Toward Ecologically Scaled Landscape Indices

Abstract

Nature conservation is increasingly based on a landscape approach rather than a species approach. Landscape planning that includes nature conservation goals requires integrated ecological tools. However, species differ widely in their response to landscape change. We propose a framework of ecologically scaled landscape indices that takes into account this variation. Our approach is based on a combination of field studies of spatially structured populations (metapopulations) and model simulations in artificial landscapes. From these, we seek generalities in the relationship among species features, landscape indices, and metapopulation viability. The concept of ecological species profiles is used to group species according to characteristics that are important in metapopulations' response to landscape change: individual area requirements as the dominant characteristic of extinction risk in landscape patches and dispersal distance as the main determinant of the ability to colonize patches. The ecological profiles and landscape indices are then integrated into two ecologically scaled landscape indices (ESLI): average patch carrying capacity and average patch connectivity. The field data show that the fraction of occupied habitat patches is correlated with the two ESLI. To put the ESLI into a perspective of metapopulation persistence, we determine the viability for six ecological profiles at different degrees of habitat fragmentation using a metapopulation model and computer-generated landscapes. The model results show that the fraction of occupied patches is a good indicator for metapopulation viability. We discuss how ecological profiles, ESLI, and the viability threshold can be applied for landscape planning and design in nature conservation.

Connectivity in urbanizing landscapes: The importance of habitat configuration, urban area size, and dispersal

“…Connectivity metrics that include some form of dispersal behavior and/or dispersal distance show the strongest relationship to ecological measures (Moilanen and Nieminen 2002) and CONNECT fulfills this criteria. Other metrics with strong relationships to ecological measures include buffer-based measures (e.g., incorporating territory size) (Moilanen and Nieminen 2002), incidence function models (Moilanen and Hanski 2001;Vos et al 2001;Moilanen and Nieminen 2002), and percolation models (Gardner et al 1989;With et al 1999;King and With 2002). I investigated changes in connectivity at several dispersal distances, 500, 1,000, 2,000, and 5,000 m. CONNECT essentially measures the percentage of all habitat patches reachable in one dispersal step from each habitat patch by calculating all possible connections between patches given a distance less than or equal to the dispersal distance measured.…”

Borders without barriers – Structural functionality and green infrastructure in the Austrian–Hungarian transboundary region of Lake Neusiedl

“…Bierwagen, 2007;Moser et al, 2002;Pascual-Hortal and Saura, 2008;Torras et al, 2009;Vos et al, 2001). Especially in cultural landscapes it is essential to evaluate the qualitative state of remnant (semi)-natural areas along with the prevailing agrarian matrix in order to outline the major structural driving forces behind ecofunctional issues like the support of local/regional biodiversity (Walz, 2011).…”

Length-based connectivity metrics and their ecological interpretation

“…However, if one calculates enough of these metrics it may be possible to observe some empirical correlations between geometric attributes of habitats and field data on the presence of species (Vos et al, 2001). A number of authors have advocated the use of metrics that reveal underlying ecosystem processes, rather than just landscape patterns (Kupfer, 2012;Moilanen and Hanski, 2001;White et al, 2014;Vos et al, 2001).…”