Multi-scale assessment of river-floodplains

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Riverine ecosystems are highly dynamic and heterogeneous ecosystems, due to both natural and anthropogenic forces. The heterogeneity of coastal riparian forests makes them among the most biodiverse of temperate forests, but also challenging to map over broad areas. A variety of ecologically important structures within coastal floodplain forests result in spatial patterns at different scales. Many of these patterns include textural, spatial and spectral properties which aid in their discrimination using high spatial resolution satellite imagery. The potential of fine-scale imagery (with sub-metre resolution) for use in riparian mapping is particularly compelling, as such areas have been challenging to discern using coarser imagery. The goal of this proposed research program is to rigorously quantify hierarchical patterns of natural and anthropogenic variability in river-floodplains using a suite of new remote sensing tools and ground-truth information. We emphasize the use, extension, and testing of techniques developed in our pilot site to new larger floodplains within Clayoquot Sound, with an emphasis on rare habitats of conservation concern and patterns of natural and anthropogenic disturbance. We will classify high spatial resolution imagery along three rivers in coastal British Columbia using state-of-the-art object-based classification software, as well as assess broad-scale variability using coarser-scale imagery and landscape pattern indices. Using this combination of tools to understand the variability within river-floodplains, at both fine and broad spatial scales, will help disentangle the anthropogenic and natural agents of change in river-floodplain ecosystems. As part of our long-term objectives, we also examine additional sites in Haida Gwaii and along the Skeena River, which include pristine areas as well as those modified by historic forest management. These same river systems will also be examined within an historical framework, by quantifying past variability using historic reconstruction and aerial photos. These different approaches will add a critical dimension to our understanding of some of the most biodiverse and heavily managed river-floodplain systems in BC.