Integrating ecosystem-service tradeoffs into land-use decisions.

Recent high-profile efforts have called for integrating ecosystem-service values into important societal decisions, but there are few demonstrations of this approach in practice. We quantified ecosystem-service values to help the largest private landowner in Hawaii, Kamehameha Schools, design a land-use development plan that balances multiple private and public values on its North Shore land holdings (Island of O'ahu) of ∼10,600 ha. We used the InVEST software tool to evaluate the environmental and financial implications of seven planning scenarios encompassing contrasting land-use combinations including biofuel feedstocks, food crops, forestry, livestock, and residential development. All scenarios had positive financial return relative to the status quo of negative return. However, tradeoffs existed between carbon storage and water quality as well as between environmental improvement and financial return. Based on this analysis and community input, Kamehameha Schools is implementing a plan to support diversified agriculture and forestry. This plan generates a positive financial return ($10.9 million) and improved carbon storage (0.5% increase relative to status quo) with negative relative effects on water quality (15.4% increase in potential nitrogen export relative to status quo). The effects on water quality could be mitigated partially (reduced to a 4.9% increase in potential nitrogen export) by establishing vegetation buffers on agricultural fields. This plan contributes to policy goals for climate change mitigation, food security, and diversifying rural economic opportunities. More broadly, our approach illustrates how information can help guide local land-use decisions that involve tradeoffs between private and public interests.

Projecting global land-use change and its effect on ecosystem service provision and biodiversity with simple models.

BACKGROUND: As the global human population grows and its consumption patterns change, additional land will be needed for living space and agricultural production. A critical question facing global society is how to meet growing human demands for living space, food, fuel, and other materials while sustaining ecosystem services and biodiversity [1]. METHODOLOGY/PRINCIPAL FINDINGS: We spatially allocate two scenarios of 2000 to 2015 global areal change in urban land and cropland at the grid cell-level and measure the impact of this change on the provision of ecosystem services and biodiversity. The models and techniques used to spatially allocate land-use/land-cover (LULC) change and evaluate its impact on ecosystems are relatively simple and transparent [2]. The difference in the magnitude and pattern of cropland expansion across the two scenarios engenders different tradeoffs among crop production, provision of species habitat, and other important ecosystem services such as biomass carbon storage. For example, in one scenario, 5.2 grams of carbon stored in biomass is released for every additional calorie of crop produced across the globe; under the other scenario this tradeoff rate is 13.7. By comparing scenarios and their impacts we can begin to identify the global pattern of cropland and irrigation development that is significant enough to meet future food needs but has less of an impact on ecosystem service and habitat provision. CONCLUSIONS/SIGNIFICANCE: Urban area and croplands will expand in the future to meet human needs for living space, livelihoods, and food. In order to jointly provide desired levels of urban land, food production, and ecosystem service and species habitat provision the global society will have to become much more strategic in its allocation of intensively managed land uses. Here we illustrate a method for quickly and transparently evaluating the performance of potential global futures.

[Ecosystem service valuation of Ertan Reservoir watershed in mitigating reservoir sand sedimentation].

By using software ArcGIS 9.2, an evaluation model was established to simulate the ecosystem service of Ertan Reservoir watershed in mitigating the sand sedimentation in the reservoir. In the meantime, sediment delivery ratio and universal soil loss equation were used to simulate the spatial patterns of the annual sediment yield and sediment retention in the watershed as well as the value during the service life period. In 2000, the total quantity of soil retention in the watershed was 12. 1 x 10(8) t x a(-1). The region with higher soil retention was near the main and branch streams of Yalong River, and that with higher sediment delivery ratio was near the streams and the Ertan Reservoir. The region with higher sediment yield and sediment retention was around the reservoir. The actual sediment yield in the study area was 629.3 x 10(4) t x a(-1), occupying 12.7% of the actual soil erosion volume. Farmland was the most important source of sediment yield, with its sediment yield occupying 62.9% of the total. The contribution of forestland to the mitigation of reservoir sand sedimentation was higher than that of the other lands on a per unit area basis. For the reservoir's designed operating life (100 a), the total value of the watershed in the service of mitigating Ertan Reservoir sand sedimentation was 2.75 billion yuan.