Assessment of Arctic Protected Areas to Represent Tundra Ecosystem Functional Diversity

Abstract:

Conservation priorities need to be based geographically not only on species composition or ecosystem structure, but also on the functional dimensions of biodiversity. In the arctic tundra, global change is causing rapid alterations in the functional characteristics of these ecosystems, and they therefore should be assessed for conservation from a functional perspective. The Arctic is also a region that has a relatively high degree of spatial variability in ecosystem functioning, resulting from differences in climate, geological history, and land-use. Our goal is to incorporate satellite-derived variables that describe ecosystem functioning into the establishment of geographic conservation priorities for the Arctic. In this study, we explored how the current protected area network represents the regional heterogeneity of ecosystem functioning. We used two approaches based on continuous and discrete characterizations of ecosystem functioning, derived from key attributes of the seasonal dynamics of the MODIS Normalized Difference Vegetation Index (NDVI), related to productivity and phenology. In the continuous approach, the characterization of ecosystem functioning was done with three Ecosystem Functional Attributes (EFAs), specifically the annual mean of NDVI, and the timing of growing season start and end. The discrete approach is based on the classification of Ecosystems Functional Types (EFTs) using categories of the EFAs. Unique EFTs are assumed to represent patches of the land surface that process energy and matter in similar ways and potentially show coordinated responses to environmental drivers. We identified the singularity and representativeness of protected areas, and we considered conservation gaps to be those ecosystems with functional behavior not yet protected. Our results show that most EFTs are well represented in the protected area network. However, some of the rarest EFTs (9 out of 45 possible) are protected in less than 17% of their extension (the minimum set by the Aichi Target 11).