Living biomass

Fig. 3-9 Trophic levels in ecosystems. Thin arrows show flow of energy up the food chain (through living biomass) and the broad arrows show the complementary flow of dead organic matter (detritus) back down. R indicates respiration.

Biosorption is a general phenomenon that can occur in either dead or living biomass. However, this process usually refers to a passive uptake mechanism carried out by nonviable microorganisms (dead yeasts). The biosorption process involves physical-chemical interactions between the yeast surface and the azo dyes, as well as possible passive diffusion inside dead cells. 

The biomass of Tundra ecosystems gradually increases from 4-7 ton/ha for moss-lichen tundra to 28-29 ton/ha by dry weight for low-bush tundra. In the northern tundra, the plant biomass and dead organic matter are eventually shared. Southwards this percentage tends to diminish, and low-bush living biomass is smaller than dead plant remains mass. A typical feature of the Tundra ecosystems plant species is the prevalence of underground matter (roots) up to 70-80% of the total biomass. 

We can see that the tree vegetation absorbs annually from soil tens of grams per hectare of Zn and Ba, units of grams of Ni, V, and Co. The absorption of trace metals by low bush species is smaller by an order of magnitude. Simultaneously, a similar amount of metals is released from the living biomass of the Spruce Forest ecosystems. 

Biosorption or bioaccumulation, the process of passive cations binding by dead or living biomass, represents a potentially consecutive way of removing toxic metals from industrial wastewaters. Biosorption could be employed most effectively in a concentration range below 100 mg L 1, where other techniques are inactive or too expensive. 

Disturbance may influence the allelochemlcal environment in various ways. Living biomass is reduced, and fire reduces or eliminates litter and humus layers as well. Hence we should expect the total production of allelochemlcals to be lowered following disturbance. As succession proceeds and total biomass and litter layers rebuild. 

Petsch, S. T., T. I. Eglinton, and K. J. Edwards. 2001. 14C-dead living biomass Evidence for microbial assimilation of ancient organic carbon during shale weathering. Science 292 1127-1131. 

Carbon reserves in the World Ocean surface 100 m layer 45 GtC carbon of living biomass 2 GtC photosynthesis 50 GtC/yr... 

Let RK(photosynthesis production for vegetation of type n at latitude [Pg.194]

Structural changes to the land cover are not exclusively due to human activity. In some regions of the globe, hurricanes introduce considerable changes in the carbon balance of forest ecosystems. For example, in the U.S.A. two hurricanes happen on average every three years, which accelerates the transition of the living biomass of... 

H20 = p 6M , where RD is the rate at which dead organic matter decomposes Rwo is precipitation over the ocean R is the production of phytoplankton and other living organisms in the ocean M is the rate at which living biomasses die off and pi (i = 8-16) are proportion constants. 

Beek and Frissel (1973) Growth of nitrifier and ammonifer bacteria by Michaelis-Menten kinetics NH4 oxidation by first-order kinetics with environmental variables mineralization of proteins, sugars, cellulose, lignin, and living biomass by first-order kinetics immobilization by first-order kinetics including considerations for microbial biomass and C/N ratio NH3 volatilization by diffusion NH4 clay fixation by equilibrium model. 

The terrestrial living biomass is about 200 times larger than the marine biomass, although it turns over at a rate that is 140 times slower than the oceanic rate. Notice that for both the land and ocean reservoirs the dead organic carbon masses are greater than the living. The former represent, if oxidized, large sources of CO2 for the atmosphere. 

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