Multifunctionality and biodiversity: Ecosystem services in temperate rainforests of the Pacific Northwest, USA

Forests produce a myriad of ecosystem related benefits known as ecosystem services. Maximizing the provision of single goods may lead to the overexploitation of ecosystems that negatively affects biodiversity and causes ecosystem degradation. We analyzed the temperate rainforest region of the Pacific Northwest, which offers a multitude of ecosystem services and harbors unique biodiversity, to investigate linkages and trade-offs between ecosystem services and biodiversity. We mapped nine actual and potential ecosystem services, grouped into provision, supporting, regulating and cultural ecosystem service categories, as well as species richness of four taxonomic groups (mammals, birds, trees, and amphibians). We analyzed linkages and tradeoffs between ecosystem services, their overall diversity, and species richness as well as different levels of taxon diversity. We also tested if ecosystem service categories, in addition to climate and land cover parameters, could indicate species richness. We found significant positive linkages between ecosystem service diversity and species richness of all considered taxa. The provision of the majority of ecosystem services was higher in areas of high taxon diversity, indicating both positive relationships and slight trade-offs in maximizing single ecosystem services. In general, ecosystem service categories were a comparable indicator of species richness as climate. Our findings show that multifunctionality largely coincides with high levels of biodiversity within the study region. Hence, an integrative ecosystem management approach that incorporates ecosystem services and biodiversity concerns is needed to both provide diverse ecosystem benefits and conserve biological diversity.