Spatial conservation of water yield and sediment retention hydrological ecosystem services across Teshio watershed, northernmost of Japan

There is a growing call for spatial conservation prioritization of ecosystem services (ESs) models that is both simple and scientifically credible, in order to serve ecological and environmental decision-making processes. Pressure on ecosystems to provide various and conflicting services is immense and likely to increase. Despite increasing attention to the human dimension of conservation projects, a rigorously spatial conservation planning on balancing multiple ESs has not been developed. The impacts and success of spatial conservation planning will be enhanced if the needs of competing and compromising ESs are recognized. We developed such a framework integrating watershed model into spatial conservation prioritization model and illustrated it about competing and compromising ESs in the Teshio River watershed, with the aim of developing a spatial conservation priority ranking map that balances interactive relationships between water yield and sediment retention. The sediment retention was concentrated in southeastern and some northern areas with higher precipitation, more forest lands and steeper slope, but the water yield was concentrated in southwestern and some northern places with agricultural land. The spatial priority conservation ranking map of individual ES is closely related to its spatially distributed pattern. The spatial priority conservation areas for sediment retention in southwest are traded off against those for water yield in southeast, but there are some overlaps on spatial priority conservation areas for sediment retention and water yield in north of Teshio River watershed. There are obvious differences between the spatial priority conservation ranking maps of individual ESs and those of multiple services together. The spatial priority conservation areas for multiple ESs together simultaneously include southeastern, more eastern and some northern places of study watershed, which can balance the conflict existing between sediment retention and water yield. The proposed framework in this study could be applied to similarly structural conservation prioritization problems of other more ESs, which could sustain ecosystem conservation and economic development across watershed.