Agricultural intensification has a notable impact on biodiversity. Habitat loss and subsequent loss of connectivity can alter wildlife populations’ viability. Species in agriculture-dominated landscapes often use narrow linear features, such as hedgerows and vegetated ditches, as corridors to get from one habitat patch to another. However, the understanding of the use of these woody linear features (WLF) by wildlife is limited and could be improved by including structural data, such as canopy and strata characteristics. These data are often acquired in the field but high resolution remote sensing can provide unbiased, detailed and repeatable datasets. The aim of this study is to assess the usefulness of remote sensing data to model WLF occupancy by medium and large mammals in an agriculture-dominated landscape in southern Québec, Canada. Twenty-three WLF were selected and characterized. Wildlife frequentation of each WLF was measured using camera traps during nine weeks. Each WLF was also surveyed using two remote sensing technologies, LiDAR and multispectral imagery. Metrics and vegetation indices with strong ecological significance were derived from this imagery. The general hypothesis of this study is that frequentation of the WLF will differ depending on their structure (e.g. tree height) and their spatial organization (e.g. connectivity).
Results/Conclusions
We obtained 431 mammal detections amongst all WLF. From this, seven species were recorded, all of them opportunistic and well adapted to agricultural environment. The white-tailed deer (Odocoileus virginianus) represented more than half of the detections (n=225). A principal component analysis (PCA) showed the importance of several variables to explain the variability in the WLF's occupancy, such as the WLF's width and the Normalized difference vegetation index. Combined with a variance inflation factor analysis, the PCA identified the variables of interest for the model selection. Preliminary analyses showed that the abundance and diversity of mammals may differ significantly between the WLF. They also revealed that the herbaceous cover could have a significant negative impact on the number of detection, suggesting that wildlife avoid WLF with a dense herbaceous stratum.
Very few studies tried to link the structure characteristics of the vegetation to the species distribution, even less in agricultural landscapes and for the mammal taxa. Therefore, this study will contribute to a better understanding of wildlife response towards structural features in intensive agriculture landscapes and will provide insights for efficient management in this kind of environment.