The question is complete, please read it. and please answer it asap a) The NPP o

Question

The question is complete, please read it. and please answer it asap

a) The NPP of the autotrophs (= primary producers) in a community represents the energy available to the different trophic levels of consumers in the community. In a typical community, about what proportion of NPP is eaten by herbivores? Of the energy consumed what sources would represent “lost” energy and what would contribute to Net Herbivore Production (NHP)?

        b) In our discussion of the study of African elephants, about what proportions of the energy consumed by elephants are lost in waste products and in maintenance? About what proportion of the energy consumed is converted into new elephant biomass? How does this Net Secondary Production compare to that observed in typical insects? What are some possible reasons for the difference? Given that the same processes observed in the herbivore trophic level will occur at higher tropic levels, explain why the flow of energy through a food chain results in a Pyramid of Energy, leading to a Pyramid of Biomass in the “standing crop of organisms” at different trophic levels in a community (explain figs 55.10, 55.11, 55-12a; skip 55-12b, an unusual example of an inverse pyramid of biomass). (see class notes and Campbell pp. 1244-1246).

        c) How does the loss of energy at each tropic level affect the length of typical food chains in a community?

Explanation / Answer

Net primary productivity = Gross primary productivity – Respiratory loss.

Primary productivity depends on the plant species inhabiting a particular area, availability of nutrients and photosynthetic capacity of plants. This is available to herbivore level.

a. Gross Primary Productivity (GPP) : It is the rate of organic matter synthesized by producers per unit area per unit time.

b. Net Primary Productivity. It is the rate of organic matter built up or stored by producers in their bodies per unit time and area. Net productivity is equal to gross primary productivity minus loss due to respiration and other reasons.

NPP is the available biomass for the consumption to heterotrophs i.e. herbivores and decomposers.

b) Respiratory loss gradually increases in successive trophic levels. It is 20%, 30% and 60% respectively at producer, consumer and top carnivore level.

Standing State or Standing Quality: Amount of all the inorganic substances present in an ecosystem per unit area at a given time.
Standing Crop: Amount of living material present in different trophic levels at a given time. It is commonly expressed as the number of organisms per unit area.?

c) Due to coniteous loss of energy at each trophic level, the energy decreases at each trophic level of food chain, as part of the energy is lost as heat and major part of energy is liberated during respiration for use in various activities. as Only 10% of the energy of previous trophic level is received by next trophic level, as proposed by 10 per cent law of Lindeman (1942). Just to illustrate 1,000 calories of solar energy is needed to produce 10 calories of energy stored in a plant (if plants trap 1 % solar energy). Herbivores, feeding upon plant, will retain 1 cal of available stored energy and carnivores feeding upon them will gain only 0.1 cal of usable energy. Thats why Chain of Food chain is dependent on no. trophic level.

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