Terrestrial Ecosystems In China Research Articles

A CALCULATION METHOD OF ECOSYSTEM SERVICE VALUE BASED ON PRODUCT OF NATIONAL GEOGRAPHIC CONDITIONS MONITORING IN CHINA

Abstract. By 2015, Chinese government had completed the project of China's First National Geographic Conditions Census. In this project, high resolution land cover product all over the country had been generated, and would be updated continuously every year. On the basis of this excellent data source, a big data calculating method of land’s ecosystem service value was proposed, in which many other remote sensing information were used too, such as EVI (Enhanced Vegetation Index), NPP (Net Primary Productivity), vegetation growing season data derived from MODIS product. It analyzed the characters of data type, data time phase, and data structure for all the remote sensing information, also the big data’s engendering background and process. A revised ecosystem service value assessment model was used for calculating. Combining the classification system of terrestrial ecosystem in China and the equivalent value factor per unit ecosystem area, the big data calculating algorithm was designed. Shiyan city, Hubei province, China was selected as the study area for validating the calculating method. The results showed that the total ecosystem service value in Shiyan city in 2015 was 1.97 × 1011 CNY, and the per capita ecosystem service value was 5.69 × 104 CNY. Specially, forest supplied the most ecosystem service value which accounted for 78.54 %, followed by water, grassland, farmland, and desert. The research shows that on the basis of multi-source of remote sensing information mainly the high resolution land cover product obtained in the project of China's First National Geographic Conditions Census, high-precision quantification and spatialization ecosystem service value can be calculated and obtained; multi scale spatial display of the calculating results could be achieved to meet different spatial scaling demands; the big data calculating algorithm has solved the problems of design and computation of structured and unstructured big data computing models; the independent research and development software has solved the problem of software requirements, and the operational efficiency and performance can meet the calculating needs.

An atmospheric perspective on the carbon budgets of terrestrial ecosystems in China: progress and challenges

An atmospheric perspective on the carbon budgets of terrestrial ecosystems in China: progress and challenges

Nitrogen addition stimulates soil aggregation and enhances carbon storage in terrestrial ecosystems of China: A meta‐analysis

China is experiencing a high level of atmospheric nitrogen (N) deposition, which greatly affects the soil carbon (C) dynamics in terrestrial ecosystems. Soil aggregation contributes to the stability of soil structure and to soil C sequestration. Although many studies have reported the effects of N enrichment on bulk soil C dynamics, the underlying mechanisms explaining how soil aggregates respond to N enrichment remain unclear. Here, we used a meta-analysis of data from 76N manipulation experiments in terrestrial ecosystems in China to assess the effects of N enrichment on soil aggregation and its sequestration of C. On average, N enrichment significantly increased the mean weight diameter of soil aggregates by 10%. The proportion of macroaggregates and silt-clay fraction were significantly increased (6%) and decreased (9%) by N enrichment, respectively. A greater response of macroaggregate C (+15%) than of bulk soil C (+5%) to N enrichment was detected across all ecosystems. However, N enrichment had minor effects on microaggregate C and silt-clay C. The magnitude of N enrichment effect on soil aggregation varied with ecosystem type and fertilization regime. Additionally, soil pH declined consistently and was correlated with soil aggregate C. Overall, our meta-analysis suggests that N enrichment promotes particulate organic C accumulation via increasing macroaggregate C and acidifying soils. In contrast, increases in soil aggregation could inhibit microbially mediated breakdown of soil organic matter, causing minimal change in mineral-associated organic C. Our findings highlight that atmospheric N deposition may enhance the formation of soil aggregates and their sequestration of C in terrestrial ecosystems in China.

Characteristics and influencing factors of Bowen ratio variation in typical terrestrial ecosystems in China

Characteristics and influencing factors of Bowen ratio variation in typical terrestrial ecosystems in China

Effects of Land Cover Changes on Net Primary Productivity in the Terrestrial Ecosystems of China from 2001 to 2012

The 2001–2012 MODIS MCD12Q1 land cover data and MOD17A3 NPP data were used to calculate changes in land cover in China and annual changes in net primary productivity (NPP) during a 12-year period and to quantitatively analyze the effects of land cover change on the NPP of China’s terrestrial ecosystems. The results revealed that during the study period, no changes in land cover type occurred in 7447.31 thousand km2 of China, while the area of vegetation cover increased by 160.97 thousand km2 in the rest of the country. Forest cover increased to 20.91%, which was mainly due to the conversion of large areas of savanna (345.19 thousand km2) and cropland (178.96 thousand km2) to forest. During the 12-year study period, the annual mean NPP of China was 2.70 PgC and increased by 0.25 PgC, from 2.50 to 2.75 PgC. Of this change, 0.21 PgC occurred in areas where there was no land cover change, while 0.04 PgC occurred in areas where there was land cover change. The contributions of forest and cropland to NPP exhibited increasing trends, while the contributions of shrubland and grassland to NPP decreased. Among these land cover types, the contributions of forest and cropland to the national NPP were the greatest, accounting for 40.97% and 27.95%, respectively, of the annual total NPP. There was no significant correlation between changes in forest area and changes in total annual NPP (R2 < 0.1), while the correlation coefficient for changes in cropland area and total annual NPP was 0.48. Additionally, the area of cropland converted to other land cover types was negatively correlated with the changes in NPP, and the loss of cropland caused a reduction in the national NPP.

Modeling the Effects of Global and Diffuse Radiation on Terrestrial Gross Primary Productivity in China Based on a Two-Leaf Light Use Efficiency Model

Solar radiation significantly affects terrestrial gross primary productivity (GPP). However, the relationship between GPP and solar radiation is nonlinear because it is affected by diffuse radiation. Solar radiation has undergone a shift from darker to brighter values over the past 30 years in China. However, the effects on GPP of variation in solar radiation because of changes in diffuse radiation are unclear. In this study, national global radiation in conjunction with other meteorological data and remotely sensed data were used as input into a two-leaf light use efficiency model (TL-LUE) that simulated GPP separately for sunlit and shaded leaves for the period from 1981 to 2012. The results showed that the nationwide annual global radiation experienced a significant reduction (2.18 MJ m−2 y−1; p < 0.05) from 1981 to 2012, decreasing by 1.3% over this 32-year interval. However, the nationwide annual diffuse radiation increased significantly (p < 0.05). The reduction in global radiation from 1981 to 2012 decreased the average annual GPP of terrestrial ecosystems in China by 0.09 Pg C y−1, whereas the gain in diffuse radiation from 1981 to 2012 increased the average annual GPP in China by about 50%. Therefore, the increase in canopy light use efficiency under higher diffuse radiation only partially offsets the loss of GPP caused by lower global radiation.

Possible NPP changes and risky ecosystem region identification in China during the 21st century based on BCC-CSM2

Based on simulations by the Beijing Climate Center climate system model version 2 (BCC-CSM2), the possible changes in net primary productivity (NPP) of the terrestrial ecosystem in China during the 21st century are explored under the Shared Socioeconomic Pathway 2 (SSP2) 4.5 scenario. We found both the near-term and long-term terrestrial NPP basically shows a unanimously increasing trend, which indicates low ecosystem productivity risk in the future. However, the simple linear regression is insufficient to characterize the long-term variation of NPP. Using the piecewise linear regression approach, we identify a decreasing trend of NPP in large areas for the latter part of the 21st century. In the northeast region (NER) from east Inner Mongolia to west Heilongjiang province, NPP decreases significantly after 2059 at a rate of −0.9% dec−1. In the south region (SR) from Zhejiang to Guangxi provinces, a rapid decline of −2.4% dec−1 is detected after 2085. Further analysis reveals that the rapid decline in SR is primarily attributed to the decrease in precipitation, with temperature playing a secondary role, while the NPP decline in NER seems to have no evident relations with climate change. These findings are useful for making preparations for potential ecosystem crisis in China in the future.

Spatiotemporal changes in vegetation coverage and its causes in China since the Chinese economic reform.

With the rapid development of the economy over 40 years since the initiation of Chinese economic reform, terrestrial ecosystems in China have undergone large-scale changes. In this study, we investigated vegetation dynamics in China and their relationships with climatic factors and anthropogenic drivers over 15 progressive periods of 18-32 years starting in 1982. This was accomplished by using the third-generation global satellite Advanced Very High Resolution Radiometer (AVHRR), Normalized Difference Vegetation Index (NDVI) dataset, night-time satellite data, and climate data. Across China, NDVI increased significantly during 1982-2013; especially significant increases were observed in all periods during the growing season and spring. At the pixel scale, 21-38% of the vegetated area in the 15 periods experienced a significant positive trend in vegetation growth. This increase was mostly located in central and southern China. A significant negative trend was observed in 1-8% of the vegetated area pixels, and this pattern was mainly seen in northwestern China, the Yangtze River Delta region, and the Pearl River Delta region. The contribution of spring NDVI to vegetation improvement increased, while the contribution of summer NDVI decreased. Vegetation activity in China was mainly regulated by thermal factors, especially pronounced in mountainous regions of northern China. However, the restrictive effect of moisture factors was very marked to vegetation growth in areas with less than 400 mm of precipitation. Urbanization in China has led to vegetation degradation in most urban centers and surrounding areas in central and eastern China. The increase of agricultural plantations, the Grain for Green Project, and a series ecological restoration projects in some areas have promoted vegetation coverage.

Impacts of drought and heatwave on the terrestrial ecosystem in China as revealed by satellite solar-induced chlorophyll fluorescence

Droughts and heatwaves have been and will continue to bring large risks to terrestrial ecosystems. However, the understanding of how plants respond to drought and heatwave over broad spatial scales is still limited. In this paper, we use the 2009/2010 drought in Yunnan and the 2013 heatwave over southern China as case studies to investigate the potential of using satellite-observed solar-induced chlorophyll fluorescence (SIF) to monitor vegetation responses to drought and heatwave over broad spatial scales. The 2009/2010 drought onset follows a strong soil moisture deficit due to the yearlong below-normal precipitation in Yunnan from the autumn of 2009 to the spring of 2010. In the summer of 2013, southern China experienced the strongest heatwave due to the sudden temperature increase and rainfall deficit. The results show that SIF can reasonably capture the spatial and temporal dynamics of drought and heatwave development, as indicated by the large reduction in fluorescence yield (SIFyield). Moreover, SIFyield demonstrates a significant reduction and earlier response than traditional vegetation indices (enhanced vegetation index, EVI) during the early stages of drought and heatwave events. For both study areas, the spatial and temporal correlation analysis demonstrates that the SIFyield anomalies are more sensitive to a high vapor pressure deficit (VPD) than low soil moisture. This study implies that satellite observations of SIF have great potential for accurate and timely monitoring of drought and heatwave developments.

Ion Concentrations and Their Spatial Variability in Underground Water and Surface Water in Typical Terrestrial Ecosystems in China

The water chemistry data monitored during 2010-2015 by 33 terrestrial ecological stations from the Chinese Ecosystem Research Network (CERN) and the National Ecosystem Research Network of China (CNERN) were used to characterize ion concentrations and their spatial variability in underground water, still surface water, and flowing surface water from typical terrestrial ecosystems. The results showed the presence of mass-based concentrations of major anions, including HCO3- > SO42- > Cl- > CO32-. Among them, HCO3- and SO42- were dominant, and their sums accounted for 71.7%, 75.3%, and 74.9% of the total anions in underground water, still surface water, and flowing surface water, respectively. Cations were mainly Ca2+ and Na+, and their sums accounted for 69.7%, 64.8%, and 68.9% of the total cations in underground water, still surface water, and flowing surface water, respectively. The ion concentration and ion ratio in the underground water, still surface water, and flowing surface water differed largely among the studied regions. The hydrochemical type varied regionally, e.g., Na-Mg-SO4-Cl type, usually with high content of salinity, was found in the underground water of ecological systems in the Northwest arid and semiarid areas and in the East Huanghuaihai Plain; Ca-SO4-HCO3 type in underground water and Ca-HCO3-SO4 type in surface water were found in hilly areas with subtropical red soil; Na-Ca-HCO3-Cl type was present in underground water of south hilly areas with subtropical latosolic red soil; and Ca-HCO3 and Ca-Mg-HCO3 types were found in other ecological systems. Hydrochemical types had low inter-annual variation for both underground water and surface water.

A National Key R&D Program: Technologies and Guidelines for Monitoring Ecological Quality of Terrestrial Ecosystems in China

A National Key R&D Program: Technologies and Guidelines for Monitoring Ecological Quality of Terrestrial Ecosystems in China

Multi-scale assessment of eco-hydrological resilience to drought in China over the last three decades

Understanding to what extent can terrestrial ecosystems maintain their structure and functions and recover after being hit by drought is critical for sustainable ecosystem management and drought mitigation practices. This study assesses multi-scale (i.e., at grid, climate type, land use, basin, province scales) eco-hydrological resilience to drought over China during the period of 1982–2015, based on Standard Evapotranspiration Deficit Index as well as satellite-retrieved evapotranspiration (ET) and net primary production (NPP). Over the last three decades, the ecosystem water use efficiency (eWUE) increased in most regions of China (especially in Northeast China and North China Plain) in the context of climate change. The western China showed a significant wetting trend with ascending ET, GPP and eWUE. The SEDI and ET showed significantly increasing tendencies but the ecosystem GPP and eWUE did not exhibit obvious responses to regional wetting in the middle and lower reaches of Yangtze River basin. Most terrestrial ecosystems in China were found overall resilient to drought except for mild temperature-fully humid-warm summer at the climate type scale, water type at the land use scale, Northwest Rivers at the basin scale as well as Ningxia, Qinghai, Shanghai and Hong Kong at the province scale. These findings would facilitate the identification of most drought-vulnerable regions for ecosystem management and taking reasonable adaptation measures (e.g., use of alternative water resources or reuse water, water conservation and smart irrigation) to ensure the sustainability of terrestrial ecosystems during the drought periods over China.

Altered trends in carbon uptake in China's terrestrial ecosystems under the enhanced summer monsoon and warming hiatus.

The carbon budgets in terrestrial ecosystems in China are strongly coupled with climate changes. Over the past decade, China has experienced dramatic climate changes characterized by enhanced summer monsoon and decelerated warming. However, the changes in the trends of terrestrial net ecosystem production (NEP) in China under climate changes are not well documented. Here, we used three ecosystem models to simulate the spatiotemporal variations in China's NEP during 1982–2010 and quantify the contribution of the strengthened summer monsoon and warming hiatus to the NEP variations in four distinct climatic regions of the country. Our results revealed a decadal-scale shift in NEP from a downtrend of –5.95 Tg C/yr2 (reduced sink) during 1982–2000 to an uptrend of 14.22 Tg C/yr2 (enhanced sink) during 2000–10. This shift was essentially induced by the strengthened summer monsoon, which stimulated carbon uptake, and the warming hiatus, which lessened the decrease in the NEP trend. Compared to the contribution of 56.3% by the climate effect, atmospheric CO2 concentration and nitrogen deposition had relatively small contributions (8.6 and 11.3%, respectively) to the shift. In conclusion, within the context of the global-warming hiatus, the strengthening of the summer monsoon is a critical climate factor that enhances carbon uptake in China due to the asymmetric response of photosynthesis and respiration. Our study not only revealed the shift in ecosystem carbon sequestration in China in recent decades, but also provides some insight for understanding ecosystem carbon dynamics in other monsoonal areas.

From Environmental Soundness to Sustainable Development: Improving Applicability of Payment for Ecosystem Services Scheme for Diverting Regional Sustainability Transition in Developing Countries

In developing and emerging countries, rapid urbanization at an unprecedented pace and degradation of ecosystem services at an alarming rate have caused many regions, especially those in environmentally sensitive areas (ESAs), to encounter the “regional development dilemma” (RDD), in which regions can hardly divert their current development pattern to achieve a transition to sustainability. The main research focus of this study is to introduce—by means of a case study—a payments for ecosystem service (PES) scheme as a policy instrument that incorporates an ecosystem services (ES)-based baseline for payments and a spatial-targeting-based allocation plan to address that dilemma and to bridge, as well as achieve, sustainable development goals simultaneously at a regional scale. The water source areas of the Middle Route Project in the South-to-North Water Diversion Project in China were used as the case study. Land Use/Land Cover Change (LUCC) of this area between 2002 and 2010 was detected by adopting remote sensing and spatial analysis technologies. The ecosystem services value (ESV) variation was then estimated and the eco-compensation plan was determined through comprehensively applying equivalent weighting factors of the ecosystem service of terrestrial ecosystems in China and the adjustment coefficient of the ecosystem service based on the notion of willingness to pay for ecosystem services. Results show that rapid urbanization has substantial impacts on the spatial dynamics and quality of ecosystems in the research area. From 2002 to 2010, the total ESV declined by CNY 6 billion. Therefore, the baseline eco-compensation from the benefit zone to the research area was CNY 1.1 billion under the assumption of commensurability. Responsibility ought to be shared by Henan and Hebei provinces, and Beijing and Tianjin, with payment of CNY 422.3, 388.5, 110.9, and 133 million, respectively. We drafted the allocation plan of eco-compensation based on the spatial pattern of ESV variation, and suggested policy tools tailored for subregions in the research area defined by LUCC change categories. Such an integrated study can lead to a more comprehensive understanding of regional PES schemes and provide a set of policy instruments with upgraded spatial-targeting and better cost-efficiency, particularly as blueprints for regional governments in developing and emerging countries that aim at leveraging regional sustainability through bridging and achieving SDGs.

Estimating N2O emissions from soils under natural vegetation in China

BackgroundNatural and managed soils have been identified as the largest sources of atmospheric nitrous oxide (N2O). However, the quantification of N2O emissions from soils under natural vegetation in China and their possible responses to changing climate and atmospheric nitrogen deposition remains uncertain. In particular, information regarding N2O emissions from Chinese shrublands is lacking.MethodThis study used 28 sets of N2O field measurements in China to validate a process-based dynamic nitrogen cycle model (DyN-LPJ), which was then used to investigate the N2O fluxes from soils under natural vegetation in China from 1970 to 2009.ResultsN2O emissions from Chinese forests, grasslands, and shrublands in the 2000s were estimated to be 0.10 ± 0.06 Tg N yr.−1, 0.09 ± 0.09, Tg N yr.−1 and 0.14 ± 0.07 Tg N yr.−1, respectively. Monthly N2O fluxes were linearly correlated with precipitation, and exponentially (Q10 = 3) with air temperature. The total N2O fluxes from natural terrestrial ecosystems in China increased from 0.28 ± 0.03 Tg N yr.−1 in the 1970s to 0.46 ± 0.03 Tg N yr.−1 in the 2000s. Warming and atmospheric nitrogen deposition accounted for 37% (or 0.07 ± 0.03 Tg N) and 63% (0.11 ± 0.01 Tg N) of this increase respectively.ConclusionsOur results indicate that when compared to grassland ecosystems, N2O emissions from forest and shrubland ecosystems contain larger uncertainties due to either their uncertain areal extent or their emission rates. Long-term and continuous field measurements should be conducted to obtain more representative data in order to better constrain shrubland N2O emissions.

Land degradation monitoring using terrestrial ecosystem carbon sinks/sources and their response to climate change in China

AbstractGlobal warming, which is mainly caused by greenhouse gases, can greatly aggravate land degradation; therefore, the examination of the NEP (net ecosystem productivity) and the analysis of its response to climate change are very critical for understanding carbon cycling. Based on Moderate Resolution Imaging Spectroradiometer data, meteorological data, and soil organic carbon data, this study examined the NEP from 2000 to 2013 and investigated how ongoing climate change affects the NEP. The study results indicate that the terrestrial ecosystems in China generally act as net carbon sinks with increasing NEP values. The western inland region and part of northeast China mainly act as carbon sources, with the NEP exhibiting an increasing trend, whereas the other regions mainly act as carbon sinks, with the NEP showing a decreasing trend across large areas of southern China, where the most obvious land degradation occurs. Homogeneity and heterogeneity co‐occur. The general pattern is that ecosystems with high biomass usually have a high NEP value, acting as high carbon sinks in relatively wet and warm environments, but have a low value and even act as carbon sources in dry and cold environments. Both moderate precipitation and temperature are essential in increasing the NEP, whereas lower precipitation and temperatures might have negative effects. Heterogeneity also widely breaks up the general pattern. Temporally, more NEP grids were positively correlated with changes in temperature and showed stronger correlation coefficients with temperature than with precipitation, but the grids showing a significant correlation with these factors accounted for only a small proportion of the total for both precipitation and temperature.

Detection of Positive Gross Primary Production Extremes in Terrestrial Ecosystems of China During 1982–2015 and Analysis of Climate Contribution

AbstractGross primary productivity (GPP) quantifies the photosynthetic uptake of carbon by terrestrial ecosystems. High‐temperature extremes and associated droughts significantly reduce terrestrial ecosystem carbon uptake, but there is uncertainty as to whether climatic extremes can be beneficial to ecosystem carbon uptake. In this study, we used three ecological models: the Boreal Ecosystem Productivity Simulator, the Terrestrial Ecosystem Carbon flux model, and the Global Production Efficiency Model coupled with the Carbon Exchange between Vegetation, Soil, and the Atmosphere model, to simulate China's terrestrial ecosystem GPP during the study period of 1982–2015. Positive GPP extremes were identified on yearly scales and analyzed for their temperature, precipitation, and solar radiation attributions. We found that the 3 years of positive GPP extremes occurred in 1990, 1998, and 2013, with the detrended GPP anomalies of 0.4 PgC/year, 0.2 PgC/year, and 0.3 PgC/year, respectively. Maximum GPP years were associated with an increased carbon uptake in response to increasing temperature and solar radiation under adequate precipitation for plant growth. China's subtropical‐tropical monsoonal region, a region dominated by managed forests and agricultural lands, contributed the largest in GPP extremes and accounted for 46%, 50%, and 46% of the total detrended GPP anomalies in 1990, 1998, and 2013, respectively. Positive GPP extremes were associated with increasing temperature and solar radiation, indicating favorable positive climate extremes would be beneficial to carbon uptake in China's terrestrial ecosystem. This study provides a method to assess positive GPP extremes in response to global climate change.

Research on Models of Overall Land-use Planning Based on Ecological Protection Thought

Environmental problems and climate change are the severe challenges facing the mankind today. Ecological protection has become the new element that the overall land-use planning should take into account. In this paper, the land use ecosystem is divided into six types: forest, grassland, farmland, wetland, water area and the land difficult to use. After investigation and research, the equivalent table of ecological service value of unit square of terrestrial ecosystem in China is obtained. Based on the theory of ecosystem service value and combined with the characteristics of regional land, this paper revised the equivalent value. At the same time, we should pay attention to land consolidation work, including strengthening ecological protection objective of land-use planning, optimizing the current situation of land ecology evaluation, reinforcing influence evaluation of ecological environment after planning implementation, setting up management department of land resources protection and perfecting ecological protection laws of land-use planning to ensure the scientific and effective development of land use planning in China and the sustainable development of land ecology.

Disentangling Climate and LAI Effects on Seasonal Variability in Water Use Efficiency Across Terrestrial Ecosystems in China

AbstractWater use efficiency (WUE), the ratio of gross primary productivity (GPP) over evapotranspiration (ET), is a critical ecosystem function. However, it is difficult to distinguish the individual effects of climatic variables and leaf area index (LAI) on WUE, mainly due to the high collinearity among these factors. Here we proposed a partial least squares regression‐based sensitivity algorithm to confront the issue, which was first verified at seven ChinaFlux sites and then applied across China. The results showed that across all biomes in China, monthly GPP (0.42–0.65), ET (0.33–0.56), and WUE (0.01–0.31) showed positive sensitivities to air temperature, particularly in croplands in northeast China and forests in southwest China. Radiation exerted stronger effects on ET (0.55–0.78) than GPP (0.19–0.65), resulting in negative responses (−0.44 to 0.04) of WUE to increased radiation among most biomes. Increasing precipitation stimulated both GPP (0.06–0.17) and ET (0.05–0.12) at the biome level, but spatially negative effects of excessive precipitation were also found in some grasslands. Both monthly GPP (−0.01 to 0.29) and ET (0.02–0.12) showed weak or moderate responses to vapor pressure deficit among biomes, resulting in weak response of monthly WUE to vapor pressure deficit (−0.04 to 0.08). LAI showed positive effects on GPP (0.18–0.60), ET (0–0.23), and WUE (0.13–0.42) across biomes, particularly on WUE in grasslands (0.42 ± 0.30). Our results highlighted the importance of LAI in influencing WUE against climatic variables. Furthermore, the sensitivity algorithm can be used to inform the design of manipulative experiments and compare with factorial simulations for discerning effects of various variables on ecosystem functions.

近30年中国陆地生态系统NDVI时空变化特征

近30年中国陆地生态系统NDVI时空变化特征