Trend in seasonal amplitude of northern net ecosystem production:Simulated results from IAP DGVM in CAS-ESM2

北方陆地净生态系统生产力(NEP)具有明显的季节变化特征,这是大气CO_(2)季节变化的关键驱动.研究这些碳循环过程并理解潜在的驱动因素是气候研究的一个关键问题.本文利用第二代中国科学院地球系统模式(CAS-ESM2)中的全球植被动态模型(IAPDGVM),研究了1990-2014年北方NEP(40°-90°N)的季节振幅及其变化趋势.在初始化试验的基础上,本文开展了一个控制试验来评估模拟的北方NEP季节幅度的变化趋势,同时开展了三个敏感性试验来研究气候和大气CO_(2)的贡献.结果表明:1990-2014年,模拟的北方NEP季节振幅显著增加,趋势为9.69万吨碳/月/年,这主要是由于最大NEP增加所致.当分别排除CO_(2)施肥效应和气候效应时,上述增加趋势大大减弱.这些显著的减少表明大气CO_(2)和气候变化对北方NEP的季节性振幅有重要影响.尽管模式存在不确定性,但这些结果有利于进一步提升IAPDGVM对陆地碳循环的精确模拟,也为CAS-ESM研究碳-气候相互作用的应用提供了重要参考.

The Dynamics and Driving Force of Farmland Ecosystem Productivity

Based on the experimental data of crop yield, soil water and fertility of a dryland farming ecosystem in northwest China, asystematic analysis is carried out to study the dynamics of dryland farming ecosystem productivity and its limitingfactors. This paper also discusses which of the two limiting factors, i.e., soil water or fertility, is the primary factor and theirdynamics. The result shows that fertility is the primary limiting factor when the productivity is rather low. As chemicalfertilizer input increases and the productivity promotes, water gradually becomes the primary limiting factor. Chemicalfertilizers and plastic film mulching are the two major driving forces that determine the crop productivity and its stabilityin these areas.

How Does the Agricultural Ecosystem Productivity Respond to Climate Fluctuations in the Northern Farming-pastoral Region?

Using meteorological data and mathematical statistics analysis,we take Jungar Banner in the northern farming-pastoral region of China for example,to analyze the fluctuations in the precipitation and average temperature in Jungar Banner during the period 1961-2009.We calculate the NPP of agricultural ecosystem and climatic yield of the main crops in the region during the period 1961-2009,and expound the response of agricultural ecosystem productivity to climate fluctuations in Jungar Banner.Indubitably the climate changes impose great effects on the structure and function of regional ecosystem,and there is a need to take a number of measures to minimize the detrimental effects of climate changes on climatic yield of the main crops.

Succession and Enhancement Mechanism of Ecosystem Productivity in the De-farming Area of the Ecotone Between Agriculture and Animal Husbandry in North China

The succession and enhancement mechanism of the ecosystem productivity with the characteristics ot de-tarmlng in me ecotone between agriculture and animal husbandry in North China was discussed in order to provide an ideaology or a technical basis for maintaining the impetus of ecological restoration and economic development in this region. A case study was applied in combination with the theoretical analysis. The results indicated that the biomass productivity of the de-farming subsystem decreased by 38.4-72.3% compared with that of farming subsystem in the ecosystem. The main function of de-farming subsystem was focused on ecological productivity, it caused the ideal beneficial recycling ‘defarming → planting grass → raising animals → earn money＇ difficult to be realized. With the differentiation of de-farming subsystem, the natural and social resources input to the farming subsystem were accumulated. This laid a basis for the new attributes of economic productivity to be upgraded. The case study indicated that the economic productivity of the ecosystem was increased by 8.85-13.35 times due to re-coupling between the de-farming subsystem and the farming subsystem as well as coupling between microhabitat differentiation and crop production in the subsystems, where the microhabitat differentiation could enrich water and fertilizer in the same field. It was concluded that the important mechanisms to enhance the system productivity in the ecotone between agriculture and animal husbandry of North China included structure rebuilding and opening of the de-farming ecosystem and taking the advantage of complementary cooperative production among different regions under the market economy and rebuilding an open agro-pasture production structure,

Analyzing the spatiotemporal evolution and driving forces of gross ecosystem product in the upper reaches of the Chaobai River Basin

The Chaobai River Basin,which is a crucial ecological barrier and primary water source area within the Beijing-Tianjin-Hebei region,possesses substantial ecological significance.The gross ecosystem product(GEP)in the Chaobai River Basin is a reflection of ecosystem conditions and quantifies nature’s contributions to humanity,which provides a basis for basin ecosystem service management and decision-making.This study investigated the spatiotemporal evolution of GEP in the upper Chaobai River Basin and explored the driving factors influencing GEP spatial differentiation.Ecosystem patterns from 2005 to 2020 were analyzed,and GEP was calculated for 2005,2010,2015,and 2020.The driving factors influencing GEP spatial differentiation were identified using the optimal parameter-based geographical detector(OPGD)model.The key findings are as follows:(1)From 2005 to 2020,the main ecosystem types were forest,grassland,and agriculture.Urban areas experienced significant changes,and conversions mainly occurred among urban,water,grassland and agricultural ecosystems.(2)Temporally,the GEP in the basin increased from 2005 to 2020,with regulation services dominating.At the county(district)scale,GEP exhibited a north-west-high and south-east-low pattern,showing spatial differences between per-unit-area GEP and county(district)GEP,while the spatial variations in per capita GEP and county(district)GEP were similar.(3)Differences in the spatial distribution of GEP were influenced by regional natural geographical and socioeconomic factors.Among these factors,gross domestic product,population density,and land-use degree density contributed significantly.Interactions among different driving forces noticeably impacted GEP spatial differentiation.These findings underscore the necessity of incorporating factors such as population density and the intensity of land-use development into ecosystem management decision-making processes in the upper reaches of the Chaobai River Basin.Future policies should be devised to regulate human activities,thereby ensuring the stability and enhancement of GEP.

Basic Principles of Gross Ecosystem Product(GEP)Accounting

Gross ecosystem product(GEP) is the gross value of all ecosystem products and services provided by ecosystems for human society. In practice, GEP measures the ecosystems’ contributions to human well-being and constitutes one of the core issues in the construction of ecological civilization systems. Currently, GEP accounting faces a series of problems, such as the inconsistency of accounting subjects and a lack of accounting standards,the result of which is the non-reproducibility and weak applicability of accounting results. In this paper, mainstream models for ecosystem service valuation are summarized in a systematic manner. On this basis, eight basic principles are established for screening accounting indicators: biological productivity, human benefits, production territoriality, current increment, actual effectiveness, physical metrizability, data availability, and harmlessness. Next, a series of ecosystem service subjects are identified that need to be excluded from accounting, and the detailed reasons for their exclusion are presented. Finally, three ideas for improving GEP accounting are offered from the perspectives of the relationship between biological production and human production, the circulation-transport relationship and spatial differences, and harms to the ecosystem carrying capacity. The purpose is to provide positive considerations aimed at promoting the socio-economic applications of accounting and to contribute to the scientific quantification of the values of ecological products.

The relative controls of temperature and soil moisture on the start of carbon flux phenology and net ecosystem production in two alpine meadows on the Qinghai-Tibetan Plateau

Aims Variations in vegetation spring phenology are widely attributed to temperature in temperate and cold regions.However,temperature effect on phenology remains elusive in cold and arid/semiarid ecosystems because soil water condition also plays an important role in mediating phenology.Methods We used growing degree day(GDD)model and growing season index(GSI)model,coupling minimum temperature(T_(min))with soil moisture(SM)to explore the influence of heat requirement and hydroclimatic interaction on the start of carbon uptake period(SCUP)and net ecosystem productivity(NEP)in two alpine meadows with different precipitation regimes on the Qinghai-Tibet Plateau(QTP).One is the water-limited alpine steppe-meadow,and the other is the temperature-limited alpine shrub-meadow.Important Findings We observed two clear patterns linking GDD and GSI to SCUP:SCUP was similarly sensitive to variations in preseason GDD and GSI in the humid alpine shrub-meadow,while SCUP was more sensitive to the variability in preseason GSI than GDD in the semiarid alpine steppe-meadow.The divergent patterns indicated a balance of the limiting climatic factors between temperature and water availability.In the humid meadow,higher temperature sensitivity of SCUP could maximize thermal benefit without drought stress,as evidenced by the stronger linear correlation coefficient(R2)and Akaike’s information criterion(AIC)between observed SCUPs and those of simulated by GDD model.However,greater water sensitivity of SCUP could maximize the benefit of water in semiarid steppe-meadow,which is indicated by the stronger R2 and AIC between observed SCUPs and those of simulated by GSI model.Additionally,although SCUPs were determined by GDD in the alpine shrub-meadow ecosystem,NEP was both controlled by accumulative GSI in two alpine meadows.Our study highlights the impacts of hydroclimatic interaction on spring carbon flux phenology and vegetation productivity in the humid and semiarid alpine ecosystems.The results also suggest that water,together with temperature should be included in the models of phenology and carbon budget for alpine ecosystems in semiarid regions.These fi ndings have important implications for improving vegetation phenology models,thus advancing our understanding of the interplay between vegetation phenology,productivity and climate change in future.

Multimodel projections and uncertainties of net ecosystem production in China over the twenty-first century

Ecosystems in China have been absorbing anthropogenic CO2 over the last three decades. Here, we assess future carbon uptake in China using models from phase 5 of Coupled Model Intercomparison Project under four socio-economic scenarios. The average of China's carbon sink from 2006 to 2100 represented by multimodel mean net ecosystem production(NEP) is projected to increase(relative to averaged NEP from 1976 to 2005) in the range of 0.137 and 0.891 Pg C a-1across differentscenarios. Increases in NEP are driven by increases in net primary production exceeding increases in heterotrophic respiration, and future carbon sink is mainly attributed to areas located in eastern China. However, there exists a considerable model spread in the magnitude of carbon sink and model spread tends to be larger when future climate change becomes more intense. The model spread may result from intermodel discrepancy in the magnitude of CO2 fertilization effect on photosynthesis, soil carbon turnover time, presence of carbon-nitrogen cycle and interpretation of land-use changes. For better quantifying future carbon cycle, a research priority toward improving model representation of these processes is recommended.

Interannual Variation in Terrestrial Ecosystem Carbon Fluxes in China from 1981 to 1998

A dynamic biogeochemical model was used to estimate the responses of China's terrestrial net primary productivity (NPP), soil heterotrophic respiration (HR) and net ecosystem productivity (NEP) to changes in climate and atmospheric CO2 from 1981 to 1998. Results show that China's total NPP varied between 2.89 and 3.37 Gt C/a and had an increasing trend by 0.32% per year, HR varied between 2.89 and 3.21 Gt C/a and grew by 0.40% per year, Annual NEP varied between -0.32 and 0.25 Gt C but had no statistically significant interannual trend. The positive mean NEP indicates that China's terrestrial ecosystems were taking up carbon with a total carbon sequestration of 1.22 Gt C during the analysis period. The terrestrial NEP in China related to climate and atmospheric CO2 increases accounted for about 10% of the world's total and was similar to the level of the United States in the same period. The mean annual NEP for the analysis period was near to zero for most of the regions in China, but significantly positive NEP occurred in Northeast China Plain, the southeastern Xizang (Tibet) and Huang-Huai-Hai Plain, and negative NEP occurred in the Da Hinggan Mountains, Xiao Hinggan Mountains, Loess Plateau and Yunnan-Guizhou Plateau. China's climate at the time was warm and dry relative to other periods, so the estimated NEP is probably lower than the average level. China's terrestrial NEP may increase if climate becomes wetter but is likely to continue to decrease if the present warming and drying trend sustains.

Quantification of Ecosystem Services Provided by <i>Pterocarpus lucens</i>Lepr. Ex Guill. and Perrott.: Forage Production, Timber and Carbon Sequestration in the Biosphere Reserve of Ferlo (Northern Senegal)

This study aims at quantifying the most important ecosystem services: forage production, timber production and carbon sequestration provided by Pterocarpus lucens to local communities of Ferlo Biosphere Reserve. The results suggested that the ecological structure of Pterocarpus lucens revealed a bell-shaped form with left dissymmetric distribution indicating a predominance of individuals with small circumference and height. A regression using the software Minitab 16, with circumference and the height as explanatory variables, has allowed a development of predictive models for the estimation of the produced forage and the quantification of the timber supplied by one of the most used plant species in Sahelian pastures. Forage production of Pterocarpus lucens was estimated at 178 kg DM/ha. This large value of forage showed the predominance of this species in animal feed in the Sahel. The quantity of wood produced was 545 kg DM/ha while the quantity of above ground sequestered carbon was 325.35 kg of C/ha. Those estimations are interesting in the implementation context of the Ferlo Biosphere Reserve which aims at matching the productive capacity of ecosystems with the needs of local communities.

A process model for simulating net primary productivity (NPP) based on the interaction of water-heat process and nitrogen: a case study in Lantsang valley

Terrestrial carbon cycle and the global atmospheric CO2 budget are important foci in global climate change research. Simulating net primary productivity （NPP） of terrestrial ecosystems is important for carbon cycle research. In this study, a plant-atmosphere-soil continuum nitrogen （N） cycling model was developed and incorporated into the Boreal Ecosystem Productivity Simulator （BEPS） model. With the established database （leaf area index, land cover, daily meteorology data, vegetation and soil） at a 1 km resolution, daily maps of NPP for Lantsang valley in 2007 were produced, and the spatial-temporal patterns of NPP and mechanisms of its responses to soil N level were further explored. The total NPP and mean NPP of Lantsang valley in 2007 were 66.5 Tg C and 416 g？m-2？a-1 C, respectively. In addition, statistical analysis of NPP of different land cover types was conducted and investigated. Compared with BEPS model （without considering nitrogen effect）, it was inferred that the plant carbon fixing for the upstream of Lantsang valley was also limited by soil available nitrogen besides temperature and precipitation. However, nitrogen has no evident limitation to NPP accumulation of broadleaf forest, which mainly distributed in the downstream of Lantsang valley.

Comparing the seasonal variation of parameter estimation of ecosystem carbon exchange between alpine meadow and cropland in Heihe River Basin,northwestern China

Grasslands and agro-ecosystems occupy one-third of the global terrestrial area. However, great uncertainty still exists about their contributions to the global carbon cycle. This study used various combinations of a simple ecosystem respiration model and a photosynthesis model to simulate the influence of different climate factors, specifically radiation, temperature, and moisture, on the ecosystem carbon exchange at two dissimilar study sites. Using a typical alpine meadow site in a cold region and a typical cropland site in an arid region as cases, we investigated the response char- acteristics of productivity of grasslands and croplands to different environmental factors, and analyzed the seasonal change patterns of different model parameters. Parameter estimations and uncertainty analyses were performed based on a Bayesian approach. Our results indicated that： （1） the net ecosystem exchange （NEE） of alpine meadow and seeded maize during the growing season presented obvious diurnal and seasonal variation patterns. On the whole, the alpine meadow and seeded maize ecosystems were both apparent sinks for atmospheric CO2; （2） in the daytime, the mean NEE of the two ecosystems had the largest values in July and the lowest values in October. However, overall carbon uptake in the cropland was greater than in the alpine meadow from June to September; （3） at the alpine meadow site, temperature was the main limiting factor influencing the ecosystem carbon exchange variations during the growing season, while the sensitivity to water limitation was relatively small since there is abundant of rainfall in this region; （4） at the cropland site, both temperature and moisture were the most important limiting factors for the variations of ecosystem carbon exchanges during the growing season; and （5） some parameters had an obvious characteristic of seasonal patterns, while others had only small seasonal variations.

Biomass and productivity in sal and miscellaneous forests of Satpura plateau (Madhya Pradesh) India

The paper deals with the biomass and productivity of sal (SF) and miscellaneous forests (MF) of Satpura plateau (Madhya Pradesh) India. These forest types were divided into four sites namely open miscellaneous (OMF, site-I), closed miscellaneous (CMF, site-II), open sal (OSF, site-III) and closed sal (CSF, site-IV). The degree of disturbance followed the order: III (0.70) 109 (III) > 79.80 (I) > 52.69 (II), while for NPPherb, the order of importance was, 109.50 (IV) > 73.27 (I) > (II), 71.75 (III) > 55.71 (II). NPPtotal was highest for closed forest stands than of the open ones. NPPteak was lower for high-disturbed site than of the less disturbed site. Photosynthetic/ non - photosynthetic ratio follows the order: 0.067 (II) > 0.030 (III) > 0.026 (IV) > 0.018 (I). Open forests showed lower values for this ratio. NEP was higher for SF than of the MF. Further closed forests showed higher values of NEP. OSF showed lower values of NEPsal than of the CSF. Disturbances in open forests not only reduced stand biomass of tree species, dominant species in particular, but also declined the tree productivity. So, gap filling plantation in side the forest is suggested to improve the productivity of open forests.

Functionally assessing the sustainability of regional ecosystem services:a case study of Hohhot City

"The value of the world’s ecosystem services and natural capital" by R.Costanza et al.in 1997 is generally regarded as a monument to the research of valuing ecosystem services.However,the classification of ecosystem services,the method of various services summation,and the purpose for static global value had many criticisms.Based on a summary of these criticisms and suggestions,further study direction—on the sustainability of ecosystem services—is presented.The two basis indicators in ecology—productivity and biodiversity,respectively characterize the ability of producing and self-organizing—not only represent the internal function of ecosystem,but also can be proportioned to its external function of supporting and providing for human life.Theoretically,the two indicators combined could physically assess the sustainability of ecosystem services based on the traditional procedure of Costanza’s.The case study of Hohhot City in 1995-2005 shows that the new model reflects the changes of ecosystem services at spatial and temporal scale,and the functionally adjusted assessment shows the sustainability of Hohhot City became gradually stronger during the study decade.But due to the enormous value per unit of water ecosystem,the minimal loss of water area leads to the final result being opposite to the processing analysis,which gives a clue to the further experimental testing research.

基于BEPS模型的云南省碳源/汇时空特征及其适用性分析

净初级生产力(NPP)和净生态系统生产力(NEP)是估算陆地生态系统碳源/汇的重要指标,云南为我国碳汇的主要区域之一,开展云南NPP和NEP时空变化特征分析对科学评估陆地生态系统碳源/汇功能,以及开展碳排放交易具有重要意义。基于BEPS模型1981-2019年NPP和NEP产品,采用线性趋势分析、文献对比等方法,研究云南NPP和NEP时空变化特征及其在云南的适用性。结果表明:(1)1981-1999年云南NPP和NEP呈水平波动,2000年后云南NPP和NEP呈明显波动上升趋势,2000-2019年云南NPP高值区域主要分布在西部和南部,而NEP高值区则主要分布在东部和西部局部地区;(2)2000-2019年云南NPP和NEP除西北部部分地区为下降趋势外,其余大部地区为上升趋势;(3)云南NPP峰值出现在7、8月,谷值出现在2月,NEP峰值出现月份与NPP基本相同,但谷值出现月份较NPP滞后1-3个月,6-10月是云南碳汇的主要月份;(4)BEPS模型估算的NPP与目前广泛应用的CASA和遥感模型结果较为一致,时空变化特征与云南生态恢复措施和气候特征吻合,其估算的NEP与陆地生物圈模型(IBIS)模型和中国通量观测研究联盟(ChinaFLUX)碳水通量观测数据较为接近,时空变化大部地区与云南生态恢复措施和气候特征基本吻合,表明BEPS模型在云南具有较好的适用性。

A Semantic Metadata Enrichment Software Ecosystem (SMESE) Based on a Multi-Platform Metadata Model for Digital Libraries

Software industry has evolved to multi-product and multi-platform development based on a mix of proprietary and open source components. Such integration has occurred in software ecosystems through a software product line engineering (SPLE) process. However, metadata are underused in the SPLE and interoperability challenge. The proposed method is first, a semantic metadata enrichment software ecosystem (SMESE) to support multi-platform metadata driven applications, and second, based on mapping ontologies SMESE aggregates and enriches metadata to create a semantic master metadata catalogue (SMMC). The proposed SPLE process uses a component-based software development approach for integrating distributed content management enterprise applications, such as digital libraries. To perform interoperability between existing metadata models (such as Dublin Core, UNIMARC, MARC21, RDF/RDA and BIBFRAME), SMESE implements an ontology mapping model. SMESE consists of nine sub-systems: 1) Metadata initiatives & concordance rules;2) Harvesting of web metadata & data;3) Harvesting of authority metadata & data;4) Rule-based semantic metadata external enrichment;5) Rule-based semantic metadata internal enrichment;6) Semantic metadata external & internal enrichment synchronization;7) User interest-based gateway;8) Semantic master catalogue. To conclude, this paper proposes a decision support process, called SPLE decision support process (SPLE-DSP) which is then used by SMESE to support dynamic reconfiguration. SPLE-DSP consists of a dynamic and optimized metadata-based reconfiguration model. SPLE-DSP takes into account runtime metadata-based variability functionalities, context-awareness and self-adaptation. It also presents the design and implementation of a working prototype of SMESE applied to a semantic digital library.

Functional Diversity: An Important Measure of Ecosystem Functioning

Functional diversity is a component of biodiversity that generally covers the range of functional traits of microorganisms prevailing in an ecosystem. Functional diversity is of high ecological importance because it is capable of influencing several aspects of ecosystem functioning like ecosystem dynamics, stability, nutrient availability, etc. Functional diversity of a community can be measured by functional richness and evenness. Functional richness refers to the number of species inhabiting a particular niche and functional evenness reveals how evenly the species are being distributed. Increase or decrease in functional richness and evenness simultaneously increases and decreases the functional diversity respectively. Decrease in functional richness and evenness decreases the ecosystem productivity and stability which ultimately decreases functional diversity of the same ecosystem. The effects of functional diversity on the productivity of an ecosystem can be quantitatively explained by the sampling effect model and the niche differentiation model. There are other proposed mechanisms like Niche complementarity and species redundancy relating functional diversity with ecosystem functioning. Rivets and idiosyncratic models relate functional diversity and species richness with ecosystem functioning. By considering the above proposed models on ecosystem functioning, it can be considered that functional diversity is a principal component of ecosystem functioning. So it can be assumed that, knowledge about a particular ecosystem reveals its richness and evenness which enable an individual knowing about the diversity of functional traits prevailing in the ecosystem. Thus, it opens up a new way in understanding and carrying out ecology related studies more efficiently and precisely in ecosystem.

Terrestrial Ecosystem Carbon Fluxes Predicted from MODIS Satellite Data and Large-Scale Disturbance Modeling

The CASA (Carnegie-Ames-Stanford) ecosystem model based on satellite greenness observations has been used to estimate monthly carbon fluxes in terrestrial ecosystems from 2000 to 2009. The CASA model was driven by NASA Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation cover properties and large-scale (1-km resolution) disturbance events detected in biweekly time series data. This modeling framework has been implemented to estimate historical as well as current monthly patterns in plant carbon fixation, living biomass increments, and long-term decay of woody (slash) pools before, during, and after land cover disturbance events. Results showed that CASA model predictions closely followed the seasonal timing of Ameriflux tower measurements. At a global level, predicting net ecosystem production (NEP) flux for atmospheric CO2 from 2000 through 2005 showed a roughly balanced terrestrial biosphere carbon cycle. Beginning in 2006, global NEP fluxes became increasingly imbalanced, starting from -0.9 Pg C yr-1 to the largest negative (total net terrestrial source) flux of -2.2 Pg C yr-1 in 2009. In addition, the global sum of CO2 emissions from forest disturbance and biomass burning for 2009 was predicted at 0.51 Pg C yr-1. These results demonstrate the potential to monitor and validate terrestrial carbon fluxes using NASA satellite data as inputs to ecosystem models.

我国生态产品总值统计核算问题研究

文章在分析GEP概念内涵、分类与核算方法相关研究的基础上,充分借鉴国际统计核算的经验,结合我国GEP统计核算实践,从通用性和可操作性出发,建立了一套与自然资源部门土地利用现状分类相匹配、符合我国实际的GEP核算分类标准,重新划分了森林、草地、湿地、农田、城市、荒漠、海洋等生态系统的分类范围。同时,基于GEP概念、特征、逻辑准则,提出了我国生态产品清单筛选的五个基本原则,讨论了现有GEP实物量和价值量核算方法存在的不足,指出了核算方法选取时需注意把握的问题及未来改进方向。

Net Ecosystem CO2 Flux and Effect Factors in Peatland Ecosystem of Central China

Peatland ecosystems play an important role in the global carbon cycle because they act as a pool or sink for the carbon cycle. However, the relationship between seasonality effect factors and net ecosystem CO2 exchange (NEE) remains to be clarified, particularly for the non-growing season. Here, based on the eddy covariance technique, NEE in the peatland ecosystem of Central China was examined to measure two years’ (2016 and 2017) accumulation of carbon dioxide emissions with contrasting seasonal distribution of environmental factors. Our results demonstrate the cumulative net ecosystem CO2 emissions during the study period was in the first non-growing season 2.94 ± 4.83 μmolCO2 m-2.s-1 with the lowest values in the same year in first growing season was -2.79 ± 4.92 μmolCO2 m-2.s-1. The results indicate the effect of seasonal variations of NEE can be directly reflected in daily and seasonal variations in growth and respiration of peatland ecosystem by environmental parameters over different growing stages.