Terrestrial biomass

Estimates of terrestrial biomass vary considerably, ranging from 480 Pg C (Garrels et ah, 1973) to 1080 Pg C (Bazilevich et al., 1970). Bazilevich et al. attempted to estimate the magnitude of the biomass before mankind s perturbation of the ecosystems. The latest work that undoubtedly had the most data available estimates the total terrestrial biomass, valid as of 1970, as 560 Pg C (Olson et al, 1983). 

Terrestrial biomass is divided into a number of subreservoirs with different turnover times. Forests contain approximately 90% of all carbon in living matter on land but their NPP is only 60% of the total. About half of the primary production in forests yields twigs, leaves, shrubs, and herbs that only make up 10% of the biomass. Carbon in wood has a turnover time of the order of 50 years, whereas turnover times of carbon in leaves, flowers, fruits, and rootlets are less than a few years. When plant material becomes detached from the living, plant carbon is moved from the phytomass reservoir to litter. "Litter" can either refer to a layer of dead plant material on the soil or all plant materials not attached to a living plant. A litter layer can be a... 

Fig. 14-4 Schematic representation of the transport of P through the terrestrial system. The dominant processes indicated are (1) mechanical and chemical weathering of rocks, (2) incorporation of P into terrestrial biomass and its return to the soil system through decomposition, (3) exchange reactions between soil interstitial waters and soil particles, (4) cycling in freshwater lakes, and (5) transport through the estuaries to the oceans of both particulate and dissolved P.

According to recent studies, the forests covering about 30% of the earth s surface [1] contain 80% terrestrial biomass and provide habitat for about half of the world s known species of plants and animals [2]. Forests provide a wide range of ecological, economic, and social assets, as well as services such as climate regulation through the storage of carbon in complex physical,... 

Using our definition for alkalinity or ANC whereby any decrease (increase) in concentrations of base cations (e.g., K+, Ca2+, Fe2+, etc.) or any increase (decrease) in concentrations of "acid anions" (e.g., NO3, HPO2, SOf, etc.) is accompanied by a decrease (increase) in alkalinity. Thus, as illustrated in Fig. 5.17 net synthesis of terrestrial biomass (e.g., on the forest and forest floor, where more cations than anions are taken up by the plants (trees), is accompanied by a release of H+ to the environment. 

Terrestrial biomass is of course dependent on a non renewable resource - the soil - for mechanical support and the supply and transport of nutrients to the growing plant. The Canadian total land area of 996,6991000 ha has the following land classification (4). 

Such conversion of Ci into organics can occur either under natural conditions-that is, via the uptake of C02 from the atmosphere, where it reaches a concentration equal to 0.038% (v/v)-or under enhanced or industrial conditions, that are much different from natural conditions. Typical examples of the enhanced biological fixation are (i) the cultivation of terrestrial biomass (ornamental plants, some vegetables) in greenhouses under a C02 concentration in the gas phase of approximately 600 ppm and (ii) the farming of aquatic biomass by dissolving C02 in water or under a gas-phase concentration up to 5-10%-that is, 130- to 260-fold the natural concentration. 

The natural carbon cycle is represented schematically in Figure 13.1. The total amount of carbon cycled per year ranges around 200 Gtc, including fixation into the terrestrial biomass (of any type), and in the watery environments. 

The terrestrial biomass has been used as source of energy since man lit the first fire on Earth. The direct combustion of any form of biomass is not the best process... 

Historic Terrestrial Biomass Contemporary Biomass Historic Soil Carbon Contemporary Soil Carbon Net Carbon Flux From Land Biosphere Since 1800 Gross Annual Terrestrial Plant CO2 Uptake Net Primary Production Annual Tropical Forest Area Conversion (1970-1980) Annual Net Carbon Flux From Land Conversion (1970-1980)... 

The simplest path to this target is presumably indirect, but close at hand. The most effective and cost-free CO2 collector is Mother Nature herself, and she is also the most massive sink for carbon. A rough estimate of the terrestrial biomass production (not including the contributions of oceans) amounts to 120 Gt/year as dry matter, these are approximately 60 Gt bound carbon or 220 Gt sequestered CO2 per year [1, 2], The natural CO2 cycle is therefore still one order of magnitude larger than the anthropogenic one, except that nature has been in equilibrium for hundreds of millions of years. This perpetuated binding and liberation of CO2 can indeed serve as the role model for future chemistry. 

T° temperature q runoff d distance to ocean QH Quaternary history V terrestrial biomass t water residence time T volcanism, tectonic uplift and rifting. 

Typical organic components in representative, mature biomass species are shown in Table 3.9 along with the corresponding ash contents. With few exceptions, the order of abundance of the major organic components in whole-plant samples of terrestrial biomass is celluloses, hemicelluloses, lignins, and proteins. Aquatic biomass does not appear to follow this trend. The cellulosic components are often much lower in concentration than the hemicelluloses as illustrated by the data for water hyacinth. Other carbohydrates and derivatives are dominant in species such as giant brown kelp to almost complete exclusion of the celluloses. The hemicelluloses and lignins have not been found in this species. 

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