ENERGY FLOW IN ECOSYSTEM :)
In ecology, energy flow, also called the calorific flow, refers to the flow of energy through a food chain. In an ecosystem,ecologists seek to quantify the relative importance of different component species and feeding relationships.
A general energy flow scenario follows:
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Ecosystems maintain themselves by cycling energy and nutrients obtained from external sources. At the first trophic level, primary producers (plants, algae, and some bacteria) use solar energy to produce organic plant material through photosynthesis. Herbivores—animals that feed solely on plants—make up the second trophic level. Predators that eat herbivores comprise the third trophic level; if larger predators are present, they represent still higher trophic levels. Organisms that feed at several trophic levels (for example, grizzly bears that eat berries and salmon) are classified at the highest of the trophic levels at which they feed. Decomposers, which include bacteria, fungi, molds, worms, and insects, break down wastes and dead organisms and return nutrients to the soil.
On average about 10 percent of net energy production at one trophic level is passed on to the next level. Processes that reduce the energy transferred between trophic levels include respiration, growth and reproduction, defecation, and nonpredatory death (organisms that die but are not eaten by consumers). The nutritional quality of material that is consumed also influences how efficiently energy is transferred, because consumers can convert high-quality food sources into new living tissue more efficiently than low-quality food sources.
The low rate of energy transfer between trophic levels makes decomposers generally more important than producers in terms of energy flow. Decomposers process large amounts of organic material and return nutrients to the ecosystem in inorganic form, which are then taken up again by primary producers. Energy is not recycled during decomposition, but rather is released, mostly as heat (this is what makes compost piles and fresh garden mulch warm). Figure 6 shows the flow of energy (dark arrows) and nutrients (light arrows) through ecosystems.
In ecology, energy flow, also called the calorific flow, refers to the flow of energy through a food chain. In an ecosystem,ecologists seek to quantify the relative importance of different component species and feeding relationships.
A general energy flow scenario follows:
- Solar energy is fixed by the photoautotrophs, called primary producers, like green plants. Primary consumers absorb most of the stored energy in the plant through digestion, and transform it into the form of energy they need, such asadenosine triphosphate (ATP), through respiration. A part of the energy received by primary consumers, herbivores, is converted to body heat (an effect of respiration), which is radiated away and lost from the system. The loss of energy through body heat is far greater in warm-blooded animals, which must eat much more frequently than those that arecold-blooded. Energy loss also occurs in the expulsion of undigested food (egesta) by excretion or regurgitation.
- Secondary consumers, carnivores, then consume the primary consumers, although omnivores also consume primary producers. Energy that had been used by the primary consumers for growth and storage is thus absorbed into the secondary consumers through the process of digestion. As with primary consumers, secondary consumers convert this energy into a more suitable form (ATP) during respiration. Again, some energy is lost from the system, since energy which the primary consumers had used for respiration and regulation of body temperature cannot be utilised by the secondary consumers.
- Tertiary consumers, which may or may not be apex predators, then consume the secondary consumers, with some energy passed on and some lost, as with the lower levels of the food chain.
- A final link in the food chain are decomposers which break down the organic matter of the tertiary consumers (or whichever consumer is at the top of the chain) and release nutrients into the soil. They also break down plants, herbivores and carnivores that were not eaten by organisms higher on the food chain, as well as the undigested food that is excreted by herbivores and carnivores. Saprotrophic bacteria and fungi are decomposers, and play a pivotal role in the nitrogen and carbon cycles.
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Ecosystems maintain themselves by cycling energy and nutrients obtained from external sources. At the first trophic level, primary producers (plants, algae, and some bacteria) use solar energy to produce organic plant material through photosynthesis. Herbivores—animals that feed solely on plants—make up the second trophic level. Predators that eat herbivores comprise the third trophic level; if larger predators are present, they represent still higher trophic levels. Organisms that feed at several trophic levels (for example, grizzly bears that eat berries and salmon) are classified at the highest of the trophic levels at which they feed. Decomposers, which include bacteria, fungi, molds, worms, and insects, break down wastes and dead organisms and return nutrients to the soil.
On average about 10 percent of net energy production at one trophic level is passed on to the next level. Processes that reduce the energy transferred between trophic levels include respiration, growth and reproduction, defecation, and nonpredatory death (organisms that die but are not eaten by consumers). The nutritional quality of material that is consumed also influences how efficiently energy is transferred, because consumers can convert high-quality food sources into new living tissue more efficiently than low-quality food sources.
The low rate of energy transfer between trophic levels makes decomposers generally more important than producers in terms of energy flow. Decomposers process large amounts of organic material and return nutrients to the ecosystem in inorganic form, which are then taken up again by primary producers. Energy is not recycled during decomposition, but rather is released, mostly as heat (this is what makes compost piles and fresh garden mulch warm). Figure 6 shows the flow of energy (dark arrows) and nutrients (light arrows) through ecosystems.
PRINCIPLES OF TEACHING 1
1. Learning is an experience which occurs inside the learner and is activated by the learner. This means that learning will not take place unless the learner her/himself allows it to happen in his/her mind. It is not primarily controlled by the teacher, rather on the learners' wants, interests and motivation to learn. In real classroom setting, the teacher must engage learners in activities that are connected to their lives.
2. Learning is the discovery of the personal meaning and relevance of ideas. This is somewhat the same with principle number one. Learners can easily understand concepts if these are relevant to their needs and problems. Hence, as teachers, we must relate the lesson to the learners' needs, interests and problems.
3. Learning is a consequence of experience. In short, use experiential learning as much as possible period. Experiential learning is the process of making meaning from direct experience, i.e., "learning from experience".
4. Learning is a cooperative and collaborative process. Learners will learn more if they are given chances to work together and share ideas. Make use of group activities.
5. Learning especially if this means a change in behavior, does not happen in a click. This requires time and diligence. So as teachers, be patient. Be patient. Be patient. Be patient.
6. Learning is sometimes a painful process. This means that learning requires sacrifice, hardwork, study time. Let the learners realize this okay?
7. One of the richest resources for learning is the learner him/herself. Let's not be too "centered" upon ourselves. Let's draw the discussion not only on our own experiences as teachers but on the learners' experiences as well. Listen and let the learners share their prior knowledge, stories, information, etc that can enrich the learning process. Encourage free sharing inside the classroom.
8. The process of learning is emotional as well as intellectual. Learners can't learn that much if they have something that is bothering their minds. These can be problems and worries they have either in or out of the classroom. Thus, as teachers, let us be sensitive to our students' problems. We can't teach learners with empty stomachs remember?
9. The process of problem solving and learning are highly unique and individual. Make use of different teaching strategies that can cater multiple intelligences and learning styles.
1. Learning is an experience which occurs inside the learner and is activated by the learner. This means that learning will not take place unless the learner her/himself allows it to happen in his/her mind. It is not primarily controlled by the teacher, rather on the learners' wants, interests and motivation to learn. In real classroom setting, the teacher must engage learners in activities that are connected to their lives.
2. Learning is the discovery of the personal meaning and relevance of ideas. This is somewhat the same with principle number one. Learners can easily understand concepts if these are relevant to their needs and problems. Hence, as teachers, we must relate the lesson to the learners' needs, interests and problems.
3. Learning is a consequence of experience. In short, use experiential learning as much as possible period. Experiential learning is the process of making meaning from direct experience, i.e., "learning from experience".
4. Learning is a cooperative and collaborative process. Learners will learn more if they are given chances to work together and share ideas. Make use of group activities.
5. Learning especially if this means a change in behavior, does not happen in a click. This requires time and diligence. So as teachers, be patient. Be patient. Be patient. Be patient.
6. Learning is sometimes a painful process. This means that learning requires sacrifice, hardwork, study time. Let the learners realize this okay?
7. One of the richest resources for learning is the learner him/herself. Let's not be too "centered" upon ourselves. Let's draw the discussion not only on our own experiences as teachers but on the learners' experiences as well. Listen and let the learners share their prior knowledge, stories, information, etc that can enrich the learning process. Encourage free sharing inside the classroom.
8. The process of learning is emotional as well as intellectual. Learners can't learn that much if they have something that is bothering their minds. These can be problems and worries they have either in or out of the classroom. Thus, as teachers, let us be sensitive to our students' problems. We can't teach learners with empty stomachs remember?
9. The process of problem solving and learning are highly unique and individual. Make use of different teaching strategies that can cater multiple intelligences and learning styles.