What is common to earthworm, mushroom, soil mites and dung beetle in an ecosystem.
They all are designated as primary consumer in a detritus food chain and are termed as detritivores.
Organisms at a higher trophic level have less energy available. Comment.
Energy flow in the ecosystem follows the 10\% energy flow law, proposed by Lindman. According to this law only $10 \%$ of the energy available at each trophic level, gets transferred to the next trophic level, the rest is lost in the environment as heat.
As we move to higher trophic levels, the energy available to organisms keeps on decreasing. Thus, the top carnivore gains the lesst energy in a food chain. Heat energy last during Respiration.
$$ \text { 10% energy flow low showing transfer of energy from one trophic level to others } $$
The number of trophic levels in an ecosystem are limited. Comment.
The number of trophic level in an ecosystem are each limited and are not more than 4-5. because the amount of energy flow decreases with successive trophic level as only $10 \%$ of energy is transferred from one trophic level to the next successive level.
So rest of the energy is lost in the form of respiration and other vital activities to maintain life. If more trophic levels are present, the residual energy will be limited and decreases to such an extent that it cannot further support any trophic level by the flow of energy.
So, the food chain is generally limited to $3-4$ trophic levels only.
$$ \text { e.g., } \quad \underset{(30,000 \mathrm{~J})}{\text { Sun }} \xrightarrow{1 \% \text { asborbed }} \underset{(300 \mathrm{~J})}{\text { Plants }} \xrightarrow{10 \% \text { transferred }} \underset{(30 \mathrm{~J})}{\text { Deer }} \xrightarrow{10 \% \text { transferred }} \underset{(3 \mathrm{~J})}{\text { Tiger }} $$
Is an aquarium a complete ecosystem?
Aquarium is a man made ecosystem (artificial). If an ecosystem possess all physical and biological component, then it is said to be complete. Since aquarium has biotic (plants and fishes) and abiotic component (air, water) required for survival of fishes, so it is an complete ecosystem.
What could be the reason for the faster rate of decomposition in the tropics?
Tropics are characterised by high temperature and moisture and soil is rich in humus and minerals. As the decomposition rate is regulated by climatic factors, thus optinum temperature and humidity enhance the activity of decomposrs while the dead remain is also available in rich amount, which supports the faster rate of decomposition in the tropics.