In this study, the effects of fine root (grass root) decomposition to the soil active organic carbon were investigated in a laboratory microcosm under 10, 20 and 30 ℃. The roots were mixed with the soil in the following four treatments: mixture of birch (Betula luminifera) roots and grass (Hemarthria compressa) roots (treatment 1), birch (Betula luminifera) roots (treatment 2), grass (Hemarthria compressa) roots (treatment 3), cedar (Crytomeria fortunei) roots (treatment 4) and no roots (CK). The results showed that fine root source, incubation time and incubation temperature all influenced soil microbial biomass carbon (SMBC),water soluble organic carbon (WSOC),readily oxidized carbon (ROC),total organic carbon (TOC). After 120 d, the contents of SMBC,WSOC,ROC,and TOC in the treatments were higher than those in CK (P＜0.05). The contents of SMBC,WSOC,ROC,and TOC in treatment 1 were higher than those in the other treatments in 60 or 120 d. The effect of incubation temperature on MBC and WSOC in four treatments was ranked in an order as the following, 30 ℃＞20 ℃＞10 ℃, while the effect on ROC and TOC was in an order of 10 ℃＞20 ℃＞30 ℃(P＜0.05).

Interspecies relationships between the dominant species of wetland vegetation on Lianbotan in Fen River, Shanxi by Fishers exact test, Pearsons correlation coefficient and Spearmans rank correlation based on the data collected from 42 field plots. Ecological species groups of those dominant species were studied by using group averaging clustering. The results indicated that: Sixteen species-pairs had positive association coefficient and one species-pair had negative association coefficient by Fisher's exact test. In addition, 20 species-pairs had positive correlation coefficient and 5 species-pairs had negative correlation coefficient by Pearsons correlation analysis. Furthermore, 34 species-pairs displayed positive and 7 were negative correlations by Spearman. Associations and correlations between most species-pairs were not significant, which suggested that the dominant species distributed in an isolated pattern and their inches separated. On the basis of the results of association and correlation of those dominant species as well as that of analysis of clustering, those dominant species were divided into 4 ecological species groups: Phragmites australis group, Leymus secalinus group, Imperata cylindrical group, and Artemisia lavandulaefolia group, which reflected the characteristic of the vegetation community in this region with the moisture gradient.

Litter on forest floor was collected and sampled in 14 different patterns of planting arrangement in the protective greenbelt in northern Karamay, China. Vertical distribution of the litter in the forest floor was investigated and the dry mass and chemical composition of litter were measured and analyzed. The results showed that the litter dry weight on the forest floor varied from about 117.34 -719.36 g ·m^-2. The planting pattern with trees and shrubs mixed by rows had significantly (P<0.05) greater dry weight than other patterns. The litter pools in the different sampling layers of the forest floor displayed in an order of the litter layer > fermentation layer > humus layer. Leaf litter was the main component, accounting for 97.0%-53.8% of the litter mass. Branch (bark) contents varied among the different arrangement patterns, and flowers (fruits) accounted for the smallest proportion of the forest floor litter. Nutrient contents and storage on the forest floor differed greatly among the arrangement patterns, and they were higher in the pattern with both trees and shrubs (Amorpha fruticosa) mixed by rows. The content of organic C was the highest, the total Ca was the second, the total P the lowest and the other nutrients also lower. The nutrients storage was mainly in the litter layer and the fermentation layer.

Malus sieversii is an important germplasm resource, and valuable for genetic improvement and conservation of genetic diversity of apples. In this paper, one-year-old seedlings from 7 populations of Malus sieversii in Gongliu and Xinyuan of Xinjiang were used. Cold hardiness of the seedlings was determined by means of the EIS method in comparison with EL method. The results with different cold hardiness determination methods indicated that there was no obvious difference in the semilethal temperature within populations of Gongliu and Xinyuan. In contrast, there was significant difference in the semilethal temperature between the two populations. The semilethal temperature of Gongliu populations was significantly lower than that of Xinyuan populations. Thus, the cold resistance of Gongliu populations was higher than that of Xinyuan populations. Among the six parameters (τ,ψ,r,r₁,r_e and r_i) in the Single DEC model of electrical impedance spectroscopy, was obtained by three parameters (r₁,r_e and τ) was able to be used t determine semilethal temperature of the tested samples. The semilethal temperature obtained by r₁ and r_e was extremely significantly correlated with the conductivity method, suggesting that r₁ and r_e could be used to determine the M. sieversii cold resistance. The cold hardiness estimated by the EIS method was basically similar to that, assessed by means of the traditional EL method. The EIS method is superior over the EL owing to its time saving and no incubation.

Pyrus pyrifolia 'Sunhwang was used as experimental material.the canopy structure characteristics and photosynthetic capacity were comparatively investigated among the horizontal trellis system, V-shaped system and the sparse shaped canopy with WinsCanopy2005a and photosynthetic analyzer.The sugar content and activities of the sorbitol-invertase were measured during the fruit development stage to determined.It studied the effects of tree shape on the sugar accumulation process and activities of sorbitol-invertase in fruits. The results showed that canopy openness and photosynthetic photon flux density (PPFD) were significantly higher in Horizontal trellis system than that in the other two tree shapes.The light transmittance and photosynthetic capacity in Horizontal trellis system was the best among the three tree forms. Contents of the soluble sugar,starch,glucose,fructose, sucrose,sorbitol and the activities of sorbitol-invertase were the highest in the fruit of the level-shaped system,following by V-shaped system, and then the Sparse shaped canopy. The differences were significant.The accumulation sugars in the fruit mainly were starch and sorbitol at the early development stage and fructose at the late stage.The activities of SDH and SOX increased gradually in the fruit from early to middle development stage and decreased at the late stage but still were higher than that in prophase.

In order to study the photosynthetic characteristics of green apple fruit, photosynthesis in different position of apple fruits and the dynamic variation of photosynthetic capacity as well as pigment contents in Starkrimson fruit peel were investigated at different development stages using Oxygen Electrode System and Spectral Analysis System. The result showed that photosynthetic rate in sun-exposed peel was higher than that in peel on shaded side. In longitudinal direction, the photosynthetic rate of sun-exposed peel gradually decreased from calyx-end peel to stalk cavity. The sun-exposed peel at the middle part of a fruit had an average photosynthesis along the longitudinal direction, which could be used as the representative photosynthesis of an apple fruit. With development of an apple fruit, photosynthetic O₂ evolution rate gradually declined, and chlorophyll content remarkably decreased, but the ratio of carotenoids /chlorophyll increased. At the late stage of green fruit development, the reduced chlorophyll content could decline the absorbed light energy, mitigating photoinhibition of apple fruit peel when the photosynthetic ability decreased greatly, which might be an adaptive mechanism of apple fruits in light environment.

The leaves of Cotinus coggygria in Fragrant Hills Park at different altitudes were taken as the materials. The correlation between the leaf color and pigments composition of C. coggygria was analyzed. The results showed that the value of leaf color chroma a^* was negatively with the contents of chlorophylls and positively with anthocyanins, respectively. The descending chlorophylls and ascending anthocyanins contents were the main factors responsible for the leaf color reddening. The content of flavonols was in an upward trend, affecting the values of lightness L^* and chroma b^*, while the content of carotenoids kept stable, and was no significant correlated with the values of leaf color parameters. Based on the investigation in fall of 2007, temporal and spatial variation of the leaf color at different altitudes from Fragrant Hills Park was obtained. In time domain, the variation of the leaf color chroma a^* at high altitude area (564 m) and middle altitudes areas (466 m and 315 m) showed the same trend, take high altitude area (564 m) as an example, the values of leaf color chroma a^* ascended steeply from October 12 and reached the peak on October 24, and then descended slowly. The values of leaf color chroma a^* at low altitude area (195 m) ascended continuously from October 4 to November 9. In space domain, the values of leaf color chroma a^* at high altitude area (564 m) increased quickly, and decreased fast, it can be seen that the leaves of C. coggygria in this area changed color earlier, but defoliated quickly, so this area was suitable for appreciating in the early time (from October 20 to October 28). While the leaves of C. coggygria at middle altitudes areas (466 m and 315 m) changed leaf color together with those at high altitude area, but had longer duration of coloring to appreciating (from October 24 to November 5). The leaves of C. coggygria at low altitude area (195 m) changed color at latest, and defoliated slowly, so this area was suitable for appreciating in the late time (after November 1).

This research investigated the physiological and biochemical diagnosis indices of the weak and senescent ancient pines, Pinus tabulaeformis which were expected to provide scientific basis for their rejuvenation and management. The annual pine needles were used as materials from healthy or weak pines with different ages in the Summer Palace in Beijing. The ratio of mass to length, chlorophyll content, MDA content, SOD activitiy of pine needles were measured. The results showed that, comparing with healthy pine, the senescing and weak one had irregular crown, soft and slim needles with higher ratio of mass to length, lower chlorophyll content and ratio of chlorophyll a/b. The MDA content increased with needle development during growth period, and was higher MDA content in senescing and weak ancient pines, The senescing pine had lower total SOD activitiy and SOD specific activitiy. It was summarized that the ratio of mass to length, chlorophyll content, MDA content, SOD activitiy of pine needles could be used as indices to diagnose the senescence and weakness of ancient pines.Finally it was discussed that these physiological indices were used to indicate the growth status of ancient pines.

A cDNA clone encoding DREB2Awas isolated from a cDNA library prepared under drought stress by the gene-specific PCR amplification from Populus tomentosa. The cDNA was 946 bp in length with an open reading frame (ORF, 864 bp in length) which is capable of encoding a protein of 287 amino acids. The deduced protein sequence of the PtDREB2A shares 80.3％, and 83.3％ identity with functional domain of AP2/ERF of Arabidopsis thaliana AtDREB2A, and Oryza sativa OsDREB2A, respectively. Tissue differential expression detected with realtime-PCR indicated that PtDREB2Atranscripts had their mRNA products in roots, stems, leaves and apical shoot meristems with varied levels. The PtDREB 2Atranscripts were the most abundant mRNA products in leaves, with medium expression in stem bark and roots, but a weak expression was detected in apical shoot meristems, and in the phloem, cambium, and xylem of stem. We analyzed the expression patterns of PtDREB2Aunder abiotic stress conditions and phytohormone treatment, and revealed that expression of PtDREB2A was induced by heat-shock, cold, drought and high-salt stress, but also by IAA, NAA, and GA₃, not by ABA. The genomic sequences of PtDREB2A in 45 individuals were aligned, compared and analyzed using the software MEGA4.0 and DnaSP4.50.4. A total of 49 single nucleotide polymorphisms (SNPs) were detected and the frequency and diversity of SNPs were 1/18 bp and 0.010 48, respectively. In total, 46 SNPs were detected in the coding regions of PtDREB2A, of which 19 and 27 were silent and missense mutations, respectively. The results, therefore, would provide the important foundation for gene-assisted improvement of tolerance to abiotic stresses in P. tomentosa.

It is well known that there is an obvious heterosis occurred in interspecific hybrid of Liriodendron, however its genetic basis is not clear. In this paper, the heterosis of growth was estimated for 12 interspecific crossing combinations, and their heterozygosities and parentage genetic distances were also evaluated by using SSR markers. It was found that there were no significant correlations between heterosis and genetic distance and heterozygosity, which indicated there would be other factors relating to the heterosis of hybrid Liriodendron besides the genetic distance and heterozygosity.

Granier-type thermal dissipation probes (TDP) were applied to measure tree sap flow dynamics in a naturally-regenerated Quercus liaotungensis forest in semiarid Loess Plateau region near Yanan, Shaanxi Province. Air temperature, relative air humidity, solar radiation, and soil water content were monitored at the same time. In this paper, we measured diurnal courses of sap flow characteristics and analyzed relationships between sap flux density and environmental factors with three dominant trees during the growing season of 2009. The results showed that sap flux densities in Q. liaotungensis reached their daily peaks earlier than solar radiation and vapor pressure deficit, usually around 10:00 am, though the diurnal courses of sap flux density were generally similar to the changes of environmental factors. As the season and leaf phenology progressed, the overall performance of sap flux density was relatively low at early stage (April to June), high in the mid and late stage (July to September), and rapidly declining in the last stage (October). Exponential saturation function was applied to fit the data sets of sap flux density and vapor pressure deficit, and the fitted curves effectively reflected the sap flow characteristics in different months. Differences in the fitted curves and parameters among months suggested that the transpiration process in these trees was also affected by soil moisture conditions or other environmental factors.

This paper studied nutshell structure indexes (seal grade, thickness, density and mechanical strength) of different walnut cultivars which were harvested from various production localities, in different harvesting periods and at different tree-crown locations. The results showed that there were significant differences in shell structure indexes among different cultivars, especially between Juglans regia and J. sigillata. Except for a few cultivars, there were significant differences in shell density and thickness of the same cultivars produced in different regions for all other cultivars. Seven different harvesting time was implemented in this study. From early to late of the harvesting time, the shell seal grade of walnuts descended gradually; the shell density ascended at the early period but descended afterwards; and the mechanical strength had an ascending trend. The shell mechanical strength of walnuts grown on the sunny side was higher than that of those grown on the shady side; but the shell density of walnuts grown on the sunny side was lower. In summary, the cultivars, irradiation and harvesting time were the key factors that influenced walnut shell structure.

The composition of landscape and function types of Xiannangou watershed in loess hilly-gully region was studied based on a field investigation on which the landscape patch type maps were drawn. After digitizing the maps with geographical information technology, the landscape classification system and patch type database of Xiannangou watershed were established. The relevant landscape indices were calculated in order to analyze the landscape composition of this watershed, which would provide evidence for optimizing landscape pattern and evaluating the watershed management effect. The result showed: 1) Robinia pseudoacacia (both mature and young) occupied the largest area of Xiannangou watershed, followed by Bothriochloa ischaemun-Artemisia giraldii+Artemisia sacrorum association, farmland, Sophora viciifolia and Artemisia sacrorum+Artemisia giraldii association. The 6 landscape types occupied 82.26% of landscape area and 60.23% of landscape patches, thus they constituted the main part of Xiannangou watershed. 2) The eco-protection type occupied more than 3/4 of total patch number and area in Xiannangou watershed. The area ratio of three landscape function types (eco-protection type, pro-economics type and living-service type) was around 3.63 ∶1 ∶0.08. 3) The area ratio of human directed landscape and natural landscape was almost 2 ∶1 and eco-protection type occupied about 2/3 area of human directed landscape. The landscape composition of Xiannangou watershed was characterized by diverse landscape types, abundant patches, tiny landscape granularity, landscape fragmentation and great human influence on landscape composition. In the future, the vegetation quality of eco-protection type should be improved and prevented from pollution caused by pro-economics type, meanwhile the living-service type should be planned reasonably, and all of these measures can favor establishing the small watershed model which is healthy in ecology and sustainable development in economy.

Pinus massoniana forests in Yuelue Mountain play an important role in improving and maintaining urban environment of Changsha city. Based on data collected through a field investigation in Yuelu mountain, the community types of Pinus massoniana forests were classified via TWINSPAN, flexible beta clustering, DCA and NMDS. Four indices of species diversity were used to analyze differences in richness, evenness and heterogeneity between the communities. Results showed that, compared to TWINSPAN and DCA, NMDS coupled with flexible beta clustering was a better quantitative classification method, with which 10 community types of Pinus massoniana in 28 plots were identified, representing four vegetation types, 10 formations. Pinus massoniana forests in Yuelue Mountain formed Pinus Massoniana and four coniferous-broad mixed leaved forests, including Pinus massoniana+Cinnamomum camphora+Liquidambar formosana, Pinus massoniana+Choerospondias axillaries, Pinus massoniana+Camellia euryoides, Pinus massoniana+Cinnamomum camphora and Liquidambar formosana+Pinus massoniana+Symplocos setchuensis. The lowest richness, evenness and heterogeneity, particularly extremely low for the herbs, were measured in the pure Pinus Massoniana forests. In contrast, the coniferous-broad mixed leaved forests, especially in the Pinus massoniana+Castanopsis sclerophylla, showed relatively higher species diversity. The important value of the Pinus Massoniana in stands was negatively correlated with richness, evenness and heterogeneity indices of the trees, evenness and heterogeneity indices of the herbs, but not correlated with diversity of the shrubs.

Soil aggregate stability, as a key indicator of soil structure, is a product of interactions between soil environment, management practices, and land use types. Soil samples were collected from land with different vegetation in the loess hilly-gully region. The content of the soil water stable aggregate was measured by the fast wetting and slow wetting method of Le Bissonnais. The impact of land use and wetting velocity on soil aggregate stability was analyzed. The results indicated that percentage composition of water stable aggregate with a diameter larger than 0.2 mm, mean weight diameter (MWD), geometrical mean weight (GMD) from planted forest land were larger than those of the soil from orchard and farmland. Fractal dimensions of water stable aggregate size distribution of the soil from orchard and farmland were larger than those of the soil from forests, which indicated that the soil structure under forest lands had been improved. There were significant relationships between organic matters, >0.2 mm aggregate content, MWD, GMD and D. Organic matter was the main cementing and stabilizing agent of aggregate formation. Soil aggregate stability was different with measurement methods of the fast wetting and the slow wetting. The fast wetting caused greater disruption than the slow wetting, indicating that dissipations played an important role in the collapse of soil aggregates.

In this study, the sample data were based on stem analysis of 84 trees from Dahurian Larch (Larix gmelinii) plantations located in Dailing Forest Bureau in Heilongjiang Province. Max and Burkhart segmented taper model was used to model tree stem taper. Parameters estimates of 4 parameters and 2 inflection points were obtained simultaneously using Seemingly unrelated regression procedure in SAS. This model is suitable for describing dahurian larch stem taper based on significant test of parameter estimates and F-test. Then, a nonlinear mixed-effects modeling approach was used to model stem taper based on the base model. The best performances were obtained for this model with parameters b₁ and b₂ as mixed effects when considering plot effects and with parameters b₂ and b₄ as mixed effects when considering tree effects. The mixed-effects models provided better model fitting than original model, moreover, the precision of mixed-effects model when considering tree effects is better than that when considering plot effects. Validation confirmed that the mixed model with calibration of random parameters could provide more accurate and precise prediction.

Leaf area (LA) as an essential part of crown structure affects both the growth of forests and protective effects of shelterbelt. The variation in specific leaf area (SLA) and leaf area with position in the crown was investigated for 5-year-old and 7-year-old Populus × euramericana cv."74/76"stand in Henan Eastern Plain. Allometric equations describing the leaf area of the entire crown were developed. The results showed that SLA on individual tree were 136.6,138.2 cm² ·g^-1 in 5-year-old and 7-year-old trees, respectively. However, leaf area on individual tree was significantly influenced by tree age, on average it were 45.4,85.8 m² in 5-year-old and 7-year-old trees, respectively. Specific leaf area and leaf area were significantly by the position in the crown. Specific leaf area increased significantly from the top to the bottom of the crown. Leaf area increased significantly from the top to the bottom of the crown for 5-year-old stand, however, it in the middle was significantly higher than that in the upper and the lower of the crown for 7-year-old stand, and both increased significantly from the interior to the exterior of the crown. There were different classes of shoots in different stand age, three classes of shoots in Populus × euramericana cv."74/76" aged 5 years and four classes of shoots in it aged 7 years. Leaf area among several orders of shoots had both significantly difference for 5-year-old and 7-year-old stand. Allometric relationships of leaf area with different tree characteristics indicated that stem diameter at breast height (DBH), tree height (H) and crown length (CL) were reliable predictors of leaf area at the tree-level, however, the allometric relationships between DBH and leaf area at the tree-level were more reliable and convenient to predict the tree-level leaf area and to estimate leaf area index (LAI).

Prediction of fuel moisture content based timelag and equilibrium moisture content is a accurate method, which is commonly employed in the American National Fire Danger Rating System and the Canadian Forest Fire Danger Rating System. The timelag and equilibrium moisture content constants vary with fuel types and structure. A preliminary study was conducted on the effects of fuelbed structure features on these parameters in desorption process of fuelbeds composed of Scots pine needles. The results indicated that with the Catchpoles method, the fuel moisture was well modelled with errors within 0.01, which approved the validity of the estimated parameters. Further analysis revealed that fuelbed depth and load affected these parameters: timelag and constant b of Nelson(1984) model were positively, and constant a of the model was negatively, correlated with these features. Models established for predicting these parameters from these fuelbed structure features overestimated timelag and constant b but underestimate constant a. There exist some uncertainty in the analysis, and futher research is needed on both desorption and absorption processes with other equilibrium moisture models and under broader weather conditions.

Habitat selection of Francois' Langur (Trachypithecus francoisi francoisi)was studied by using Resource Selection Functions and Resource Selection Index in the Jinfo Mountain Natural Reserve from March to May of 2007. The results indicated that the key factors notably influencing habitat selection were canopy density, shrub size, human disturbance and distance of cave. Francois' Langurs preferred the tree-shrub forests in the area studied with higher canopy density(CA)(>0.5), higher density of tree and shrub ·(400 m²)^-1], greater shrub DBH(>8 cm), far from human disturbance (HD) (＞1 000 m), closer the cave and near water source (<250 m). Francois' Langurs preferred habitats with a southward aspect. Resource selection functions is a log-linear model: logit (P)=-21.964+2.126×DBH+2.108×CA+2.081×HD-1.829×DC. From this model, we can estimate a habitat selection probability: P=e^{logit (P)}/(1+e^logit(P)).

In order to make nondestructive evaluation of the health of standing trees,120 standing trees including 4 species were detected by Arobotom,Resistograph and RSM-SY5 ultrasonic instrument respectively. The data on the propagation velocity of stress wave and ultrasonic wave transmitting in indefectible cross section of standing trees were analyzed. Results showed that: when standing tree was detected with 8 testing points, stress and ultrasonic wave transmitted most slowly along Path A (adjacent point) and most quickly along Path D(radial direction) on indefectible cross section, the propagation velocity was increasing from Path A to Path D. For indefectible Populus simonii,Ulmus pumila,Salix matsudana and Fraxinus mandshurica,the radial propagation velocity of stress wave tested by Arobotom was 788.46,1 025.45,940.62 and 1 146.06 m ·s^-1 respectively; the corresponding radial propagation velocity of ultrasonic wave tested by RSM-SY5 was 1 159.57,1 537.5,1 323.15 and 1 558.6 m ·s^-1 respectively. Through regression analysis,the correlation between the radial propagation velocity of stress wave and ultrasonic wave was significant,R²>0.77,so it was feasible to non-destructive test standing trees with these two instruments.

In this study, the main load-bearing melon-shaped columns of the grand hall of Ningbo Baoguo Temple were examined by nondestructive testing method, and a resistograph was used to probe into the interior structure of these columns based on the resistance curve outline and shape generated by this instrument, combined with different feeding direction of the probe pin. The current study was aimed at providing fundamental data for the renovation and preservation of the grand hall. The results showed that C5,C6,D6,E3,E6,F3,F4,F5,F6 are melon-shaped columns, D4,D5,E4,E5 are jointed melon-shaped columns, C4,D3 are melon-shaped columns with bundles, C3 is special melon-shaped column.

Dialdehyde cellulose(DAC)was prepared from microcrystalline cellulose with periodate sodium as oxidant. The influences of oxidant concentration, reaction temperature, reaction time and pH of solution on the aldehyde content were investigated. DAC was characterized by XRD, FTIR, element analysis and measuring the aldehyde group. The relation between aldehyde content of DAC and urea adsorption capacity (AC) was discussed. The adsorption equilibrium and kinetics of urea onto dialdehyde cellulose were studied. Experimental results showed that the optimal synthetical condition was that the ration of NaIO₄ to MCC was 2.4 by weight, reaction temperature was 35 ℃, reaction time was 3.5 h and pH was 2, and the DAC with aldehyde content of 97.74% under this condition. As the increase of aldehyde content, the AC for urea first increased and then decreased. The max. AC for urea was 59.23 mg ·g^-1 and it is ten times as much as that coated dialdehyde-starch adsorption capacity of urea adsorption(6 mg ·g^-1), that is four times as much as what capsulated enzymie starch dialdehyde AC,equilibrium reached after 4 h. The adsorption isotherm curve of DAC fit well with Freundich equation.

The carbon/pottery composite for removing fluoride is prepared from bone dust, bamboo power, clay by carbonization and activation process. Research on the effect of material proportion, heating rate, activation temperature and holding time for defluoridation capacity and the efficiency of defluoridation of carbon/pottery adsorption composite, and the characteristics of carbon/pottery composite have been studied by SEM and FTIR. It is found that, with heating rate, activation temperature and holding time increasing, defluoridation capacity and the efficiency of defluoridation of carbon/pottery adsorption composite tend to increase at first and then reduce. Meanwhile, physical adsorption and chemical adsorption occur when the carbon/pottery composite is used for removing fluoride. Therefore, a kind of synergistic effect appears, which improves the effect of carbon/pottery composite for removing fluoride. Under the optimized conditions, the defluoridation capacity of carbon/pottery adsorption composite is 2.214 mg ·g^-1, and the efficiency of defluoridation is 88.56%.

In order to evaluate tourism competition of the National Forest Parks, this paper proposed a tourism niche overlap theory and models based on the niche theory. Based on a field survey, an evaluation index system of tourism niche was established with Delphi and AHP methods. The system was used to measure the tourism competition between Zhangjiajie National Forest Park and Tianmenshan National Forest Park with the tourism niche overlap models. The results showed that: the tourism niche overlap of Zhangjiajie and Tianmenshan National Forest Park was 0.190 4 and showed there was no apparent tourism competition. But there exited competition between Zhangjiajie and Tianmenshan National Forest Park with tourism resource and tourism service, resource location, infrastructure service and tourism information service, entertainment, shopping, free traffic, the degree of communication network, advocacy effort and resource to promote environmental protection because the tourism niche overlap between Zhangjiajie and Tianmenshan National Forest Park was 0.320 5, 0.327 5, 0.623 2, 0.487 0, 0.471 0,0.608 1, 0.540 7, 0.637 9, 0.615 2, 0.993 6. Both Zhangjiajie and Tianmenshan National Forest Park should avoid the tourism competition of these indicators in the future.

Plant stem cells are characterized with two main features of the self-renewal and their potential to differentiate into multiple cell types. Plant stem cells are believed to have important roles in controlling the balance between organ formation and meristem maintenance. We review the studies on the organization models in the three kinds of meristems (shoot apical, root apical and vascular cambium) and the WUSCHEL/CLAVATA(WUS/CLV) feedback regulatory mechanisms in plant stem cell niche. In summary, the three kinds of meristems not only have similar potential for maintaining initials over long periods in the plant stem cell niche, but also have a similar cell niche (or zone) to regulate the adjacent stem cell division or differentiation by their structural comparison. A similar feedback regulatory mechanism exists in shoot apical meristem (SAM) and in root apical meristem (RAM), respectively identified as WUS/CLV and WOX 5 /CLE 40 , and they all have a function in maintaining a balance between stem cell division and other tissues formation. There are limited reports on the WUS/CLV feedback regulatory mechanism in vascular cambium (VCAM), especial on woody plants. However, we propose that there would be a similar mechanism in VCAM stem cell niche.

The community characteristics of Asterothamnus centrali-asiaticus and Gymnocarpos przewalskii in the north Subei of Gansu Province were investigated from 2006 to 2009. The results showed that A. centrali-asiaticus and G. przewalskii mainly distributed over piedmont alluvial fan, proluvial fan, gravel gobi and dry river bed regions. They distributed at a range from about 1 500 to 1 600 m a.s.l.in the northern mountain region of Subei, and at a range from about 1 900 to 2 900 m a.s.l. in the southern mountain region of Subei. G. przewalskii, as companion species, emerged in A. centrali-asiaticus community on West gobi of Subei, while A. centrali-asiaticus and G. przewalskii, as constructive or dominant species, formed plant community in Hongliu Gap region. The species composition of A. centrali-asiaticus and G. przewalskii community consisted of 44 species, which belong to 31 genera of 13 families. The flora of the ancient Mediterranean and the West Asia to Central Asia accounts for 54.8%; The flora of the north temperate distribution pattern accounts for 19.4%, and world-distributed species constitute 9.7%. There was close relation among the floras of A. centrali-asiaticus, G. przewalskii desert communities and those of the ancient Mediterranean. The species diversity indexes of A. centrali-asiaticus and G. przewalskii community were all high, However, evenness index was very low in Hongliu Gap region, although species were abundant. Species distribution was not uneven in the community, and the number of old age plants of G. przewalskii was more than that of young age plants in all communities which implied that G. przewalskii population was inclining to recession.

The physiological and biochemical indexes of Malus micromalus and the biological parameters of Aphis citricola and its predator Harmonia axyridis were investigated after Abamectin, a pesticide treatments. The results showed: 1) Leaves from M. micromalus displayed lower leaf wax content, chlorophyll content and superoxide dismutase (SOD) activity, and higher total aminophenol content and soluble sugar content, compared with the control. The various trends of these indexes were showed as the pesticide concentration increased. 2) A. citricola, an aphid reared on leaves of M. micromalus after Abamectin treatments displayed significantly longer longveity and higher fecundity than those of the control . With increasing of the pesticide concentration, the longveity prolonged, while the fecundity decreased. 3) H. axyridis, who fed the aphids after 8 000 and 10 000 times Abamectin treatmeats had a significantly higher daily predacious number of the aphids, while those fed aphids after 4 000 times Abamectin treatment displayed lower daily predacious number , compared with the control. H. axyridis, who fed aphids after 4 000 and 8 000 times Abamectin treatments, were longer preoviposition period, whereas those fed aphids after 10 000 times Abamectin treatment were shorter preoviposition period, compared with the control. H. axyridis fed aphids after Abamectin treatments showed a significantly lower fecundity and incubation rate than those of the control. Our results indicated that Abamectin could affect A. citricola and its predator H. axyridis through the food chain.

Ambrosiella hartigii, Acremonium kiliense and Fusarium sp. were inoculated and cultivated on PDA in Petri dishes and on semi-artificial diet in test tubes for rearing Xylosandrus germanus larvae and adult females, respectively. Effect of the three species of ambrosia fungi on development and reproduction of X. germanus were studied. The results showed that the larvae were able to feed on three species of fungi and complete development, however, the larvae feeding on A. hartigii grew fastest and had the highest survival, while the larvae feeding on Fusarium sp. grew slowest and had the lowest survival, the survival was only 12.3%. The adult females were all able to reproduce offspring feeding on three species of fungi, however, the fecundity of the females feeding on A. hartigii was highest of three species of ambrosia fungi.

The toxicity of lambda-cyhalothrin、beta-cypermethrin plus emulsion, E,C、alathion、azadirachtin and xylene at the different concentration and treating time was studied with five insect cell lines, applying Blackman viability analysis instrument. The results showed that the four types of pesticides had toxic effect on the cell lines, while xylene at three concentrations had no obvious toxic effect on the cell lines. The tests indicated that azadirachtin was significantly more toxic than other pesticides, then in turn were beta-cypermethrin plus emulsion,E,C, alathion, and lambda-cyhalothrin. The five cell lines responded differentially to the same testing concentration of same pesticide, and had different sensitivity to the chemicals. Amonge them, cell line Sf 9 was more sensitive than other cell lines, followed in turn by NIAS-MaBr-85,SL2, NIH-SaPe-4 and C6/36. The results indicated that the sensitivity of insect cell lines to the pesticides was in accord to the mechanism of pesticides, and the insect cell lines used for the determination of pesticide cytotoxicity is feasible.

Based on different drying schedule of wood, the drying evenness of small-diameter Larix gmelinii in polygonal cutting was experimental studied by using usual drying method. The result showed that the drying evenness of small-diameter Larix gmelinii in polygonal cutting was different under different drying schedule. Specifically, the drying period of usual drying method was long, but the drying evenness was good. When wave-drying and hard drying schedule were adopted, the drying evenness was worse than that of usual drying method. Moreover, the drying period and evenness of wave-drying were better than those of hard drying. Through this test, the wave-drying schedule was proved to use suitably for drying of small-diameter Larix gmelinii in polygonal cutting.

A new variety of Chinese chestnut named 'Duanhuayunfeng’ was selected from the North China Cultivar Group. Average weight of the nut is 8.2 g.The content of sugar, starch, portein and fat is 20.5%, 31.1%, 5.7% and 0.25% of the nut dry weigh respectively. Average length of its catkin is 2.07cm and about 1/8 of common cultivars catkin;each mother branch sprouts 3.26 fruitful shoots; the number of burs on each fruitful shoots is 1.58, each bur bears 2.6 nuts. The variety is capable of growing in mountainous or drought and barren regions.