The area on both sides of the Greater Xingan Mountain is crucial region for the Filifolium sibiricum steppe. On the basis of our survey in this district the flora compositions, the ecological groups, the synusiae, the above ground biomass and spatial pattern etc. have been compared and analysed. According to the opinion of the authors, the diversity of the communities of Filifolium sibiricum steppe on both sides of the Greater Xingan Mountain reflects concretly the syngenetic characteristics of this type of steppe and it should be taken into consideration for regionalism of vegetation.

Since the Tertiary period, Quercus liaotungensis which were affected several times by cold, warm, dry and wet climatic variations, has displayed eurytopic characteristic in climate, it is the basis on which was formed the modern distribution range. This type of forest may occur as zonal vegetation in loess district near steppe zone or vegetation of vertical zone on Qinling mountain. The Quercus liaotungensis forests of Qinling are more complex than that of loess district in the floristic component, stratification and structure of synusia as well as ecological type etc. From now on, Quercus liaotungensis forests in present area on Qinling mountains and loess plateau are still one of the stablest plant communities.

Bracken young shoots oil Ha mpsfell in England appeared above ground in the middle or end of April and grew rapidly in the first two months. The maximum height of fronds was reached in September and the peak weight of fronds appeared in August.The peak biomass of bracken aerial part on Hampsfell averaged 792g.m-2 in August and then declined. The bracken aerial part died in November. The seasonal variation of bracken below ground biomass was not marked but the below ground biomass more or less increased with the growth of aerial part. The depth of soil was the most important factor influenced on the bracken biomass of Hampsfell. The primary production of bracken ecosystem averaged 778g.m-2yr-1, with maximum yield of 918g.m-2yr-1 on deep soil and minimum yield of 525g.m-2yr-1 on shallow soil.

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The biocycling of nitrogen and mineral elements of wheat, barley, maize, Sorghum and peanut grown on the calcareous cinnamon soil in Beijing was studied. The results are shown as follows:

1. Analysis shows great differences in the amount of different elements in various crops. It is characteristic that peanut, the legume crop, absorbs large amounts of calcium and magnesium, while grass crops absorb higher amounts of silicon, iron, aluminium, manganese and sodium. The sorghum takes higher amounts of nitrogen, phosphorus, potassium, calcium, magnesium and silicon, and the barley absorbs higher amounts of sodium, manganese and sulfur.

2. Eleven elements returned to soil by roots and stubbles may be grouped into three types:

( 1 ) Type of low returning includes nitrogen, phosphorus and potassium, the ratio of returning is generally lower than 10%.

( 2 ) Type of moderate returning includes magnesium, calcium, sulfur, silicon, sodium and mineral, the ratio of returning is between 10% to 30%.

( 3 ) Type of high returning includes iron, aluminium and manganese, and their ratio of returning is generally higher than 30%.

3. The features of biocycling of different crops has important significance for studying element balances of farm ecosystems, change of fertility in cultivated soils and its forming processes, fertilization and cropping system.

Due to discover the characteristics of the translocation, distribution of heavy metal cadmium in soil-plant system and its effect on plant growth and development, the influence of cadmium applied to soil on crops was studied under simulated pot-culture.The results demonstrated that amending with various chemical form of cadmium to soil (a loamy-sand drab soil, pH8.2),the amounts of Cd uptaked by rice (Oryza sativa L.) showed following pattern: CdCl2>CdSO4>CdO>CdS>CdCO3 and chinese cabbage (Brassica pekinensis Rugr) followed the pattern of CdSO4>CdCl2>CdO>CdCO3. Under the treatment of cadmium concentrations (added as CdCl2, on the basis of Cd ), the critical concentrations of cadmium in soil while cadmium concentration was 0.4 ppm in crops and 0.2 ppm in vegetables for various crops was

"Grass-Slope" is a secondary vegetation widely distributed Guangdong Province, China.As for the utilization and reconstruction of grass-slope, first of all we must restore it into forest vegetation.It is rather easy to reconstruct the grass-slope into Masson’s pine forest, not only because there are Masson’s pines sparsely lived but also because the tendency of plant succession. In addition, we may try to plant bamboo (Phyllostachys edulis) and Cunninghamia lanceolata.The utilization and reconstruction of grass-slope is significant to develop agricultural economy of mountainous regions. It is important to make regional planning. Also, we must pay attention to introduce the best forage crops for the development of domestic animals. In regions of lower altitude we may plant fruit trees and economic trees as much as possible, for example, Litchi chinensis, Canarium pimela, Castanea mollissima, Diospyros kaki, Camellia oleifera and Aleurites fordii etc.