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Calcareous Grasses
Calcareous grassland (or alkaline grassland) is an ecosystem associated with thin Base (chemistry), basic soil, such as that on chalk and limestone downland. Plants on calcareous grassland are typically short and wikt:hardy, hardy, and include grasses and herbs such as clover. Calcareous grassland is an important habitat for insects, particularly butterflies and ants, and is kept at a plagioclimax by grazing animals, usually sheep and sometimes cattle. Rabbits used to play a part but due to the onset of myxomatosis their numbers decreased so dramatically that they no longer have much of a grazing effect. There are large areas of calcareous grassland in northwestern Europe, particularly areas of southern England, such as Salisbury Plain and the North Downs, North and South Downs. The machair forms a different kind of calcareous grassland, where fertile low-lying plains are formed on ground that is calcium, calcium-rich due to shell sand (pulverised sea shells). See also * Alvar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecosystem
An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the system through photosynthesis and is incorporated into plant tissue. By feeding on plants and on one another, animals play an important role in the movement of matter and energy through the system. They also influence the quantity of plant and microbial biomass present. By breaking down dead organic matter, decomposers release carbon back to the atmosphere and facilitate nutrient cycling by converting nutrients stored in dead biomass back to a form that can be readily used by plants and microbes. Ecosystems are controlled by external and internal factors. External factors such as climate, parent material which forms the soil and topography, control the overall structure of an ecosystem but are not themselves influenced by the ecosystem. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
