According to the theory of forest growth cycle, forest communities are dynamic mosaic systems composed of patches in different developmental stages. On basis of the quandrats investigation carried out in a 1 hm² tropical montane rain forest in Bawangling, Hainan Province, the community characteristics of the whole forest stand were analyzed.The population and community features were studied based on the theory of forest cycle. The result showed that the utilization of ecological resources in the horizontal and vertical directions for trees of different life forms were relatively separate. Most shrubs and small statured trees had greater niche breadth values in the horizontal direction, and had less niche breadth values in the vertical direction ,and those for the middle or tall trees were on the contrary. The niche breadth for the rare and low density species were the least in both directions. With the progress of forest cycle, the frequency of different species presented in different patch types changed accordingly. The distribution patterns for most dominant trees and shrubs in the community were clumped, those for the trees having moderate individuals were uniform, and those for the low density species were random. In the process of forest cycle, the individuals owned by each species and the space occupied by each species decreased gradually. The numbers of species in different patch types in the forest cycle decreased with the increase of numbers of individuals. The numbers of species with 1 individuals and 2 individuals were most abundant ,and the numbers of species with more than 3 individuals decreased apparently in the investigated forest. Similarity analysis showed that the dynamic changes of patches in the forest cycle were somewhat continuous and gradual, the similarities between the neighboring stages were greater than those non_neighboring stages in the forest cycle. Calculation of niche breadth for different species on basis of the theory of forest cycle showed that the utilization of ecological resources in different patches by the low density species or those confined only in certain patches were comparatively less, while those species presented in most patches and had moderate numbers of individuals or moderate basal areas had greater utilizations for the ecological resources in the forest cycle.

The use of Eucalyptus as plantation trees in the tropics has been criticized in the world wide on the grounds that they consume water in excessive amounts, but it is no general answer to the question of whether Eucalyptus consume water in excessive quantities because site conditions, climate and species all influence water use. In south China, however, there is little information on water use by Eucalyptus plantations. The purpose of this paper was to discuss effects of meteorological factors on dry seasonal dynamics of soil water content in Eucalyptus plantation on Leizhou peninsula of southern China. Based on the data obtained from locate oriented observation throughout the dry season from Oct. 1999 to Mar. 2000, the method, canonical correlation analysis, which could puts emphasis upon holistic meteorological factors and soil water content(SWC), was employed to analyze the relationship between them. The main results indicated as followings:(1)Soil water content varied markedly in different layers and mean water content of layers increased with the depth of soil(P=0.001);(2)The coefficient of weight for daily maximum temperature(T_max )and minimum temperature(T_min )was 1 260 and 0.840 ,respectively. And the main meteorological factors that changed soil water content of deeper layers(SM150, SM250, SM350)were vapour pressure deficit(VPD), daily minimum temperature(T_min ),solar radiation (R_s ), and maximum temperature (T_max ); SWC at SM350 had a significant relationship with precipitation (P_r)(P=0.001), while the main factors influencing SWC at SM50 were P _r and wind speed.(3)The canonical correlation coefficients between canopy meteorological factors and SWC were 0.841 and 0.548(P=0.001), respectively. And the multiple correlation coefficients between the two canonical variables was 70.7%;(4)The total variance in soil water content explained by first canonical covariates (U₁,W₁ ) was 40.4%. The two canonical variables, (U₁,W₁) and (U₂,W₂), explained total variation in soil water content was 43.0%. The first canonical variables U₁ can account for total variation in dependent variables of soil water content up to 57.2%; (5)The soil water content at SM350、SM250、SM150 were mainly affected by daily maximum temperature, minimum temperature, and solar radiation among the canopy meteorological factors.

The origin, development and the ultrastructure of secretory cavities in leaf of Ginkgo biloba and its relation to the secretory products were studied under light and electron microscopes. The results indicated that the formation pattern of the secretory cavities was schizo lysigeneous. First, some original secretory cells in the center of secretory cavities began to expand and dissolved, and small spaces appeared between the cells. Then more secretory cells dissolved and made the space larger, meanwhile the former secretory cells in the center degenerated, autolyzed and sloughed off in the cell spaces. The secretory product in the secretory cavities of G. biloba was mainly synthesized in ER and plastids. More or less, mitochondria, Golgi body and ground cytoplasm also took part in the synthesis and transportation of secretory products. After synthesized in ER and plastids, the secretory products approached the plasmalemma and fused their membranes with the latter in the form of small vesicles, and then was eliminated to the spaces between the plasmalemma and the wall. At last the secretory products percolated through the wall that faded into an even looser mesh of fibrillar material toward the cavity.

In this study, three breeds of cultivated hawthorns(Crataegus pinnatifida var.Major )with extremely low fertilization rates `Mianzha', `Changkou' and `Dajinxing' were pollinated by the pollen of wild hawthorns(C.pinnatifida) with high fertilization rates, and some physiological and biochemical indexes of pollen and pistil were compared between wild hawthorns and cultivated hawthorns. The results showed that the kernel contents of the seeds of cultivated hawthorns were increased significantly by the treatment of pollination with the pollen of wild hawthorns. There was no significant difference between cultivated hawthorns and wild hawthorns in pollen viability, but the germination rate of the pollen and the growth speed of pollen tubes of the former were lower than those of the latter. The pollen of `Dajinxing' could not germinate after cultivated for 24 h at 25℃. The germination of the pollen of wild hawthorns and cultivated hawthorns was inhibited by the pistil extracts of the cultivated hawthorns. Compared with wild hawthorns, cultivated hawthorns were of lower carotenoid, free proline and soluble protein contents,and higher phenolic compound content and POD activity in the pollen, of which the `Dajinxing' was of the lowest carotenoid and soluble protein contents, and the highest phenolic compound content and POD activity in the pollen, and higher IAA oxidase activity and lower soluble sugar content in pistil. The POD isozymes in pistil of `Dajinxing', `Changkou' and `Mianzha' had 2, 3 and 4 bands respectively more than that of the wild hawthorns, however, there was no difference between cultivated hawthorns and wild hawthorns in the POD isozymes in pollen.

Three Quercus mongolica populations located at Jiayin, Xiaoxing′anling Mountain in Heilongjiang Province, Daqinggou in Inner Mongolia Autonomous Region, and Wulingshan in Hebei Province, and one Q. liaotungensis (a variety of Q. mongolica) population at Donglingshan in Beijing, totally 96 individuals were selected and analyzed by amplifications using 4 pairs of AFLP primers screened, each primer pair produced 63～113 bands and 346 polymorphic bands were obtained.As for Q.mongolica at species level, the effective number of alleles per locus (Ae) was 1 220, the percentage of polymorphic band (P) was 96.8%, and the Nei gene diversity index (H) was 0 145, Shannon's information index (I) was 0 246. At population level, the estimates were Ae=1.208,P=67.2%, and H=0.134,I=0 208 . In contrast, the estimates for Q.liaotungensis were almost the same (Ae=1.5,P =67.6%, H=0.134, I=0.220 ). As for Q.mongolica, genetic differentiation coefficient among populations (Gst) was 0.077. According to the UPGMA cluster analysis, the genetic distance among Q.mongolica populations became larger with the increase of geographical distance. The low level of genetic diversity of Q.mongolica might relate to the long term utilization as economic tree species in history, comparatively serious disturbance and environmental damage by human beings, and secondary forests of the existed stands.

In this paper,a systematic study was made on the impact of cultivation activities,such as slash burning,site preparation,new planting tending,stand thinning and final logging etc.,on the long term site productivity of Chinese Fir plantations.Each of the above mentioned cultivation activities was considered upon the biomass and nutrient cycling of the plantation ecosystem as well as the reduction of soil organic matter and mineral nutrients in yellow red earth derived from granite and slate respectively.The results showed that,in the plantation ecosystem with yellow red earth derived from slate the reduction of soil organic matter and mineral nutrients was mainly caused by the slash burning and clear cutting activities,while in the plantation ecosystem with yellow red earth derived from granite the reduction of the soil organic matter and mineral nutrients was mainly caused by slash burning,soil erosion and clear cutting activities.For the Chinese Fir plantation with age of 19 years on the soil derived from slate,the total reduction of organic matter was 34.06t·hm^-2 and the total reduction of mineral nutrients was 2371.96kg·hm^-2,while in the Chinese Fir plantation with age of 27 years on the soil derived from granite,the total reduction of organic matter was 16.33t·hm^-2 and the total reduction of mineral nutrients was 2 323.24kg·hm^-2.It is concluded that the significant impact on soil nutrient loss existed when a series of cultivation activities were conducted following the normal cultural methods in the Chinese Fir plantation.It is impossible to maintain the site productivity without supplement of enough nutrients and organic matter to the soil in Chinese Fir plantations.

The article analyses the situation and cause of soil fertility degradation in National Afforestation Project(NAP)'s areas,elaborates the countermeasures to prevent the degradation of soil fertility.Based on the monitoring results of soil fertility,the article also discusses the changes of soil fertility under implementation of NAP,and provides a fundamental theory for the environmental protection and plantation establishment in a right way.The results indicate:the project has been carried out for 5 years,the guideline of environmental protection has been strictly followed and the soil fertility has increased slightly.

Based on the theory of ecology and previous experience,system engineering method was used to construct a model to analyse hierarchy structure of forest site types.In this method,referential theories and experience were transformed into distal data,then sort into certain order,then determine the effect of site conditions on ecological factors in turn,thereby the growth of trees was affected.On these grounds,the classification system of genesis of site hierarchy structure was established so that forest sites were zoned and sorted.

The reciprocal equation of the C-D effect, I.e. 1/ w = Aρ_I +B ( w and ρ_I respectively represent mean stem volume and density,A and B are coefficients) was used to describe the C-D effect in Populus × euramericana (Dode) Guinier cv. `San Martion' plantations. The data observed from different growth stages were well fitted with the C-D curve given by the reciprocal equation of the C-D effect on logarithmic coordinates, and the C-D curve shifted upward with the progress of time. The change trends of biological time τ, the coefficient A and B, the coefficient of growth λ(t) and the final yield Y(t) were given. The biological meanings of coefficient A and B were obtained. Biological time τ increased gradually with physical time t . With increasing τ, the coefficientA increased abruptly up to its maximum value, and then decreased gradually, whereas the coefficient B decreased exponentially and tended to close to zero. With stand growth the coefficient of growth λ(t) decreased gradually and final yield Y(t) increased gradually. Based on the C\|D effect, intermediate cutting for 7-year-old P. euramericana plantation with high-density was proposed.

This paper described two new species in the Howardi species group of the genus Tetrastichus (Hymenoptera: Eulophidae): Tetrastichus shandongensis sp. Nov. and Tettrastichus nigricoxae sp. Nov., which were gregariously endoparasitic in the pupae of Fall Webworm, Hyphantria cunea (Drury) (Lepidoptera: Arctiidae) from China. They were important natural enemies of the invasive pest and have played certain role in suppression of the population of Fall Webworm with the parasitic ratios 6 2% and 9 8% respectively. The two parasitoid species could be selected as biological control agents for the pest's IPM. The type specimens of the new species were deposited in the Insect Museum of Chinese Academy of Forestry. Tetrastichus shandongensis Yang, sp. Nov. (Fig.1(1-9), Pl. I) Length: ♀1.6～2.2 mm, ♂1.3～1.6 mm. The species is close to T. septentrionalis Yang 2001, but can be distinguished from it by the key (to three Chinese species) below. Holotype ♀, Wuning, Muping Dist. Of Yantai City, Shandong Province, reared out on Apr 29. 1997 from the pupa of Fall Webworm collected on Feb 18. 1997, by Yang Zhongqi, Liu Yuming, Shi Liantong and Wang Chuanzhen. Paratypes 156♀♀48♂♂, The same data as holotype. Biology: It was endoparasitic in the pupa of Fall Webworm with 48～115 adult wasps reared out from one host pupa. Its parasitic ratio in the overwinter host was 6 2% and the proportion of female and male was 3 2∶1. The egg, larva and pupa stages of the parasitoid were all developed in the host pupa and overwinter as mature larva. After emergency the wasps bited holes in host pupa shell and come out. The female adult survived for 12～15 days in the condition of temperature 25～28℃. Distribution: Till now it was only found in Shandong Province, maybe it also occurred in north China. Tetrastichus nigricoxae Yang, sp. Nov. (Fig 2(1—3), Pl. II) Length: ♀1.33～2.3 mm, ♂1.2～1.8 mm. This species is close to other two Chinese species, but can be separated with the key below. It is also similar to T. sculpturatus Wasterston, a species of Uganda, but the present species with female having antenna funicle 1 thinner and longer (length almost 3 times breadth), 1.7 times the funicle 2 and as broad as pedicel is different from the latter, which with funicle 1 much shorter (length 1.8 times breadth), about the same length as funicle 2, and with breadth 1 25 times pedicel. Holotype ♀, Yangling, Shaanxi Prov, July 9,1993, Yang Zhongqi, reared from pupa of Fall Webworm. Paratypes 20♀♀5♂,the data is the same as holotype; 24♀♀1♂, Yangling, Shaanxi Prov., 10 May 1994,Yang Zhongqi and Xie Enkui, Reared from pupa of Fall Webworm; 60♀♀15♂♂, Yangling, Shaanxi Prov., 20 Aug.1990, Yang Zhongqi, reared from Fall Webworm pupa; 42♀♀20♂♂, Damiao, Tongshan County of Xuzhou City, Jiangsu Prov., July 20,1997, Guo Tongbing and Liang Bo, reared from the pupae of Micromelalopha troglodyta Graeser ( Micromelalopha troglodyta Graeser)(Lepidoptera: Notodontidae); 5♀♀, Yangling, Shaanxi Prov., 10 June 1996, Guo Xinrong and Li Menlou, reared from the pupa of Stilpnotia candida Staudinger (Lepidoptera: Lymantridae). Biology: gregariously endoparasitic in the pupa of Fall Webworm with 86～168 adult wasps reared out from one host pupa, and the proportion of female and male is 1 9∶1 It overwintered as mature larva in its host pupa. The parasitic ratio of the species in Fall Webworm was 6.2%～13.4%. Besides Fall Webworm it also parasitized the pupa of other severe poplar defoliators: Micromelalopha troglodyta Graeser and Stilpnotia candida Staudinger. It needed 25 days for developing a generation under the temperature 25℃ by our experiment. Distribution: Guanzhong area of Shaanxi and Xuzhou of Jiangsu Provinces. Perhaps it distributes in many other areas of north China. Key to species in Tetrastichus howardi species group known in China 1 Female and male having fore and hind coxae concolor with thorax which with blue green metallic tint, mid coxa dark brown, and all other segments of legs yellow; female antenna with funicle 1 thin, 2.7～3 0 times as long as broad, and its breadth merely greater than pedicel (7.5∶7) slightly; Scutellum with crescentic hind margin which divided by a deep suture from the main area and its median length 0.6 time dorsellum Tetrastichus nigricoxae sp. Nov. - Female with all coxae and other segments yellow, male with fore coxa yellow and hind or mid and hind coxae brown; female having antenna funicle 1 shorter with length less than 2.0 times breadth, its breadth obviously grater than pedicel (1.2～1.3 times); Scutellum only with crested hind margin divided by a suture2 2 Male with propodeum median carina bi crestiformed, the carinated hind margin of the sclerite with reversed V shaped medially; female with propodeum median carina reversed Y shaped because of the carinated hind margin forward as reversed V shaped as male's, plicae connected with inner carinated hind margin forming an 45° angle which exserted posteriorly; female and male with propodeum having latero-posterior corner blunt, never dentate (Fig. 1-5); female with hind wing having apex cuspidal (Fig. 1-4) T. shandongensis sp. Nov. - Female and male with propodeum having median carina normal, not bi crestiformed, and its hind margin not forward as reversed V shaped; female with plicae connected inner hind margin forming an angle greater than 90° which not exserted posteriorly; female and male with latero posterior corner exserted dentately (Fig. 1-9); female with hind wing apex round (Fig. 1-8) T. septentrionalis Yang

Codariocalyx motorius growed as a common perennial pioneer plant in slash and burn shifting field in tropical and subtropical mountains of Yunnan Province, China. The field investigations showed a mutualism between ants and C. motorius.It was observed that ants moved seeds of C. motorius into their nests. The effect of ants on C. motorius seeds′ vitality during slash and burn process was studied in field. The results showed that all of the seeds on surface lost their germinating ability after burning. However, germinating rates of the seeds, which were buried in depth of soils from 5cm to 10cm and experienced a burning period of 5, 30, 60, 90 and 120 min respectively, increased significantly compared to those of the control seeds. And moreover germinating rate of the seeds in 5cm below surface was higher than that of seeds in 10cm deep under the surface, and germinating period of the former was lower than the one of the latter. So, due to ants′ moving, the seeds of C.motorius during a slash and burn cultivation could survive from burning. Subsequently, C. motorius community recovered and dispersed. It could be considered mutualism between ants and C. motorius.

The niche and competition among species of natural enemies and pests in different intercropped and managed jujube orchard ecosystems in Taigu were studied. The results showed that there were obvious niche overlaps and competitions in different species which used the same resources. The niche overlaps competition among species and spatial niche width were not disturbed by insecticide,weeds and intercropped plants. Time niche width was affected by insecticide, weeds and intercropped plants. The laws of distribution, and changes of natural enemies and pests in time and space were revealed by niche studies.

The influence of the process factors on the wood-plastics composite panels' physical-mechanical properties were studied in the paper. Two tree species 〔Masson Pine(Pinus massoniana ) and poplar(Populussp.)〕 and three plastics (polyethylene, polypropylene and polystyrene) were used as main raw materials. The different process factors, such as tree species, wood component forms and sizes, kinds of plastics, densities of the composite panels, strengthening additive and the mixing ratio between the wood material and the plastics, were examined in the cold mixing-hot pressing processes for making wood-plastics composite panels. The results showed that the tree species, wood material forms and sizes, the plastics varieties and proportion, panel densities and the strengthening additive affected the properties of the composite panels. The property of composite increasing the ratio of plastics in the panels was as good as adding phenol formaldehyde resin strengthening additive to the panels. With the significance test and the factor level effect value comparing, it could be known that the poplar wood material, slighter and longer flakes, high polypropylene plastics and high panel density (1g·cm^-3) were excellent process factors. The properties of the composite formed with the factors mentioned above exceeded that of the common flake board including the structure flake board.

This paper studied on the effort of pre-freezing process on wood drying and collapse properties, analyzed the regulations of the size changing of cell lumen and cell wall caused by free water in pre freezing process, and calculated the extension to which the cell wall intension increased theoretically,as Populus ussuriensis to be material. By using electronic microscope,the effect of freezing process on the cell wall structure was studied, and the mechanism on how pre-freezing deleted wood collapse was discussed. The results showed that freezing treatment could reduce collapse.

For different silvicultural measures, the radial growth properties of Pinus koraiensis plantations were measured and analyzed. The results showed that the variances of growth percentage, growth-ring width(except pruning), growth ring density(except slope aspect and pruning) were remarkable, and the variance of latewood percentage(except pruning) was not significant. In order to increase growth percentage and cultivate the large diameter wood ,the stands on north slope or at the bottom of slope, and with acluster of three trees, density of 2 0?m×2 0?m, properly thinning and pruning could be selected.

The technology for the manufacture of aqueous corn starch/synthetic rubber latex/isocyanate adhesive system API was systematically studied in the paper. Corn starch was firstly esterified at a certain Ph to form a emulsion that was condensed with synthetic rubber latex to yield the main component A of API. This component A was then mixed with isocyanate as a cross-linking agent to form the adhesive system API that was used as the adhesive of three-layer composite flooring board,blockboard,plywood,laminated stuff and other glued products. After production trail,performance of all products mentioned above reached the requirement of the national standard. There are no poison materials released from the products. This API is an applicable,easily handled adhesive and meet the need of present technology. Its cost is half the similar import adhesive. It has remarkable social and environmental benefits and economic profit.

The progress and developing trends abroad in genetic engineering of forest tree were summarized in this paper. Meanwhile the advances in basic and applied research in genetic engineering of forest tree on insect resistance, disease resistance, stress resistance, quality improvement and sterile ect. In China were introduced. According to the practical demands of ecological environment and wood industry, some proposals were tabled on the key fields of the genetic engineering of forest tree in China for the future.

The recent progress in induced resistance of pines to Pine Caterpillar in China was reviewed in this paper. The four aspects including chemical change of the damaged pine needles, the effect of damaged pine needles on the population dynamic of Pine Caterpillar, the characteristics and influenced parameters of the induced resistance of pines to Pine Caterpillar were analyzed. The reported results suggested that the content of some nutrient substances(sugar, amino acid, protein, fatty acid et al.) were degradation, and the content of secondary metabolites (volatile and nonvolatile) were risen in the damaged pine. In turn, the longer growth period, higher mortality and lower fecundity were found in the Pine Caterpillar after fed in damaged pine. Furthermore, the mechanism of the periodic outbreak of Pine Caterpillar and its management were also discussed.

Schleichera oleosa, a kind of Lac Insect's host plants, was concluded and summed up; progress and research on category,physiology,biology and ecology of Lac Insects' host plants were also generally analyzed; In agamous propagation aspect which is rarely studied, technique was also given; At last prospects of Lac Insects' host plants were viewed.

This paper makes a comprehensive and detailed review on the international research into cell wall mechanics of tracheids, including its history and present research status. Furthermore, some important experimental methods for the determination of mechanical properties of tracheids as well as some mechanical models are relatively emphasized. Finally, several proposals are also presented for the way to carry out researches on cell wall mechanics of tracheids in China.

Sandy desertification in China is very severe, endangering the living space of the Chinese nation. Annual rate of desertified land expansion is 3 436 km², equaling to a medium_size county in China. At present, desertified land area amounts to 1.74×10⁶km², accounting for 18% of the total land territory, or 10 times of the area of Guangdong Province. 100 million population, 2.4×10⁴ villages and townships are directly affected, with an annual direct economic loss of RMB 54 billion yuan. The causes of sandy desertification expansion are mainly attributed by natural factors and human activities. Overgrazing of?grassland, indiscriminate reclamation of ecologically sensitive lands for?grain production, deforestation and excessive fuelwood collection, digging of herbal plants and irrational use of water resources are the five main human factors causing sandy desertification, being the results of the human being's pressure on ecological environment. Concluded from the previous experiences as well as lessons learned since 1949 in combating desertification, desertification combating must deal with the root causes of sandy desertification, focusing on human centered measures and comprehensive approaches as key solution. The control activities should fully take into account local farmers and herders' requirements of living and development, which should be the basic consideration, and take comprehensive measures combining forestry, agriculture,?grassland, water resources, rural energy, ecological migration, etc. Desertification combating should take protection as the first priority and keep prevention as the key measure. Different types of land should be treated with different policies accordingly, and “Three Shelterbelts” should be set up to contain land desertification. As for substantial measures, firstly, the natural vegetation in the 8 Deserts and 4 Desertified lands should be protected, with sand_fixing desert species, especially dry-land-dependent arbor, shrubbery, such as Populus driversifolia, Haloxylon ammodendron. Protected; secondly, large_scale forest and?grassland shelterbelts should be set up, according to the nature of different kinds of damages; thirdly, desertified croplands should be converted to forests, desertified pastoral areas should be enclosed for regeneration, oasis croplands should be protected with optimized forest shelterbelts. Quality and fund management are key to implementing national sandy desertification combating projects. The check and acceptance measures should be strengthened, and reimbursement management system should be applied. Quality monitoring and control should be executed through the whole process of projects, as for each phase from designing, planning to implementing. The responsibility system of?government officials should be applied. The tasks, objectives, responsibilities, cash and food subsidies should be allocated to each household, and contracts be signed with them. The bottom-up supervising system should be set up through the means of inspection-and-check cards and cash-and-food allocation cards. The responsibility system composed of administrative leaders, technical heads and farmer/herder responsibility rules should be set up, so that obligations and rights, rewards and punishments are clarified. China's course of combating desertification will surely achieve its ambitious objectives.

The hydrological character parameters of the litter amount, the maximum water capacity and water absorption speed of the litter on the forest land under four type of Abies fabri forest (young, half-mature,mature and overmature stand)on the Gongga Mountain were studied in this paper. The result showed that the litter amount under the overmature stand was the maximum(67.8?t·hm^-2), the second was the mature stand(53.4 t·hm^-2), the third was the half mature stand(40.4 t·hm^-2), the fourth was the young stand(32.6t·hm^-2). The maximum water capacity of the undecomposed litter under the mature stand was 428.8% of the litter's dry weight, that of the litter under the overmature stand was 411.6%, that of the litter under the half-mature stand was 378.8%, that of the litter under the young stand was 296.7%. The maximum water capacity of the half-decomposed litter under the mature stand was 234.5% of the litter's dry weight, that of the litter under the overmature stand was 175.6%, that of the litter under the half mature stand was 160.3%, that of the litter under the young stand was 132.5%. The equation between the water absorption speed of the litter and the soaked time is S=ktⁿ. The result also shows that the litter's variation with the time has no relation to forest age, while its decomposition degree is positively related to stand age.

The soil thermal regime and the effect of forest harvest in the watershed were studied in virtue of thermal conductivity equation in soil and physical principle by 6 years data in Chinese Fir plantation. The results showed that the content of water in the soil determined the change of the thermal capacity, thermal diffusivity and thermal conductivity according to the time in the watershed. With the increasing of soil thermal capacity, the percent of solid and the decreasing of porosity, all thermal factors increased. After forest harvesting, the surface soil became more tighten because of the artificial strong disturbing. So the ratio of solid, liquid and?gas in the soil was changed and the soil thermal regimes were changed, especially the thermal diffusivity and thermal conductivity in 0～5 cm depth soil increased more than one times. The soil thermal regimes were affected by the soil structure and the soil components. But for the each factors of soil thermal regimes, the effect of each components was different, especially to the interaction of each components, which made the thermal diffusivity and thermal conductivity more complex. Therefore, it was very difficult to evaluate the effect of every soil structure and every component.

The Xiangtou Mountain National Reserve has an extremely rich biodiversity characterized by its abundant biota species, ancient region origin, typical floras and faunas as well as a diversity of animal species that are of?great benefit to human or of?great economic or research value. However, the Reserve is weak in ecological environment protection and is subject to much potential disturbances by human. As as effort to protect the species diversity of the Reserve, we must take such measures as (1) strengthening the system for biodiversity protection; (2)protecting the ecological environment indispensable to species survival; (3) establishing a reliable finance system; (4) promoting related research and (5) cultivating a public awareness of environmental protection.

The purpose of the paper was to study salt tolerance and its indexes of Ginkgo biloba varieties. The potted plants of five Ginkgo biloba varieties (Fozhi, Dajinzhui, Meihe, Dayuanling and Maling) were treated with 0%, 0.1%, 0.2% and 0.3% of NaCl. The results indicated that:(1) With the salt concentration increasing, the Na⁺ concentration and the ratio of Na⁺/K⁺ in the leaves of five varieties also increased, and the K⁺ concentration was highest in the treatment of 0.1%, then decreased in the treatment of 0.2% and 0.3%. (2) Leaf water potential increased with the salt concentration increasing, and free proline content in the leaves also increased in the treatment of 0.2% and 0.3%, but decreased in the treatment of 0.1%; A little change of root viability happened in the treatment of 0.1%, but there was a significant decrease in the treatment of 0.2% and 0.3%; SOD activity in the leaves and growth of plant height decreased gradually with the salt concentration increasing; There was a little change in membrane leakage in the treatment of 0.1% and 0.2%, but it increased obviously in the treatment of 0.3%. (3) According to the plant growth of height, the salt tolerance of five varieties in the treatment of 0.3% was Meihe>Dayuanling> Maling>Dajinzhui>Fozhi. (4) The analysis methods of BACKWARD, FORWARD and STEPWISE all showed that the ratio of Na⁺/K⁺ had the greatest influence on the plant growth of height, so the ratio of Na⁺/K⁺ was a very important index in the study on salt tolerance of plant.

control methods were used for preventing and curing Schizotetranychus nanjingensis, they were bamboo cavity injection, bamboo cavity-injection+organic manure, pesticide+fertilizer, and organic manure. The results showed that the control method of bamboo cavity-injection was best, it was economical and effective, easy to operate and popularize. However its effective on turning green of bamboo forest was not evident. The method of adding organic manure after bamboo cavity-injection promoted bamboo forest turning green, but its cost was too high to be suitable to extension. The control method of pesticide and fertilizer had obvious effects on bamboo forest increasing production, continuous control, and turning green of bamboo forest, it was suitable to extension in the distracts where the economic conditions were good because of its higher cost. The method of adding organic manure clone was not good for prevention since the control effect was worse.