For all seagrass species, the above-ground component (shoots and leaves) possessed greater total nitrogen than the below-ground component (roots and rhizomes), which possessed greater total starch.
Sample trees were then felled at ground level, and the above-ground component was removed off-site for partitioning into foliage, branch and stem and then dried and weighed.
The mean carbon concentrations in above-ground components for all of the ecosystems under evaluation are presented in Fig. 1.
In general, maximum nutrients (N, P and K) were allocated to above-ground components (leaves > stem > branches) than below-ground components.
However, the partitioning of biomass to above-ground components is often contradictory between studies (Snowdon and Benson, 1992; Watt et al. 2003).
Most of this turnover is the mortality of fine roots of living trees, same as the litterfall of above-ground components.
After this time, all living broom seedlings from each treatment pot were cut at the base of their stems and the above-ground components were oven dried at 80°C to a constant mass then weighed.
The potential for sequestering carbon in above-ground components of agroforestry systems is estimated to be 2.1 χ 10 9 MgC yr-1 in tropical and 1.9 χ 10 9 MgC yr-1 in temperate biomes (Oelbermann et al., 2004).
As expected, above-ground biomass component weights were influenced by treatment (P < 0.001).
Total above-ground and component biomasses were determined by destructively harvesting 48 trees at the end of the experiment (12 trees per treatment).
Because fpgs1 mutants had no dramatic defects in above ground biomass, selective down-regulation of individual components of C1 metabolism is an approach that should be explored further for the improvement of lignocellulosic feedstocks.
