Dr Rana Hamza Shakil thank you for your contribution to the discussion

Biomass is the mass of living biological organisms in a given area or ecosystem at a given time. In an ecosystem, the rate of generation of biomass is called biomass productivity. Forest Ecosystem has the highest biomass as it includes organism of all tropic level as compared to other ecosystems. The greatest biomass amount is found at the base trophic level that includes the producers. Since the primary consumers rely on producers for sustenance, the biomass amount of the producers would, therefore, be a limiting factor to the biomass of the primary consumers. Biomass has been in use since people first began burning wood to cook food and keep warm. Wood is still the largest biomass energy resource today. Measurements show that tropical rainforests typically have biomass values on the order of 400 to 700 metric tons per hectare, greater than most temperate forests and substantially more than other vegetation with fewer or no trees. In terrestrial ecosystems tropical rain-forests show the highest productivity. In aquatic ecosystems, coral reefs have the highest productivity. The biomass is maximum in a forest ecosystem because of their size and longevity of trees. Forest ecosystem has formed the most massive and complex ecosystems of the earth.The highest net primary productivity in terrestrial environments occurs in swamps and marshes and tropical rainforests; the lowest occurs in deserts. We find that the biomass of plants dominates the biomass of the biosphere and is mostly located on land. The marine environment is primarily occupied by microbes, mainly bacteria and protists, which account for ≈70% of the total marine biomass. The remaining ≈30% is mainly composed of arthropods and fish. Wetlands are among the most productive ecosystems in the world, comparable to rain forests and coral reefs. The most productive ecosystems are fertile estuaries and marshes, coral reefs, terrestrial vegetation on moist alluvial deposits, and intensive agriculture, which can have productivities of 10-25 × 103 kcal/m2/yr. Within all biological communities, energy at each trophic level is lost in the form of heat (as much as 80 to 90 percent), as organisms expend energy for metabolic processes such as staying warm and digesting food (see biosphere: The organism and the environment: Resources of the biosphere. Trophic level is defined as the position of an organism in the food chain, and ranges from a value of 1 for primary producers up to a level of 5 for marine mammals and humans value that ranges from 1 to 5. Environment marine trophic index provides a measure of ecosystem integrity. There is no complete transfer of energy from one trophic level to the next. Therefore there is loss of energy in the form of heat from one trophic level to the next trophic level.

Dear doctor

Go To

Trophic level determinants of biomass accumulation in marine ecosystems

• July 2012
• Marine Ecology Progress Series 459:185-201
• Follow journal
• DOI: 10.3354/meps09738

Pranovi et al. (2012)

"Metrics representative of key ecosystem processes are required for monitoring and understanding system dynamics, as a function of ecosystem-based fisheries management (EBFM). Useful properties of such indicators should include the ability to capture the range of variation in ecosystem responses to a range of pressures, including anthropogenic (e.g. exploitation pressures) and environmental (e.g. climate pressures), as well as indirect effects (e.g. those related to food web processes). Examining modifications in ecological processes induced by structural changes, however, requires caution because of the inherent uncertainty, long feedback times, and highly nonlinear ecosystem responses to external perturbations. Yet trophodynamic indicators are able to capture important changes in marine ecosystem function as community structures have been altered. One promising family of such metrics explores the changing biomass accumulation in the middle trophic levels (TLs) of marine ecosystems. Here we compared cumulative biomass curves across TLs for a range of northern hemisphere temperate and boreal ecosystems. Our results confirm that sigmoidal patterns are consistent across different ecosystems and, on a broad scale, can be used to detect factors that most influence shifts in the cumulative biomass−TL curves. We conclude that the sigmoidal relationship of biomass accumulation curves over TLs could be another possible indicator useful for the implementation of EBFM."

Dr Sundus F Hantoosh thank you for your contribution to the discussion

Biomass is the mass of living biological organisms in a given area or ecosystem at a given time. In an ecosystem, the rate of generation of biomass is called biomass productivity. Forest Ecosystem has the highest biomass as it includes organism of all tropic level as compared to other ecosystems. In terrestrial ecosystems Tropical rain-forests show the highest productivity. In aquatic ecosystems, coral reefs have the highest productivity. The trophic level that contains the greatest biomass in most ecosystems is the producers. Producers are organisms that are able to make their own food from sunlight or chemicals. Biomass productivity is determined by dividing the biomass per unit area by the age of the forest ecosystem. Biomass productivity of plantations can be determined accurately but the biomass productivity of uneven or all age stands are estimates of questionable value because of the age variation encountered.The greatest biomass amount is found at the base trophic level that includes the producers. Since the primary consumers rely on producers for sustenance, the biomass amount of the producers would, therefore, be a limiting factor to the biomass of the primary consumers. Fungi are the group of microorganisms that have the highest biomass in the soil. The maximum limit is up to 790 μg C/g soil and it is found in the soil with surface organic horizons in the form of thin moss/lichen litters, in which the development of fungal mycelium is most active. The tropical rainforest is a luxuriant forest found in wet tropical uplands and lowlands around the Equator. These forests are dominated by broad-leaved trees that form a dense upper canopy (layer of foliage) and contain a diverse array of vegetation and other life. Forest Ecosystem it has the highest primary productivity. Primary productivity is defined as the amount of energy stored at the producer level. Then comes secondary productivity which is the energy reserved at the secondary level. Tertiary productivity is consumer-level productivity. Within all biological communities, energy at each trophic level is lost in the form of heat as organisms expend energy for metabolic processes such as staying warm and digesting food: The organism and the environment and resources of the biosphere and the flow of energy. There is no complete transfer of energy from one trophic level to the next. Therefore there is loss of energy in the form of heat from one trophic level to the next trophic level. Only about 10% of the energy is transferred from one trophic level to another. The rest is used for life processes of the organism and some is lost as heat. Living organisms cannot convert heat to other forms of energy. Heat is lost from ecosystems. Energy losses between trophic levels restrict the length of food chains and the biomass of higher trophic levels. The amount of energy transferred from a lower trophic level to a higher trophic level always decreases as energy is lost at each step as heat. Only 10 percent of energy is transferred from one trophic level to the next.