ABSTRACT
Landscapes: In art, they are paintings of places, usually from a distance, a mosaic of forms interwoven to portray a recognizable place familiar and pleasing to the eye. That is the function of the painting. Ecological landscapes also are a mosaic. They have structure, as portrayed by the pattern of the patches comprising the landscape. They have composition as portrayed by the types of patches on the landscape. And they have function, as defined by the resources of concern, in our case, patches of habitat for a species or collection of species. Forested landscapes as habitat for vertebrates are patterns of habitat patches distributed over forest-dominated areas, with each patch representing a set of resources used or needed by the species. Hence, the pattern of habitat patches across a landscape differs with species. We, as humans, tend to view forested landscapes as collections of forest stands, a mosaic of units of vegetation, each relatively uniform within itself. We do that because, to us, those stands represent different resources, such as economic value, places to hike, or different aesthetics. To some other vertebrates, stands also represent patches of different values, habitat values, which may not be the case with other species. Take the shrub-associated Hermit thrush, which is widely distributed across North America (Figure 11.1). What type of mosaic of patches would a Hermit thrush see? Their search image for a territory likely includes patches of shrubs and small trees with varying quality for foraging on insects in the leaf litter and foliage, as well as nest sites in the shrubs and small trees. The overstory vegetation seems to have little, if any, influence on what Hermit thrushes see as habitat patches except through the effect it has on shrub and small tree development.
