The scale of effect depends on operational definition of forest cover—evidence from terrestrial mammals of the Brazilian savanna

Abstract

ContextThe underlying mechanisms determining the scale at which species interact with their environment are still poorly known.Objective We investigated the spatial extent at which landscape structure affects the occurrence of four species of terrestrial mammal herbivores in the Brazilian savannas and tested whether those scales could be explained by species ecological traits and habitat definition.Methods Using maps of forest cover, camera trapping and occupancy modelling, we determined the relations between three landscape metrics (percentage of forest cover, patch density and edge density) and the occurrence of four species. To determine the optimal scale of effect for each species, we computed landscape metrics at different spatial extents (from 0.5 to 10 km radius) from camera trap locations and for three forest maps, considering different definitions of what is a "forest" (minimum of tree cover of 25, 50 or 75% per pixel). ResultsThe occupancy models revealed scales of effect of 0.5 to 2 km, and those scales overlapped highly among species. However, the strength of the effect depends highly on how forest is defined, being stronger when forest was defined with greater tree cover, particularly for forest-dwelling species.Conclusions Besides biological traits, the way habitat is defined shapes our ability to detect scale of effects. Thus, if we want to properly identify scales of effect for multiple species, it is necessary not only to adopt a multi-scale approach, but also to use multiple definitions of habitat, considering particularities of how each species interact with their environment.

Orchid bees respond to landscape composition differently depending on the multiscale approach

“…Individuals and species within populations and communities can perceive and respond to the environment differently, resulting in different scales of effect (Boscolo and Metzger 2009;Miguet et al 2016;Amiot et al 2021). The scales of effect of landscape attributes on biological responses are generally unknown (Miguet et al 2016;Martin 2018).…”

“…The scales of effect of landscape attributes on biological responses are generally unknown (Miguet et al 2016;Martin 2018). The criteria of which spatial scales will be used are often based on the researcher's perception of the species features, such as dispersal distance and home range (Jackson and Fahrig 2012;Amiot et al 2021). However, studies have generally sub-optimized the accurate detection of the scale of effect because they use one or a few spatial scales or these scales are larger or smaller than the true scale of effect (Jackson and Fahrig 2015;Miguet et al 2016).…”

“…Multiscale approaches have been used to detect the scale of effect of landscape structure on biological attributes or ecological responses related to different taxonomic groups, such as terrestrial mammals (Lyra-Jorge et al 2010;Nagy-Reis et al 2017;Amiot et al 2021), primates (Nagy-Reis et al 2017Gestisch et al 2018), plants (Collevatti et al 2020 ), birds (Boscolo and Metzger et al 2009;Morante-Filho et al 2016) andinsects (Steffan-Dewenter 2002;Rossi & van Halder 2010;Franceschinelli et al 2017). Most of these studies were developed using a focal patch design (Brennan et al 2002;Miguet et al 2016), wherein the quantification of the landscape structure occurs in each of the landscapes nested in different sizes (e.g.…”

“…In the scope of this study, we defined that the coupled multiscale approach represents the local landscape composition, and the decoupled multiscale approach the regional landscape composition. Because landscape structure and ecological parameters have many interaction levels (Miguet et al 2016;Amiot et al 2021), we address several questions with the main hypotheses summarized in Fig. 1.…”

Bee responses to landscape composition on coupled and decoupled multiscale approaches

“…Multiscale approaches have been used to detect the scale of effect of landscape structure on biological attributes or ecological responses related to different taxonomic groups, such as terrestrial mammals (Lyra-Jorge et al 2010;Nagy-Reis et al 2017;Amiot et al 2021), primates (Nagy-Reis et al 2017;Gestisch et al 2018), plants (Collevatti et al 2020, birds (Boscolo and Metzger et al 2009;Morante-Filho et al 2016) and insects (Steffan-Dewenter 2002;Rossi & van Halder 2010;Franceschinelli et al 2017). Most of these studies were developed using a focal patch design (Brennan et al 2002;Miguet et al 2016), wherein the quantification of the landscape structure occurs in each of the landscapes nested in different sizes (e.g.…”