DSST Environment-Humanities DANTES II

Phosphorus is an essential nutrient for plants and

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Phosphorus is an essential nutrient for plants and animals in the form of ions. Phosphorus forms parts of important life sustaining molecules but is not very common in the biosphere. Definition of evolution Evolution is the change in the inherited traits of a population of organisms through successive generations. Differences between food chains and food webs Food chains - Food chains are overly simplistic as representatives of the relationships of living organisms in nature. Most consumers feed on multiple species and in turn, are fed upon by multiple other species. The relationship is basically a line of predator-prey relationships. Food webs - A food web is a series of related food chains displaying the movement of energy and matter through an ecosystem. There are many food chains contained in these food webs Irrigation and Salinization Irrigation - is an artificial application of water to the soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall. Irrigation has a large impact on costs and energy since it affects downstream users, available land for use, and can affect soil salinity. Salinization – is the salt content in soil. Salinity from irrigation can occur over time wherever irrigation occurs, since almost all water (even natural rainfall) contains some dissolved salts. When the plants use the water, the salts are left behind in the soil and eventually begin to accumulate. Since soil salinity makes it more difficult for plants to absorb soil moisture, these salts must be leached out of the plant root zone by applying additional water. This water in excess of plant needs is called the leaching fraction.
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Salination from irrigation water is also greatly increased by poor drainage and use of saline water for irrigating agricultural crops. Producers and consumers in an aquatic ecosystem (Question was like what is the primary producer in the oceans.) Autotrophs (producers)-are organisms that can manufacture the organic compounds they need as nutrients from simple inorganic compounds obtained from their environment. These are mainly phytoplankton. Heterotrophs(consumers)-are organisms which cannot synthesize the organic nutrients they need and get their organic nutrients by feeding on the tissues of producers or other consumers. There are several classes of consumers, depending on their food source. Trophic levels (food chain, food web, producers, consumers) (Know “How does a primary producer in a tropic level receive its energy from the sun. .answer. .as heat.) Producers (autotrophs) are typically plants or algae. Plants and algae do not usually eat other organisms, but pull nutrients from the soil or the ocean and manufacture their own food using photosynthesis. For this reason, they are called primary producers. In this way, it is energy from the sun that usually powers the base of the food chain. Consumers (heterotrophs) cannot manufacture their own food, and need to consume
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Phosphorus is an essential nutrient for plants and animals...

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