Biodiversity is the measure of diversity of all organisms at any place and all living things are comprised of biomass. Thus, understanding the role of biomass in ecosystem management is critical. It has been stated that, “biomass is the thread that connects all of life and biodiversity represents its strength and pattern”. While biodiversity reflects the history of life in any ecosystem, biomass needs to be looked at in terms of the living capital of any ecosystem. When considering biomass, it is useful to separate it into three categories each reflecting the role it plays in the ecosystem, Photosynthetic Biomass, Respiring Biomass and Inert Biomass
Photosynthetic Biomass
Photosynthetic biomass is that part of the global stock that contains chlorophyll and performs the act of primary production or ecosystem initiation.
The act of capturing the energy of the sun to power the biological processes on the planet, is termed primary productivity. Photosynthetic biomass can be represented as a simple algal cell containing chlorophyll or a complex leaf structure with chlorophyll bearing cells within the matrix. The photosynthetic biomass of cells in a liquid medium being the most efficient because they have little respiration costs to maintain structures. The reason why oceanic phytoplankton, has a greater production of Oxygen than forests on land, no high respiration costs. The complex structures of a leaf and plant organs have a much higher respiration cost. However, the ecosystem services of a functioning leaf is much greater.
Two examples of the ecosystem services generated by the leaves are ; transpirative cooling and water cleansing. These services are created by the movement of water through a plant and out of its leaves into the atmosphere. When plants release water into the atmosphere from their leaves via transpiration, the surrounding air is cooled as water goes from liquid to a vapor. Studies on cooling by trees suggest that a single tree transpiring a hundred litres of water a day has a cooling power equivalent to two household air-conditioning units. This is accomplished by water moving into the tree’s roots from the soil and traveling through the tree’s water-conducting system, to eventually be transpired from the leaves as gas vapor, which has a cooling effect on the surrounding air.
The movement of water from the soil into the plant has another consequence. Plants use water through the process of osmosis where only water molecules are admitted into the root. Thus, water entering the plant and transpired from the leaves is clean, free of any contaminants in the soil. This water cleaning aspect of leaf transpiration has been largely ignored and needs to be addressed as an Ecosystem Service.The amount of water released via transpiration can be incredibly high; a single irrigated corn plant growing in Kansas can use 200 L of water during a typical summer, while some large rainforest trees can use nearly 1200 L of water in a single day.
This means that the photosynthetic biomass on land, is responsible for filtering and cleaning polluted groundwater, to return it as pure water in rain.
Respiring Biomass
Plants use the energy gathered by photosynthesis to grow and maintain their physical structures through the process of respiration, where glucose is oxidized to form carbon dioxide and water with the release of energy.
Respiration occurs in two ways, as aerobic respiration (a process that uses oxygen) and anaerobic respiration (a process that doesn’t use oxygen). All biomass that is not photosynthetic and is participating in the process of life is respiring biomass, Thus the life activity of plant growth, animals and microorganisms are all considered respiring biomass.
Respiration is a key factor in accounting for net – primary productivity of a given plant or land area but respiration is not linearly related, either to photosynthesis or to biomass, but it is more strongly controlled by recent photosynthates (and reserve availability) than by total biomass.
Inert Biomass
Inert biomass is that portion of biomass that does not actively participate in electron transfer between molecules and are composed of extra cellular polymeric substances (EPS), A wide range of microorganisms produce EPS, a mix of highly hydrated polymers that are mainly comprised of polysaccharides, proteins and DNA. Inert biomass is commonly seen in anoxic, wet ecosystems such as peat bogs and forms the major part of the long-lived fraction of Soil Organic Matter (SOM) of undisturbed forests and other mature ecosystems.
Biomass is the component of every ecosystem that signifies the action of life on any environmental substrate. The quantity of which is measured by weight and can be presented as a ratio between it’s three fractions. Biodiversity or the measure of variability of life at any geographical point represents the patterns wrought in biomass over time. Stated another way, ‘Biomass is the thread that connects all life, Biodiversity indicates the condition of that thread, its pattern and its strength’. Therefore, the relation between biodiversity and biomass is a useful measure of the state of the ecosystem and its sustainability. Thus a Biomass to Biodiversity ratio (B:B) as a measure to evaluate the state of an ecosystem, could become an analytical tool by which to gauge the progress of restoration efforts in the future.