白洋淀流域生态系统服务评估及其调控

政策制定者在制定土地利用相关政策时需要权衡各方面的利益关系,协调资源保护和经济发展之间的关系.由于缺乏有效的评价与权衡办法,目前对这方面研究还较少.采用InVEST模型,评价了白洋淀流域7种服务功能指标,分析了其空间分布特征.通过情景(政策情景与保护情景)分析,较好的反映了农业直接经济收入与服务功能之间的关系.结果表明:生物多样性、水源涵养、土壤保持和固碳重要区域主要分布在流域西部、北部和流域中部山区;水质保护和授粉重要区域主要分布于流域东部、南部和中部平原区.政策情景下,产水量第二,农业产出有所下降,固碳能力较保护模式差,N/P输出最少.保护情景下产水量最大,农田产出价值不变,氮磷保持与政策情景差不多,但固碳效果最好.通过权衡不同情景下服务功能得失,筛选既不损害流域居民实际经济收入,又能使得水文服务功能得到提高的管理模式.研究表明InVEST模型可以很好的用于对自然资本评估和空间化特征分析,通过建立不同情景,评价结果可以用于权衡不同管理策略下服务功能得失,是一种评价和预测自然资本变化的有效方法,对政策制定和策略筛选具有重要的指导意义.     

Variability of soil carbon sequestration capability and microbial activity of different types of salt marsh soils at Chongming Dongtan

Variations in the soil carbon sequestration capability of different types of salt marsh soils at Chongming Dongtan and its influencing factors were studied by analyzing the soil organic carbon (SOC) content, organic matter input and microbial activities. The results indicated that the total SOC content at Area A (southeast of Dongtan, sandy soil with Phragmites communis) was only 46.11% of that of Area B (northeast of Dongtan, clay soil with mixed P. communis and Spartina alterniflora) (P = 0.000 < 0.05), but their organic matter input per year was almost identical. These findings implied that Area B had a lower output of SOC. The microbial biomass at Area A was 3.83 times greater than that at Area B (P = 0.049 < 0.05); the soil catalase and invertase activities at Area A, which were related to carbon metabolism, were 60.31% (P = 0.006 < 0.05) and 34.33% (P = 0.021 < 0.05) higher than at Area B, respectively; and the soil respiration at Area A was also higher than at Area B. These findings implied that the microbial activities at Area A were greater than those at Area B, and therefore the carbon metabolism was rapid, resulting in increased SOC output at Area A. Increased water content and salinity in the clay soil at Area B may inhibit the microbial activities, thereby reducing the decomposition of the organic matter and enhancing carbon sequestration. In addition, some artificial measures for controlling spread of S. alterniflora at Area B (mowing/digging and tillage (M + D); mowing/digging and tillage/waterlogging (M + D + W)) were found to generally improve the microbial activity of soil, thereby increasing SOC output. However, when the two different physical controlling modes were compared, the SOC and microbial activities of the soil subjected to the M + D + W treatment were relatively high and low, respectively, due to waterlogging restraining the microbial metabolism. These findings indicated that the difference in microbial activities was the important factor leading to variability in the SOC sequestration capability between Areas A and B. Additionally, with the exception of soil texture and vegetation types, environmental conditions and artificial turbulence also influenced microbial activities of soil, and hence SOC output and organic carbon sequestration capability.     

Carbon sequestration potential of green roofs using mixed-sewage-sludge substrate in Chengdu World Modern Garden City

Green roofs which use sewage sludge to sequestrate urban carbon dioxide may represent a potential opportunity to evaluate carbon sequestration benefits for the urban development under increasing global climate change. In this study, green roofs composed of 6 small green segments with two different substrates, mixed-sewage-sludge substrate (MSSS, volume ratio of sewage sludge and local-natural soil 1:1), and local-natural soil (LNS), three different substrate depths (20 cm, 25 cm and 30 cm), and three types of native plants (Ligustrum vicaryi, Neottia auriculata, and Liriope spicata) in Chengdu City were established to determine carbon sequestration from July 2012 to July 2013 through assessment of the carbon storage and sequestration. Results show that the average carbon storage of MSSS and LNS on green roofs was respectively 13.15 kg C m⁻² and 8.58 kg C m⁻², and the average carbon sequestration followed the order of LNS (3.89 kg C m⁻² yr⁻¹) > MSSS (3.81 kg C m⁻² yr⁻¹). Thus MSSS could be considered as a potential material for carbon sequestration. The carbon storage and carbon sequestration by native plants on the green roofs followed the order of L. vicaryi > L. spicata > N. auriculata. The whole green roof had a mean carbon storage of 18.28 kg C m⁻² and average carbon sequestration of 6.47 kg C m⁻² yr⁻¹ in the combined biomass and substrate organic matter. The best green roof configuration was L. vicaryi together with MSSS substrate, with a middle-high level of carbon sequestration. It will be feasible and worthwhile to scale-up the adaptable green roof configurations in Chengdu World Modern Garden City.     

Island urbanization and its ecological consequences: A case study in the Zhoushan Island,East China

Islands, which provide multiple ecosystem services, are subject to increasing urbanization pressure due to the ongoing marine development, especially in developing countries. Insights into the island urbanization mechanism and its ecological consequences are essential to sustainable development. In the present paper, the satellite images, nighttime lights, and topographic data were integrated to characterize the spatially explicit urbanization process and mechanism during 1995–2011 in the Zhoushan Island, East China. Furthermore, the corresponding spatially explicit changes in ecosystem services, including net primary productivity (NPP), carbon sequestration and oxygen production (CSOP), nutrient cycling, crop production, and habitat quality, were quantified based on the Carnegie–Ames–Stanford Approach (CASA) and Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) models. The results showed that the Zhoushan Island had experienced a rapid urbanization over the years, with significant urban encroachment on the farmland and tidal flat. Moreover, the urban land expansion was positively correlated with that of the nighttime lights and negatively correlated with the elevation, slope, and the distance to shoreline. These indicated that the urban expansion was resulted from the enhancement of socioeconomic activities, and concentrated in the near-shore areas with low altitude and gentle slope. The urban encroachment on other land use types resulted in a decrease of 3.4 Gg C a⁻¹ NPP, 8.7 Gg a⁻¹ CSOP, 13.2 Gg a⁻¹ nutrient cycling, and 12.3 t a⁻¹ crop production, respectively. In addition, the habitat quality in 11% area of this island degraded substantially. Therefore, to achieve sustainable development of islands, it is urgent to implement more stringent policies, such as island spatial regulation, environmental impact assessment, intensive land use, and urban greening, etc.     

Tillage effects on carbon footprint and ecosystem services of climate regulation in a winter wheat–summer maize cropping system of the North China Plain

Inappropriate farm practices can increase greenhouse gases (GHGs) emissions and reduce soil organic carbon (SOC) sequestration, thereby increasing carbon footprints (CFs), jeopardizing ecosystem services, and affecting climate change. Therefore, the objectives of this study were to assess the effects of different tillage systems on CFs, GHGs emissions, and ecosystem service (ES) values of climate regulation and to identify climate-resilient tillage practices for a winter wheat (Triticum aestivum L.)-summer maize (Zea mays L.) cropping system in the North China Plain (NCP). The experiment was established in 2008 involving no-till with residue retention (NT), rotary tillage with residue incorporation (RT), sub-soiling with residue incorporation (ST), and plow tillage with residue incorporation (PT). The results showed that GHGs emissions from agricultural inputs were 6432.3–6527.3 kg CO₂-eq ha⁻¹ yr⁻¹ during the entire growing season, respectively. The GHGs emission from chemical fertilizers and irrigation accounted for >80% of that from agricultural inputs during the entire growing season. The GHGs emission from agricultural inputs were >2.3 times larger in winter wheat than that in the summer maize season. The CFs at yield-scale during the entire growing season were 0.431, 0.425, 0.427, and 0.427 without and 0.286, 0.364, 0.360, and 0.334 kg CO₂-eq kg⁻¹ yr⁻¹ with SOC sequestration under NT, RT, ST, and PT, respectively. Regardless of SOC sequestration, the CFs of winter wheat was larger than that of summer maize. Agricultural inputs and SOC change contributed mainly to the component of CFs of winter wheat and summer maize. The ES value of climate regulation under NT was ¥159.2, 515.6, and 478.1 ha⁻¹ yr⁻¹ higher than that under RT, ST, and PT during the entire growing season. Therefore, NT could be a preferred “Climate-resilient” technology for lowering CFs and enhancing ecosystem services of climate regulation for the winter wheat–summer maize system in the NCP.     

Carbon profiles of typical forest types across Europe assessed with CO2FIX

This paper presents for 16 typical forest types across Europe a standard carbon sequestration profile. The study was carried out with the model CO2FIX which was parameterised with local yield table data and additional required parameters. CO2FIX quantifies the carbon of the forest ecosystem–soil–wood products chain at the stand level. To avoid misleading results annual net sequestration rates are not presented here, because these strongly fluctuate in time. Therefore, only its advancing mean is presented as a more reliable indicator. This avoids a great deal of uncertainty for policy makers. The variation between forest types is large, but mean sequestration rates mostly peak after some 38 years (with a net source lasting up to 15 years after afforestation) at an average value of 2.98 Mg C ha⁻¹ per year (ranging between forest types from 4.1 to 1.15). After 200 years, the net sequestration rate saturates to a value of 0.8 Mg C ha⁻¹ per year (ranging from 1.4 to 0.13). The long-term mean carbon stock in tree biomass and products amounts on average to 114 Mg C ha⁻¹ (ranging from 52 to 196).     

Using assessment of net ecosystem services to promote sustainability of golf course in China

Golf courses have been shown to have a positive impact on local biodiversity, quality of life and the economy. However, the impacts of golf courses on local environment, including ecosystem services and dis-services are not clearly understood. To explore this relationship, we took two golf courses in Beijing (a links course and a parkland course) to develop an assessment framework and present estimates of economic values of net ecosystem services, in aspects of ecosystem goods, carbon fixation, soil retention, flood storage, recreation, water consumption and nonpoint-source pollution. The results showed that the two golf courses have provided remarkable net ecosystem services values (links 51.58 × 10⁴ yuan/ha/yr, parkland 42.60 × 10⁴ yuan/ha/yr, 6.19 yuan = 1 US$ in 2013). Over 95% of this value is generated by three services: recreation, ecosystem goods and flood storage. Our results indicate that the parkland course has better performance in sustainable supply of ecosystem services than the links course. In addition, this study provides useful improvements for golf course design and management concerning positive environmental externalities optimizing, including the scaling of non-playing areas to maximize golf course ecosystem services supply capacity, appropriate grass species selecting and irrigation with recycled water. Moreover, a policy analysis suggests that the development of public golf course in China is a necessary complement to resolve the mismatch between private and public benefits and let more people enjoy the ecosystem services.     

三江源区基于生态系统服务价值的生态补偿额度

以青海三江源区为例,探讨了基于生态系统服务价值的生态补偿额度测算方法。以分析和筛选生态补偿需求下的生态系统服务价值评估指标为前提,估算了生态保护和建设活动实施前(2005年)三江源区草地生态系统服务价值,并采用专家咨询法提出的不同退化程度草地的生态功能系数对其进行修正,得到未退化、轻度退化、中度退化和重度及重度以上退化草地的单位面积生态价值分别为74.70×104、59.76×104、37.35×104元/km2和14.94×104元/km2。根据三江源区草地退化现状和生态恢复的目标,确定该区基于退化草地完全恢复的生态补偿总量为911.62×108元。     

Variation of soil nutrients and particle size under different vegetation types in the Yellow River Delta

The Yellow River Delta wetland, located at the southern coast of Bohai Gulf, provides important ecosystem services such as flood control, water purification, biodiversity conservation, nutrient removal and carbon sequestration, shoreline stabilization, tourism attraction and wetland products maintains in the Yellow River Delta. This study assessed how agricultural activities in a reclamation wetland changed soil pH, soil electric conductivity, soil nutrient and soil particle size as compared to natural vegetation by using a combination of field experiments and lab analysis. The vegetation type included adjacent alfalfa field (Medicago sativa), cotton field (Gossypium spp.), Chinese tamarisk shrub (Tamarix chinensis), and reed marsh (Phragmites sage). The results indicated that the soil pH was higher (pH > 8) in alfalfa field and cotton field, and alfalfa field and reed marsh had significant function in reducing soil salt content, soil electric conductivity of alfalfa field at 0–30 cm were 140.38 ± 14.36, 114.48 ± 14.36, 125.30 ± 11.37 μs/cm. The effect of different vegetation types on soil nutrient was significant (P < 0.05). Soil organic matter at 0–10 cm in Chinese tamarisk shrub and reed marsh was 21.66 ± 3.82 g/kg and 16.51 ± 4.60 g/kg, which was higher than that of alfalfa field (10.47 ± 2.36 g/kg) and cotton field (9.82 ± 1.27 g/kg), but soil total nitrogen content in alfalfa field was the highest, which is significantly higher than that of cotton field, Chinese tamarisk shrub and reed marsh(P < 0.05), the content of soil total nitrogen at 0–10 cm and 10–20 cm was 7.67 ± 0.38 g/kg and 5.97 ± 0.51 g/kg, respectively, while the content of available P and available K was reversed. The difference of soil particle size between layers was not significant (P > 0.05), the sand content of Chinese tamarisk shrub soils in 0–10 cm was the highest, the next was alfalfa field and cotton field, and the content of silt and clay in reed marsh was higher than the others. The correlation and significant degree between soil particle size and soil nutrient was related with vegetation types, and soil organic matter was significantly positively correlated with soil silt and clay content on the alfalfa field. The results demonstrated that wetland cultivation was one of the most important factors influencing on the nutrient fate and reserves in soil, which could lead to rapid nutrient release and slow restoration through abandon cultivation. Consequently, compared with cotton field, alfalfa field is more favorable to sustainable management of wetland cultivation in the Yellow River Delta. It should be considered in wetland restoration projects planning.     

Verification of a threshold concept of ecologically effective precipitation pulse: From plant individuals to ecosystem

In water-limited ecosystems, an ecologically significant rainfall pulse was defined as a rainfall event that altered both soil water status and plant physiological activity. We developed a new threshold concept of an ecologically effective precipitation pulse (EEPP) applicable to both plant individual and ecosystem scales. The concept was tested in a typical steppe on Inner Mongolia plateau. Two EEPPs, single 3-mm rainfall and 5-mm rainfall, were applied to investigate their effects on soil and plant water status, CO₂ assimilation of five species (four C₃ plants and one C₄ plant), whole-plot soil respiration (R_s), and net ecosystem CO₂ exchange (NEE) on 1 June and 28 July 2009, respectively. Both EEPPs increased leaf water potential (Ψ_l) of all the species, which peaked 1–3 days after rainfall pulses. Soil water content (SWC) in two depths (5 cm and 20 cm) significantly increased after the two EEPPs for 1–3 days. Soil water potential (Ψ_s) within 20‐cm soil layer in EEPP treatments significantly differed (p < 0.05) from control. Net assimilation rates (A_net) of all C₃ plants had a slight increase at the next day after two EEPPs, in contrast to the C₄ species. R_s elevated and peaked 1–3 days later after water supply. Ecosystem net CO₂ absorption rate rose to maximum value 3 days after the 5-mm pulse on 28 July, higher than the response to 3-mm pulse on June 1. The grassland turned to net emission of CO₂ after 3-mm pulse on 28 July. The results supported that there was an ecosystem level threshold for EEPP, and the threshold was temporally variable. It also highlighted the necessity of considering the response threshold of EEPP in rainfall manipulative experiment. In addition, effective rainfall amount was more approriate than total rainfall amount in modeling ecosystem carbon balance.     

Ecological Footprint: Refining the carbon Footprint calculation

Within the Ecological Footprint methodology, the carbon Footprint component is defined as the regenerative forest capacity required to sequester the anthropogenic carbon dioxide emissions that is not absorbed by oceans. A key parameter of the carbon Footprint is the Average Forest Carbon Sequestration (AFCS), which is calculated from the net carbon sequestration capacity of forests ecosystems.The aim of this paper is to increase the clarity and transparency of the Ecological Footprint by reviewing the rationale and methodology behind the carbon Footprint component, and updating a key factor in its calculation, the AFCS. Multiple calculation options have been set to capture different rates of carbon sequestration depending on the degree of human management of three types of forest considered (primary forests, other naturally regenerated forests and planted forests). Carbon emissions related to forest wildfires and soil as well as harvested wood product have been included for the first time in this update of the AFCS calculation. Overall, a AFCS value range of 0.73 ± 0.37 t C ha⁻¹ yr⁻¹ has been identified. The resulting carbon Footprint and Ecological Footprint values have then been evaluated based on this value range. Results confirm that human demand for ecosystem services is beyond the biosphere's natural capacity to provide them.     

秦岭生态系统服务协同与权衡的时空异质性

秦岭是我国重要的生态功能区,探究秦岭生态系统服务权衡与协同关系对区域的生态保护和高质量发展意义重大。本研究基于遥感、气象、土壤质地等数据,在分析2000、2010和2020年土地利用时空变化的基础上,采用CASA、InVEST和RUSLE模型计算秦岭地区植被固碳量、产水量、生境质量和土壤保持量,并探讨空间异质性特征及生态系统服务关系。结果表明: 2000—2020年,研究区耕地、草地面积持续减少,林地和建设用地面积增长,水域和未利用地变化不明显。研究区固碳量东高西低,呈增长趋势;产水量持续减少,呈现南坡高、北坡低的格局;生境质量稳定增长;土壤保持量先增后减。不同地类的生态系统服务各有差异,同一地类的各个生态系统服务也各不相同。全域尺度下固碳与土壤保持、生境质量与土壤保持、固碳与生境质量皆呈协同关系,固碳与产水、土壤保持与产水、生境质量与产水为权衡关系,但不同条件下服务量间的关系存在明显差异。研究结果有助于降低权衡风险,使总体效益最大化,可为促进生态高质量发展、实现自然资源管理与人类福祉的双赢提供参考依据。     

Sensitivity and resistance of soil fertility indicators to land-use changes: New concept and examples from conversion of Indonesian rainforest to plantations

Tropical forest conversion to agricultural land leads to a strong decrease of soil organic carbon (SOC) stocks. While the decrease of the soil C sequestration function is easy to measure, the impacts of SOC losses on soil fertility remain unclear. Especially the assessment of the sensitivity of other fertility indicators as related to ecosystem services suffers from a lack of clear methodology. We developed a new approach to assess the sensitivity of soil fertility indicators and tested it on biological and chemical soil properties affected by rainforest conversion to plantations. The approach is based on (non-)linear regressions between SOC losses and fertility indicators normalized to their level in a natural ecosystem. Biotic indicators (basal respiration, microbial biomass, acid phosphatase), labile SOC pools (dissolved organic carbon and light fraction) and nutrients (total N and available P) were measured in Ah horizons from rainforests, jungle rubber, rubber (Hevea brasiliensis) and oil palm (Elaeis guineensis) plantations located on Sumatra. The negative impact of land-use changes on all measured indicators increased in the following sequence: forest < jungle rubber < rubber < oil palm. The basal respiration, microbial biomass and nutrients were resistant to SOC losses, whereas the light fraction was lost stronger than SOC. Microbial C use efficiency was independent on land use. The resistance of C availability for microorganisms to SOC losses suggests that a decrease of SOC quality was partly compensated by litter input and a relative enrichment by nutrients. However, the relationship between the basal respiration and SOC was non-linear; i.e. negative impact on microbial activity strongly increased with SOC losses. Therefore, a small decrease of C content under oil palm compared to rubber plantations yielded a strong drop in microbial activity. Consequently, management practices mitigating SOC losses in oil palm plantations would strongly increase soil fertility and ecosystem stability. We conclude that the new approach enables quantitatively assessing the sensitivity and resistance of diverse soil functions to land-use changes and can thus be used to assess resilience of agroecosystems with various use intensities.     

Economic values and dominant providers of key ecosystem services of wetlands in Beijing,China

This study estimates the economic values of and the dominant contributors to five key ecosystem services of wetlands in Beijing, by using the wetland inventory data in 2014 and economic valuation methods. Results indicate that the 51,434 ha of wetlands in Beijing annually provide 2.07 billion m³ of flood regulation, 944.01 million m³ of water provision, 42,154 tons of chemical oxygen demand (COD) purification, 3.03 PJ of heat absorption, and 9587 ha of habitat. Their economic values are estimated to be 15.89 billion RMB, 1.19 billion RMB, 169 million RMB, 421 million RMB, and 1.08 billion RMB in 2014 (RMB: Chinese currency, US$1 = RMB 6.14), respectively. The total values of five key wetland ecosystem services reach 18.76 billion RMB. In addition, the reservoir and river wetlands in Miyun, Yanqing, Fangshan, Huairou, and Mentougou Districts contribute 78% of key ecosystem services, whereas the urban wetlands in Xicheng, Dongcheng, Haidian, Chaoyang, and Tongzhou Districts more conveniently serve densely local people, hence they should be given particular attentions. In this paper, we develop the valuation methods of wetland ecosystem services, and recommend diversified strategies, regulations, and programs to protect the remaining wetlands in Beijing. This work can also provide a reference for the valuating of wetland ecosystem services for other urban-rural areas.     

Role of ecosystem components in Cd removal process of aquatic ecosystem

An experiment was conducted using 15 glass aquariums to ascertain the pathways of removal of cadmium through numerical and compositional manipulation of ecosystem components and their role in Cd removal in different aquatic ecosystems. Each aquarium was provided with surface sediment @ 2 kg, filled with 15 L tap water and randomly distributed into five treatments having three replicates in each. Cadmium chloride (CdCl₂) of analytical grade was added @ 2 mg/L to the water of each aquarium and mixed gently. Except for the first one, the other four systems received unio (Lamellidens marginalis, 55 ± 2.5 g) @ 6 pieces/aquarium. Tilapia (Oreochromis mossambicus, 35 ± 3 g) was introduced @ 6 fish/aquarium in the third and fifth systems, whereas pistia (Pistia stratiotes) was introduced @ 50 g/aquarium in the fourth and fifth systems for a 28-day observation period. The samples of water, sediment, unio, fish and pistia were collected from different systems at 7-day intervals and analyzed. Results revealed that mean substantial reduction of Cd in water varied between 1.820 and 1.994 mg/L in different simulated ecosystems. Ecosystem efficiency of Cd removal varied in the different ecosystems and showed highest (11%) value in the ecosystem carrying five components, which suggested a cumulative effect of increasing number of components employed in different simulated aquatic ecosystems significantly facilitated the reduction of the level of Cd concentration in water column. Pistia exerted (12.88–547.5 times) higher rate of Cd accumulation over the other components employed in five simulated ecosystems of various component structures. Therefore, in the present study, it may be concluded that ecosystems carrying five components exhibited the best performance for optimum minimization of Cd removal from water column. It can also be concluded that ecosystem components showed a variable performance and pistia was the efficient component from the perspective of Cd removal.     

Carbon allocation dynamics one decade after afforestation with Pinus radiata D. Don and Betula alba L. under two stand densities in NW Spain

Silvopastoral systems can contribute to the mitigation of climate change by functioning as sinks for greenhouse gases better than exclusively agricultural systems. Tree species, density, and an adequate management of the pasture carrying capacity contribute to the capacity of carbon sequestration. In this study, the capacities for carbon sequestration in silvopastoral systems that were established with two different forest species (Pinus radiata D. Don and Betula alba L.) and at two distinct densities (833 and 2500 trees ha^?1) were evaluated. Tree, litterfall, pasture and soil carbon storage determinations were carried out to deliver carbon sequestration in the different pools within the first 11 years of a plantation establishment. The results show that the global capacity for carbon sequestration in silvopastoral systems with pine canopy was higher than with birch cover. Independently of the forest species, the capacity for carbon sequestration increased when the systems were established at higher plantation densities. There were found strong differences in the relative proportions of carbon in each component of the system (litterfall, tree, pasture and soil). The soil component was found to be most important in the case of the broadleaf forest established at low density. The establishment of a silvopastoral system enhanced soil carbon storage, since afforestation was carried out, which results in a more enduring storage capacity compared with treeless areas.     

From instantaneous to continuous: Using imaging spectroscopy and in situ data to map two productivity-related ecosystem services

Spatially well-informed decisions are essential to sustain and regulate processes and ecosystem services (ES), and to maintain the capacity of ecosystems to supply services. However, spatially explicit ES information is often lacking in decision-making, or exists only as ES maps based on categorical land cover data. Remote sensing (RS) opens new pathways to map ES, in particular biophysical ES supply. We developed an observation-based concept for spatially explicit and continuous ES mapping at landscape scale following the biophysical part of the ES cascade. We used Earth observations in combination with in situ data to map ecosystem properties, functions, and biophysical ES supply. We applied this concept in a case study to map two ES: carbon dioxide regulation and food supply. Based on Earth observations and in situ data, we determined the ecosystem property Sun-Induced chlorophyll Fluorescence (SIF) to indicate ecosystem state and applied scaling models to estimate gross primary production (GPP) as indicator for ecosystem functioning and consequently carbon dioxide regulation and food supply as ES.Resulting ES maps showed heterogeneous patterns in ES supply within and among ecosystems, which were particularly evident within forests and grasslands. All investigated land cover classes were sources of CO₂, with averages ranging from ‐66 to ‐748 g C m^‐2 yr^‐1, after considering the harvest of total above ground biomass of crops and the storage organ, except for forest being a sink of CO₂ with an average of 105 g C m^‐2 yr^‐1. Estimated annual GPP was related to food supply with a maize grain yield average of 9.5 t ha^‐1 yr^‐1 and a sugar beet root yield of 110 t ha^‐1 yr^‐1. Validation with in situ measurements from flux towers and literature values revealed a good performance of our approach for food supply (relative RMSE of less than 23%), but also some over- and underestimations for carbon dioxide regulation. Our approach demonstrated how RS can contribute to spatially explicit and continuous ES cascade mapping and suggest that this information could be useful for environmental assessments and decision-making in spatial planning and conservation.     

Influence of management and precipitation on carbon fluxes in great plains grasslands

Suitable management and sufficient precipitation on grasslands can provide carbon sinks. The net carbon accumulation of a site from the atmosphere, modeled as the Net Ecosystem Productivity (NEP), is a useful means to gauge carbon balance. Previous research has developed methods to integrate flux tower data with satellite biophysical datasets to estimate NEP across large regions. A related method uses the Ecosystem Performance Anomaly (EPA) as a satellite-derived indicator of disturbance intensity (e.g., livestock stocking rate, fire, and insect damage). To better understand the interactions among management, climate, and carbon dynamics, we evaluated the relationship between EPA and NEP data at the 250 m scale for grasslands in the Central Great Plains, USA (ranging from semi-arid to mesic). We also used weekly estimates of NEP to evaluate the phenology of carbon dynamics, classified by EPA (i.e., by level of disturbance impact). Results show that the cumulative carbon balance over these grasslands from 2000 to 2008 was a weak net sink of 13.7 g C m⁻² yr⁻¹. Overall, NEP increased with precipitation (R² = 0.39, P < 0.05) from west to east. Disturbance influenced NEP phenology; however, climate and biophysical conditions were usually more important. The NEP response to disturbance varies by ecoregion, and more generally by grassland type, where the shortgrass prairie NEP is most sensitive to disturbance, the mixed-grass prairie displays a moderate response, and tallgrass prairie is the least impacted by disturbance (as measured by EPA). Sustainable management practices in the tallgrass and mixed-grass prairie may potentially induce a period of average net carbon sink until a new equilibrium soil organic carbon is achieved. In the shortgrass prairie, management should be considered sustainable if carbon stocks are simply maintained. The consideration of site carbon balance adds to the already difficult task of managing grasslands appropriately to site conditions. Results clarify the seasonal and interannual dynamics of NEP, specifically the influence of disturbance and moisture availability.     

Valuation of the loss of plant-related ecosystem services caused by water stress in the wetland of China’s Yellow River Delta

China’s Yellow River Delta is ecologically important because of its role as an eco-tone between terrestrial and aquatic ecosystems. However, water stress caused by drought or flooding creates ecological risks for this important ecosystem. In this study, we assessed community biodiversity, plant biomass, and the plant total nitrogen, total phosphorus, and potassium contents to quantify the potential loss of ecosystem services value arising from water stress. The annual ecosystem services and function value of the wetlands totaled 3.68 × 10⁸ Yuan, of which biomass production and local climate regulation accounted for 39.4% and 49.5% of the total, respectively. The area with the highest value (>2 Yuan m⁻²) lies along both banks of the downstream reaches of the river, whereas areas with the lowest values (<1.5 Yuan m⁻²) were located on the northern bank, near the Bohai Sea coastline. We defined scenarios based on three levels of water stress: drought, sufficient water, and flooding. The potential annual value loss in the drought scenario was 3.60 × 10⁸ Yuan, versus 2.78 × 10⁸ Yuan in the flooding scenario. The minimum loss (with sufficient water) was 2.06 × 10⁸ Yuan. The wetland’s soil water content should therefore be managed to protect the vegetation and minimize the ecological risks (and associated ecosystem service value losses) caused by water stress. Our approach provides a tool for assessing the potential loss of ecosystem services and functions and for calculating ecological compensation payments for wetland damage.     

黄土高原典型退耕区生态系统服务权衡与协同关系研究——以延安市为例

在退耕还林的背景下,从多尺度分析黄土高原生态系统服务的时空变化及权衡协同关系对促进该区经济发展和生态效益多赢具有重要意义。以黄土高原退耕还林典型区延安市为例,运用InVEST模型评估1988-2018年农作物生产、碳储量、生境质量、土壤保持、产水量5种关键生态系统服务物质量,采用偏相关分析法探讨生态系统服务间的权衡与协同关系及其时空变化特征。研究结果表明：（1）受土地利用变化影响,延安市农作物生产水平、土壤保持年际变化趋势波动较大,农作物生产水平呈波动增加的趋势,土壤保持退耕还林前呈减少,退耕还林后呈波动增加的趋势,碳储量和生境质量呈逐渐增加的趋势,产水量呈逐渐减弱的趋势。（2）生态系统服务与土地利用格局联系紧密。碳储量、生境质量的高值区域以及产水量的低值区域随林地分布格局变化而变化。（3）协同关系是延安市生态系统服务间相关关系的主体,主要发生在碳储量、生境质量、土壤保持、农作物生产之间,权衡关系主要存在于产水量和其他生态系统服务之间。（4）市、县域生态系统服务间关系的差异主要发生在生境质量和土壤保持之间。