The method for reconstructing the disturbance history of Pinus koraiensis mixed forest is developed in this paper basing on the information of release from the data of growth ring collected from more than 300 individual trees. The result indicates that it is a reliable and accurate method for reconstructing disturbance history of forest; such as Pinus koraiensis mixed forest with wind as a main factor of disturbance. Abies nephrolepis; Picea jezoensis and Pinus koraiensis are three useful tree species for analyzing the disturbance history in Pinus koraiensis mixed forest. The ratio of suppression trees in the stand is closely related to the disturbance. Each disturbance makes a large decrease of the ratio of suppression trees, and when no disturbance occurs for long time, the ratio of suppression trees will increase gradually.

Based on the detrended correspendence analysis (DCA), and environmental interpretation mathematical models and 136 subalpine dark coniferous forest (spruce and fir are dominant species community samples collested from Northwest Sichuan an South Gansu, the main vegetation types and ecological gradients, and their quantitative relations with environmental factors of the region are given. The data from 40 meteorological stations in this region are used to get the multivarite regression for estimating the climatic information of various Spruce and Fir forests according to the longitude, latitude and altitude of each sample plot- It is shown by the analysis that the vegetation types of spruce and Fir forest and their distribution are mainly determined by the thermal and moisture (including soil fertility) gradients. In moisture gradients, Moss-Abies, Moss-Picea, Rhododendron-Abies and Rhododendron-Picea forests are dominating moist habitat, Sinarundinar-Abies, Sinarundinar-Picea forest in mesotrophic habitat Quercus-Abies and Quercus-Picea are predominant in drier habitat. In thermal gradients, from warm to cold, the vegetation types are Shrub-Picea forest Betula forest--Deciduous broad-leaved forest—Quercus-Picea forest—Sinarundinar-Picea forest—Sinarundinar-Betula forest—Quercus-Abies forest—Moss-Betula forest—Moss-Picea forest—Sinarundinar-Abies forest—Moss-Picea-Abies forest--Moss-Abies forest—Calamagrostis-Picea forest—Rhododendron-Abies forest. The thermal demand of Picea is higher than that of Abies. The moisture demand of Picea-Abies forest in Northwest Sichuan is higher than that in South Gansu.The analysis of spatial distribution of plant communities, key environmental factors and environmental interpretation by mathematical models and are presented in this paper.

The morphological and anatomical features of Quercus Section Suber, the dominant species of the sclerophyllous evergreen broad leaved-forest, from different habitats were compared The results show that Quercus Section Suber possesses dual morphological characteristics of non-succulent xerophyte and alpine plants. This is believed to be the basis for them to be adapted to a wide range of environmental conditions. The size and density of the stomata, the shape and pattern of the anticlinal walls of the epidermal cells, and the thickness of leaves and cuticles were modified to a large extent by the ecological environment. On the contrary, the types of stomatal apparatus and the two layers of the adaxial epidermal cells are stable characteristics with important value for classification. Quercus ilex, which is mainly distributed in the Mediterranean basin has similar epidermal features to Quercus Sect. Suber.

The litter mass in Cryptocarya concinna, Lindera chunii community belonging to monsoon evergreen broad-leaf forest in the Dinghushan Biosphere Reserve was 12.16 and 6.58t·ha-1 yr-1, investigated from February 1989 to January 1990 and from June 1990 to May 1991. The litter mass not only varied in different months and years, but also varied in the same month of different years due to the influence of climatic fluctuations.The rate of litter decomposition was determined by natural decomposition method Ⅰ and Ⅱ. The results were 72.4 and 70.2%, respectively. There was no significant difference by t-test. The rate of litter decomposition determined by using the nylon bag method was 64.9%, which was lower than that by natural decomposition methods because nylon networks prevented some animals from entering the nylon bags. The mass and nitrogen content in the litter layer at the beginning of our experiment were 2.87t·ha-1 and 36.63kg·ha-1, respectively. On the other hand, the amount of yearly nitrogen input to the litter layer by litterfall during the experimental period was 172.19kg·ha-1. However, there were only 4.3t·ha-1 of litter mass and 55.2kg of nitrogen in litter layer at the end of the experiment. Therefore, 153.57kgN·ha-1·yr-1 was released from litter layer to the soil. The amount of nitrogen released from litter decomposition is 71% of the nitrogen requirement for vegetation growth

The changes of soil fertility in a 70-year-old fast-growing, highyield Chinese fir stand, which was originally occupied by a broadleaved stand, were studied for 2 consecutive years in Anchaoxia, Qihou, Nanping The results showed that the soil fertility of the 70-year-old fast-growing, high-yield-Chinese fir stand had declined obviously. In comparison with the original broad-leafed forest stand, the Chinese fir site showed increased soil bulk density, decreased soil organic matter content and nutrient element concentrations, and diminishing soil enzyme and other biological activities. The reason that the 70- year-old Chinese fir stand still maintains relatively high fertility is that the increased undercanopy space facilitates the maintenance of high species diversity and biomass production.

In this article, we have analysed the characteristics of Malus pumila intercropping with Triticum sativum and Arachis hypogaea(M.T.A.)community in the northern Henan province in Huang-Huai-Hai Plains and compared them with Farmland system (Triticum sativum and Arachis hypogaea). The results showed that (1) The system is one that has multi-population, multi-levels, multi-performance and multi-benefits;(2)The M. T.A. system can resist hot-dry wind, high and low temperature, and can increase soil natrient, change the structure of species population and increase the stability of system; (3)In M.T.A.system, the Economic yield was 5218.6kg·ha-1,the annual productivity was 17645.6kg· ha-1·yr-1, the litterfall amount was 206.9kg·ha-1·yr-1, the net economic benefit from 1988 to 1991 was 50781.2yuan·ha-1·yr-1, the standing crop of energy was 78.4699× 1010J·ha-1, the annual net energy production Was 49.6× 1010J·ha-1·yr-1, the energy transfermation efficiency of PHAR (ETE = NEP/PHAR × 100%)was 1.138%. (4) In M. T.A. system,the accumulations of N, P and K were 640.8, 130.8 and 328.4kg·ha-1, respectively; the annual uptakes were 554.5, 96.7 and 253.9kg·ha-1·yr-1 respectively; the annual returns were 16.4, 3.4 and 10.4kg·ha-1·yr-1,respectively;the return rates were 2.9%, 3.5% and 4.1%, respectively.

Tea plants in the Three Gorges area mainly grow on three soil geochemical types: siallitic ferrallisols, potash-silicic ferrallisols, and siferric ferrallisols, Siallitic ferrallisols have light soil texture, high content of Si, Al, and K, and low content of Fe, Ca, and Mg; Potash-silicic ferrallisols usually have sandy-loam soil texture and high content of Si and K; and siferric ferral lisols are usually deep and clay, and containt more Si and Fe, and less P and K. Relationship between soil geochemical characteristics and tea quality is close. Sandy soil can promote the increase of amino acid in the tea, clayey soil, on the contrary, make it decrease; higher base content decreases the alkaloid caffeine, polyphenols, and water-extracted matters, but may be beneficial for the formation of amino acid. Quickly available P has significant positive correlation with water-extracted matters, but it has significant negative correlation with alkaloid caffeine. Slow-released K has significant positive correlation with amino acid. Tea plants on the siallic ferrallisols and potash-silicic ferallisols usually produce higher quality tea than that on the siferric ferrallisols. So, the former two soil types are suitable to plant tea, and the third type is unsuitable if no special improving method is employed.

Betula albo-sinensis forest is an important type of forest vegetation of the Taibai Mountain region, distributed From 1950 to 2650m on the south slope and from 2200 to 2750m above sea level on the north slope.Using clustering analysis (UPGMA), twenty plots of Betula albo-sinensis forest were classified into seven types, i) B. albo-sinensis + Quercus liaotungensis forest ii)B. albo-sinensis +Q. liaotungensis +Pinus armandii forest; iii) B. albo-sinensis+P, armandii forest; iv) B. albo-sinensis forest; v)B. albo-sinensis P. armandii + B. utilis fargesis forest; vi) B. albo-sinensis + B. utilis +Abies fargesii forest; vii) B albo-sinensis + B. utilis forest. Seven types of B. albo-sinensis forests were regularly distributed in this order along the altitudinal gradient, but B.albo-sinensis forest always dominates and the forest structure is relatively stable.The analysis of the Betula albo-sinensis population structure, dynamics and natural regeneration indicated the Betula albo-sinensis forest was in a degrading stage.Betula albo-sinensis forests are mature or over-mature at present, artificial regeneration should be strengthened.

The plant communities in the Maxian Mountain Forest Region were classified and ordinated using Two-way Indicator Species Analysis (TWINSPAN), PCA (Prinicipal Components Analysis), RA(Reciprocal Averaging) and DCA (Detrended Correspondence Analysis). Thirty-two plant community samples are classified into seven formations and two vegetation types of higher class. The classification results are: Ⅰ. Hill forest: (1)Form. Populus davidiana + Betula platyphylla (2) Form. Picea wilsonii (3) Form. Picea wilsonii+ Betula platyphylla + Populus davidiana (4) Form. Populus davidiana + Salix paralesis + Betula utilis, Ⅱ. Hill shrub: (1) Form. Salix paraplesis +Betula utilis (2) Form. Betula utilis +Rhododendron rufum+ Rhododendron anthopogonoides (3) Form. Rhododendron rufum+Rhododendron anthopogonoides. The first axis of DCA ordination reflected elevation gradient. The second axis was shade gradient. The methods used in this paper were compared and discussed.

By analysing the relatedness degree adopted in the grey system theory, priliminary study on the relatedness of the growth of the dominant populations′, distribution and notability vs. the ecological factors in the secondary sere of the evergreen broadleaved forest communities in Mt. Jinyun of Sichuan was reported,in this paper. After the adoption of the basic idea that the spatial difference can substitute for the time change, each tree in the contiguous grid quadrats is measured. The result reveals the relationship between the growth of eight dominant populations, distribution and notability of the secondary sere of forest communities in Mt. Jinyun and the nine ecological factors. The analysis of the values of relational grades expresses that the pioneer species, i.e. Pinus massoniana, is controlled by much weak environmental conditions, and the climax species, namely, Gordonia acuminata, Castanopsis fargesii, Castanopsis carlesii var. spinulosa, etc., are mainly controlled by the conditions of the soil, such as organic matter, thickness, moisture and pH. The sequence of the latent effect of the nine environmental factors on the eight dominant populations from the strongest to the weakest is organic matter content of soil>thickness of soil>richness of species > pH of soil >moisture content of soil>interference>elevation>slope gradient>transparence of community. And the order of the eight dominant populations synthetically influenced by the nine ecological factors from the strongest to the weakest is probably Castanopsis fargesii>Schima argentea>Gordonia acuminata> Castanopsis carlesii var. spinulosa> Pinus massoniana>Neolitsea aurata var. glauca > Symplocos setchuanensis > Symplocos lancifolia.

We studied the P allocation, dynamics, accumulation and return rate, major fluxes and turnover in a Leymunes chineses grassland community in the northeastern part of China. Our results show 1) that over 99% of the P in the system is distributed in the soil; 2) that the P re-utilization rate in the community is 3.6755 kg·ha-1·yr-1 3) that the P uptake rate, return rate from the aboveground, return rate from the belowground and net community accumulation rate are 3.4063 kg·ha-1·yr-1, 0.1447 kg·ha-1·yr-1, 1.8111 kg·ha-1·yr-1, and 0.35 kg·ha-1·yr-1, respectively, and the total P output accounts for 42.24% of the total P uptake; 4)that the P turnover times in live plant, standing dead matter, dead roots, live roots and organic phosphorus are 1.3364, 6.4350, 2.4378, 1.0887 and 833.3 years, respectively.