Biomass, above-ground

The results from the survey of 13 forested tesserae in the LU1 of Mori-Talpina are shown in table 5, where pB measure the plant biomass above ground BTC is the biological territorial capacity of vegetation (Mcal/mVyear) Q represent the four ecological qualities of the tessera (Ect = ecocenotope, LU = landscape unit, Ts = tessera, pB = plant biomass, B = % of coniferous species, BTC maturity threshold, 85% of the model curve). 

Value after (7) total biomass density calculated by multiplying above ground estimate by 1.23. 

The difference in the distribution and amount of organic matter in the soils developed under prairie vegetation and forest vegetation can be explained in part by its mode of addition to the soil. Under prairie vegetation, more than 50 percent of the biomass is added to the soil annually - almost all the above ground parts and at least 30 percent of the underground parts. 

The DEF was primarily dominated by Hopea ferrea and Shorea spp. that formed the upper story 20-40 m above ground. A typical DEF fosters more than 1,000 trees (trunk diameter at breast height, DBH >5 cm) ha-1, and the total basal area at 1.3 m height exceeded 30 m2 ha-1 and the above ground biomass was over 200 tons ha-1 (Kanzaki et al. 1995). 

The DDF was more open in comparison with the DEF and had uniformly spaced trees. The upper story, 11-35 m above ground, was formed by canopies of Shorea obtusa, Pentamo suavis, Dipterocarpus intricatus, Gardenia spp. and others. In the DDF, 875 trees (DBH>5 cm) ha-1 were enumerated, and the total basal area at 1.3 m height was 15 m2ha-1 and the above ground biomass was 73 tons ha-1 (Sahunalu and Dhanmanonda... 

SHOAL GRASS, Halodule wrightii 10, 40, or 120 pg/L for 22 days 420 pg/L for 22 days 1490 pg/L for 22 days Enhanced growth when compared to controls (Mitchell 1985) Above-ground biomass reduced 26% (Mitchell 1985) Above-ground biomass reduced 45% compared to controls (Mitchell 1985)... 

Fig. 8.4 Relationship between root to shoot ratio and the amount of above-ground biomass that can be harvested and still maintain the SOC level at the current level...

Below-ground biomass is typically estimated from the root to shoot ratio (Johnson et al. 2006 Bolinder et al. 2007). Extreme care must be used when using published root to shoot ratios because different scientists define root to shoot ratios differently. For example, Johnson et al. (2006) defined root to shoot ratios for com (Zea mays) as the ratio between root biomass and total above-ground biomass (grain, stover, and cob), whereas Amos and Walters (2006) defined this value as the ratio between root biomass and com stover. In addition, a standardized root to shoot ratio has not been used in maintenance calculations. For example, Barber (1978) used a value of 0.17 for com, Huggins et al. (1998) used a value of 0.53, and Larson et al. (1972) did not consider roots. 

Sensitivity analysis showed that the amount of com stover that could be harvested increased with root to shoot ratio (Fig. 8.4). If roots were not considered in the NHC value, then the estimated amount of above-ground biomass that could be safely harvested was about 35%, whereas if the root to shoot ratio was 1.00 then 70% of the above-ground biomass could be harvested. These findings are attributed to a relative increase in importance of the below-ground biomass. Based on these calculations, underestimating the root to shoot ratio will result in underestimating com stover removal rates, which, while having a positive influence on future... 

Allmaras et al. (2004) developed a C-budgeting approach based on combining experimental and isotopic techniques. The data needed to use calculations derived by Allmaras et al. (2004) required that the experiment contain com stover harvested and removed treatments. These calculations assume that the removal of above-ground biomass will not influence the sequestering of below-ground biomass. The SOC derived from com stover (sSOC) is calculated with the equation ... 

Carbon turnover in production fields can be determined, using non-isotopic techniques, by combining historical soil samples, current soil samples, and whole field yield monitor data. Sensitivity analysis of such data shows that the amount of above-ground biomass that could be harvested decreases with root to shoot ratio (Table 8.1). For example, if root biomass is ignored, analysis suggests that only 20-30% of the above-ground biomass can be harvested, whereas if the root to shoot ratio is 1.0, then between 40% and 70% of the residue could be harvested. 

In soils of non-agricultural ecosystems, above ground biomass (foliar uptake) and metal cycling is considered important (see Figure 8), due to large impact on the metal distribution in the humus layer and mineral soil profile. Especially in soils of Forest ecosystems, it may affect the accumulation in the humus layer, which is considered a very relevant compartment regarding the calculation of a critical load. In these soils, however, a steady-state element cycle is assumed, which implies that mineralization, Minj, equals litterfall, Mjf. 

In soils of agroecosystems, above ground biomass (foliar) uptake and metal cycling by mineralization and total root uptake can be lumped into a net removal term due to harvest (indicated as growth uptake, Mgu) when the critical load is calculated for the root zone, e.g., for upper 20-30 cm. In this situation we can calculate root uptake as a function of the growth uptake, whereas the net effect of litterfall and foliar uptake is assumed to be negligible. 

Table 1.3 The distribution of above-ground woody biomass by region (FAO, 2001)...

Enhanced growth when compared to controls (Mitchell 1985) Above-ground biomass reduced 26% (Mitchell 1985)... 

Figure 7. DMSP inventory in S. altemiflora and above-ground biomass at four S. altemiflora sites in Great Marsh, Lewes, Delaware, in June, 1986. Most above ground DMSP is concentrated in live leaves although stems and dead leaves represent the majority of above-ground biomass at this time. Roots have less DMSP per unit biomass but may represent a larger pool on an aerial basis. Below-ground DMSP is less likely, however, to play a role in DMS emission as discussed by Dacey et al. (19).

Herbivory in benthic marine systems is intense. For example, on coral reefs, herbivores can remove almost 100% of the biomass produced daily by marine macroalgae, whereas in the most intensely grazed terrestrial systems — African grasslands — herbivores only consume about 66% of the above-ground plant biomass.9-21-102 While terrestrial plants produce subterranean structures such as roots, bulbs, and tubers that are generally inaccessible to most animals, most marine algae do not... 

Uptake of B is species dependent. Greenhouse pot experiments were conducted to study B uptake by different plant species, Brassica juncea (L.) Czern (wild brown mustard), Festuca arundinacea Schreb. L. (tall fescue), and Brassica napus (canola) (Banuelos et al., 1993). Results showed that the greatest total amount of above ground biomass and below surface biomass was produced by tall fescue and the highest concentrations of tissue B were from roots of tall fescue. A correlation for B and Ca has been reported by Dixon et al. (1973), where B sprays have been shown to increase Ca transport into apples ( Malus spp.). 

Buchmann, N., Gebauer, G. Schulze, E.-D. (1996). Partioning of N-labeled ammonium and nitrate among soil, litter, below- and above-ground biomass of trees and understory in a 15-year-old Picea ahies plantation. Biogeochemistry, 33, 1-23. 

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