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

Biomass is a clean, renewable energy source. Its initial energy comes from the sun, and plants or algae biomass can regrow in a relatively short amount of time. Trees, crops, and municipal solid waste are consistently available and can be managed sustainably. We have seen here that biomass is a sustainable energy source that can easily replace the use of conventionally used fossil fuels while at the same time offering several positive environmental advantages. Wood wastes of all types make excellent biomass fuels and can be used in a wide variety of biomass technologies. Combustion of woody fuels to generate steam or electricity is a proven technology and is the most common biomass-to-energy process. Most electricity generated from biomass is produced by direct combustion. Biomass is burned in a boiler to produce high-pressure steam. This steam flows over a series of turbine blades, causing them to rotate. The rotation of the turbine drives a generator, producing electricity.Biomass is a clean, renewable energy source. Its initial energy comes from the sun, and plants or algae biomass can regrow in a relatively short amount of time. Trees, crops, and municipal solid waste are consistently available and can be managed sustainably. Biomass reflects the distribution of both energy and materials in the community. Plant biomass absorbs carbon dioxide during growth and emits it during combustion; therefore, it recycles atmospheric carbon. Due to this; biomass is capable of replacing fossil fuels. Organic materials which can be recycled like wood, agricultural wastes and municipal wastes serve as excellent sources to produce biomass fuel. The biomass can be burnt directly and later converted into methane and ethanol biofuels. In most ecosystems, the largest energy level and largest biomass can be found on the producer level. This occurs because producers obtain their energy from the sun, which is the most readily available resource and hence the most abundant at that level. Autotrophs, the producers in a food web, convert the sun's energy into biomass. Biomass decreases with each trophic level. There is always more biomass in lower trophic levels than in higher ones. Because biomass decreases with each trophic level, there are always more autotrophs than herbivores in a healthy food web. On average, only about 10% of the energy stored as biomass in one trophic level gets stored as biomass in the next trophic level. Put another way, net productivity usually drops by a factor of ten from one trophic level to the next.

Dear doctor

Energy Transfer in Ecosystems

Energy needs to be transferred through an ecosystem to support life at each trophic level.

ENCYCLOPEDIC ENTRY

"Living things need energy to grow, breathe, reproduce, and move. Energy cannot be created from nothing, so it must be transferred through the ecosystem. The primary source of energy for almost every ecosystem on Earth is the sun. Primary producers use energy from the sun to produce their own food in the form of glucose, and then primary producers are eaten by primary consumers who are in turn eaten by secondary consumers, and so on, so that energy flows from one trophic level, or level of the food chain, to the next. The easiest way to demonstrate this energy flow is with a food chain. Each link in the chain represents a new trophic level, and the arrows show energy being passed along the chain. At the bottom of a food chain is always the primary producer. In terrestrial ecosystems most primary producers are plants, and in marine ecosystems, most primary producers are phytoplankton. Both produce most the nutrients and energy needed to support the rest of the food chain in their respective ecosystems. All the biomass generated by primary producers is called gross primary productivity. Net primary productivity is what is left over after the primary producer has used the energy it needs for respiration. This is the portion that is available to be consumed by the primary consumers and passed up the food chain. In terrestrial ecosystems, primary productivity is highest in warm, wet places with plenty of sunlight, like tropical forest regions. In contrast, deserts have the lowest primary productivity. In marine ecosystems, primary productivity is highest in shallow, nutrient rich waters, such as coral reefs and algal beds.

To show the flow of energy through ecosystems, food chains are sometimes drawn as energy pyramids. Each step of the pyramid represents a different trophic level, starting with primary producers at the bottom. The width of each step represents the rate of energy flow through each trophic level. The steps get smaller further up the pyramid because some of that energy is changed to a form that cannot be consumed by organism at the next higher step in the food chain. This happens at every step of the pyramid.

Not all of the energy generated or consumed in one trophic level will be available to the organisms in the next higher trophic level. At each level, some of the biomass consumed is excreted as waste, some energy is changed to heat (and therefore unavailable for consumption) during respiration, and some plants and animals die without being eaten (meaning their biomass is not passed on to the next consumer). The waste and dead matter are broken down by decomposers and the nutrients are recycled into the soil to be taken up again by plants, but most of the energy is changed to heat during this process. On average, only about 10 percent of energy stored as biomass in a trophic level is passed from one level to the next. This is known as “the 10 percent rule” and it limits the number of trophic levels an ecosystem can support."

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

Biomass is a clean, renewable energy source. Its initial energy comes from the sun, and plants or algae biomass can regrow in a relatively short amount of time. Trees, crops, and municipal solid waste are consistently available and can be managed sustainably. Wood wastes of all types make excellent biomass fuels and can be used in a wide variety of biomass technologies. Combustion of woody fuels to generate steam or electricity is a proven technology and is the most common biomass-to-energy process. Due to this, biomass is capable of replacing fossil fuels. Organic materials which can be recycled like wood, agricultural wastes and municipal wastes serve as excellent sources to produce biomass fuel. The biomass can be burnt directly and later converted into methane and ethanol biofuels. The key features associated with biomass efficiency are its renewability and neutral CO2 impact. Moreover, biomass is the only truly renewable carbon source that provides energy storage unlike other sustainable energy forms, such as solar or wind whose energy is produced at the time and needs to be stored in batteries. In most ecosystems, the largest energy level and largest biomass can be found on the producer level. This occurs because producers obtain their energy from the sun, which is the most readily available resource and hence the most abundant at that level. Autotrophs, the producers in a food web, convert the sun's energy into biomass. Biomass decreases with each trophic level. There is always more biomass in lower trophic levels than in higher ones. Because biomass decreases with each trophic level, there are always more autotrophs than herbivores in a healthy food web. 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. With less energy at higher trophic levels, there are usually fewer organisms a s well . Organisms tend to be larger in size at higher trophic levels, but their smaller numbers result in less biomass. Biomass is the total mass of organisms at a trophic level.The bottom and largest level of the pyramid is the producers and contains the largest amount of energy. As you move up the pyramid, through the trophic levels to primary, secondary and tertiary consumers, the amount of energy decreases and the levels become smaller.