The results indicated that the forest damaged by coal exploitation was 133.68 km2. The Hg arid Cd content of soil in coal exploitation area were 3.26 and 2.73 times respectively as much as those of soil mean content in Shanxi.
It shows remarkable growth which is expressed by 2 cm of annual average diameter growth and 1.5 m of annual average height growth under the favorable conditions of deep and soft soil,sufficient water and fertilizer.
The nutrient concentrations,microbe and enzyme and their spatial distribution were analyzed for different types in Dongying county of Shandong province in silting coastal area,the main results indicated: ①soil microbes,enzyme and nutrient distribute mainly in 0~20 cm of soil layer,and less in 20~50 cm.
The average bulk density, total porosity, capillary porosity and non-capillary porosity in 0—100 cm soil layer were 1.41 g·cm-3, 52.31%, 46.11% and 6.20% under broadleaved Korean pine forest, and 0.98 g·cm-3, 50.65%, 40.32%, 10.33% under dark coniferous forest, respectively.
An antibiotic producing strain Streptomyces violaceusniger was isolated from soil sample, characterized and studied for antibacterial and antifungal activity profile.
These points can be estimated by introducing the soil factor (Ks) and tree species factor (Kt) to potential evapotranspiration with the Penman formula.
Root biomass, length, and the number of roots in every diameter class, for each soil layer and for each plant species, are regarded as observation variables.
The results show that most of the vertical distributions of plant roots belong to the type wherein the roots are concentrated in the topsoil layer (0-20 cm), far more than those in the lower soil layers.
1、The most important point of reforestation in the saline and alkaline soil dis- trict is, first of all, to understand the conditions of the habitat form of planting area. In accordance with the different conditions of habitat form, the principle of right species in tbe right site and the rational composition of plantation, the plant percent is promoted. 2、Based upon the conditions of climate, topography and soil, such three main factors as the amount of salt in soil, the water level of #...
1、The constitution of the quick-growing and good harvest forest of Populus canadensis consists of the form of planting composition and planting distance. It de- termines the nursing and leaves' space, large or small, of forest tree, hence it in- fluences the amount of out-pat aud quality of timbers. There are differeut opinions to the proper constitution. To study it is very important. 2、In foreign countries the constitution of poplar forest is quite different. The form of planting is sometimes square or r...
1、The most important point of reforestation in the saline and alkaline soil dis- trict is,first of all,to understand the conditions of the habitat form of planting area.In accordance with the different conditions of habitat form,the principle of right species in the right site and the rational composition of plantation,the plant percent is promoted. 2、BaSed upon the conditions of climate,topography and soil,such three main factors as the amount of salt in soil,the water level of soil...