Ecotone conservation

An ecotonal species can be defined as one significantly more frequent in ecotones than in either of the adjacent communities and as having a wide habitat range (based on Lloyd et al., 2000). Baker et al. (2002), studying avian communities in SE Australia, described birds as ecotone neutral, ecotone shy, and ecotone conspicuous. They found no evidence, however, of entirely ‘ecotonal species’. Species need to be more than just conspicuous at the edge, they warned, to be ‘ecotonal’.

The real function of areas that are increasingly ecotonal needs to be carefully evaluated. Ecotones may be a source of evolutionary novelty according to a 1997 article in Science by Smith et al. One example of morphological divergence between forest-ecotone populations includes longer wing length (for aerodynamic efficiency in an open area) in greenbuls in an ecotone. The conservation of ecotones would safeguard their role in generating behavioral diversity, morphological divergence, and ultimately, biodiversity. However, ecotonal regions are often considered unimportant as they are mosaics of 'pure' habitat types (Smith et al., 2005 in Tropical Rainforests: Past, Present and Future). How does a conservationist decide that a landscape is overly homogenous (without ecotones) or overly heterogeneous (with ecotones)? By the presence and abundance of 'fluid ecotypes'?