Integrating beneficiaries into assessment of ecosystem services from managed forests at the Hubbard Brook Experimental Forest,USA

Background：Forests contribute to human wellbeing through the provision of important ecosystem services.Methods：In this study,we investigated how the perceived importance of ecosystem services may impact the overall benefit provided by managed watersheds at the Hubbard Brook Experimental Forest over a 45-year period,using standardized measures of service capacity weighted by service importance weights derived from a survey of beneficiaries.Results：The capacity of watersheds to regulate water flow and quality was high in all watersheds throughout the study period,whereas cultural services such as scenic beauty declined after harvest.Impacts on greenhouse gas regulation depended on the efficiency with which harvested biomass was used.Surveys revealed that stakeholders placed high value on all ecosystem services,with regulating and cultural services seen as more important than provisioning services.When service metrics were weighted by survey responses and aggregated into a single measure,total service provision followed the same overall trend as greenhouse gas regulation.Where biomass use was less efficient in terms of greenhouse gas emissions,harvesting resulted in an overall ＂ecosystem service debt＂;where use was more efficient,this ＂ecosystem service debt＂ was reduced.Beneficiaries＇ educational backgrounds significantly affected overall assessment of service provision.Beneficiaries with college or university degrees incurred smaller ＂ecosystem service debts＂ and were less negatively affected by harvesting overall.Conclusions：This study highlights the importance of including empirical measures of beneficiary preference when attempting to quantify overall provision of ecosystem services to human beneficiaries over time.

Non-Algorithmically Integrating Land Use Type with Spatial Interpolation of Surface Soil Nutrients in an Urbanizing Watershed

Integrating land use type and other geographic information within spatial interpolation has been proposed as a solution to improve the performance and accuracy of soil nutrient mapping at the regional scale. This study developed a non-algorithm approach, i.e., applying inverse distance weighting （IDW） and ordinary kriging （OK）, to individual land use types rather than to the whole watershed, to determine if this improved the performance in mapping soil total C （TC）, total N （TN）, and total P （TP） in a 200-km2 urbanizing watershed in Southeast China. Four land use types were identified by visual interpretation as forest land, agricultural land, green land, and urban land. One hundred and fifty soil samples （0-10 cm） were taken according to land use type and patch size. Results showed that the non-algorithm approach, interpolation based on individual land use types, substantially improved the performance of IDW and OK for mapping TC, TN, and TP in the watershed. Root mean square errors were reduced by 3.9% for TC, 10.770 for TN, and 25.9% for TP by the application of IDW, while the improvements by OK were slightly lower as 0.9% for TC, 7.7% for TN, and 18.1% for TP. Interpolations based on individual land use types visually improved depiction of spatial patterns for TC, TN, and TP in the watershed relative to interpolations by the whole watershed. Substantial improvements might be expected with denser sampling points. We suggest that this non-algorithm approach might provide an alternative to algorithm-based approaches to depict watershed-scale nutrient patterns.

Nitrogen regulation by natural systems in“unnatural”landscapes:denitrification in ultra-urban coastal ecosystems

Dense cities represent biogeochemical hot spots along the shoreline,concentrating fixed nitrogen that is subsequently discharged into adjacent coastal receiving waters.Thus,the ecosystem services provided by natural systems in highly urban environments can play a particularly important role in the global nitrogen cycle.In this paper,we review the recent literature on nitrogen regulation by temperate coastal ecosystems,with a focus on how the distinct physical and biogeochemical features of the urban landscape can affect the provision of this ecosystem service.We use Jamaica Bay,an ultra-urbanized coastal lagoon in the United States of America,as a demonstrative case study.Based on simple areal and tidal-based calculations,the natural systems of Jamaica Bay remove~24%of the reactive nitrogen discharged by wastewater treatment plants.However,this estimate does not represent the dynamic nature of urban nitrogen cycling represented in the recent literature and highlights key research needs and opportunities.Our review reveals that ecosystem-facilitated denitrification may be significant in even the most densely urbanized coastal landscapes,but critical uncertainties currently limit incorporation of this ecosystem service in environmental management.