Nested design has been widely used in animal and plant breeding, but there still exist some problems in calculating the estimates of genetic parameters and the statistics of some hypothesis tests with unbalanced data. In this paper, both fixed and random linear models were applied to estimate the genetic parameters and to perform tests of corresponding hypotheses with unbalanced data from the nested experiment design. For the fixed-effect model, we applied the methods of restricted linear model to estimate the general combining abilities of parents and to calculate the statistics for testing whether or not the general combining abilities of any two parents are different. For the random effect model, we used the theory of variance component model to derive the formulae for computing the variance components, their standard errors, and the statistics for hypothesis tests. Furthermore, formulae for calculating the heritabilities and estimating their standard errors were also given. Based on these results, a Windows-based software was developed to implement the calculations of all the genetic parameter estimates and the statistics for various hypotheses, and it would be a useful tool for forest breeders.

The soil organic carbon(SOC) and carbon storage of Zoigê alpine Kobresia meadows wetland under no water logging, perennial water-logging and seasonal water-logging(during June to October)conditions were studied. The results showed that the SOC of Zoigê alpine Kobresia meadows wetland was extreme high and that in the surface layer of the soil (0-10 cm) reached to 73.2 g·kg^-1, 6-10 times higher than the forest, farmland and grassland ecosystem in China. The vertical distribution reached to 400 cm under ground, which was far more than the forest, farmland and grassland ecosystem in China. There were significant differences (P<0.05) in SOC between shallow soil layer (0-50 cm) and deep soil layer (200-400 cm) over different hydrologic conditions. In the shallow soil layer (0-50 cm) the SOC rank was: perennial water-logging >seasonal water-logging >no water-logging, and in the layer 200-400 cm the rank was: no water-logging > seasonal water-logging > perennial water-logging, while in the soil layer 50-200 cm there was no significant difference in the SOC (P>0.05). In the soil layer 0-400 cm, the C/N ratio of alpine Kobresia meadows wetland over different hydrologic conditions mostly was less than 15, which was beneficial to the accumulation of soil carbon. The carbon storage of Zoigê alpine Kobresia meadows wetland was at a very high level, the soil carbon storage of perennial water-logging, seasonal water-logging and no water-logging was 64.87,71.21 and 76.45 kt·km^-2 respectively, which was 20-40 times higher than the forest, farmland and grassland ecosystem in China. Approximate 60% of soil carbon storage distributed under the 1m soil layer. The total soil carbon storage of Zoigê alpine Kobresia meadows wetland was about 0.245 Pg.

The vertical distribution, seasonal dynamic of soil total organic carbon (SOC), micro-biomass carbon (MBC), hot water-extraction organic matter (HWC), water-soluble organic carbon (WSOC), easily oxidized organic carbon (ROC) and the soil environmental factors were studied in pure Phyllostachy edulis plantations, P. edulis and Cunninghamia lanceolata mixed forests in the hilly region, central Hunan Province. The result showed that: The content of SOC, MBC,HWC,WSOC, and ROC decreased with the increase of soil depth, and in the soil layer of 0-60 cm, SOC and WSOC had the highest average contents in January, while MBC in July and ROC in October. However, HWC in P. edulis plantations had the highest content in July, while that in P. edulis and C. lanceolata mixed forests had the highest content in January. P. edulis and Cunninghamia lanceolata mixed forests had higher the contents and the ratios of different types of organic matters, but with lower stability than the pure P. edulis plantations. Temperature and moisture were very significantly negatively correlated with WSOC (P < 0.01), but very significantly positively correlated with MBC (P < 0.01). Decrease in soil density and increase in soil ventilation and water-holding capacity were conductive to increasing soil organic matter; soil organic matter was very significantly positively correlated with SOC, MBC, and HWC (P<0.01), while significantly positively correlated with ROC (P<0.05). Moreover, there existed very significantly positively relationships between the contents of total N and available P with SOC, and between total N content with MBC (P<0.01),and there were significantly positively relationships between available N, total P and total K with SOC and MBC, available K with SOC, and between available P with MBC. Increasing quality of bacteria and actinomycetes was beneficial to SOC accumulation, however, increase in fungi was not beneficial for stability of SOC; catalase was more closely correlated with SOC compared with the other enzymes and significantly positively correlated with SOC and ROC.

Carbon storage, carbon density and carbon sequestration potential of Cunninghamia lanceolata plantations in Hunan Province were estimated based on the database of the forest resource inventory in 2005 and 2010, that was done by forest resources monitoring center of Hunan Province, and the database from the national field scientific observation and research station of C. lanceolata plantation ecosystem, Huitong, Hunan Province. The results showed that the total carbon storage in C. lanceolata. plantations accounted for 30.39×10⁶ t in 2005 and 32.92×10⁶ t in 2010, and the middle-aged forests had the highest proportion of the carbon storage with carbon storage of 17.64×10⁶ t in 2005 and 17.31×10⁶ t in 2010, respectively The amount of carbon storage in C. lanceolata plantations ranged from 0.34×10⁶ t to 6.45×10⁶ t varied with different prefectures in 2010. Carbon density of Cunninghamia lanceolata plantations increased as the stand age increased, reaching the maximum (more than 23.90 tC·hm^-2) at over mature forest stage, with an average carbon density of 10.83 tC·hm^-2 in 2005 and 12.05 tC·hm^-2 in 2010, respectively, and ranged from 6.03 to16.58 tC·hm^-2 in different prefectures, which showed a trend of lower carbon density in the northern prefectures to higher carbon density in the southern prefectures. The reality carbon sequestration potential of C. lanceolata plantations in Hunan was up to 90.75×10⁶t, varying with different stand age classes allocating to middle-aged forest of 53.62×10⁶ t, to near mature forest of 32.77×10⁶ t, to young forest of 4.36×10⁶ t, respectively, and that also varied from 1.18×10⁶ to 17.39×10⁶t with different prefectures. The future carbon sequestration potential of immature C. lanceolata forests was estimated as 176.77×10⁶ t in 2020 with annual carbon sequestration potential of 17.68×10⁶ t·a^-1 and as 211.67×10⁶ t at mature stage. These results indicated that the stand quality of C. lanceolata plantations was very poor in Hunan due to higher proportion of young stage and middle-aged stage, which suggested that C. lanceolata forests. would be a huge potential carbon sinks in the future with implementation of better cultivation and management measures.

The aim of this study was to investigate the effects of shading on the transgenic Lespedeza formosa with expressing BADH. Two transgenic L. formosa lines and wild-type plants were selected as materials and were shaded. The betaine aldehyde dehydrogenase activity, glycinbetaine, chlorophyll, leaf shape, net photosynthetic rate, transpiration rate, light compensation point, light saturation point et al. were assayed in transgenic and wild-type plants under different irradiation regimes (light transmittance 100%, 75%, 34% and 11%).The result was as follows: 1) The T1 generation of transgenic L. formosa plants showed trait differentiation in leaf color. The proportion of green leaves and yellow leaves was 3 ∶1 and accorded with Mendelian Law separation. 2) Low light induced the expression of BADH gene and increased betaine aldehyde dehydrogenase activity. Higher glycinbetaine content was accumulated under low light. 3)The chlorophyll a and b concentrations, leaf length, leaf width, specific leaf dry mass, fresh mass per unit area of leaf, daily net photosynthetic rate, daily transpiration rate and apparent quantum yield in transgenic plants were significantly higher than those in wild-type plants under low light of light transmittance 34% or 11%. But chlorophyll a/b ratio, specific leaf area, light compensation point and light saturation point in transgenic plants were significantly lower than those in wild-type plants. 4)There was no significant difference between transgenic and wild-type plants in most of assayed indexes when plants grew in full nature light or light transmittance 75%. 5)The transgenic L. formosa with expressing BADH could more adapt to weak light than wild-type plants.

In the present study, 11 pairs of SRAP primers were selected from 126 combinations and applied to analyze genetic diversity of 514 samples from 19 populations of Camellia meiocarpa in its whole distribution area. The results showed that a total of 226 fragments was amplified, and the average amplified fragments of each primer pair were 20.55. There were 226 polymorphic bands, and the percentage of polymorphic bands (PPB) was 100%. The genetic distance between 19 populations ranged from 0.021 6 to 0.164 5, indicating that their genetic relationship was very close. The UPGMA clustering showed that the all populations, apart from 3 populations of Jiangxi Province and 6 populations of Fujian Province, were not clustered together according to their geographical locations. The PPB, Nei’s genetic diversity index(H) and Shannon’s information index(I) of different populations were 84.96%-95.58%, 0.321 3-0.388 7 and 0.473 2-0.567 6, respectively. At species level, the three parameters were 100%, 0.422 3 and 0.612 6, respectively, showing rich genetic diversity at both population and species levels of C. meiocarpa. The molecular variance analysis displayed the genetic variation mainly existed within populations (86.58%) and few among them (13.42%) in all genetic variation.

The needles of two superior provenances, with different cold tolerance, of Pinus massoniana were used as the materials to measure photosynthetic metabolism, nitrogen metabolism, endogenous protective enzyme system and membrane lipid reaction, and to examine relationships between these physiological and biochemical indices and the cold resistance. Chlorophyll content generally increased with the decrease of temperature, indicating a highly cold-resistant P. massoniana trees associated with high capability of photosynthesis. The changing trend of soluble sugar and proline contents at 0℃ and 4℃ temperatures could be used to estimate the cold resistance of P. massoniana. Their positive and negative values respectively represented strong and poor cold-resistance. Soluble protein content was inversely correlated with the cold resistance, and the higher content associated with poorer cold-resistance. Superoxide dismutase (SOD) was a chilling-sensitive regulating enzyme and peroxidase (POD) was a freezing-sensitive regulating enzyme. Trees had stronger resistance to cold when their SOD as well as POD activities increased and could remain at high level for longer time under the stress of low temperature. Under the stress, the activity of SOD started earlier than that of POD. However, trees with a stronger cold-resistance had lower content of malondialdehyde (MDA) and their MDA peak level arrived later. The six indices measured in the current study interacted with each other under the stress of low temperature.

Two 2-year-old hybrid clones with high (H4) and low (L3) growth vigor of Populus deltoides and their paternal parent (F) were used as the experimental materials to illustrate their difference of diurnal changes of photosynthesis, light response curves and CO₂ response curves. The result showed that diurnal changes of the net photosynthetic rate of H4, L3 and F all displayed a single peak curve H4 started its efficient photosynthesis significantly earlier than L3 and F. The analysis of light response curves indicated that the maximum net photosynthetic rate (P_nmax), apparent quantum yield (AQY), light compensation point(LCP) and light saturation point (LSP) expect dark respiration rate (R_d) all exhibited significant differences over the clones. The P_nmax of H4 was largest, reaching to 21.47 μmol ·m^-2s^-1, and 52.8% higher than L3, and the LSP was also largest and 17.03% and 10.35% higher than L3 and F respectively, but the LCP was the lowest, only 15.09 μmol ·m^-2s^-1. The result of CO₂ response curves showed that there were no significant differences in the carboxylation efficiency, the CO₂ compensation point (CCP) and photorespiration rate except P_nmax. The carboxylation efficiency and CCP of H4 were slightly higher and lower than L3 and F respectively, which revealed the clone with high growth vigor had a little advantage in the utilization of CO₂. In a word, the clone with high growth vigor had a stronger ability to make use of low light and performed relatively efficient photosynthesis in strong light, only with a little advantage in the absorption and utilization of CO₂.

The male flowers of Eucommia ulmoides were extracted by the solvents with different polarities, namely, petroleum ether, ethyl acetate, n-butanol, and water. The contents of total phenols in the obtained extracts were measured, and their antioxidant activities were examined in vitro and compared with those of BHT and VC, which were the two conventional reductants, from the aspects of scavenging rate of DPPH and hydroxyl free radicals, reducing power, and anti-lipid per-oxidation activity, respectively. The results indicated that Eucommia male flower was rich in phenols. The content of phenols in ethyl acetate extract (EE) (393.47 mg ·g^-1) and n-butanol extract (BE) (287.33 mg ·g^-1) were higher than those in water extract (WE) (114.74 mg ·g^-1) and petroleum extract (PE) (105.42 mg ·g^-1). The rates of scavenging DPPH free radical of the EE and BE were 91.55% and 80.32%, respectively, close to those of BHT and VC. The rate of scavenging hydroxyl free radical of BE was relatively higher (80.47%), while the reducing power of EE was higher than those of BHT and VC. The activities of anti-lipid per-oxidation of EE, BE and WE were higher than that of VC. The reducing power, rate of scavenging DPPH free radical and activity of anti-lipid per-oxidation of the extracts were positively correlated to the content of total phenols (R²>0.9), and exhibited significant concentration dependent effect. The relatively higher antioxidant activity of Eucommia male flower demonstrated that it could be developed as a health care beverage.

Symplocos setchuanensis is a common species in Phyllostachys edulis forests. In order to study the response of leaf functional traits of S. setchuanensis to different disturbances induced by P. edulis, three disturbance degrees (pure bamboo forest, bamboo and broad-leaved forest, and pure broad-leaved forest) of P. edulis were studied. Results showed that specific leaf area (SLA) of S. setchuanensis seedlings decreased significantly with increasing bamboo disturbance degree. Leaf nitrogen content (LNC) increased with increasing disturbance degree, but no significant difference was found between leaf phosphorus content (LPC) and LNC/LPC ratio. In terms of leaf chlorophyll, both chl a and chl b reduced with increasing disturbance degree, whereas an increase in chla/chlb ratio was found. These results showed that leaf functional traits of S. setchuanensis had brought about a series of adaptive changes to disturbances induced by P. edulis. Furthermore, correlation analyses showed that chla and chlb were significantly positively correlated, chlb and total chlorophyll content were significantly negatively correlated with chla/chlb ratio. There was a positive correlation of LNC with SLA, LPC, and LNC/LPC, while LNC/LPC ratio was significantly negatively correlated with LPC, suggesting that phosphorus was still a limiting element in the plots disturbed by P. edulis. However, no correlation was found between LNC or LPC and chlorophyll content in our experiment, and further studies may be needed to explore the reasons.

Scientific and accurate estimation of the forest carbon sequestration is the key to evaluate forest functions of mitigating CO₂ concentration in atmosphere and responding to climate change, however the special biological and ecological characters of bamboo greatly increased the difficulty in accounting the carbon sequestration. The biometric approach was used to estimate the carbon density, storage and spatial distribution pattern of the Pleioblastus amarus Forest Ecosystem in Southern Sichuan Province, as well as the annual carbon sink. The results showed: 1) There was not significant difference in carbon density between various ages and organs in stumpage bamboo, and the mean value was 450.792 g ·kg^-1. The mean soil carbon density was 19.410 g ·kg^-1, however there were extremely significant differences in the density between various soil layers. 2) The total carbon storage of the P. amarus forest ecosystem was 156.823 t ·hm^-2, and the carbon stored in soil, stumpage bamboo and litter accounted for 84.5% (132.568 t ·hm^-2), 12.4% (19.432 t ·hm^-2) and 3.1% (4.823 t ·hm^-2), respectively. 3) For the carbon storage in stand bamboo approximate 49.13% was stored in stem. The carbon stored in the over-ground parts and underground parts accounted for 68.68% and 32.32%, respectively. The carbon stock above ground was 2.19 times more than that underground. 4) Carbon sequestration capacity of the P. amarus stand was 8.262 t ·hm^-2a^-1, equivalents to 30.292 t ·hm^-2 of CO₂, greater than Phyllostachys edulis forest ecosystem.

The recreational forest is an important type of special-purpose forests in China, which can provide general public with comfortable recreational environments. Scientific management of the forest is vital important to peoples’ physical and mental health and also to development of forest tourism industry. The Platycladus orientalis recreational forests, which are widely distributed in Beijing, have long been well received by local residents. To determine optimal tending regime and interval for the forest, three different tending regimes were applied to middle-aged stands on shady and sunny slope in the Xishan National Forest Park of Beijing. The dynamics of scenic quality and major scenic factors of both stands were monitored for five successive years before and after tending. Based on Scenic Beauty Estimation Method, effect of these applied tending regimes on scenic quality and its duration were analyzed. The results showed that: 1) Different tending regimes greatly increased preference degree of two stands in short terms, and significantly improved their scenic quality. 2) Three tending regimes (A1, A2 and A3) for shady slope stand had similar excellent scenic effect, while for sunny slope stand the B1 regime had better effect than the other two (B2 and B3). 3) When the scenic effect and its duration were both taken into consideration, A3 regime (clear bole height of 2－3 m above ground, remained cover of shrub layer about 20% plus ground clearing) was better for shady slope stand, and corresponding tending interval could be 2 years; while for the sunny slope stand, B1 regime (clear bole height of 2－3 m above ground, remained cover of shrub layer about 25% plus ground clearing) was more appropriate and its tending interval could be at least 4 years. From the perspective of forest aesthetics, tending regimes and corresponding intervals proposed in this study would provide technical support for tending practice of the P.orientalis recreational forest in Beijing mountainous areas.

We studied the different effects of extensive forest management regime and target tree management regime on plant community structure and biodiversity of natural secondary coniferous forest, broad-leaved forest and mixed forest in Danqinghe Forestry Farm which locates in Harbin, Heilongjiang Province, no disturbance forest stand was selected as reference. The results showed that: 1) Compared with extensive forest management regime and no disturbance, the basal area of the first canopy layer under target tree management regime was the highest, proportion of basal area was 95.00%, 90.00%, 87.00% in coniferous forest, broad-leaved forest and mixed forest respectively. The basal area of the second and third canopy layer under target tree management regime was the lowest. All of these implied that stand under target tree management regime have the best canopy structure. 2) The average stand density under target tree management regime(408-858 tree ·hm^-2)was significantly lower than that under extensive forest management regime(992-1 917 tree ·hm^-2)(P<0.05), there was no difference in average basal area. Average tree height(11.8-14.9 m)and DBH (15.94-27.34 cm)under target tree management regime were significantly higher than that under extensive forest management regime(tree height is 7.1-11.0 m and DBH is 10.18-19.00 cm)(P<0.05). 3) Above 60% of trees under extensive forest management regime and no disturbance regime were small-diameter tree(DBH smaller than 12 cm), but above 60% of trees under target tree management regime were middle-diameter tree(DBH 14-18 cm)and large-diameter tree(DBH above 20 cm).4) Diversity in tree layer under extensive forest management regime was higher than that under target tree management regime; exception of broad-leaved forest, diversity in shrub layer under extensive forest management regime was higher than that under target tree management regime; while diversity in herb layer under target tree management regime was the highest. 5) These findings confirm extensive forest management regime purse more timber production and neglect ecology requirements, while no disturbance regime just focus on ecology and neglect the requirement in using forest resources, neither of them can meet the human's needs. Target tree management regime can improve community structure, get more economic benefit and balance ecological functions simultaneously which comply with objective of sustainable forest management.

The pine sawyer, Monochamus alternatus (Coleoptera: Cerambycidae), is the most important pest of pine Pinus massoniana throughout China. In this study, the parasitoid Dastarcus helophoroides (Coleoptera: Bothrideridae) eggs and adults were released in six plots of the pine forests for controlling M. alternatus. The control effect was evaluated by two indexes, i.e., infested trees number and the pest larvae number in a host tree. Meanwhile,the parasitism rate of this parasitoid to its host was measured in indoor mesh and field mesh. Results showed that, releasing both eggs and adults was able to effectively control M. alternatus. In three plots of releasing the parasitoid eggs, the mean adjusted reduced rate of the pine sawyer larvae per tree was 48.54%, and the mean adjusted reduced rate of infested trees was 63.07%. In three plots of releasing the parasitoid adults, mean adjusted reduced rate of the pine sawyer larvae per tree was 47.00%, and the mean adjusted reduced rate of infested trees was 68.00%. The controlling effects by releasing adults of the parasitoid were a little better than that by releasing eggs of the parasitoid, without significant difference between them. The parasitoid responded differentially to DBH of 5-8 cm, 10-15 cm, or >18 cm pine sawyer-infested cutlogs. The highest parasitism rate was 72.41% in DBH of 5-8 cm cutlogs, significantly higher than the others. During three periods (May, July, September) of releasing the parasitoid, the parasitism rates of the pine sawyer larvae orderly were 68.50%, 21.63% and 30.29%, respectively. These findings determined that controlling larva of M. alternatus by releasing D. helophoroides to the forest in May was feasible, which is a new technology in biocontrol method.

In order to further study the inhibiting activity and mechanism of ethyl acetate extracts of introduced Trichoderma harzianum strain T28 fermentation liquid to the growth of Phytophthora infestans, we investigated bacteriostasis of the extracts in different concentrations on P. infestans and their effects on several enzyme activities in the pest physiological metabolism. The results indicated that all the studied concentrations of the extracts had inhibiting effects on the growth, sporangium germination and spore released zoospores of P. infestans, and among the concentrations the 10 and 100×diluted had slightly better effects without significant differences. The activities of protective enzymes (SOD, CAT, POD and GSH-Px) of P. infestans treated with the extracts in 48 hours reduced by 89.06%, 86.96%, 97.47% and 97.63%, respectively. Meanwhile, the activities of carbohydrate metabolic enzymes(HK、PK and LDH)and TCA aerobic catabolic enzymes (SDH and MDH)also decreased by 93%, 89.56%, 88.5%, 97.66% and 97.43%, energy-metabolic enzyme activities (ATP) decreased by 98.5% and 98.67%. The MDA contents enhanced 60.98%. This research determined that the ethyl acetate extract from fermentation liquid of T. harzianum strain T28 was able to reduce the metabolic enzyme activities of P. infestans and increase the MDA contents. The extracts could cause the damage to P. infestans and prevent from normal working of its glycometabolism, tricarboxylic acid cycle, energy metabolism and etc, which may be one of inhibiting mechanisms of ethyl acetate extracts of T. harzianum strain T28 on the growth of P. infestans.

The bamboo-based fiber composite container flooring was made of bamboo fibrous veneer, where a series of dotted and/or linear shaped cracks were formed on the cylinder wall of a semicircular bamboo tube so as to form a netty structural bamboo fibrous veneer which was composed of interlaced fiber bundles, using the moso bamboo and D.O. bamboo as raw material and phenolic-formaldehyde as adhesive and then was contrasted and analyzed with traditional container flooring such as Apitong plywood, bamboo-wood composite plywood and sliver plybamboo. The results show that the physical and mechanical properties of bamboo-based fiber composites can meet or exceed the requirement of the plywood for container flooring reference to the national standard GB/T 19536-2004 without moving the outer and inner layer of bamboo through the rational structure and process design. The properties of bamboo-fiber based composites exceed that of Apitong plywood, bamboo-wood composite plywood and sliver plybamboo. The split bamboo tube is fluffed directly to make the bamboo fibrous veneer with the outer and inner layer of bamboo, which change the traditional component units structure of bamboo-based panel such as bamboo strips and bamboo sliver, so that the unavailable big-sized cluster bamboo in the existing technology can be fully used, and the process is easier, and the production efficiency is higher.

The dowel-bearing property is very important in compression yield strength calculation of bolted connections and is a critical component of wood or bamboo connection design. In this paper, the dowel-bearing strength was studied based on dimension, bolt diameter as test parameters. The application of NDS/LRFD and Eurocode 5 in dowel-bearing strength prediction was assessed. Besides, the damage modes in two loading directions were analyzed. It showed no dimension effect on dowel-bearing strength which ranged between 104.40 MPa and 169.77 MPa in either direction, if the dimension reaches the minimum requirements. The dowel-bearing strength test values showed a decreasing trend with the bolt diameter increasing. NDS/LRF and Eurocode 5 all under predicted the dowel-bearing strength of recombinant bamboo. The damage modes of the two loading direction samples were obviously different.

Growth rhythm, cell wall composition, anatomical structure, physical and mechanical properties of poplar 741 were observed and measured. The results showed that, poplar 741 had a long growth period, high growth rate, and plant height, stem diameter and the growth rate of individual volume in growing season had the obvious characteristics of fast-growing. With the scanning electro microscope analysis, we found that fiber cell wall was thin, the shape of its cross section was circular or polygonal, the vessel cells were pitted vessel, wood rays were usually uniseriate; S-lignin content in stem cell wall of poplar 741 was markedly higher than the G-lignin, moreover, with the growing of the poplar 741, the S-lignin content increased year by year. Basic density of poplar 741 was less than Populus wood, volume shrinkage rate was in a low level, the flexural strength was higher than other kind of Populus wood. According to national standard of impact toughness in wood, the impact toughness of poplar 741 was medium among the main timber tree species. Poplar 741 could be widely applied in green, construction, furniture, plywood, paper and other industries.

To further understand light reaction of Pinus (pine) species, the fast chlorophyll fluorescence induction curves and parameters of four species (P. armandii, P. bungeana, P. tabuiaeformis, P. densiflora) were compared with that of two Populus (poplar) species (P. tomentosa, P. euramericana) chosen as representatives of angiosperm trees in this study. The main differences in the fast chlorophyll fluorescence induction kinetics between the two kinds of trees were summarized as the follow. The chlorophyll fluorescence induction curves of the two poplar species were typical OJIP induction curves, while the OJIP induction curves of Pinus species exhibited relatively lower J phase, obscure I phase and earlier P phase. Light reaction characteristics of the four pine species were demonstrated by fluorescence parameters in detail. The RC (RC: PSⅡ reaction centre) density per excited cross section (CS) of pine trees leaves was lower than poplar trees, which led to more energy fluxes per RC (ABS/RC, TR_o/RC, ET_o/RC, DI_o/RC) of pine trees. However the primary photochemistry rate (M_o) had no difference between the two kinds of trees. Electron transport efficiency of Q_A (ψ_ET) in pine trees was even higher than poplar trees. Pine needles had greater values in relative variable fluorescence of I phase (V_i), which indicated that pine trees had lower efficiency of electron transport fluxes from Q_B to PSI acceptors (ψ_RE). Meanwhile, pine trees had smaller plastoquinone pool (S_m) and less turn-over number of Q_B (N), along with the faster plastoquinone pool redox rate (S_m/T_fm). These results could be the major cause of obscure I phase and earlier P phase appeared on the OJIP induction curve of pine trees, which further caused smaller values of performance index ( PI_CSm), quantum yield of electron transport flux until PSI (φ_Ro) and bigger values of dissipated energy ratio of PSⅡ (K_n, F_o/F_m) in pine trees. The results above suggested that the density of RC per excited cross section and the size of plastoquinone pool would be the two major factors that affected light reaction activity of pine trees, so as to affected photosynthetic function of pine trees.

The dynamic observation of the mid-montane humid evergreen broad-leaved forest and the community characteristics analysis were conducted in a 4-hm² permanent plot located in ecological corridor in southern region of Gaoligong Mountains National Nature Reserve during 2009-2010. The results showed that there were 10 546 free-standing individuals with DBH≥1.0 cm in the 4 hm² plot, belonging to 95 species, 64 genera and 35 families. The species richness was higher and the proportion of rare species was lower in the plot, compared with other plots of the same kind forest. Lauraceae, Theaceae, Araliaceae, Fagaceae, and Symplocaceae were dominant families in the plot and they comprised 44.21% of all species and 56.70% of all individuals. Symplocas ramosissima, Eurya pseudocerasifera, Gordonia longicarpa, Neolitsea lunglingensis, Lithocarpus hancei, and Cyclobalanopsis lamellosa had more importance value in the plot, but no one had obvious advantage, namely the plot did not contain an obviously dominant species. Floristic characteristics of the community indicated that the tropical elements were much more than temperate elements, implying that this area could be an origin of tropics. The minimal area of the community is 1. 32 hm²,which could comprise more than 80% of all species. The structure of DBH size class of all species and some dominant species in the plot showed a typical pyramid structure with a wide bottom and a narrow top, implying a good regeneration in the community. The survival curve of most of dominant species tended to be of the Deevey-Ⅲ type, with a high mortality rate at small DHB size class and a low and stable mortality rate at large DBH size class.

A laboratory incubation experiment was conducted to investigate nitrous oxide (N₂O) emissions in the soil, which was sampled from a red soil of a Pinus massoniana forest in a typical hilly red soil region in subtropical central China, and to study impacts of the soil temperature and moisture on N₂O emissions. The experiment was designed with two environmental factors (temperature and moisture) and 4-5 levels of factors. The results showed that at temperatures of 15, 25 and 30℃ and at soil moistures of WFPS=40%－60% for 15 days the N₂O emissions all displayed a similar trend with a low rate at first, rapid increase during the middle period and no emission in the end. The cumulative N₂O fluxes of the treatments for a period of 15 days were up to 242.85 mg N ·kg^-1. Both the nitrification and denitrification processes were inhibited at 5℃, as a result, the average value of the cumulative N₂O fluxes was just 0.55 mg N ·kg^-1. At WFPS=20%-30%, the cumulative N₂O fluxes for 15 days were very low, ranging from 1.92 to 2.72 mg N ·kg^-1. The average cumulative N₂O fluxes increased with the increases of soil temperature and moisture, especially when WFPS was greater than 40%. A N₂O emission prediction model was established and the model parameters were determined by the nonlinear optimization estimation. The optimization results suggested that the Q₁₀ of N₂O emissions for soil nitrification and denitrification processes was 1.15 and 3.0, respectively; the optimal soil moisture for nitrification-induced N₂O emissions was at WFPS=56%; and the soil WFPS exponential response coefficient for N₂O emissions from soil denitrification was 8.8.

In this study, the habitat, soil seed banks and natural regeneration of Acer griseum were investigated systematically. As a sub-climax species and an associated tree species, A. griseum scattered in the mountainous broad-leaved mixed forests, and the mountainous coniferous and broad-leaved mixed forests in addition to the mountaintop shrub forests. The species thrived mostly on semi-sunny slopes, semi-shade slopes, shade slopes and gullies. It grew in the mountain brown soil, yellow brown soil and mountain cinnamon soil. The thickness of soil layer, in which the species grew, was from the bare rock to about 30 cm soil range, some trees even grew in rock crevices. It naturally regenerated mainly by seeds, followed by some stump-sprouting and root sprouting. Most of the seeds in soil seed bank were stored in the litter layer. There were 172 seeds ·m^-2 in the litter, while only 42 seeds ·m^-2 between 0 to 10 cm soil layer in Yuanling, Hunan province. Few or no seeds were found in deeper soil layer than 10 cm. The amount of seeds was negatively correlated with the distance from the parent tree and the wind also could contribute to seed dispersal. All the above results indicated that reduction of the quantity of A. griseum wild resources might be due to bad habitat, low seed yield and high percentage of empty seeds, difficulty of seed germination, as well as the poor environmental conditions for natural regeneration of the seedlings.

Distribution of carboxylesterase (CarE) and glutathione-S transferase (GST) in the midgut, fat body, head and epidemis tissues of Dendrolimus superans 6^th instar was determined. The results showed that both CarE and GST distributed in all the four tested tissues, however, CarE predominated in midgut (61.36%) while GST in fat body (36.15%). The susceptibility of CarE and GST to DDVP, avermectins and lambda-cyhalothrin was also measured in vitro. The three pesticides had different degree inhibition to either CarE or GST. There were distinct dose-effect relationships between each pesticide and each enzyme. DDVP showed the highest inhibitive effect to CarE(IC₅₀<1.000×10^-4 mg ·mL^-1), followed by avermectins (IC₅₀=1.259×10^-2 mg ·mL^-1) and then lambda-cyhalothrin (IC₅₀=4.529×10^-1 mg ·mL^-1). However, avermectins showed the highest inhibitive effect to GST, followed by lambda-cyhalothrin, DDVP showed the weakest inhibition to GST. The IC₅₀ values were 8.044×10^-3, 9.224×10^-3 and 1.755×10^-2 mg ·mL^-1 respectively. These results provide important information for reasonable insecticide application to control D. superans.

There was higher taxol content(60.5 μg ·g^-1) in superior provenance of Taxus cuspidata (the provenance is Daxinggou ), which was 1.5-3 times than others, and its growth quantity was similar with other provenances. It is planted by sowing or cutting breeding methods. Cording seed was necessary before sowing, and changging temperature could shorten period of seed dormancy. Dormant or green branches were made cuttage. Seedling management was shelter from heat or light, keeping soil and air humit, preventing freeze injury and dry wind. There was higher survive rate and growing well if planting seedling under crown. The superior provenance is adaptable to grow in the northeast, and growing better in humit air and acid sandy loam(pH≤7.0).