Water Retention Services Research Articles

Ecosystem Services Supply from Peri-Urban Watersheds in Greece: Soil Conservation and Water Retention

The main objective of this study is to investigate the supply of ecosystem services (ESs) within peri-urban watersheds (PUWs) across Greece, utilizing earth observation (EO) data and empirical models. To achieve these goals, several open-access geospatial datasets were utilized and processed within a GIS environment. Specifically, the supply of soil conservation and water retention services was assessed at the watershed scale. The results indicates that the supply soil conservation service withing the examined PUWs range from 44.41 t ha−1 y−1 to 441.33 t ha−1 y−1 with an average value of 161.99 t ha−1 y−1. Water retention services vary from 35.09 to 154.63 mm within the PUWs, with an average of 91.45 mm. Additionally, the variation in ES values across distinct altitudinal zones and ecosystem types provides useful insights for implementing protection and management measures. It is evident from the analysis that the soil conservation service gradually increases with elevation, with alpine and subalpine areas exhibiting the highest values. Moreover, mountainous and semi-mountainous regions demonstrate higher values compared to the estimated average soil conservation services of the entire study area. Furthermore, the provision of water retention services varies across different altitudinal zones. Specifically, the mountainous and semi-mountainous areas exhibit the highest values, followed by the subalpine and hilly regions, while lower values are observed in the lowland and alpine regions. The analysis also reveals distinct patterns in ecosystem services across various ecosystem types within the PUWs. Woodland and forest, along with heathland and shrubs, demonstrate higher values in terms of both soil conservation and water retention services. Our findings contribute to understanding the dynamics of ESs in PUWs, highlighting their significance for sustainable land management, and informing policy decisions aimed at preserving ecosystem health and resilience.

Ecosystem services relationship characteristics of the degraded alpine shrub meadow on the Qinghai-Tibetan Plateau.

Alpine shrub meadows hold significant importance as grassland ecosystems on the Qinghai-Tibetan Plateau (QTP). They provide a range of vital ecosystem services (ESs) and are commonly utilized as summer pastures by herders, resulting in short grazing periods and high grazing intensities. Unfortunately, these practices have led to varying degrees of degradation, thereby affecting the sustainable provision of ESs. However, the current knowledge regarding changes in ESs and their characteristics under the influence of degradation, particularly the differences between alpine shrub and alpine meadow ecosystems, is insufficient. To address this gap, this study aimed to investigate and analyse changes in four ESs within alpine shrub meadows across different levels of degradation, as well as explore their relationships. The research was conducted in a summer pasture located in the northeastern QTP. The findings revealed a substantial reduction of 85.9% in forage supply due to degradation in alpine shrub meadows. Moreover, regulating services experienced a decline followed by an increase in instances of heavy degradation. Trade-offs were observed between provisioning and regulating services, while synergistic relationships were identified among different regulating services. Degradation exacerbated imbalances between provisioning and regulating services, whereas light degradation allowed for a better equilibrium between the two. Comparatively, alpine meadows exhibited higher levels of forage supply and carbon storage services, whereas alpine shrub ecosystems displayed greater nutrient supply and water retention services. It was observed that changes in ESs and relationship patterns within alpine shrub meadows were significantly influenced by the presence of alpine meadows. Consequently, safeguarding the structural integrity of alpine meadows and addressing conflicts over ESs is essential to ensure coordination and sustainability of ESs within alpine shrub meadows. The outcomes of this study provide valuable insights for ecosystem management and ecological restoration initiatives in alpine shrub meadows on the QTP.

Ecosystem Service Relationships, Drivers, and Regulation Strategies in a Degraded Alpine Shrub Meadow on the Northeastern Qinghai-Tibetan Plateau

One of the challenges of managing grasslands sustainably is the conflict between the different ecosystem services they provide. This is especially evident in the Qinghai-Tibetan Plateau (QTP) region, where fragile alpine ecosystems make balancing the needs of grassland conservation and development difficult. However, our current understanding of the relationships and drivers of ecosystem services in degraded alpine shrub meadows on the QTP is insufficient. To address this, we studied forage provisioning and water retention services in a degraded alpine shrub meadow in the northeastern QTP. We analyzed the changes and relationships between these services at different levels of degradation and identified those factors that influenced ecosystem service relationships. The results showed that the forage supply service and the water retention service of the alpine shrub meadow increased and decreased by 23.6% and 27.07%, respectively, due to degradation. The trade-offs between these two services varied depending on the degree of degradation, with light and moderate degradation showing a preference for water retention service, and heavy and extreme degradation showing a preference for forage supply. Water retention was constrained by forage supply and both services showed an exponential function form of decay. The physical and chemical properties of the soil in the alpine shrub meadow remained relatively stable during the degradation process, with only soil organic carbon (SOC), total potassium (TK), and total nitrogen (TN) decreasing significantly. SOC may have indirectly influenced the relationship between the two services by affecting water retention. This study provides insights into alpine shrub meadow management and conservation on the QTP.

Comparison of Five Models for Estimating the Water Retention Service of a Typical Alpine Wetland Region in the Qinghai–Tibetan Plateau

Model evaluation of water retention (WR) services has been commonly applied for national or global scientific assessment and decision making. However, evaluation results from different models are significantly uncertain, especially on a small regional scale. We compared the spatial–temporal variations and driving factors of the WR service by five models (i.e., the InVEST model (InVEST), precipitation storage model (PRS), water balance model I (WAB I), water balance model II (WAB II), and NPP-based surrogate model (NBS) based on partial correlation analysis and spatial statistics on the Ramsar international alpine wetland region of the Qinghai–Tibetan Plateau (QTP). The results showed that the wetland area continued to decrease, and built-up land increased from 2000 to 2015. The average WR volume ranged from 2.50 to 13.65 billion m3·yr−1, with the order from high to low being the PRS, WAB I, WAB II, and InVEST models, and the average total WR capacity was 2.21 × 109 by the NBS model. The WR service followed an increasing trend from north to south by the InVEST, PRS, WAB I, and WAB II models, while the NBS model presented a river network pattern of high values. The WR values were mainly reduced from 2000 to 2010 and increased from 2010 to 2015 in the PRS, WAB I, WAB II, and InVEST models, but the NBS model showed the opposite trend. Precipitation determined the spatial distribution of WR service in the InVEST, PRS, WAB I, and WAB II models. Still, the spatial variation was affected by climate factors, while the NPP data influenced the NBS model. In addition, the InVEST model in estimating WR values in wetlands and the PRS and WAB I models poorly estimate runoff, while the WAB II model might be the most accurate. These findings help clarify the applicability of the WR models in an alpine wetland region and provide a valuable background for improving the effectiveness of model evaluation.

Evaluating the inter-annual surplus/deficit dynamic of water retention service in the Yellow River Basin, China

The water retention service (WRS) in the Yellow River Basin is highly critical for the ecological security in northern China. Since the implementation of Grain for Green project during 2000, the changes of WRS and land cover in the Yellow River Basin have not been fully revealed, which limited the knowledge of how anthropogenic activities affected ecological processes. To address the issue, this study chose the water yield-based parameter correction method, and adopted the Sen’s slope test, Mann-Kendall analysis and Hurst index methods, firstly analyzing the inter-annual WRS changes in the Yellow River Basin from 1990 to 2020. Specifically, a new index, Ecosystem Service Deficit Index was proposed to accurately distinguish the deficit/surplus state of WRS. The results of land cover change showed that from 1990 to 2020, forest and grassland were both increasing at the rate of +556.5 km2/yr and +508.4 km2/yr, respectively, and cropland was decreasing with a trend of −965.5 km2/yr. Temporally, WRS was weakening (−0.03 mm/yr) during 1990–2000 but was strengthening in 2000–2020 (+0.08 mm/yr). Spatially, the decreases of WRS mainly occurred in the downstream, with the detectable increases in the headwaters of upstream and the midstream; it is noteworthy that the spatial increases of WRS was unsustainable in the future because Hurst index was less than 0.45 in the study area. The ecosystem service deficit index clearly revealed that WRS experienced a long (at least for 3/4 of study period) deficit period until 2011, and was capable of accurately distinguishing WRS surplus/deficit. The new index can also be applied to assess other ecosystem services. Overall, the integrated roles of the local Grain for Green practices and climate change contributed to the recovery of WRS in the Yellow River Basin, but this recovery may not last. More active human interventions needed to be implemented to mitigate future WRS degradation risks.

Scenario simulation of water retention services under land use/cover and climate changes: a case study of the Loess Plateau, China

Scenario simulation of water retention services under land use/cover and climate changes: a case study of the Loess Plateau, China

Impacts of alpine shrub-meadow degradation on its ecosystem services and spatial patterns in Qinghai-Tibetan Plateau

• UAV is used to detect the spatial pattern of alpine shrub-meadow degradation. • Ecosystem services changes in degraded alpine shrub meadow are non-linear. • Spatial pattern characteristics may fail to interpret ecosystem service changes. Alpine shrub-meadow is an important ecosystem type on the Qinghai-Tibetan Plateau, providing a variety of ecosystem services while supporting the livelihoods of pastoralists. However, there is a clear lack of understanding of the changes in spatial patterns and ecosystem services of alpine shrub-meadow degradation. This study combined aerial photography and ground surveys to investigate and analyse the impact of degradation on the spatial patterns of alpine shrub-meadow and their ecosystem services, and the relationships between the spatial patterns and ecosystem services. The results showed that degradation led to fragmentation and patchiness in alpine shrub-meadow, as evidenced by a decrease in the proportion of shrub and meadow area and average patch size, as well as the complexity of patch boundaries and shapes. Light and moderate degradation reduced all ecosystem services in alpine shrub-meadow, with carbon storage, nutrient supply and water retention services decreased by an average of 27.4%, 17.3% and 13.8% respectively, while forage supply services decreased by 65.2% at heavy degradation, and the reduction in alpine meadow ecosystem services was even greater. Regulating services increased again at heavy degradation due to the accumulation and slow decomposition of plant underground roots, and rodent activity. The spatial patterns of the meadow layer were more closely related to its ecosystem services than the shrub layer, and fragmentation and patchiness were positively related to ecosystem services. Our findings suggest that the impact of degradation on alpine shrub-meadow ecosystem services may be non-linear and that the relationships between spatial patterns and ecosystem services need to be interpreted with caution and should be analysed comprehensively with a wider range of influencing factors. Our results have implications for grassland restoration and ecosystem service management on the Qinghai-Tibetan Plateau.

国土空间生态修复与保护空间识别——以北京市为例

PDF HTML阅读 XML下载 导出引用 引用提醒 国土空间生态修复与保护空间识别——以北京市为例 DOI: 10.5846/stxb202103150692 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金重点项目（71533005）；中国科学院青年创新促进会（2013030） Spatial identification of territory space ecological conservation and restoration: A case study of Beijing Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:构建国土空间修复与保护识别体系可以有效实现区域生态系统修复与保护，然而，当前国土空间生态修复与保护研究和规划缺乏从系统性和完整性的角度识别关键生态修复与保护区。因此构建了系统的生态修复与保护空间识别方法，以实现区域协调发展、保障区域生态安全。基于该方法，以北京市为例，通过评估生态系统服务、生态系统质量和生态问题，构建生态修复与保护空间格局。研究结果表明：① 2000-2015年生态系统服务和质量退化区主要集中在平原区和密云水库北部，面积为760.4 km2；生态系统质量低下区主要分布在西南部山区和东北部山区，面积为4925 km2；水土流失问题区零星分布在山区，面积为130.1 km2；基于以上三者的北京生态修复建议区总面积5606 km2。②建议北京生态保护区6391 km2，主要分布在北部山区和西南部山区，保护了79.63%的水源涵养功能，74.97%的土壤保持功能，58.79%的洪水调蓄功能和60.3%的自然栖息地。本研究构建的生态修复与保护空间识别方法体系，为北京生态修复和保护规划与生态安全格局构建提供科学依据，还可以为其他地区的生态修复与保护规划提供参考。 Abstract:A robust identification system of territory space ecological restoration and conservation can make effective contribution to regional ecosystem restoration and conservation. However, current research and planning lack the identification of key ecological restoration and conservation areas from the perspective of systematicness and integrity. This study established a systematic spatial identification method for ecological restoration and conservation to provide basis for regional coordinated development and regional ecological security. On the basis of the method, taking Beijing as a case, the spatial pattern of ecosystem restoration and conservation was explored through assessing of ecosystem services, ecosystem quality and ecological problems. The results showed that:(1) the ecosystem quality and ecosystem services increased generally in Beijing from 2000 to 2015. Ecosystem quality of forest, shrub and grassland improved by 39%. Correspondingly, water retention service, soil conservation service and flood mitigation service increased by 11%, 3% and 10%, respectively. However, ecological degradation occurred in some regions because of nature or human activities impact. The degraded areas of ecosystem services and ecosystem quality from 2000 to 2015 were mainly concentrated in the plain and the north of Miyun Reservoir, covering a total area of 760.4 km2 dominated by farmland and urban land. The areas with low ecosystem quality were mainly distributed in the mountainous areas of southwest and northeast, covering an area of about 4925 km2 dominated by forest and shrub ecosystems. The areas with severe soil erosion were scattered in mountainous areas, covering an area of about 130.1 km2 dominated by farmland and shrub. The suggested ecological restoration regions in Beijing consisted of the above mentioned three, with a total area of about 5606 km2., accounting for 34.16% of the total area of Beijing. (2) The area of ecological conservation suggested was 6391 km2, accounting for 38.95% of the total area of Beijing, mainly distributed in the northern and southwestern mountainous areas. The forest, shrub, grassland and wetland accounted for 54.81%, 34.38%, 6.53% and 4.27% of the total area of the ecological conservation space, respectively. The ecological conservation areas of Beijing could conserve 79.63% of Beijing's water retention service, 74.97% of soil conservation, 58.79% of flood regulation and storage, and 60.3% of Beijing's natural habitat. The spatial identification system of ecological restoration and conservation constructed in this study could not only serve as scientific basis for ecological restoration and conservation planning and ecological security pattern construction in Beijing, but also provide references for ecological restoration and conservation in other areas. 参考文献 相似文献 引证文献

Evaluation of the value of water retention service in the middle and upper reaches of Hunhe River based on SWAT Model.

The upper and middle reaches of the Hunhe River, with forest coverage rate up to 68%, is an important water source protection area in Liaoning Province. Based on the SWAT model and shadow engineering method, we aimed to estimate the function and service value of water retention in the upper and middle Hunhe River basin from 2000 to 2019, to analyze the spatial heterogeneity, and to provide a scientific basis for the ecological compensation and ecological restoration of the region. Our results showed that the function and service value of water retention in the upper and middle reaches of the Hunhe increased first, and then decreased from 2000 to 2019. The mean annual amount and service value of water retention were 2.46 billion m3 and 15.04 billion yuan, respectively. The spatial distribution of water conservation service functions in the study area was uneven. The areas of high water retention service value were mainly distributed in Qingyuan County and Xinbin County, while the low-value areas were located in municipal districts of Shenyang City. The value of water retention services was obviously different among the ecosystems, with water retention capacity per unit area of forests being much higher than that of grassland, farmland, and cities.

Alpine grassland management based on ecosystem service relationships on the southern slopes of the Qilian Mountains, China

Grassland management is one of the most important means to address grassland degradation on the Qinghai-Tibet Plateau, but at present, the primary goal is still to improve grassland productivity, and little research has been conducted on grassland management based on its ecosystem service relationships. Based on remote sensing and meteorological data, we calculated and analyzed the spatial and temporal changes, trade-offs and synergistic relationships between livestock production and water retention services in alpine grassland on the southern slopes of the Qilian Mountains (SSQM), and designed a grazing management plan for sustainable development in the region. The results showed that the value of livestock production and water retention services of alpine grassland decreased from east to west, and their relationship is dominated by synergy and complemented by trade-offs. The synergistic relationships are concentrated in the Qinghai Lake Basin in the south and the river valleys in the north, while the trade-offs are scattered in the steeper terrain in the western and eastern parts of the study area. The scenario of preserving all water retention services and losing some livestock production services is sustainable. Based on this scenario we divided the alpine grassland of the study area into maintenance grazing, rotational grazing and grazing exclusion of 65.8%, 32.0% and 2.2%, respectively. Our study demonstrates that ecosystem service relationships have the potential to guide grassland management, and the results will provide new approaches to alpine grassland management.

Linking ecosystem services and subjective well-being in rapidly urbanizing watersheds: Insights from a multilevel linear model

In rapidly urbanizing watersheds with conflicts between socioeconomic development and ecological protection, understanding the relationship between ecosystem services (ESs) and human well-being is important for regional sustainability. However, quantifying their relationship over multiple scales remains challenging. We selected a typical rapidly urbanizing watershed, the Baiyangdian watershed in China, and used surveys and a multilevel linear model to analyze the influence of regional ESs and individual characteristics on subjective well-being (SWB). Our results showed that the multilevel linear model could effectively capture the influences of regional ESs on the residents’ SWB. For the watershed, 95.9% of the total variance in the residents’ SWB was attributed to variation between individuals, and the remaining 4.1% was attributed to variation between regions. The SWB of rural residents was more likely to be affected by regional ESs than urban residents. In the Baiyangdian watershed, which has a water supply shortage, the SWB of low-income and elderly residents in the rural areas was more sensitive to water retention services, and the association was significant. The results suggest that in rapidly urbanizing watersheds, government should pay attention to maintaining and improving key regulating services to effectively maintain and promote the SWB of rural residents and regional sustainability.

Impacts of climate and vegetation leaf area index changes on global terrestrial water storage from 2002 to 2016

Terrestrial water storage (TWS) has a major impact on the water, energy, and biogeochemical fluxes of the land surface. The spatiotemporal features of TWS variations, as well as the roles of climate change and human activities in TWS variations, have been of key concerns and need to be further investigated. Here, using the data products from the Gravity Recovery and Climate Experiment and the Global Land Data Assimilation System, together with some auxiliary data on climate, evapotranspiration, and vegetation leaf area index (LAI), we investigated the spatiotemporal variations of global TWS and how TWS was partitioned into its different components. We further quantified the sensitivity of TWS to changes in climate and vegetation LAI, as well as the impacts of climate and vegetation LAI changes on TWS during 2002–2016. The results showed that global TWS declined at a rate of 0.04 mm month−1 during 2002–2016 with a spatially explicit pattern and a distinct seasonal pattern, although the trend was negligible before October 2009 and only became obvious after that. With the seasonal variations of precipitation, temperature, and LAI together, the seasonal variations of TWS were able to be explained by ≥50% in the tropical and subtropical regions. With the joint changes in LAI, temperature, and precipitation, TWS increased by ≤ ~10 mm month−1 in the subarctic and inland temperate regions, and some tropical and subtropical regions; by contrast declined by ≤ ~10 mm month−1 in some regions such as the Central Africa. Our study shed light on the spatiotemporal characteristic of the TWS variations and quantified the impacts of climate and vegetation LAI changes on TWS. The findings can provide not only important evidence for the effectiveness of past ecosystem management intervention programs in water retention service but also guidance for planning ecosystem management intervention programs in the near future.

Regional Impacts of Climate and Land Cover on Ecosystem Water Retention Services in the Upper Yangtze River Basin

Water retention is an important factor in ecosystem services, owing to its relationships with climate and land-cover change; however, quantifying the independent and combined impacts of these variables remains a challenge. We use scenario analysis and the InVEST model to assess individual or combined impacts of climate and land cover on water retention in the Upper Yangtze River Basin. Water retention decreased from 1986 to 2015 at a rate of 2.97 mm/10a in response to increasing precipitation (3.94 mm/10a) and potential evapotranspiration (16.47 mm/10a). The rate of water retention change showed regional variability (from 68 to −18 mm/a), with some eastern regions experiencing an increase and most other regions experiencing a decrease. Farmland showed the highest decrease (10,772 km2), with land mainly converted into forest (58.17%) and shrub land (21.13%) from 2000 to 2015. The impact of climate change (−12.02 mm) on water retention generally was greater than the impact of land cover change (−4.14 mm), at the basin scale. Among 22 climate zones, 77.27% primarily were impacted by climate change; 22.73% primarily were impacted by land cover change. Our results demonstrate that both individualistic and integrated approaches toward climate and vegetation management is necessary to mitigate the impacts of climate change on water resources.

Simulating runoff generation and its spatial correlation with environmental factors in Sancha River Basin: The southern source of the Wujiang River

Runoff generation is an important part of water retention service, and also plays an important role on soil and water retention. Under the background of the ecosystem degradation, which was caused by the vulnerable karst ecosystem combined with human activity, it is necessary to understand the spatial pattern and impact factors of runoff generation in the karst region. The typical karst peak-cluster depression basin was selected as the study area. And the calibrated and verified Soil and Water Assessment Tool (SWAT) was the main techniques to simulate the runoff generation in the typical karst basin. Further, the spatial variability of total/surface/groundwater runoff was analyzed along with the methods of gradient analysis and local regression. Results indicated that the law of spatial difference was obvious, and the total runoff coefficients were 70.0%. The groundwater runoff was rich, about 2–3 times the surface runoff. Terrain is a significant factor contributing to macroscopic control effect on the runoff service, where the total and groundwater runoff increased significantly with the rising elevation and slope. The distribution characteristics of vegetation have great effects on surface runoff. There were spatial differences between the forest land in the upstream and orchard land in the downstream, in turn the surface runoff presented a turning point due to the influence of vegetation. Moreover, the results of spatial overlay analysis showed that the highest value of total and groundwater runoff was distributed in the forest land. It is not only owing to the stronger soil water retention capacity of forest ecosystem, and geologic feature of rapid infiltration in this region, but also reflected the combining effects on the land cover types and topographical features. Overall, this study will promote the development and innovation of ecosystem services fields in the karst region, and further provide a theoretical foundation for ecosystem restoration and reconstruction.

Achieving Sustainable Valuations of Biotopes and Ecosystem Services

The results of a broader notion of value for measuring ecosystem services (ESs) are presented, as recently demanded by R. Costanza, with attention to the biophysical, thermodynamic aspects of value. The unifying basis in any ecosystem is the solar energy inflow and the growing efficiency of its use with higher stages of self-organized succession processes. The authors utilize two methods of nonmarket valuation (Biotope Valuation Method, Energy-Water-Vegetation Method) which show the range of the environmental values of nature, from how costly it is for nations to restore the quality of a landscape (biotopes as specific habitats for specific species) to their real abilities to replace the core supporting and regulating services of ecosystems (climatizing service, water-retention service, oxygen production, habitats for biodiversity). The role of natural forests and wetlands as the most effective solar energy users is shown and compared with agricultural lands and other human-altered ecosystem groups. A comparison of ESs value ratios with the welfare-method results of Costanza’s team shows much higher importance of natural forests as the best climatic and water regulators in sustainable landscape decision-making. The authors show that it is not the replacement-cost method that overestimates, but rather, preferential methods that underestimate the values of ESs.

Assessing the conservation effects of nature reserve networks under climate variability over the northeastern Tibetan plateau

To evaluate the effectiveness of China’s largest nature reserve network in providing and protecting habitats, we performed a series of studies consisting of field investigation, model simulation, remote sensing and GIS analysis by using a before-after-control-impact (BACI) design. Data from the non-protected areas (non-PAs) surrounding the nature reserve network served as a baseline for comparison. We found that some indexes of ecological restoration in the nature reserve network were superior to those in the non-PAs, such as average annual vegetation coverage and net primary production. After the establishment of the nature reserve network, ecosystem water retention service increased by 72% compared to those in the non-PAs. In the non-PAs, intensified or new degradation occurred due to overgrazing and over-exploitation. In recent years, the wetting and warming climate has been the main driver of ecological restoration in the region. The establishment of the nature reserve networks and the implementation of conservation projects both promote the improvement of local ecosystems. Therefore, for alpine regions under climate variability, we should protect entire regions rather than specific areas, and management efforts should focus on long-term sustainable conservation rather than emergency rescue.

Spatial-temporal Patterns and Driving Forces of Water Retention Service in China

Overwhelming water-deficiency conditions and an unbalanced water supply and demand have been major concerns of both the Chinese government and the general public during recent decades. Studying the spatial-temporal patterns and impact factors that influence water retention in China is important to enhance the management of water resources in China and other similar countries. We employed a revised Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model and regression analyses to investigate the water retention service in China. The results showed that the southeastern China generally performed much better than Northwest China in terms of the spatial distribution of water retention. In general, the efficacy of the water retention service in China increased from 2000 to 2014; although some areas still had a downward trend. Water retention service increased significantly (P < 0.05) in aggregate in the Qinghai-Tibet Plateau, and the Da Hinggan Mountains and Xiao Hinggan Mountains. However, the service in southwestern China showed a decreasing trend (P < 0.05), which would have significant negative impact on the downstream population. This study also showed that in China the changes in water retention service were primarily due to climate change (which could explain 83.49% of the total variance), with anthropogenic impact as a secondary influence (likewise the ecological programs and socioeconomic development could explain 9.47% and 1.06%, respectively). Moreover, the identification of water retention importance indicated that important areas conservation and selection based on downstream beneficiaries is vital for optimization protection of ecosystem services, and has practical significance for natural resources and ecosystem management.

Spatio-temporal evolution of water-related ecosystem services: Taihu Basin, China.

Water-related ecosystem services (WESs) arise from the interaction between water ecosystems and their surrounding terrestrial ecosystems. They are critical for human well-being as well as for the whole ecological circle. An urgent service-oriented reform for the utilization and supervision of WESs can assist in avoiding ecological risks and achieving a more sustainable development in the Taihu Basin, China (THB). Spatially distributed models allow the multiple impacts of land use/land cover conversion and climate variation on WESs to be estimated and visualized efficiently, and such models can form a useful component in the toolbox for integrated water ecosystem management. The Integrated Valuation of Ecosystem Services and Tradeoffs model is used here to evaluate and visualize the spatio-temporal evolution of WESs in the THB from 2000 to 2010. Results indicate that water retention service experienced a decline from 2000 to 2005 with a recovery after 2005, while there was ongoing water scarcity in urban areas. Both the water purification service and the soil retention service underwent a slight decrease over the study period. Nutrients export mainly came from developed land and cultivated land, with the hilly areas in the south of the THB forming the primary area for soil loss. The quantity and distribution of WESs were impacted significantly by the shrinkage of cultivated land and the expansion of developed land. These findings will lay a foundation for a service-oriented management of WESs in the THB and support evidence-based decision making.

The impact of water management practices on subtropical pasture methane emissions and ecosystem service payments.

Pastures are an extensive land cover type; however, patterns in pasture greenhouse gas (GHG) exchange vary widely depending on climate and land management. Understanding this variation is important, as pastures may be a net GHG source or sink depending on these factors. We quantified carbon dioxide (CO2 ) and methane (CH4 ) fluxes from subtropical pastures in south Florida for three wet-dry seasonal cycles using eddy covariance, and estimated two annual budgets of CO2 , CH4 , and GHG equivalent emissions. We also estimated the impact of water retention practices on pasture GHG emissions and assessed the impact of these emissions on stakeholder payments for water retention services in a carbon market framework. The pastures were net CO2 sinks sequestering up to 163±54gCO2 -C·m-2 ·yr-1 (mean ± 95% CI), but were also strong CH4 sources emitting up to 23.5±2.1gCH4 -C·m-2 ·yr-1 . Accounting for the increased global warming potential of CH4 , the pastures were strong net GHG sources emitting up to 584±78g CO2 -C eq.·m-2 ·yr-1 , and all CO2 uptake was offset by wet season CH4 emissions from the flooded landscape. Our analysis suggests that CH4 emissions due to increased flooding from water management practices is a small component of the pasture GHG budget, and water retention likely contributes 2-11% of net pasture GHG emissions. These emissions could reduce water retention payments by up to ~12% if stakeholders were required to pay for current GHG emissions in a carbon market. It would require at least 93.7kg CH4 -C emissions per acre-foot water storage (1 acre-foot = 1233.48 m3 ) for carbon market costs to exceed water retention payments, and this scenario is highly unlikely as we estimate current practices are responsible for 11.3±7.2kg CH4 -C emissions per acre-foot of water storage. Our results demonstrate that water retention practices aimed at reducing nutrient loading to the Everglades are likely only responsible for a minor increase in pasture GHG emissions and would have a small economic consequence in a carbon market.