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Converting natural forests to plantations significantly affects the characteristics of soil organic carbon (C) pools, due to the changes of vegetation cover and management practices. In this paper, to investigate the effects of conversion from evergreen broad-leaved forest (EBF) to Chinese chestnut plantation (CP) on soil organic C pool, the soils from surface (0-20 cm) and subsurface (20-40 cm) layers were sampled from the above two forests (the CP was converted from the EBF and had been intensively managed for 10 years) in Lin'an City, Zhejiang Province. The soil orga-nic C storage, labile organic C pools, and other basic soil properties were determined. The chemical composition of soil organic C was determined by nuclear magnetic resonance (NMR) technique. Results showed that the soil organic C storage, water soluble organic C (WSOC), hot water soluble organic C (HWSOC), microbial biomass C (MBC) and readily oxidizable C (ROC) concentrations in the surface layer decreased by 19.7%, 34.4%, 25.8%, 30.4% and 25.2%, respectively, after the conversion from EBF to CP. Such values for the subsurface layers decreased by 13.5%, 38.4%, 19.8%, 34.1% and 22.2%, respectively. The O-alkyl C content, aromatic C content and aromaticity of soil organic C in the surface layer decreased signi-ficantly by the land-use conversion, while alkyl C content, carbonyl C content and alkyl C to O-alkyl C (A/O-A) ratio increased signi-ficantly. The O-alkyl C content of soil organic C in the subsurface layer decreased significantly by the land-use conversion, alkyl C content and A/O-A ratio increased significantly, and aromatic C content, carbonyl C content and aromaticity of soil organic C were not changed. In conclusion, conve-rting EBF to CP and subsequent intensive management significantly decreased the soil organic C sto-rage and labile C pool contents and altered the chemical composition of soil organic C.

With secondary forest in the montane region of eastern Liaoning Province as research object, this paper analyzed the spatial distribution and scale effect of Gleason richness index, Simpson dominance index, Shannon diversity index and Pielou evenness index in a 4 hm 2 plot. The results showed that spatial distributions of the four diversity indices showed higher spatial heterogeneity. Variance of the four diversity indices varied with increasing scale. Coefficients of variation of the four diversity indices decreased with increasing scale. The four diversity indices of the tree layer were higher than those of the shrub layer, and the variation tendency varied with increasing scale. The results indicated that sampling scale should be taken into account when studying species diversity in the montane region of eastern Liaoning Province.

Based on ArcGIS, Erdas, GuidosToolbox, Conefor and other software platforms, using morphological spatial pattern analysis (MSPA) and landscape connectivity analysis methods, this paper quantitatively analysed the scale effect, edge effect and distance effect of the Nanjing urban green infrastructure network pattern in 2013 by setting different pixel sizes (P) and edge widths in MSPA analysis, and setting different dispersal distance thresholds in landscape connectivity analysis. The results showed that the type of landscape acquired based on the MSPA had a clear scale effect and edge effect, and scale effects only slightly affected landscape types, whereas edge effects were more obvious. Different dispersal distances had a great impact on the landscape connectivity, 2 km or 2.5 km dispersal distance was a critical threshold for Nanjing. When selecting the pixel size 30 m of the input data and the edge wide 30 m used in the morphological model, we could get more detailed landscape information of Nanjing UGI network. Based on MSPA and landscape connectivity, analysis of the scale effect, edge effect, and distance effect on the landscape types of the urban green infrastructure (UGI) network was helpful for selecting the appropriate size, edge width, and dispersal distance when developing these networks, and for better understanding the spatial pattern of UGI networks and the effects of scale and distance on the ecology of a UGI network. This would facilitate a more scientifically valid set of design parameters for UGI network spatiotemporal pattern analysis. The results of this study provided an important reference for Nanjing UGI networks and a basis for the analysis of the spatial and temporal patterns of medium-scale UGI landscape networks in other regions.

Eco-services provided by non-agricultural organisms are the basis of ecosystem to keep its stability in agricultural landscapes. With the strengthening of agricultural intensification, the ongoing loss of biodiversity is one of the most extrusive issues in the development of modern agriculture. In this paper, the study area was set up in Gongyi County, a typical agricultural region in the middle and lower reaches of the Yellow River. According to its typical topography (mountain-hilly-plain) type, we explored the effects of landscape heterogeneity on the diversity of pollinators at three different scales, which were geomorphic categories, landscape and habitat. Pan traps were used to obtain pollinators in this study. The effects of agricultural landscape heterogeneity at multi-scales on the diversity of pollinators were analyzed by using multivariable ANOVA. The results showed that a total of 67012 pollinator individuals that belonged to 86 classes and 7 subjects were classified. The dominant groups inclu-ded Syrphidae and Anthomyiidae. The common groups included Drosophilidae, Calliphoridae, Bombyliidae, Pipunculidae, Cantharidae, Cynipidae, Vespidae, Chalalcididae, Megachilidae and Apidae. Geomorphic categories showed the most significant impact on pollinators (P<0.001), suggesting that hilly and mountainous areas were the pollinators' ground of nectar. It was followed by habitat scale (P<0.05), with non-significant effect on the scales of landscape and the interaction between scales. The effect of landscape heterogeneity on the diversity of pollinators in hilly and mountainous areas provided a theoretical support for landscape planning and biodiversity conservation on the local area with different geomorphic categories.

With the development of social economy, human disturbance has resulted in a variety of ecosystem service degradation or disappearance. Ecosystem services flow plays an important role in delivery, transformation and maintenance of ecosystem services, and becomes one of the new research directions. In this paper, based on the classification of ecosystem services flow, we analyzed ecosystem service delivery carrier, and investigated the mechanism of ecosystem service flow, including the information, property, scale features, quantification and cartography. Moreover, a tentative analysis on cost-effective of ecosystem services flow (such as transportation costs, conversion costs, usage costs and cost of relativity) was made to analyze the consumption cost in ecosystem services flow process. It aimed to analyze dissipation cost in ecosystem services flow process. To a certain extent, the study of ecosystem service flow solved the problem of "double counting" in ecosystem services valuation, which could make a contribution for the sake of recognizing hot supply and consumption spots of ecosystem services. In addition, it would be conducive to maximizing the ecosystem service benefits in the transmission process and putting forward scientific and reasonable ecological compensation.

Based on the measurement of 955 branch samples of 65 Korean pine (Pinus koraiensis) trees in 12 plots from Mengjiagang forest farm, Heilongjiang Province, and by using Poisson model and negative binomial model, the second-order branch count models for Korean pine were developed in this paper. AIC, Pseudo-R 2 , RMSE and Vuong test were selected to compare the goodness-of-fit statistics of the models. The results indicated that the first-order branch count in a whorl was 3 to 5, with mean value of 4, and the first-order branch count in a whorl for Korean pine plantation associated with its own characteristics. The second-order branch count of the first-order standard branch had a large discrete degree. All subset regression techniques were used to develop the second-order branch count model. The negative binomial regression model E(Y)=exp(β 0 +β 1 lnRDINC+β 2 RDINC 2 +β 3 HT/DBH+β 4 CL+β 5 DBH) was selected as the optimal second-order branch count model (β represented the parameter, RDINC represented the relative depth into crown from tree apex, HT represented the total tree height, DBH represented the tree diameter at breast height, CL represented the crown length). Pseudo-R 2 of the optimal model was 0.79, the mean error was close to 0 and the mean absolute error was less than 7. For the developed model, the parameter values of lnRDINC, CL and DBH were negative, and the parameter values of RDINC 2 and HT/DBH were positive. With the increase of RDINC, the number of second-order branch had a peak value in the tree crown. On the whole, the precision of the second-order branch count model for Korean pine plantation was 96.4%, which would be suitable for predicting the second-order branch count for the study area and provide a theoretic basis for branch photosynthesis and biomass research.

Taking 6-year-old "Chunjie" peach as test material, and the peach in natural condition as the control, this paper investigated induced effects of long-day and short-day photoperiod on dormancy and responses of chilling resistance to photoperiodic induction during dormancy induction process. The results showed that the trees of long-day and short-day treatments could both enter dormancy induction under the gradually decreasing temperature. The long-day treatment was 1 week later than the control, while the short-day treatment was 1 week earlier. The total water content and free water content both decreased, and the bound water content and the ratio of bound water/total water increased with the development of dormancy. SOD and CAT activities changed as unimodal curve during dormancy induction, and the peak values appeared at the late stage of dormancy induction, POD activity decreased rapidly after the start of dormancy induction, and rebounded to form a small peak at the late stage of dormancy induction. The soluble protein content declined, proline and malonaldehyde (MDA) increased continuously, and the injury rate increased. Long-day could increase SOD and CAT activities and proline content, alleviate the decline of POD activity and soluble protein content, and reduce the growth rate of MDA and injury rate, which indicated leaf damage was lighter in long-day treatment than in the control. However, they changed differently under short-day treatment, especially the leaf injury rate was higher than the control, exhibiting a lower chilling resistance. Prolonging illumination was suggested to improve leaf chilling resistance in practical production if environmental temperature permitted.

Soil moisture is an important component of the soil-vegetation-atmosphere continuum (SPAC). It is a key factor to determine the water status of terrestrial ecosystems, and is also the main source of water supply for crops. In order to estimate soil moisture at different soil depths at a station scale, based on the energy balance equation and the water deficit index (WDI), a soil moisture estimation model was established in terms of the remote sensing data (the normalized difference vegetation index and surface temperature) and air temperature. The soil moisture estimation model was validated based on the data from the drought process experiment of summer maize (Zea mays) responding to different irrigation treatments carried out during 2014 at Gucheng eco-agrometeorological experimental station of China Meteorological Administration. The results indicated that the soil moisture estimation model developed in this paper was able to evaluate soil relative humidity at different soil depths in the summer maize field, and the hypothesis was reasonable that evapotranspiration deficit ratio (i.e., WDI) linearly depended on soil relative humidity. It showed that the estimation accuracy of 0-10 cm surface soil moisture was the highest (R 2 =0.90). The RMAEs of the estimated and measured soil relative humidity in deeper soil layers (up to 50 cm) were less than 15% and the RMSEs were less than 20%. The research could provide reference for drought monitoring and irrigation management.

Human demand for various ecosystem services continues to increase. The previous studies focused mainly on using economic methods to assess ecosystem service values, but few studies took social attributes and spatial heterogeneity into consideration. In this paper, we selected Wusong Paotaiwan Wetland Forest Park in Shanghai as the study area, and used Social Values for Ecosystem services (SolVES) model to assess the social values of several ecosystem services, such as aesthetic, biodiversity, cultural, recreation, etc. The results showed that the "hotspots" were situated in the places which were close to the water landscape with a broad vision such as the lawn park, Wusong Fort memorial square and waterfront observation deck. Aesthetic, historic, biodiversity, cultural, recreation and therapeutic values were the visitors' preference values. Visitors' prefe-rences could be influenced by the water landscape and the roads significantly. The value indexes of aesthetic, biodiversity, recreation and therapeutics had a significant negative correlation with the distance to water (DTW) and the value indexes of aesthetic and therapeutics had a significant negative correlation with the distance to roads (DTR). Visit frequency could influence visitors' attitudes and preferences towards biodiversity and therapeutics. SolVES had the potential to explicitly assess the social values of ecosystem services at a small scale.

With a special focus on Jiangkou County in Guizhou Province, this paper explored the ecological compensation standards and compensation methods of local key public welfare forest protected area by using questionnaire and contingent valuation method. The results showed that the minimum compensation which the local foresters could accept was 314.14-365.15 yuan·hm -2 per year, and the opportunity cost was 9750 yuan multiplied by the protected forest area. The willingness to accept of foresters was affected by many factors, such as health status, education level, ethnicity and local township. The compensation methods local foresters expected were various, but mainly were cash and technology compensation. Finally, this paper put forward some policy suggestions on improving system, increasing compensation standards, strengthening propaganda, and enriching compensation methods.

Drought is the greatest agro-meteorological disaster. Risk assessment of drought is of great guiding significance to improve the regional risk management and decision-making level, and to further reduce agricultural loss. In this paper, drought risk of summer maize was analyzed accor-ding to natural disaster risk theory, using the data of weather, planting area and yield of summer maize, and local effective irrigation area of 69 stations in Huanghuaihai area. The assessing indices and models of drought risk were established from the aspects of danger, vulnerability, exposure, and disaster prevention and mitigation capacity. The results showed that, in Huanghuaihai area, the most dangerous periods for drought during summer maize season (June-September) were the follo-wing two stages: sowing to emergence and milky to maturity. Spatially, the highest drought risk was mainly distributed in central and southern Hebei, western and northern Henan. After weighting the vulnerability, exposure, and disaster prevention and mitigation capacity, the integrated highest drought risk was mainly distributed in the west and southwest of Henan Province. The sub-high risk area was distributed in the south of Henan, Cangzhou and Xingtai of Hebei, and Dezhou of Shandong. The lowest risk area was located in south of Shandong, north of Anhui, and Xinyang of Henan. The other areas were at moderate risk.

Under natural conditions, light plants receive usually changes. Thus, the plants have formed corresponding adaptation mechanism in the evolutionary process, which could maintain the energy balance between two light reactions in the process of light changing. Through the movement of leaves and chloroplasts, as well as the accumulation of light-absorbing pigments, plants could regulate light absorption. Also, plants have a mechanism for greatly regulating the distribution of energy absorbed by light-harvesting complex. Especially at low light intensities, plants could mediate reversible phosphorylation of light-harvesting complex2 (LHC2) by regulating kinase and phosphatase in relation to the redox state of the electron transfer chain, which could thereby regulate the allocation of excitation energy between photosystem I (PSI) and photosystem 2(PS2). The state transitions are the quite significant mechanism of plants for adapting to the change of light environment. In this paper, the research progresses of state transitions during the change of light environment were summarized, especially the significance and functions of reversible phosphorylation and movement of LHC2 between PS I and PS2 were discussed. Finally, the future research direction on state transitions of plants was briefly proposed.

Large-scale ecological patches play an important role in regional biodiversity conservation. However, with the rapid progress of China's urbanization, human disturbance on the environment is becoming stronger. Large-scale ecological patches will degrade not only in quantity, but also in quality, threatening the connections among them due to isolation and seriously affecting the biodiversity protection. Taking Poyang Lake Eco-economic Zone as a case, this paper established the potential ecological corridors by minimum cost model and GIS technique taking the impacts of landscape types, slope and human disturbance into consideration. Then, based on gravity quantitative model, we analyzed the intensity of ecological interactions between patches, and the potential ecological corridors were divided into two classes for sake of protection. Finally, the important ecological nodes and breaking points were identified, and the structure of the potential ecological network was analyzed. The results showed that forest and cropland were the main landscape types of ecological corridor composition, interaction between ecological patches differed obviously and the structure of the composed regional ecological network was complex with high connectivity and closure. It might provide a scientific basis for the protection of biodiversity and ecological network optimization in Poyang Lake Eco-economic Zone.

Keeping other parameters as empirical constants, different numerical combinations of the main photosynthetic parameters V c max and J max were conducted to estimate daily GPP by using the iteration method in this paper. To optimize V c max and J max in BEPSHourly model at hourly time steps, simulated daily GPP using different numerical combinations of the parameters were compared with the flux tower data obtained from the temperate deciduous broad-leaved forest of the Maoershan Forest Farm in Northeast China. Comparing the simulated daily GPP with the observed flux data in 2011, the results showed that optimal V c max and J max for the deciduous broad-leaved forest in Northeast China were 41.1 μmol·m -2 ·s -1 and 82.8 μmol·m -2 ·s -1 respectively with the minimal RMSE and the maximum R 2 of 1.10 g C·m -2 ·d -1 and 0.95. After V c max and J max optimization, BEPSHourly model simulated the seasonal variation of GPP better.

To objectively evaluate and compare the stability and sustainability of different planting patterns of typical watersheds in Loess Plateau of China after the Grain for Green Project, this paper used the emergy analysis method to quantify the emergy inputs and outputs of three watersheds with different planting patterns, i.e., both grains and fruit trees (Gaoxigou watershed), mainly grains (Wuliwan watershed) and mainly fruit trees (Miaozuigou watershed). In addition, an emergy analysis system was established to evaluate the suitability of the three patterns from the perspectives of natural resources pressure as well as social and economic development levels. More than 75% of the total emergy inputs of all the three watersheds were purchased, and nonrenewable emergy inputs had a much larger contribution than renewable emergy inputs, indicating the characteristic of low emergy self-sufficient ratio and considerable high environmental loading ratio. The pattern of planting grains had high emergy inputs but low emergy outputs, while the patterns of planting fruit trees and planting both had high emergy inputs and outputs. The energy densities of all three patterns reached two times of the average of agricultural systems in China. Especially, the net emergy of planting grains pattern was the lowest while that of planting both grains and fruit trees was the highest. The environmental sustainability index (ESI) of planting grains pattern was less than 1 and both emergy and ESI were much lower than national averages. The ESI of planting both grains and fruit trees pattern was the highest. In summary, comparison of the three patterns showed that planting both grains and fruit trees had better sustainability and high stability and the emergy production efficiency was high. Thus, it was suggested to change the agricultural development from watershed based units to multi-industry integrated mode.

The precipitation exiguity and water deficiency are the major factors limiting crop growth in dry farming regions of northern China. Dual-mulching of ridges and furrows, which have been widely concerned both domestically and internationally, could increase the utilization efficiency of precipitation and crop yield. In this paper, we reviewed the concept and model of dual-mulching of ridges and furrows, its supporting farm machinery and implements as well as its ecological effects on soil and crops. Based on the current research progress of cultivation techniques using harvested rainfall in ridge and furrow, priority of future research aspects of the dual-mulching of ridges and furrows were suggested as follows: 1) to establish the suitable ridge-furrow ratios for different crops in different types of dry farming regions of northern China; 2) to pay more attention to the study of coupling effects of soil moisture with temperature, fertility and other factors; 3) to explore better environment-friendly mulching materials; 4) to enhance the research on technical evaluation and popularization, and the design of supporting farm machinery and implements.

This paper studied the spatial-temporal characteristics and rules of land use change in Jiangsu Province using theories and methods of geo-spectrum. Based on the land use data translated from remote sensing images of 1990, 2000 and 2010, we synthesized the geo-spectrum of the mode of arable land use change and that of land use change in two corresponding phases, 1990-2000 and 2000-2010, in Jiangsu using ArcGIS 10.0. The results showed that in the phase of 1990-2000, the major characteristics of land use change were swaps between the geo-spectrum unit of arable land and urban-rural construction land, arable land and water body, and arable land and grassland. Specifically, the patterns of "arable land → urban-rural construction land" and "arable land→ water body" were highly significant. We also found the reduction of arable land area and the concentration of its spatial distribution. In the phase of 2000-2010, the "arable land → urban-rural construction land" pattern was still the most salient characteristic. In addition, the patterns of "grassland → water body" and "urban-rural construction land → water body" became more spatially concentrated and tended to expand. Compared with the previous phase, the area of the land use in the phase of 2000-2010 had been changed expanded and became more scattered. Overall, the geo-spectrum of arable land use change in Jiangsu was mainly shaped by the anaphase change type and partially by the prophase change type, with a tiny influence of the repeated and continuous change.

In order to effectively evaluate the influence of human activities on the resource and environment, this paper constructed an resource and environment pressure evaluation system based on footprint family, and calculated the ecological footprint, carbon footprint, water footprint, and resource and environment pressure in Qinghai Province. The results showed that from 1990 to 2013, the ecological footprint per capita in Qinghai Province increased from 1.32 hm 2 to 3.32 hm 2 , and biological capacity per capita decreased from 2.33 hm 2 to 2.07 hm 2 . Since 2006 there was ecological deficit. However, the biomass surplus existed during 1990-2013. The carbon footprint per capita increased from 5.82 t to 15.85 t, which had been more than 7.93 times of the target to address climate change. The water footprint per capita decreased from 967.67 m 3 to 732.05 m 3 . Since 1990, the ecological pressure was at low grade (1 b ), greenhouse gas (GHG) emissions pressure was enhanced from low grade (1 b ) to above-average grade (2 b ), the water pressure was at very low grade (1 a ), the resource and environment pressure increased from very low grade (1 a ) to low grade (1 b ). The rate of contribution of ecological pressure and water resource pressure to resources and environment pressure gradually decreased, whereas, the rate of contribution of GHG emission pressure to resources and environment pressure gradually increased. The resource and environment pressure had spatial heterogeneity. In 2013, it was at very high grade (3 b ) in Xining City, at above-average grade (2 b ) in Haidong City, at below-average grade (2 a ) in Haixi State and atvery low grade (1 a ) in the rest regions. The main resource and environment pressure source also had obvious spatial heterogeneity. In future, differentiation strategies should be taken in the decompression progress.

Greenhouse gases (GHGs) emission from arable field is a hot topic recently, adopting appropriate cropping systems is an effective way to reduce GHGs emission. This paper reviewed the impacts and mechanisms of intercropping on soil CO 2 and N 2 O emissions in upland field. Rational intercropping systems could increase soil organic carbon (SOC), promote the transformation of straw to SOC, slow down mineralization rate of SOC, and hence reduce soil CO 2 emissions. The Poaceae intercropping with legume could maintain the stability of yield while reducing synthetic N inputs, formation of inorganic N by residue decomposition and soil mineral N, and further reducing soil N 2 O emission. In addition, crop interactions in intercropping system and filed microclimate were important factors on GHGs emission as well. It is necessary to extent the period of researches in field GHGs emission in order to fully understand the underlying mechanisms of GHGs emission in farm land, especially the function of soil microorganisms at molecular level. It would provide theoretical knowledge in building environment-friendly agricultural system in the future.

This paper was aimed to assess the potential impacts of rising temperature and CO 2 concentration on the production of different rice cultivars in the cold region of China, Heilongjiang Province. Total three representative rice varieties with different maturity types were selected to conduct the simulation experiments according to the required accumulated temperature. Daily weather data and open top chamber (OTC) test yield data for year 2013 were used to initialize CERES-Rice model parameters. CERES-Rice model was executed to simulate the influence of climate change on early-mature, mid-mature and late-mature rice production under fixed weather scenarios, which consisted of three CO 2 concentrations (i.e. 390, 450 and 550 μmol·mol -1 ) and four temperature rise levels (i.e. 1, 2, 3 and 4 ℃). Results showed that with the increase in concentration of CO 2 , the rice yield would increase. With the rise in temperature, early-mature rice yield would decline significantly. However, mid-mature and late-mature rice yield would increase at first and then gra-dually decline. Without considering the effect of CO 2 fertilization, except that the medium and late varieties under 1 ℃ warming would slightly increase the yield by 3.1% and 0.27% respectively, yield under the other treatments would reduce. The most serious reduction occurred to early-mature rice, which decreased up to 57.7% when the temperature increased by 4 ℃, while mid-mature rice and late-mature rice yields decreased about 10%. Considering the effect of CO 2 fertilization, mid-mature and late-mature rice yields would even increase by 0.75% and 3.2% at 450 μmol·mol -1 CO 2 under 2 ℃ warming, respectively. Mid-mature rice yield would still increase 4.5% under 3 ℃ warming and late-mature rice yield would also increase 0.39% under 4 ℃ warming at 550 μmol·mol -1 CO 2 . However, it was identified that early-mature rice yield would always sharply decrease with temperature increasing regardless of the effect of CO 2 fertilization. Similarly, CO 2 fertilization effects could improve rice yield to certain extent with temperature increasing. However, the diffe-rence among the varieties in response to CO 2 fertilization effect was not significant. The contribution rate of CO 2 fertilization effect on rice yield was less than 10%.

China is advocating ecological civilization construction nowadays. Further researches on the relation between ecosystem service and humanity well-being are full of theoretical and practical significance. Combining related researches, this paper defined the concept and connotation of ecological well-being based on ecosystem service theory. Referencing theory of national economic accounting and relative researches, the evaluation indicators of ecological well-being supply and consumption were established. The quantitative characterization and evaluation method of red line of regional ecological well-being was proposed on the basis of location quotient. Then the evaluation of ecological well-being in mainland China in 2012 was set as an example for empirical research. The results showed that the net product values of 6 ecosystems, includingcultivated land, forest land, grassland, wetland, water area and unused land, were respectively 1481.925, 8194.806, 4176.277, 4245.760, 3177.084 and 133.762 billion CNY. Spatial heterogeneity of ecosystem net product in different provinces was distinct. Ecological well-being per capita of forest land, grassland, wetland, cultivated land and unused land in eastern and middle provinces were under the red line and less than the national average. The spatial distribution of 9 kinds of ecological well-being per capita split at Hu's line with high value in northwest and low value in southeast, and was aggravated by differences in density of population and land resources gift.

Black and odorous (BO) water body reflects very typical serious water pollution related to organic pollution, sediment re-suspension and thermal pollution. Also, the insufficiency of water cycle is one of the most important hydrodynamic factors for formatting BO water body. The blackening substances mainly include suspended particles, Fe- and S-containing substances; the odour causing substances include the small molecule gases such as H 2 S, NH 3 and some compounds such as VOSCs, Geosmin and 2-MBI. Evaluation methods of BO water were summarized from the evaluation index, BO index, multiple linear regression model and comprehensive evaluation method in this paper. Correspondingly, the relative research direction in the future was discussed. All these works not only defined the identifying technology for urban BO water body, but also would further support the water environment improvement and ecological recovery in urban region.

This paper introduced the concepts of organic agriculture as defined by different international organizations, origin and theoretical development of organic agriculture, as well as its developing trajectory in China (i.e. a late start followed by rapid growth compared to developed countries). The differences between domestic and international organic agriculture were illustrated by scale, crop types, production standards, inputs and planting techniques. Constraints limiting improvements to organic agriculture in aspects of standards, technology, marketing, certification, environmental pollution, enterprise reputation, and national policies were discussed. Future directions and strategies for developing healthy organic agriculture in China were provided.

Soil wind erosion is one of the main reasons for soil degradation in the northwest region of China. Polyacrylamide (PAM), as an efficient soil amendment, has gained extensive attention in recent years since it is effective in improving the structure of surface soil due to its special physical and chemical properties. This paper introduced the physical and chemical properties of PAM, reviewed the effects of PAM on soil wind erosion amount and threshold wind velocity, as well as the effect differences of PAM in soil wind erosion control under conditions of various methods and doses. Its effect was proved by comparing with other materials in detail. Furthermore, we analyzed the mecha-nism of wind erosion control with PAM according to its influence on soil physical characteristics. Comprehensive analysis showed that, although some problems existed in wind erosion control with (PAM), PAM as a sand fixation agent, can not only enhance the capacity of the soil resis-tance to wind erosion, but also improve soil physical properties to form better soil conditions. Besides, we proposed that combination of PAM and plant growth would increase the survival rate of plants greatly, control soil wind erosion in wind-erosive areas, and improve the quality of the ecological environment construction. Thus, PAM has practically important significance and wide application prospect in controlling soil wind erosion.

Non-point source (NPS) pollution has become a key water pollution problem under the condition of point source pollution was controlled. The complexity and uncertainty research of NPS pollution influential factors has always been important and difficult. This paper simulated NPS pollution of the Fanhe River watershed in 2003-2012 by the soil and water assessment tool (SWAT) and analyzed its spatial distribution. Meanwhile, the boosted regression tree (BRT) method was proposed to quantitatively analyze the corresponding influential factors including land use, soil, elevation and slope. The results showed that NPS pollution in the Fanhe River watershed had high spatial heterogeneity. The spatial distribution of total nitrogen (TN) had greater difference than that of total phosphorus (TP). The three pollutants, TN, TP and sediment, were all positively related to slope gradients (P<0.01). The slope gradients played the strongest role in determining the sediment and TP output with the contribution rate of 46.5% and 38.2%, respectively. Land use had important influence on sediment and TP loads, with the contribution rate of 27.2% and 35.3%, respectively. TN was produced abundantly in low-elevation and steep-slope locations and with cultivated land use. Cinnamon soil was most vulnerable to the TN load while meadow soil took the second place in terms of soil erosion and TP load. The paper overcame the complexity of influential factors for NPS pollution by BRT, and deepened the understanding of NPS pollution mechanism.

In this paper, the CENTURY-based modeling system (complying CENTURY model from a site-based model into spatial model) after being systematically calibrated was used to investigate future climate change under Representative Concentration Pathways Scenario (RCP, 4.5 and 8.5) driven spatio-temporal changes in vegetation net primary productivity (NPP) of Inner Mongolia grassland during 2011-2050. The simulation showed that Inner Mongolia grassland NPP would greatly decrease with a rate of 0.57 g C·m -2 ·a -1 (RCP4.5) and 0.89 g C·m -2 ·a -1 (RCP8.5). NPP of Inner Mongolia grassland appeared to decrease by approximately 11.6% (2020s), 12.0% (2030s) and 18.0% (2040s) under the RCP4.5 in relation to baseline period, while its reduction could be exacerbated as 23.8% (2020s), 21.2% (2030s) and 30.1% (2040s) in the RCP8.5 at the regional scale. In addition, grassland NPP induced by future climate changes varied between different grassland types and times, strongly correlating with climate scenario. Even for the RCP4.5, however, a great majority (89.7%) of the grassland exhibited a decreasing trend in annual NPP, with 15.6% of the area decreasing by more than 20% compared with the baseline term. Therefore, although future precipitation rising could benefit vegetation growth, it might be still not enough to compensate for the negative effect of warming on the NPP of Inner Mongolia grassland, and the sustainable development of grassland resources might face a greater challenge.

Research on eco-environment vulnerability assessment contributes to the ecological environmental conservation and restoration. With Changting County as the study area, this paper selec-ted 7 indicators including slope, soil type, multi-year average precipitation, elevation deviate degree, normalized difference vegetation index, population density and land use type to build ecological vulnerability assessment system by using multicollinearity diagnostics analysis approach. The quantitative assessment of ecological vulnerability in 1999, 2006 and 2014 was calculated by using entropy weight method and comprehensive index method. The changes of the temporal-spatial distribution of ecological vulnerability were also analyzed. The results showed that the ecological vulnerability level index (EVLI) decreased overall but increased locally from 1999 to 2014. The average EVLI values in 1999, 2006 and 2014 were 0.4533±0.1216, 0.4160±0.1111 and 0.3916±0.1139, respectively, indicating that the ecological vulnerability in Changting County was at the moderate grade. The EVLI decreased from 2.92 in 1999 to 2.38 in 2006 and 2.13 in 2014. The spatial distribution of the ecological vulnerability was high inside but low outside. The high vulnerability areas were distributed mainly in Hetian Town and Tingzhou Town, where the slope was less than 15° and the altitude was lower than 500 m. During the study period, Sanzhou Town had the largest decreasing range of EVLI while Tingzhou Town had the lowest.

Coastal wetlands contribute about 75% to the global oceanic CH 4 emissions, thus play a vital role in global C cycles. In this paper, we provided a perspective on researches on metabolic, phylogenetic, and ecological diversity of the methanogenic archaea and the regulating environmental factors in coastal wetlands. Because of the presence of more favorable electron acceptors such as sulfate, methanogenesis via CO 2 reduction and acetate fermentation are limited by availability of substrates, and hydrogenotrophic and acetotrophic methanogens generally express low relative abundance. In contrast, "non-competitive" substrates such as methanol and methylated compounds have been shown to contribute substantially to methane formation in coastal wetlands, and the facultative methanogens are predominant in those environments. Salinity regulates vegetation zonation and is related to SO 4 2- concentration, by regulating types of methanogenic substrates and contents of compe-titive electron acceptors, indirectly affects the structure and function of methanogens. Major uncertainties in the current studies include the following: methanogen community structure, the key environmental factors regulating methane pathway, and their effects on methane emissions in coastal wetlands.

On the basis of field soil sampling, this paper investigated the distribution characteristics of soil different nitrogen (N) forms and its influence factors in the different typical zonal soils. The results showed that the concentrations of soil extractable total N, extractable organic N and adsorbed amino acids extracted with 0.5 mol·L -1 K 2 SO 4 significantly increased along the altitudinal gradient in the different vertical soils, and their mean concentrations were greater than that in the horizontal soils. The concentrations of soil different N forms widely varied with the soil type in the different horizontal soils. On average, the concentration of soil adsorbed amino acids was approximately 5-fold greater than that of the free amino acids, representing 21.1% of soil extractable organic N. It indicated that the soil adsorbed amino acids extracted with the strong salt solution could serve as an important form of soil organic N. Pearson correlation analysis showed that extractable total N, extractable organic N, ammonium and amino acids in vertical soils were positively correlated with soil organic matter and total N (r=0.57-0.93, P<0.05), but negatively correlated with soil pH and nitrate (r=-0.37--0.91, P<0.05). In the horizontal soils, soil extractable total N, nitrate, organic matter, total N, alkali-hydrolyzable N and cation ions (e.g. K + , Ca 2+ , Mg 2+ ) were all positively correlated with soil pH (r=0.36-0.85, P<0.05), whereas negatively correlated with soil ammonium and amino acids (r=-0.39--0.81, P<0.05).

Senescence is a natural termination process at the plant or organ level of cotton, leading to the inevitable end of the growth and development process. Maturity performance is termed as senescence performance and results of a cotton plant during boll opening, including normal maturity, premature senescence and late-maturity in cotton. Senescence and maturity performance are influenced by genotype and environment interactions. This paper summarized and reviewed the research progress in eco-physiology and molecular biology of cotton leaf senescence. Strategies were proposed to regulate cotton growth and aging through breeding of stably-developed varieties, rational application of plant growth regulators and agronomic cultivation measures, to realize normal maturity and improve yield and quality of cotton.

Model based on vegetation ecophysiological process contains many parameters, and reasonable parameter values will greatly improve simulation ability. Sensitivity analysis, as an important method to screen out the sensitive parameters, can comprehensively analyze how model parameters affect the simulation results. In this paper, we conducted parameter sensitivity analysis of BIOME-BGC model with a case study of simulating net primary productivity (NPP) of Larix olgensis forest in Wangqing, Jilin Province. First, with the contrastive analysis between field measurement data and the simulation results, we tested the BIOME-BGC model' s capability of simulating the NPP of L. olgensis forest. Then, Morris and EFAST sensitivity methods were used to screen the sensitive parameters that had strong influence on NPP. On this basis, we also quantitatively estimated the sensitivity of the screened parameters, and calculated the global, the first-order and the second-order sensitivity indices. The results showed that the BIOME-BGC model could well simulate the NPP of L. olgensis forest in the sample plot. The Morris sensitivity method provided a reliable parameter sensitivity analysis result under the condition of a relatively small sample size. The EFAST sensitivity method could quantitatively measure the impact of simulation result of a single parameter as well as the interaction between the parameters in BIOME-BGC model. The influential sensitive parameters for L. olgensis forest NPP were new stem carbon to new leaf carbon allocation and leaf carbon to nitrogen ratio, the effect of their interaction was significantly greater than the other parameter' teraction effect.

In order to investigate the adaption of Locusta migratoria tibetensis to the. environment, this paper adopted the experiments with full light exposure (24L/OD), total. darkness (OL/24D), and low temperature (5 °C) to study the effects of low temperature and illumination stress on the cold-resistant substances of L. migratoria tibetensis. The results showed that the fat content of L. migratoria tibetensis reached 11.8%, which was the highest under the condition of full light exposure (24L/OD) without low temperature stress. The fat content of body in low temperature and darkness treatment (OL/24D) was 4.7%, which was the lowest. The trehalose, mannitol and sorbitol contents of locust after low temperature stress were significantly higher than that of locust without the same stress. Glycogen content of locust treated by full light exposure without low temperature 'stress was the highest (6.40 mg . g-1). Besides, low temperature and darkness treatment stimulated the accumulation of alanine, glutamic acid, lysine, and phenylalanine, benefiting the accumulation of multi-amino acids, glycerinum, micro-molecule carbohydrate, and the reduction of glycogen and fat content.

The hedgerows, also called vegetative barriers, are defined as strips of grass, trees or shrubs or combinations of herbaceous and woody plants established along the contour lines of slopes, the edge of fields, streams, ditches or other water bodies, which can play outstanding roles in soil structure improvement, such as soil texture, porosity, bulk density, and some other physical properties. Its mechanical resistance can delay and intercept runoff effectively, facilitate rainwater infiltration, and reduce the denudation power of runoff on surface land. Moreover, the hedgerows can change sloping topography through constant sediment accumulation at the upper sides of the strips. The international and domestic researches across different ecological zones and geographical regions were summarized and analyzed in this paper. On the basis of such analysis, the hedgerows were confirmed to play a positive role in soil physical and chemical properties, rainfall infiltration, erosion processes, vegetation restoration, biodiversity conservation, landscape optimization and other important ecosystem services. Meanwhile, two problems in the current research of hedgerows were put forward: the planting pattern and structure of hedgerows, species selection, and management practices should be systematized for application, while the mechanisms of hedgerows on vegetation restoration and ecological succession should be further explored in scientific research.

Based on the data of soil moisture content and indoor soil surface spectral reflectance from five sampling sites of coastal saline soil, this paper analyzed the relationship between soil moisture content and soil spectrum in wavelength 350-2500 nm. We determined spectral parameters under ratio spectral index (RSI), normalized difference spectral index (NDSI) and difference spectral index (DI), and established the quantitative model of soil moisture content. The results showed significant negative correlation between spectral reflectance and soil moisture content, and the maximum negative correlation was near 1930 nm (r=0.86). By comparison of the regression equation of RSI, NDSI and DI, it was found that the regression equation of exponential function (y=0.00001e9.7203x) built by soil moisture content based on RSI (R1407, R1459) presented the maximum R2 (0.780) and the minimum SE (0.016). The established model based on RSI (R1407, R1459) could be used to monitor soil moisture content accurately in Jiangsu coastal saline soils.

Isotopic enrichment factor (Δ, the difference between the δ value of food and a consumer tissue) is an important parameter in using stable isotope analysis (SIA) to reconstruct diets, characterize trophic relationships, elucidate patterns of resource allocation, and construct food webs. Isotopic enrichment factor has been considered as a constancy value across a broad range of animals. However, recent studies showed that the isotopic enrichment factor differed among various types of animals although the magnitude of variation was not clear. Here, we conducted a meta-analysis to synthesize and compare Δ13C and Δ15N among four types of aquatic animals (teleosts, crustaceans, reptiles and molluscs). We searched for papers published before 2014 on Web of Science and CNKI using the key words "stable isotope or isotopic fractionation or fractionation factor or isotopic enrichment or trophic enrichment". Forty-two publications that contain 140 studies on Δ13C and 159 studies on Δ15N were obtained. We conducted three parallel meta-analyses by using three types of weights (the reciprocal of variance as weights, the sample size as weights, and equal weights). The results showed that no significant difference in Δ13C among different animal types (teleosts 1.0 per thousand, crustaceans 1.3 per thousand, reptiles 0.5 per thousand, and molluscs 1.5 per thousand), while Δ15N values were significantly different (teleosts 2.4 per thousand, crustaceans 3.6 per thousand, reptiles 1.0 per thousand and molluscs 2.5 per thousand). Our results suggested that the overall mean of Δ13C could be used as a general enrichment factor, but Δ15N should be chosen according to the type of aquatic animals in using SIA to analyze trophic relationships, patterns of resource allocation and food webs.

Carbon emissions due to land use change have an important impact on global climate change. Adjustment of regional land use patterns has a great scientific significance to adaptation to a changing climate. Based on carbon emission/absorption parameters suitable for Liaoning Province, this paper estimated the carbon emission of land use change in the city and town concentrated area of central Liaoning Province. The results showed that the carbon emission and absorption were separately 308.51 Tg C and 11.64 Tg C from 1997 to 2010. It meant 3.8% of carbon emission. was offset by carbon absorption. Among the 296.87 Tg C net carbon emission of land use change, carbon emission of remaining land use type was 182.24 Tg C, accounting for 61.4% of the net carbon emission, while the carbon emission of land use transformation was 114.63 Tg C, occupying the rest 38.6% of net carbon emission. Through quantifying the mapping relationship between land use change and carbon emission, it was shown that during 1997-2004 the contributions of remaining construction land (40.9%) and cropland transform ation to construction land (40.6%) to carbon emission were larger, but the greater contributions to carbon absorption came from cropland transformation to forest land (38.6%) and remaining forest land (37.5%). During 2004-2010, the land use types for carbon emission and absorption were the same to the period of 1997-2004, but the contribution of remaining construction land to carbon emission increased to 80.6%, and the contribution of remaining forest land to carbon absorption increased to 71.7%. Based on the carbon emission intensity in different land use types, we put forward the low-carbon regulation countermeasures of land use in two aspects. In carbon emission reduction, we should strict control land transformation to construction land, increase the energy efficiency of construction land, and avoid excessive development of forest land and water. In carbon sink increase, we should improve forest coverage rate, implement cropland, grassland transform to forest land, strengthen forest land and water protection, and adjust cropland internal structure and scientifically implement cropland management.

Soil erosion is an important ecological and environmental problem in Hunshandake Desert, and the sand-fixing function determines the degree of ecological security in the entire region. In order to clarify the situation of windbreak and sand fixation in Hunshandake area, and to guide the prevention and treatment of desertification on regional scale, based on the meteorological and remote sensing data, this paper quantitatively analyzed the temporal and spatial pattern of windbreak and sand fixation ability between 2000-2010 by the revised wind erosion equation (RWEQ) model, meanwhile, the driving forces for each county ( or banner) in the functional zone were analyzed with the method of principal component analysis. The results showed that there was a fluctuation of the sand fixing capacity in Hunshandake over time, generally rendering a decline trend. The coniferous forest and grassland had strong windbreak and sand fixation capacity in unit area among the various land categories. In terms of spatial distribution, the windbreak and sand fixation function in western and southeastern region was weak and needed to be strengthened with ecological restoration efforts. Through the study of the social driving forces of each administrative region in the function zone, there were 3 main social driving forces of soil erosion in the administrative functions: the intensity of input-output, the level of economic development and the level of agriculture-husbandry development.

Landscape pattern vulnerability reflects the instability and sensitivity of ecological system to external disturbances and helps to understand the status and trend of ecological environment. This paper used landscape sensitivity index and landscape adaptability index to construct the landscape pattern vulnerability index of Yinchuan Basin, and got the distribution of the landscape pattern vulnerability in 2001 and 2013. Our study explored the effect of the land use degree composite index, the integrated land use dynamic degree, the importance index of land use change and various types of land transfer on landscape pattern vulnerability. Results showed that the land use degree composite index was mainly caused by the increase of the arable land, forest and the construction land. The higher proportion of the arable land or forest, the lower the vulnerability was, and the construction land had the opposite effect. With the increase of integrated land use dynamic degree, the construction land significantly increased the vulnerability, followed by grassland, and the forest significantly decreased the vulnerability, followed by the arable land. As the importance index of land use change increasing, the arable land could significantly decrease the vulnerability, followed by the forest, the grassland had a weaker trend with no obvious pattern, and the construction land significantly increased the vulnerability. When the arable land, forest and the grassland were the maintypes of land use transfer, the increasing proportion of the construction land increased the vulnerability. When the construction land was the main type of land use transfer, the grassland and forest improved the vulnerability and the arable land had the opposite effect. Changes in the number of land use types influenced the spatial structure of land use to a certain extent, which could offer a reference on using and developing the land resources scientifically. The ternary diagram could reflect the impact of various types of and use change on the landscape vulnerability, which diagram enriched the content of the research on the land use and change.

Based on the evaluation index system established for measuring the resource environmental bearing capacity (REBC), this paper measured the REBC of Beijing-Tianjin-Hebei region by applying the state space model and analyzed their driving factors by using the Tobit model. The results showed that the REBC of Beijing-Tianjin-Hebei region was in the available state and at the rising stage as well during 2000-2012. The social economic growth had great pressure on the resources and environment. The bearing ratios of the REBCs of Beijing, Tianjin and Hebei all presented a U curve and located at low levels, which meant that there was high REBC potential in these regions. Both of the permanent population and the urban residents 'Engel' s coefficient were the influence factors of the REBC of Beijing-Tianjin-Hebei region. The population problem was likely to become the bottleneck to restrict the regional social and economic development, and also threaten the resources and environment. The specific driving factors of the REBC were different in Beijing, Tianjin and Hebei. For example, energy consumption per unit of GDP only had significant impact on Tianjin. At last, the paper proposed that the three regions should complement each other in resources and environment, social development, and economic structure, also the REBC should be taken a reference in decision and policy making.

The relationships between litter decomposition rate and their initial quality of 14 representative plants in the alpine forest ecotone of western Sichuan were investigated in this paper. The decomposition rate k of the litter ranged from 0.16 to 1.70. Woody leaf litter and moss litter decomposed much slower, and shrubby litter decomposed a little faster. Then, herbaceous litters decomposed fastest among all plant forms. There were significant linear regression relationships between the litter decomposition rate and the N content, lignin content, phenolics content, C/N, C/P and lignin/N. Lignin/N and hemicellulose content could explain 78.4% variation of the litter decomposition rate (k) by path analysis. The lignin/N could explain 69.5% variation of k alone, and the direct path coefficient of lignin/N on k was -0.913. Principal component analysis (PCA) showed that the contribution rate of the first sort axis to k and the decomposition time (t) reached 99.2%. Significant positive correlations existed between lignin/N, lignin content, C/N, C/P and the first sort axis, and the closest relationship existed between lignin/N and the first sort axis (r = 0.923). Lignin/N was the key quality factor affecting plant litter decomposition rate across the alpine timberline ecotone, with the higher the initial lignin/N, the lower the decomposition rate of leaf litter.

Light Detection and Ranging (LiDAR) is an active remote sensing technology for acqui- ring three-dimensional structure parameters of vegetation canopy with high accuracy over multiple spatial scales, which is greatly important to the promotion of forest disturbance ecology and the ap- plication on gaps. This paper focused on mid-subtropical evergreen broadleaved forest in Hunan Province, and small footprint LiDAR point data were adopted to identify canopy gaps. and measure geomagnetic characteristics of gaps. The optimal grid model resolution and interpolation methods were chosen to generate canopy height model, and the computer graphics processing was adopted to estimate characteristics of gaps which involved gap size, canopy height and gap shape index, then field investigation was utilized to validate the estimation results. The results showed that the gap rec- ognition rate was 94.8%, and the major influencing factors were gap size and gap maker type. Line- ar correlation was observed between LiDAR estimation and field investigation, and the R² values of gap size and canopy height case were 0.962 and 0.878, respectively. Compared with field investiga- tion, the size of mean estimated gap was 19.9% larger and the mean estimated canopy height was 9.9% less. Gap density was 12.8 gaps · hm⁻² and the area of gaps occupied 13.3% of the forest area. The average gap size, canopy height and gap shape index were 85.06 m², 15.33 m and 1.71, respectively. The study site usually contained small gaps in which the edge effect was not obvious.

This paper investigated the genus diversity of soil nematodes of different agricultural areas in Jiangsu Province, analyzed the relationship between soil nematodes and soil environmental factors, and discussed the roles of soil nematodes as biological indicators of soil health. The results showed that, a total of 41 nematode genera were found in all six agricultural areas, belonging to 19 families, 7 orders, 2 classes. The numbers and community compositions of nematodes were obviously influenced by soil texture, fertilization and tillage practices. In all six agricultural areas, the numbers of nematodes in coastal agricultural area (400 individuals per 100 g dry soil) were significantly larger than that in Xuhuai, Ningzhenyang, and riverside agricultural areas. While the smallest number of nematodes was found in Yanjiang agricultural area (232 individuals per 100 g dry soil), which might be due to the differences in soil texture, annual rainfall and annual air temperature and other factors. The dominant genera of nematodes were similar in the adjacent agricultural areas. Correlation analysis showed that there was a significant positive correlation between the number of soil nematodes and levels of soil nutrients (soil organic matter, total nitrogen, available nitrogen, available potassium and available phosphorus). Redundancy analysis (RDA) indicated the total nitrogen, available potassium and pH obviously affected some soil nematode genera. The analysis of spatial distribution characteristics of soil nematode community in farmland of Jiangsu Province could provide data for health assessment of agricultural ecosystems.

Based on a new process-based model, TRIPLEX-GHG, this paper analyzed the spatio-temporal variations of natural wetland CH4 emissions over China under different future climate change scenarios. When natural wetland distributions were fixed, the amount of CH4 emissions from natural wetland ecosystem over China would increase by 32.0%, 55.3% and 90.8% by the end of 21st century under three representative concentration pathways (RCPs) scenarios, RCP2. 6, RCP4.5 and RCP8.5, respectively, compared with the current level. Southern China would have higher CH4 emissions compared to that from central and northern China. Besides, there would be relatively low emission fluxes in western China while relatively high emission fluxes in eastern China. Spatially, the areas with relatively high CH4 emission fluxes would be concentrated in the middle-lower reaches of the Yangtze River, the Northeast and the coasts of the Pearl River. In the future, most natural wetlands would emit more CH4 for RCP4.5 and RCP8.5 than that of 2005. However, under RCP2.6 scenario, the increasing trend would be curbed and CH4 emissions (especially from the Qinghai-Tibet Plateau) begin to decrease in the late 21st century.

Archival tags, a group of data storable electronic tags, are widely used as strong tools for obtaining long term and large scale activity information of marine animals, specifically highly migratory oceanic fishes, and corresponding environmental data. Though retrieving tags is an indispensable step for obtaining data, which is a shortage of archival tags, a series of achievements have been made on marine animals by using archival tags since the 1990s. With the appearance of pop-up satellite tag, which solved the problem of data retrieving and was fully independent of the fishing, both breadth and depth of marine animals' studies are extended by the end of the 1990s. Geolocation based on light intensity is the key to estimate marine animals' movement and has achieved some progress in the past 20 years. However, the accuracy of geolocation for latitude is not high enough, and there is still much room for improvement. To date, most geolocation methods that use ambient daylight involve identifying the times when the sun is at a precisely known zenith angle (e.g., sunrise and sunset). The problem of estimating longitude has been proved easy to solve, but accurate latitude estimates remain elusive. This paper mainly introduced two tags, i. e., archival tags and pop-up tags, and three geolocation methods, i.e. , 1) the "fixed reference" method, 2) the "variable reference" method, and 3) the "reflection" method. We also presented a prospect analysis on archival tags and possible research direction of geolocation methods. We believed that miniaturization and multi-sensor integration are the trends for electronic tags while more environmental factors such as depth, SST (sea surface temperature) or magnetic field intensity, instead of single factor, as auxiliary parameters would be used for improving the geolocation accuracy in the future.

Methyl halides are the major carrier of halogens in the atmosphere, and they play an important role in tropospheric and stratospheric ozone depletion. Meanwhile, methyl halides can act as greenhouse gases in the atmosphere, and they are also environmentally significant because of their toxicity. Coastal salt marshes, the important intertidal ecosystems at the land-ocean interface, have been considered to be a large potential natural source of methyl halides. In this paper, the research status of the natural source or sink of methyl halides, the mechanisms of their emission from coastal salt marshes and affecting factors were summarized. In view of this, the following research fields need to be strengthened in the future: 1) Long time-scale and large region-range researches about the emission of methyl halides and the evaluation of their source and sink function, 2) Accurate quantification of contribution rates of different plant species and various biological types to fluxes of methyl halides, 3) Further researches on effects of the tidal fluctuation process and flooding duration on methyl halides emission, 4) Effects of the global change and human activities on methyl halides emission.

It is often difficult to estimate site indices for different types of plantation by using an ordinary site index model. The objective of this paper was to establish a site index model for plantations in varied site conditions, and assess the site qualities. In this study, a nonlinear mixed site index model was constructed based on data from the second class forest resources inventory and 173 temporary sample plots. The results showed that the main limiting factors for height growth of Larix principis-rupprechtii were elevation, slope, soil thickness and soil type. A linear regression model was constructed for the main constraining site factors and dominant tree height, with the coefficient of determination being 0.912, and the baseline age of Larix principis-rupprechtii determined as 20 years. The nonlinear mixed site index model parameters for the main site types were estimated (R2 > 0.85, the error between the predicted value and the actual value was in the range of -0.43 to 0.45, with an average root mean squared error (RMSE) in the range of 0.907 to 1.148). The estimation error between the predicted value and the actual value of dominant tree height for the main site types was in the confidence interval of [-0.95, 0.95]. The site quality of the high altitude-shady-sandy loam-medium soil layer was the highest and that of low altitude-sunny-sandy loam-medium soil layer was the lowest, while the other two sites were moderate.

As a widespread natural phenomenon in the soil of middle and high latitude as well as high altitude, freeze-thawing cycles have a great influence on the nitrogen cycle of terrestrial ecosystem in non-growing season. Freeze-thawing cycles can alter the physicochemical and biological properties of the soil, which thereby affect the migration and transformation of soil nitrogen. The impacts of freeze-thawing cycles on key processes of nitrogen cycle in terrestrial ecosystem found in available studies remain inconsistent, the mechanism is still not clear, and the research methods also need to be further explored and innovated. So it is necessary to sum up and analyze the existing achievements in order to better understand the processes of soil nitrogen cycle subjected to freeze-thawing cycles. This paper reviewed the research progress in China and abroad about the effects and mechanisms of freeze-thawing cycles on key processes of nitrogen cycle in terrestrial ecosystem, including mineralization, immobilization, nitrification and denitrification, N leakage and gaseous loss, and analyzed the deficiencies of extant research. The possible key research topics that should be urgently paid more attention to in the future were also discussed.

Qinghai Lake is the largest inland and salt water lake in China, and provides important ecosystem services to beneficiaries. Economic valuation of wetland ecosystem services from Qinghai Lake can reveal the direct contribution of lake ecosystems to beneficiaries using economic data, which can advance the incorporation of wetland protection of Qinghai Lake into economic tradeoffs and decision analyses. In this paper, we established a final ecosystem services valuation system based on the underlying ecological mechanisms and regional socio-economic conditions. We then evaluated the eco-economic value provided by the wetlands at Qinghai Lake to beneficiaries in 2012 using the market value method, replacement cost method, zonal travel cost method, and contingent valuation method. According to the valuation result, the total economic values of the final ecosystem services provided by the wetlands at Qinghai Lake were estimated to be 6749.08 x 10(8) yuan RMB in 2012, among which the value of water storage service and climate regulation service were 4797.57 x 10(8) and 1929.34 x 10(8) yuan RMB, accounting for 71.1% and 28.6% of the total value, respectively. The economic value of the 8 final ecosystem services was ranked from greatest to lowest as: water storage service > climate regulation service > recreation and tourism service > non-use value > oxygen release service > raw material production service > carbon sequestration service > food production service. The evaluation result of this paper reflects the substantial value that the wetlands of Qinghai Lake provide to beneficiaries using monetary values, which has the potential to help increase wetland protection awareness among the public and decision-makers, and inform managers about ways to create ecological compensation incentives. The final ecosystem service evaluation system presented in this paper will offer guidance on separating intermediate services and final services, and establishing monitoring programs for dynamic ecosystem services valuation with the aim of helping improve management outcomes.

In this paper, the interaction between the species Population were analyzed based on the data of major nekton species in the south coastal waters of Cangnan in spring and autumn 2014. A series of methods including niche breadth, niche overlap, χ2 - test and association coefficient (AC) based on a 2x2 contingency table were used. The results showed that the major nekton species in the south coastal waters of Cangnan were classified into three groups, i.e. wide niche breadth species, moderate niche breadth species and narrow niche breadth species based on the niche breadth values. The wide niche breadth species of nekton were Harpodon nehereus, Portunus trituberculatus, mantis shrimp and other 2 species. The moderate niche breadth species of nekton were Collichthys lucidus, Parapenaeopsis hardwickii, Parapenaeopsis tenella and other 5 species. While the species with narrow niche breadths were Charybdis japonica, Amblychaeturichthys hexanema, Palaemon gravieri and other 7 species. There were great differences in the niche overlap values among the major nekton populations, with the maximum value of 0.93 and the minimum of 0, which indicated that resource utilization competition in some nekton might exist. The results of variance ratio analysis for major nekton in the south coastal waters of Cangnan showed that they were significantly positively correlated. χ2 - test results showed that there were significantly interspecific association for 78 species pairs (χ2≥3.841), among which more association coefficients (AC) of species pairs are positive.

This paper investigated soil moisture in alfalfa (Medicago sativa) cropland with different growth years (1, 3, 8, 12 and 14 years) and discussed the optimum growth years of alfalfa on the Loess Plateau of central Gansu. The results showed that the soil moisture along 0-300 cm soil profile of alfalfa croplands with different growth years was obviously lower than that of the local soil stable moisture. The soil water contents in croplands with alfalfa that had grown for 12 and 14 years were only 9.2% and 7.1% of local soil stable moisture, respectively, which were even lower than the lower limit of alfalfa growth. The average soil dryness indexes along 0-300 cm soil profile in 1, 3, 8, 12 and 14 years alfalfa croplands were 125.4%, 30.5%, 18.4%, -34.2% and -83.3% respectively. The results indicated that soil dryness occurred to varying degrees with different growth years except croplands with alfalfa grown for 1 year. With the increase of growth years of alfalfa, the soil dryness intensity increased and the soil dryness rate decreased. According to the soil moisture and alfalfa productivity results in this study, it could be concluded that the optimum growth years of alfalfa are 8-10 years in semiarid areas of the Loess Plateau.