Biomass, carbon content, carbon storage and spatial distribution in the 32-year-old
To reveal the relationship between species diversity and biomass in a eucalyptus (
We studied the biomass and its allocation in natural secondary forests, as well as the amounts, accumulation and distribution of nutrient elements (N, P, K, Ca and Mg) in sample plots established in the Loess Plateau in Shanxi Province, northern China. The results show that biomass in natural secondary forests amounted to 36.09 t/hm2, of which the tree layer accounted for 46%, the shrub layer for 29%, the herb layer for 13% and the litter layer for 12%. The total storage of the five nutrient elements is 1089.82 kg/hm2. Nutrient storage in the tree layer is the largest, at 41%. The sequence of storage of the elements varied among different layers and is given as follows: shrub layer 31.27%, herb layer 12.55% and litter layer 15.36%. The accumulation of nutrient elements in the tree layer, ordered from high to low, is: branches > roots > stems > bark > leaves. The total storage of the five nutrient elements in the soil is 634.97 t/hm2, where the accumulation of the nutrients accounts for 95.32% (N), 99.64% (P), 99.91% (K), 99.84% (Ca) and 99.95% (Mg) of the total amounts. The accumulation coefficients of different organs in the tree layer are, from high to low: leaves > branches > roots > bark > stems. The accumulation coefficients in the different layers are listed as follows: shrub layer > tree layer > herb layer and for the elements as: N > P > Ca > K > Mg.
In order to provide a basis for water conservation in the restoration of vegetation for an urban water resource area, we studied the generation of runoff characteristics in four typical forests over three time periods in Jinyun Mountain, Chongqing City, based on the observation data of rainfall and runoff processes during the period 2002-2005. The results show that: 1) Rainfall was distributed evenly during the years 2002-2005. Annual rainfall variability was 4.46% and coefficient of variation was 0.0618. Average monthly rainfall tended towards a normal distribution
The effects of site conditions and cultivation on the growth of sawtooth oak (
Using the PMS pressure chamber and isotope mass spectrometer (MAT-252), the leaf juice of
We studied ion distribution in roots and the growth of
Tetraploid
To explore theeffects of plant hormones levels excreted by ectomycorrhizal (ECM) fungi on the growth of poplars,
The improvement of wood surface wettability can clearly improve bonding properties, as well as enhance physical and mechanical properties of wood composites. In our investigation, the microwave plasma (MWP) technique was adopted to treat the surface of common teak. The treatment effect was evaluated by measuring the contact angles of liquids and calculating the free surface energy. The results show that the modification effect improved when the sample was located 120 mm from the resonance cavity, rather than at 80 mm. A MWP treatment over a short span of time is useful to lower the contact angles and improve the surface wettability considerably. The range of decreasing contact angles, tested by water, could reach 74% at a distance of 120 mm.