Relative Importance of the Area and Shape of Patches to the Diversity of Multiple Taxa

Abstract

Although enhancing reserve shape has been suggested as an alternative to enlarging nature reserves, the importance of reserve shape relative to reserve area remains unclear. Here we examined the relative importance of area and shape of forest patches to species richness, species composition, and species abundance (abundance of each species) for 3 taxa (33 birds, 41 butterflies, and 91 forest-floor plants) in a fragmented landscape in central Hokkaido, northern Japan. We grouped the species according to their potential edge responses (interior-, neutral-, and edge-species groups for birds and forest-floor plants, woodland- and open-land-species groups for butterflies) and analyzed them separately. We used a shape index that was independent of area as an index of shape circularization. Hierarchical partitioning and variation partitioning revealed that patch area was generally more important than patch shape for species richness and species composition of birds and butterflies. For forest-floor plants, effects of patch area and shape were small, whereas effects of local forest structure were large. Patch area and circularization generally increased abundances of interior species of birds and forest-floor plants and woodland species of butterflies. Nevertheless, only patch circularization increased abundances of 1 woodland species of butterfly and 2 and 6 interior species of birds and forest-floor plants, respectively. We did not find any significant interaction effects between patch area and shape. Our results suggest that although reserves generally should be large and circular, there is a trade-off between patch area and shape, which should be taken into consideration when managing reserves.

Towards the use of ecological heterogeneity to design reserve networks: a case study from Dadia National Park, Greece

“…Bohning-Gaese 1997;Farina 1997;Grand and Cushman 2003;Kati and Sekercioglu 2006;Kati et al 2009). Shape irregularity is found to be positively associated with bird abundance across different habitats and spatial scales, but also negatively associated with the winter bird species abundance in deciduous forests, as well as with the species richness of boreal forest species (Brennan and Schnell 2005;Yamaura et al 2008;Caprio et al 2009). We also found that the vertical structural complexity, and patch shape irregularity affected the species richness of woody plants.…”

Effect of management and spatial characteristics on plant species richness of Castanea sativa Mill. woodlots in the NW Iberian Peninsula

“…over plant species richness, although results are not always conclusive. Along the same line, numerous authors have also shown the importance of taking into account the effect of patch shape over species richness (Dzwonko and Loster 1992;Bastin and Thomas 1999;Hill and Curran 2003;Petit et al 2004;Heegaard et al 2007;Cousins and Aggemyr 2008;Yamaura et al 2008).…”

All natural habitat edges matter equally for endangered Maculinea butterflies

“…There have been numerous general analyses of edge effects on patterns of species richness and diversity (e.g. Yahner 1988;Kiviniemi and Eriksson 2002;Yamaura et al 2008;van Halder et al 2011), but studies documenting avoidance or preference of habitat edges by particular species of conservation interest, the results of which could be used in conservation practice, have been less popular (see reviews in Fahrig 2003;Ries et al 2004). Furthermore, species-specific studies of edge use have been predominantly conducted in vertebrates, especially mammals and birds, and considerably less abundant in other taxa (Ries et al 2004;Fletcher et al 2007).…”