibit an abundance of mosses covering the ground and vegetation, in which case they are also referred to as mossy forests. Mossy forests usually develop on the mountain pass, saddles of mountains, where moisture introduced by settling clouds is more effectively retained. Cloud forests are among the most biodiversity-rich ecosystems in the world, with a large number of species directly or indirectly depending on them. Other moss forests include black spruce/feathermoss Climax community, climax forest, with a moderately dense canopy and a forest fl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transpiration
Transpiration is the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems and flowers. It is a passive process that requires no energy expense by the plant. Transpiration also cools plants, changes osmotic pressure of cells, and enables mass flow of mineral nutrients. When water uptake by the roots is less than the water lost to the atmosphere by evaporation, plants close small pores called stomata to decrease water loss, which slows down nutrient uptake and decreases CO2 absorption from the atmosphere limiting metabolic processes, photosynthesis, and growth. Water and nutrient uptake Water is necessary for plants, but only a small amount of water taken up by the roots is used for growth and metabolism. The remaining 97–99.5% is lost by transpiration and guttation. Water with any dissolved mineral nutrients is absorbed into the roots by osmosis, which travels through the xylem by way of water molecule adhesion and coh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evergreen
In botany, an evergreen is a plant which has Leaf, foliage that remains green and functional throughout the year. This contrasts with deciduous plants, which lose their foliage completely during the winter or dry season. Consisting of many different species, the unique feature of evergreen plants lends itself to various environments and purposes. Evergreen species There are many different kinds of evergreen plants, including trees, shrubs, and vines. Evergreens include: * Most species of conifers (e.g., pine, Tsuga, hemlock, spruce, and fir), but not all (e.g., larch). * Live oak, holly, and "ancient" gymnosperms such as cycads * Many woody plants from frost-free climates * Rainforest trees * All eucalypts * Lycopodiopsida, Clubmosses and relatives * Most bamboos The Latin binomial term , meaning "always green", refers to the evergreen nature of the plant, for instance: :''Cupressus sempervirens'' (a cypress) :''Lonicera sempervirens'' (a honeysuckle) :''Sequoia sempervirens'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broadleaf Forest
A forest is an ecosystem characterized by a dense community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' Food and Agriculture Organization (FAO) defines a forest as, "Land spanning more than 0.5 hectares with trees higher than 5 meters and a canopy cover of more than 10 percent, or trees able to reach these thresholds '' in situ''. It does not include land that is predominantly under agricultural or urban use." Using this definition, '' Global Forest Resources Assessment 2020'' found that forests covered , or approximately 31 percent of the world's land area in 2020. Forests are the largest terrestrial ecosystems of Earth by area, and are found around the globe. 45 percent of forest land is in the tropical latitudes. The next largest share of forests are found in subarctic climates, followed by temperate, and subtro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deciduous
In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed Leaf, leaves, usually in the autumn; to the shedding of petals, after flowering; and to the shedding of ripe fruit. The antonym of deciduous in the botanical sense is evergreen. Generally, the term "deciduous" means "the dropping of a part that is no longer needed or useful" and the "falling away after its purpose is finished". In plants, it is the result of natural processes. "Deciduous" has a similar meaning when referring to animal parts, such as deciduous antlers in deer, deciduous teeth (baby teeth) in some mammals (including humans); or decidua, the uterine lining that sheds off after birth. Botany In botany and horticulture, deciduous plants, including trees, shrubs and herbaceous perennials, are those that lose all of their Leaf, leaves for part of the year. This process is called abscission. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conifer
Conifers () are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class (biology), class, Pinopsida. All Neontology, extant conifers are perennial plant, perennial woody plants with secondary growth. The majority are trees, though a few are shrubs. Examples include Cedrus, cedars, Pseudotsuga, Douglas-firs, Cupressaceae, cypresses, firs, junipers, Agathis, kauri, larches, pines, Tsuga, hemlocks, Sequoioideae, redwoods, spruces, and Taxaceae, yews.Campbell, Reece, "Phylum Coniferophyta". ''Biology''. 7th ed. 2005. Print. p. 595. As of 2002, Pinophyta contained seven families, 60 to 65 genera, and more than 600 living species. Although the total number of species is relatively small, conifers are ecology, ecologically important. They are the dominant plants over large areas of land, most notably ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
