No abstract

Context Human demands for ecosystem services (ES) have tremendously changed the landscape and led to degradation of ecosystems and associated services. The resolving of current eco-environmental problems calls for better understanding of the spatially explicit ES interactions to guide targeted landuse policy-making. Objectives We propose a framework to map ES in continuous time-series, based on which we further quantify interactions among multiple ES. Methods The supply of three key ES-soil conservation (SC), net primary production (NPP) and water yield (WY)-were quantified and mapped at fineresolution from 2000 to 2013 using easily-accessible spatial data. Pairwise ES interactions were quantified using a spatio-temporal statistical method. Results Spatio-temporal analyses of ES dynamics illustrated that the supply of the three ES increased over the past 14 years in northern Shaanxi, where land cover dramatically changed owing to the wide-range ecological restoration projects. Our results also revealed that ES interactions varied across locations due to landscape heterogeneity and climate difference. In the arid and semi-arid area, synergies among ES (e.g., SC vs. WY) tended to dominate in grassland, while in artificial lands ES were prone to show tradeoffs. In the semi-humid area, pairwise ES (e.g., NPP vs. WY) in woodland tended to present synergies. Conclusions The spatio-temporal variation of ES and their interactions resulted from coupling effect of human-induced climate and land-use change. In the long-term, spatially explicit quantification of ES Electronic supplementary material The online version of this article (

Water quality has suffered as humans have increased nutrient inputs across the landscape. In many cases, management actions to reduce nutrient inputs have not been met with concomitant ecosystem responses. These missed expectations are partly due to the continued slow delivery of nutrient-enriched groundwater pre-dating input reductions resulting from management actions. Land use legacies as expressed through this time lag are important to quantify in order to adjust management expectations. We present a novel coupling of nitrogen source maps with groundwater transport times to create a high-resolution (120 m) fully distributed estimate of the timing and magnitude of groundwater nitrogen deliveries to surface water across Michigan’s Lower Peninsula. This new view of the landscape has been designed around common management timelines for: elected officials looking to make a difference for re-election (<5 years), career managers hoping to see the fruits of their labor (5–30 years), and advocacy groups whose work can span generations (>30 years). One striking result is that after 100 years, in our study area, approximately 50% of the nitrogen that enters the groundwater system remains in transit. This means that actions taken now may not show the expected lower nitrogen loads to receiving ecosystems for decades to centuries. We show that differences in groundwater travel times create a heterogeneous patchwork over which managers can prioritize actions to best match their targeted response times. Across the highest nitrogen inputs in our study region, less than 10% had short enough groundwater legacies to match the management timeline of most government and agency work. Agricultural practices (manure and chemical fertilizer) are the main nitrogen contributors across the top three management classes; however, human contributions through septic tank effluent and lawn fertilizers contribute 5%–8% of nitrogen.

Climate change can have critical impacts on ecosystem services (ESs) and their inter-relationships, especially for water-related services. However, there has been little work done on characterizing the current and future changes in these services and their inter-relationships under a changing climate. Based on the revised universal soil loss equation (RUSLE), the soil conservation service curve number model (SCS-CN), and the improved stochastic weather-generator-based statistical downscaled global climate models (GCMs), we examined two important water-related services, namely, the soil conservation (SC) service and the flood mitigation (FM) service, and their inter-relationship under baseline and future climate scenarios (Representative Concentration Pathways (RCPs) 4.5 and 8.5). We took the Upper Hanjiang River Basin (UHRB), which is the core water source area of the China’s South-to-North Water Diversion Project (S–NWDP), as an illustration. The findings revealed that (1) the SC and FM services will both decrease under the two climate scenarios examined; (2) the SC and FM services showed a significant synergistic inter-relationship and the synergy will be improved by 16.48% and 2.95% under RCP 4.5 and RCP 8.5, respectively, which provides an opportunity for management optimization; (3) the ecological degradation in the UHRB will likely have serious consequences for the middle and lower reaches of the Hanjiang river basin, and therefore impact the actual economic benefits of the S–NWDP. This study points to the necessity for understanding the dynamic changes and inter-relationships of ecosystem services under future climate change and provides information regarding the consequences of climate change, which is useful for policy and infrastructure investment.

No abstract