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Bio-geoengineering
Bio-geoengineering is a form of climate engineering which seeks to increase the solar reflectivity (or albedo) of crops by modifying physiological leaf and/or canopy traits to help reduce regional surface warming. Crop Albedo Modification Bio-geoengineering relies on the manipulation of crop attributes, such as through selective plant breeding or genetic engineering, to increase a crop's net albedo. Although there are noticeable differences in albedo between distinct crop types, bio-geoengineering mainly focuses on intra crop modification and substitution, which inherently limits its overall albedo change, but the changes are much easier to be implemented. The net albedo of a set of crops can be broken down into two contributing layers: the reflectivity of individual crop leaves and the overall canopy's effective albedo due to position, angle, and coverage of leaves. Leaf Glossiness At the individual leaf level, the base amount of light reflected by a given leaf depends la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared
Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those of red light (the longest waves in the visible spectrum), so IR is invisible to the human eye. IR is generally (according to ISO, CIE) understood to include wavelengths from around to . IR is commonly divided between longer-wavelength thermal IR, emitted from terrestrial sources, and shorter-wavelength IR or near-IR, part of the solar spectrum. Longer IR wavelengths (30–100 μm) are sometimes included as part of the terahertz radiation band. Almost all black-body radiation from objects near room temperature is in the IR band. As a form of EMR, IR carries energy and momentum, exerts radiation pressure, and has properties corresponding to both those of a wave and of a particle, the photon. It was long known that fires e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agriculture
Agriculture encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to live in the cities. While humans started gathering grains at least 105,000 years ago, nascent farmers only began planting them around 11,500 years ago. Sheep, goats, pigs, and cattle were domesticated around 10,000 years ago. Plants were independently cultivated in at least 11 regions of the world. In the 20th century, industrial agriculture based on large-scale monocultures came to dominate agricultural output. , small farms produce about one-third of the world's food, but large farms are prevalent. The largest 1% of farms in the world are greater than and operate more than 70% of the world's farmland. Nearly 40% of agricultural land is found on farms larger than . However, five of every six farm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Absorptance
In the study of heat transfer, absorptance of the surface of a material is its effectiveness in absorbing radiant energy. It is the ratio of the absorbed to the incident radiant power. Mathematical definitions Hemispherical absorptance Hemispherical absorptance of a surface, denoted is defined as :A = \mathrm, where * is the radiant flux ''absorbed'' by that surface; * is the radiant flux received by that surface. Spectral hemispherical absorptance Spectral hemispherical absorptance in frequency and spectral hemispherical absorptance in wavelength of a surface, denoted and respectively, are defined as :\begin A_\nu &= \mathrm, \\ A_\lambda &= \mathrm, \end where * is the spectral radiant flux in frequency ''absorbed'' by that surface; * is the spectral radiant flux in frequency received by that surface; * is the spectral radiant flux in wavelength ''absorbed'' by that surface; * is the spectral radiant flux in wavelength received by that surface. Directional absorptance Di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crop Yield
In agriculture, the yield is a measurement of the amount of a crop grown, or product such as wool, meat or milk produced, per unit area of land. The seed ratio is another way of calculating yields. Innovations, such as the use of fertilizer, the creation of better farming tools, and new methods of farming and improved crop varieties have improved yields. The higher the yield and more intensive use of the farmland, the higher the productivity and profitability of a farm; this increases the well-being of farming families. Surplus crops beyond the needs of subsistence agriculture can be sold or bartered. The more grain or fodder a farmer can produce, the more draft animals such as horses and oxen could be supported and harnessed for labour and production of manure. Increased crop yields also means fewer hands are needed on farm, freeing them for industry and commerce. This, in turn, led to the formation and growth of cities, which then translated into an increased demand for foodst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arable Land
Arable land (from the , "able to be ploughed") is any land capable of being ploughed and used to grow crops.''Oxford English Dictionary'', "arable, ''adj''. and ''n.''" Oxford University Press (Oxford), 2013. Alternatively, for the purposes of agricultural statistics, the term often has a more precise definition: A more concise definition appearing in the Eurostat glossary similarly refers to actual rather than potential uses: "land worked (ploughed or tilled) regularly, generally under a system of crop rotation". In Britain, arable land has traditionally been contrasted with pasturable land such as heaths, which could be used for sheep-rearing but not as farmland. Arable land is vulnerable to land degradation and some types of un-arable land can be enriched to create useful land. Climate change and biodiversity loss are driving pressure on arable land. By country According to the Food and Agriculture Organization of the United Nations, in 2013, the world's arable land amo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Land Change Science
Land change science refers to the interdisciplinary study of changes in climate, land use, and land cover. Land change science specifically seeks to evaluate patterns, processes, and consequences in changes in land use and cover over time. The purpose of land change science is to contribute to existing knowledge of climate change and to the development of sustainable resource management and land use policy. The field is informed by a number of related disciplines, such as remote sensing, landscape ecology, and political ecology, and uses a broad range of methods to evaluate the patterns and processes that underlie land cover change. Land change science addresses land use as a coupled human-environment system to understand the impacts of interconnected environmental and social issues, including deforestation and urbanization. History Land change science is a recently developed field, which emerged in conjunction with the advancement of climate change and global environmental chan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leaf Angle Distribution
The leaf angle distribution (or LAD) of a plant canopy refers to the mathematical description of the angular orientation of the leaves in the vegetation. Specifically, if each leaf is conceptually represented by a small flat plate, its orientation can be described with the zenith and the azimuth angles of the surface normal to that plate. If the leaf has a complex structure and is not flat, it may be necessary to approximate the actual leaf by a set of small plates, in which case there may be a number of leaf normals and associated angles. The LAD describes the statistical distribution of these angles. Examples of leaf angle distributions Different plant canopies exhibit different LADs: For instance, grasses and willows have their leaves largely hanging vertically (such plants are said to have an erectophile LAD), while oaks tend to maintain their leaves more or less horizontally (these species are known as having a planophile LAD). In some tree species, leaves near the top of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leaf Area Index
Leaf area index (LAI) is a dimensionless quantity that characterizes plant Canopy (forest), canopies. It is defined as the one-sided green leaf area per unit ground surface area (''LAI = leaf area / ground area, m2 / m2'') in Broad-leaved tree, broadleaf Canopy (forest), canopies. In conifers, three definitions for LAI have been used: *Half of the total needle surface area per unit ground surface area *Projected (or one-sided, in accordance the definition for broadleaf canopies) needle area per unit ground area *Total needle surface area per unit ground area The definition “half the total leaf area” pertains to biological processes, such as gas exchange, whereas the definition “projected leaf area” was disregarded because the projection of a given area in one direction may differ in another direction when leaves are not flat, thick, or 3D-shaped. Moreover, “ground surface area” is specifically defined as “horizontal ground surface area” to clarify LAI on a sloping ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil
Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by restricting the former term specifically to displaced soil. Soil consists of a solid collection of minerals and organic matter (the soil matrix), as well as a porous phase that holds gases (the soil atmosphere) and water (the soil solution). Accordingly, soil is a three- state system of solids, liquids, and gases. Soil is a product of several factors: the influence of climate, relief (elevation, orientation, and slope of terrain), organisms, and the soil's parent materials (original minerals) interacting over time. It continually undergoes development by way of numerous physical, chemical and biological processes, which include weathering with associated erosion. Given its complexity and strong internal connectedness, soil ecologists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morphology (biology)
Morphology (from Ancient Greek μορφή (morphḗ) "form", and λόγος (lógos) "word, study, research") is the study of the form and structure of organisms and their specific structural features. This includes aspects of the outward appearance (shape, structure, color, pattern, size), as well as the form and structure of internal parts like bones and organs, i.e., anatomy. This is in contrast to physiology, which deals primarily with function. Morphology is a branch of life science dealing with the study of the overall structure of an organism or taxon and its component parts. History The etymology of the word "morphology" is from the Ancient Greek (), meaning "form", and (), meaning "word, study, research". While the concept of form in biology, opposed to function, dates back to Aristotle (see Aristotle's biology), the field of morphology was developed by Johann Wolfgang von Goethe (1790) and independently by the German anatomist and physiologist Karl Fried ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Irradiance
Solar irradiance is the power per unit area (surface power density) received from the Sun in the form of electromagnetic radiation in the wavelength range of the measuring instrument. Solar irradiance is measured in watts per square metre (W/m2) in SI units. Solar irradiance is often integrated over a given time period in order to report the radiant energy emitted into the surrounding environment (joule per square metre, J/m2) during that time period. This integrated solar irradiance is called solar irradiation, solar radiation, solar exposure, solar insolation, or insolation. Irradiance may be measured in space or at the Earth's surface after atmospheric absorption and scattering. Irradiance in space is a function of distance from the Sun, the solar cycle, and cross-cycle changes.Michael Boxwell, ''Solar Electricity Handbook: A Simple, Practical Guide to Solar Energy'' (2012), pp. 41–42. Irradiance on the Earth's surface additionally depends on the tilt of the measuri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
