In order to improve the accuracy and reliability of identifying wood defects and to realize the maximum wood utilization of trees, we employed an experimental method to test the stress wave propagation velocity in standing Fraxinus mandshurica trees selected from the Harbin Forest Experimental Station in winter. Thirty standing trees in good conditions were taken as test specimens and stress wave propagation velocities were measured using a FAKOPP Microsecond Timer in trees in both fall and winter. The test data were processed with the aid of Excel and SPSS software. The results show that 1) the velocities in longitudinal and radial stress wave propagation in frozen F. mandshurica trees were much higher than those in the non-frozen trees; 2) there was a highly positive correlation between longitudinal stress wave propagation velocity in frozen and non-frozen states, with a correlation coefficient of 0.82, as well as a positive correlation between radial stress wave propagation velocity in frozen and non-frozen states with a correlation coefficient of 0.87; 3) in the frozen state, the longitudinal stress wave propagation velocity was significantly affected by the moisture content (MC) of standing tree, while it was not obvious in the non-frozen state and 4) the radial stress wave propagation velocity was not significantly affected by MC in either frozen or non-frozen state.

In May 12, 2008, a strong earthquake occurred in Wenchuan County in the northern Sichuan Province of China. It registered 8.0 on the Richter scale with an 11-degree quake intensity, killing a large number of people, and causing extensive damage to the local environment. Wolong National Nature Reserve is about 30 km away from the epicenter and is one of the most important giant panda (Ailuropoda melanoleuca) habitats in China. Based on the impacts of the Wenchuan 512 earthquake and those of other strong earthquakes in the world, this paper reviews and discusses effects of strong earthquakes on geomorphology, soil chemical and physical properties, forests, bamboo growth, biodiversity, and giant panda habitat. This information may be useful for scientists when undertaking research projects on natural geography, ecological restoration, and habitat restoration in the Reserve and the disaster area.

Water shortage is a crucial problem in northern China, but in southern China, enormous floods frequently occur. The water problems seriously disturb human life and the sustainable development of the economy and society in the country. To solve the water problem, the government of China approved the South to North Water Transfer Project in 2002. The project will build the east, middle and west routes in which 44.8 billion m³ of water will be transported from the Yangtze River in the southern part to the northern region annually. The east and middle routes are 1154 and 1267 km long, and their respective constructions have been started since 2002 and 2003. The west route is reevaluated. However, the establishment of conservation buffer systems beside the routes to protect the water from severe non-point pollution from agricultural runoff was ignored. Except for pollution, change in the environment from the water exporting to importing area also alters the physical and chemical properties of the transferred water. The protection of the water quality along the routes is a critical issue that significantly influences the purpose of the project. The paper proposes the establishment of conservation buffer systems beside the routes for the protection of the water, and discusses the buffer construction based on some successful cases in western countries.

The images of post atmospheric correction reflectance (PAC), top of atmosphere reflectance (TOA), and digital number (DN) of a SPOT5 HRG remote sensing image of Nanjing, China were used to derive four vegetation indices (VIs), that is, normalized difference vegetation index (NDVI), transformed vegetation index (TVI), soil-adjusted vegetation index (SAVI), and modified soil-adjusted vegetation index (MSAVI). Based on these VIs and the vegetation fractional coverage (VFC) data obtained from field measurements, thirty-six VI-VFC relationship models were established. The results showed that cubic polynomial models based on NDVI and TVI from PAC were the best, followed by those based on SAVI and MSAVI from DN, with their accuracies being slightly higher than those of the former two models when VFC > 0.8. The accuracies of these four models were higher in medium densely vegetated areas (VFC = 0.4−0.8) than in sparsely vegetated areas (VFC = 0−0.4). All the models could be used elsewhere via the introduction of a calibration model. In VI-VFC modeling, using VIs derived from different radiometric correction levels of remote sensing images could help explore and show valuable information from remote sensing data and thus improve the accuracy of VFC estimation.

By using the forest gap model-FAREAST, we simulated the effects of future climate change on forest composition and forest biomass of typical forests in northeastern China. We selected three different climate change scenarios, developed from GCMs results, of the ECHAM5-OM and HadCM3 models: the current climate, a warmer climate and a state of changing precipitation with higher temperatures. The results are as follows: if the climate does not change, the composition and forest biomass of the northeastern forests will retain their dynamic balance. A warmer climate is detrimental to the major forest types in the northeast. The percentage of major conifers is expected to decrease, along with a proportional increase of some broad-leafed species. The southern treeline of the mixed broad-leafed tree species/Korean pine forest in the temperate zone will tend to move northward. The warmer the climate, the more distinct the transition. If, furthermore, we were to take account of rainfall, the treeline in the northeast will tend to move northward. Rainfall seems to have little effect on the mixed broad-leafed tree species/Korean pine forests in the temperate zone.

Floristic composition of the evergreen broad-leaved forest in Jiulianshan Mountain was analyzed based on field investigations and community ecology. The community is rich in species diversity, with 144 spermatophyte families including 379 genera and 647 species, in which there are 6 gymnosperm families including 8 genera and 9 species, 21 monocotyledon families including 77 genera and 116 species, and 117 dicotyledon families including 294 genera and 522 species. Dominant families of the flora are Fagaceae, Lauraceae, Aquifoliaceae, Rosaceae, Ternstroemiaceae, Theaceae, Rubiaceae, Moraceae and Euphoarbiaceae, most of which are of tropical & subtropical distribution. As for family systematic distribution, the ratio of tropical & subtropical to temperate genera is 100∶62.8 in 142 genera of 16 families. As for generic distribution in field investigation data, the tropical & subtropical areal type accounts for the majority of genera, in which there are 205 genera belonging to the tropical & subtropical areal type, 131 genera belonging to the temperate areal type, 35 genera belonging to the cosmopolitan areal type and 8 genera belonging to the endemic-to-China areal type. The ratio of the tropical & subtropical to temperate genera was 100∶63.9. Floristic composition of the evergreen forest community in Jiulianshan and the typical species of the zonal flora will provide a scientific foundation for stand rehabilitation and stand establishment approximating a natural evergreen broad-leaved forest community. This study also indicates that the sample data based on community research is valid and convenient for floristic and environmental analysis of the evergreen broad-leaved forest community from the Jiulianshan Mountain.

Forestry division has been discussed rarely since 1995 in China. The growing interest in forestry provides an opportunity to improve the research tools and approaches that can help achieve a broader understanding of forestry division. Based on research in Yong’an, Fujian Province of China, a framework that may be useful in correlative forestry division study was proposed: 1) the factor-system for Yong’an forestry division was established; 2) the factors were extracted with spatial analysis; 3) the forestry division method of integrated modeling at county level based on GIS was processed. The method was taken through principal components analysis, building the comprehensive model, discriminate analysis, seeking the ideal number of divisions and eliminating the scrappy polygons. The outcome showed that the method based on GIS with comprehensive modeling could reflect the present situation of forestry development. The relative dominant subdivisions were distinguished reasonably, and a specific direction in forestry development is presented. According to the statistics of the subdivisions’ state, the relative dominant subdivisions were clearly demonstrated.

The subalpine coniferous forests on the eastern Qinghai-Tibet Plateau provide a natural laboratory for studying the effect of climate warming on terrestrial ecosystems. Research on differences between tree species in their responses to experimental warming can provide insights into their regeneration behavior and community composition under a future warmer climate. We used open-top chamber (OTC) to determine the short-term effect of two levels of air temperature (ambient and warmed) and light (full light and ca. 10% of full-light regimes) on the early growth and physiology of Betula albo-sinensis and Abies faxoniana seedlings. The OTC manipulation increased mean air temperature and soil surface temperature by 0.51 and 0.34°C, respectively, in a 60-year-old plantation and 0.69 and 0.41°C in forest openings, respectively. Warming generally increased plant growth, biomass accumulation, and advanced physiological processes for seedlings of both species. In response to warming,both tree species allocated relatively more biomass to foliage and had significantly decreased root/shoot ratios (R/S), which might provide the two species with an adaptive advantage when other environmental factors were not limiting. Warming may enhance photosynthesis in the two seedlings by increasing efficiency of PSII in terms of increases in F_v/F_m, photosynthetic pigment concentrations, and apparent quantum yield (Φ). However, the effects of warming on seedling growth and physiological performance varied by light conditions and species. For B. albo-sinensis seedlings, the effects of warming were pronounced only under full-light conditions, while the growth and physiological responses of A. faxoniana seedlings to warming were found only under low-light conditions. Competitive and adaptive relationships between the two species may be altered as a result of response differences to warming manipulation. The short-term beneficial impact of warming on the early growth and development of the two species suggests that global warming may lead to changes in regeneration dynamics and species composition in subalpine coniferous forest ecosystems.

With the aid of canonical correlation analysis, the relations among soil nutrients, soil microorganisms, and soil enzyme activities were studied in vegetation restoration areas of degraded and eroded soils in the Nverzhai watershed in northwestern Hunan. The main results were as follows: the key factors in soil nutrients, microorganisms, and enzyme activities were N and P elements, number of bacteria, carbon and nitrogen in soil microbial biomass and the activities of urease, polyphenol oxidase, phosphatase, and invertase. The activities of urease and polyphenol oxidase are related to the inversion of N and P elements that had important impact on the accumulation of carbon and nitrogen in soil microbial biomass. Moreover, the activities of urease, polyphenol oxidase, and phosphatase could promote carbon accumulation in microbial biomass; however, invertase activities inhibited the accumulation of microbial biomass nitrogen. On the other hand, urease activities were beneficial to the N element content in soils but unfavorable for P elements. There is a negative relation between polyphenol oxidase activity and N element content. For every canonical variable group, the tendencies of soil nutrients, microorganisms, and enzyme activities to accumulate in different soil layers in different vegetation restoration communities could offer some scientific basis for the diagnosis of the health of the soil and the site type division in the process of vegetation restoration.

Leaf litter decomposition of Castanopsis fissa, Cinnamomum camphora, Michelia macclurei and Mytilaria laosensis in mixed broad-leaved plantation and pine plantation was studied by the litterbag method for 1 year. Leaf litter decomposition rates of the four species were highest in Cinnamomum camphora, followed by Mytilaria laosensis, Michelia macclurei, and Castanopsis fissa. The decomposition rates of all four species were higher in the mixed than in pine plantation. The decomposition processes of all species followed Olson’s exponential model. The decomposition coefficients (k) of all species were also higher in the mixed plantation and had the same order as the decomposition rates. The nitrogen contents of leaf litter of the different species studied increased initially and then decreased with time. Net release of N only occurred in pine plantation. Potassium contents appeared to decrease first but later increase, and net release was only found in mixed plantation. Calcium, magnesium and boron all showed similar pattern of initial increase followed by later decrease. They all had net release in both mixed and pine plantations. The release of phosphorus varied greatly between species and showed no clear trend.

It is important to study the effect of tree density on the substrate quality and decomposition rate of leaf litter in plantations. In 2002, an experiment of the effects of thinning intensities at four different levels (i.e., 0 (I), 35.7% (II), 49.2% (III), and 64.2% (IV)) on undergrowth were carried out in an 18-year-old Pinus tabulaeformis plantation at an initial density of 3130 trees/hm² in the middle of the hills of Yingpan, Yanqing County, Beijing. Three years later, the rates of decomposition, the amount of nutrients returned, and the characteristics of leaf litter were compared by a litter bag method. The results show that the annual loss of dry matter of leaf litter in plots I, II, III, and IV was 25.81%, 26.25%, 27.68%, and 25.96%, respectively. The turnover of leaf litter was 10.04, 9.84, 9.24, and 9.97 years, respectively. Therefore, it is feasible and convenient to evaluate the effect of thinning on the rate of decomposition. In the first two months, the N, P, K, and Mg nutrients were released quickly. During the entire observation period of 14 months, the return of both N and Mg nutrients in the four plots exhibited a release-accumulation type of cycle. The return of P and K indicated a trend of release-accumulation and a relative balance. However, the return of Ca was far different from that of the other nutrients in the four plots. The total nutrient return of the four elements N, P, K, and Mg in the plots was 10.806, 31.016, 31.798, and 39.365g/kg, respectively. Specifically, the quality of leaf litter in plot I was the worst in that N and Ca accumulated only 2.567 and 0.767g/kg, respectively. Thinning did decrease the ratios of lignin to N and C to N and accelerated the rate of decomposition of leaf litter. The content of crude ash in leaf litter was enhanced by thinning, which prevented acid material, such as tannins and resins, from returning to the soil. The effect of thinning intensity was evaluated by the ratio of lignin to N, the ratio of C to N, and the ash content in leaf litter.

It has been difficult to monitor the gas exchanges of tall arbor trees using portable equipment, e.g. Li-6400, as it is hard to reach to the leaf samples in situ. Due to the tree heights, we aimed to compare the gas exchange between in situ and abscised leaves of Cylobalanopsis glauca under three habitats, with the purpose of identifying a possible methodology with which we might be able to use abscised rather than in situ leaves. The results showed that after the samples were abscised, the leaf stomatal conductance (g_s) immediately increased before dropping gradually later. The extent of this change was found to be temperature-dependent. The linear relationships either between g_s and transpiration (E), or between g_s and net photosynthesis (P_n) were significant but the former had a higher correlation, indicating that the opening of the stomata has a more intensive effect on E than on P_n. Temperature is a key factor affecting the variation of gas exchanges of the abscised leaves, with higher temperature in the karst area resulting in a rapid E loss and leading to the fact that water stress occurs earlier to the part stomatal closure, which in turn decreases P_n. A reliable duration for measuring the gas exchanges from the abscised leaves is determined by leaf temperature. In the karst area where the leaf temperature is frequently over 32°C in the summer, the reliable duration can last only 3―6 min after abscission, while in the Guilin Botanical Garden (non-karst area) with leaf temperatures of about 32°C, the reliable duration can last 10 min; in the green house, it is at around 20°C, and the reliable duration will possibly last 20 min.

Due to the embarrassment that may occur from trying to define the forest in the present situation, this paper gives a new approach through the functional analysis of the forest rather than a simple physical description. Here, the forest is now actually the result of natural and social work. The forest has provided the environment, the economic resources and the infrastructure, respectively, and for now, the forest appears as a structured body and takes responsibility in modern human society. With its characteristics of varied hierarchical structure, limited functions, an open system, a dynamic system, moderate mould ability, varied stable equilibrium, etc., it is suggested that the related matching policy on forests should be updated as follows: to define the forest in its entirety, to specialize the public management, to diversify the management objectives, and to cultivate the forest as a continuous procedure. From the experiences of developed countries, we establish a new state-owned forest system.

AFLP fingerprinting analysis of Fusarium circinatum, Nirenberg and O’Donnell and relative species was carried out. Ten primer-pairs that could generate abundant polymorphism fragments were screened. A total of 298 nucleotide acid fragments were amplified with the primers from the template of the 17 strains of Fusarium spp., among which 283 fragments were polymorphic. Percentage of polymorphic loci produced by each pair of AFLP primer-pair was 94.97% in average and varied from 89.29% to 100%. All these data indicated that considerable genetic variation existed among F. circinatum and relative species at DNA level. Molecular genetic distances among Fusarium spp. were calculated, and the relationship among them was described quantitatively. Compared with biological species, the result of cluster analysis was basically similar to the phenotypic classification of species. Genetic diversity of E-AT/M-CAA AFLP fingerprinting of Fusarium spp. was analyzed, and specific and difference bands for each species and all Fusarium section Liseola tested were identified based on the E-AT/M-CAA AFLP fingerprinting.

Using electronic microscopy, ultrastructural changes were observed during differentiation in a secondary xylem vessel element (VE) in Populus deltoides. Results showed that morphological development of VE differentiation was successively divided into three stages. First was primary cell wall outspread (the initial stage), where the VE was highly vacuolated and the protoplasma distributed along the cell wall. Second was secondary cell wall construction (the pivotal stage), where substances accumulated before the tonoplast broke, and the VE organelle was distinct. Golgi bodies and vesicles, which were associated closely with synthesis and transportation of secondary cell wall substances, were also abundant. After the tonoplast broke, these substances accumulated faster. Simultaneously, the protoplasm was disaggregated and the agglomerated chromatin was distributed over the margin of the nucleus, showing the typical characteristics of programmed cell death (PCD). During secondary cell wall formation, no cell wall substances accumulated between the terminal cell walls of neighboring VEs. In addition, terminal cell wall substances were disaggregated in the post secondary cell wall formation. Later, when the remnant terminal cell wall was broken in the third stage, perforation occurred. Thus, for these successive stages of VE differentiation, the critical stage, when differentiation was not reversible, was at the start of secondary cell wall formation with succeeding VE differentiation similar to a typical PCD process.

ITS sequences of ten kinds of plants of Lespedeza and an out group were obtained by primer design PCR, sequencing and cluster analysis. The results show that ITS1 section length was 228―243 bp, 5.8S sequence length was 165 bp which was very conservative; ITS2 section lengths varied from 215 to 220 bp and the conservative sites occupied 88.1%. Phylogenetic analysis of ITS sequences using PAUP 4.0 software and their genetic relationship were discussed.

Cyclocarya paliurus seedlings of three provenances were treated with three levels of salt (0, 51.0 and 85.0 mmol/L NaCl) in a hydroponic system of a phytotron. The ultrastructural distribution of H⁺-ATPase activity and ultrastructural variation were investigated in mesophyll cells of C. paliurus seedlings after 12 or 20 days of salt treatment. The results showed that under normal growing conditions, H⁺-ATPase activity was low and localized mainly in the nucleus. After 12 days of salt treatment and an increase in salinity, we found that the greater the H⁺-ATPase activity, the lighter the damage suffered by mesophyll subcells after 20 days of salt treatment and the stronger the salt-adaptation ability of seedlings. The location of H⁺-ATPase, largely in the nucleus, indicated that salt-damage suffered by the seedlings was light, whereas its presence, mainly in the vacuoles, showed that salt-damage was more serious. Our preliminary conclusion is that the salt-tolerance level of C. paliurus seedlings for the three kinds of provenances was in the following order, from high to low: Huangshan seedlings from Anhui  Province > Kunming seedlings from Yunnan  Province > Jiujiang seedlings from Jiangxi Province.

The structure, distribution and patterns of resin ducts in processes of its initiation and development were studied with the methods of thin section and ultrathin section. This paper emphasized the ultrastructural changes during canal development by a ring of the live epithelial cells, and the epithelial cells were usually surrounded with one or two layered sheath cells, which were normal parenchyma cells in some primary resin ducts and became dead cells with thick walls in other primary and secondary resin ducts. The resin ducts were found to occur in almost all organs, except in cotyledon. The resin ducts were formed by schizogeny and their development can be divided into three stages (e.g., initial stage, formation stage and mature stage). At the initial stage, the initial cells had many plastids without integral membrane structures, which contain one or two starch grains in them, and there are a few black osmiophilic droplets on the endoplasmic reticulum and membranes. A small number of osmiophilic droplets were present in the plastids. At the formation stage, the number of plastids, mitochondria and Golgi bodies in epithelial cells increased. The plastids were commonly surrounded by endoplasmic reticulum sheath. The larger osmiophilic droplets in cytoplasm and the smaller osmiophilic droplets on the plastids envelope, mitochondrion envelope and Golgi vesicles obviously increased in number during canal developing. At the mature stage, the cytoplasm of epithelial cells became thin with small nucleus. The number of mitochondria and Golgi body decreased, but numerous plastids still existed. Osmiophilic droplets were abundant in epithelial cells as in previous status. Taken together, the structures of plastids in epithelial cells gradually became well developed and the synthesis of resin was remarkably enhanced during resin duct formation and plastids should be the main site for resin synthesis.

In this paper, the growth rate of five wood-rotting fungi, i.e., Coriolus versicolor, Irpex lacteus, Fomes fomentarius, Piptoporus betulinusand Pholiota adiposa, in solid medium and their biomass in liquid culture medium were compared by measuring mycelium length and dry mass. The activity of three main ligninolytic enzymes in those fungi, namely LiP, MnP, and Lac, were also tested by colorimetry. At the same time, these fungi were used to decay the wood samples from 300 natural trees of white birch, to study their wood-decaying ability by measuring wood mass loss. The result showed that the growth rate, biomass, ligninolytic enzyme activity, and wood-decaying ability of the fungi were incompletely correlated. The growth rates of C. versicolor and I. lacteus were faster than those of P. betulinus and F. fomentarius; P. adiposa was the slowest in growth. The biomass of P. betulinus was the highest; C. versicolor, I. lacteus and F. fomentarius were in the middle, and P. adiposa was the lowest. There existed LiP, MnP and Lac activities in all fungi except P. betulinus, and the enzyme activities induced by wood powder were all higher than those of the control. The Lac of I. lacteus and the LiP of F. fomentarius and P. adiposa were only expressed in wood powder medium; the longer the fungi were cultured, the higher activity the enzyme had. The decomposition ability of C. versicolor to wood samples was the highest, followed by F. fomentarius and P. betulinus; I. lacteus and P. adiposa were the lowest.