DOI: 10.5061/dryad.k0p2ngf57
title: Chronic anthropogenic disturbance on Caatinga dry forest fragments

description: 1. Understanding how chronic anthropogenic disturbances are distributed in
 space leads to more effective conservation and management practices. This
 study provides a large-scale overview of how the Caatinga dry forest is
 potentially altered by chronic anthropogenic disturbance. In particular,
 we investigate how the intensity of the potential disturbance varies (i)
 among geographic regions, (ii) among fragment sizes, and (iii) as a
 function of distance to the fragment edge. 2. A Chronic Anthropogenic
 Disturbance Index (CDI) was derived to represent five anthropogenic
 disturbance vectors: human population, infrastructure, grazing, logging,
 and fire. CDI was spatialized for the whole Caatinga landscape (826 411
 km2) and posteriorly averaged for ca. 47 100 remaining fragments. 3.
 Chronic anthropogenic disturbance was unevenly distributed across the
 Caatinga landscape, with more conserved sites on the western and southern
 regions. Larger fragments were, on average, as disturbed as smaller ones.
 However, smaller fragments varied from highly disturbed to very well
 preserved depending on the regional context. Strong edge effects were
 recognized for the chronic anthropogenic disturbance index and its five
 vectors. 4. Policy implications. Although half of the original Caatinga
 vegetation remains, most remnant fragments potentially suffer from chronic
 anthropogenic disturbances. This suggests that a large portion of the
 Caatinga can be currently threatened, and its biodiversity and natural
 resources eroded by processes that are less evident than habitat loss.
 Proper management practices and expansion of the existing conservation
 area network are needed to halt the Caatinga biodiversity decline.
  
description: The Chronic Anthropogenic
 Disturbance Index (CDI) surface represent the potential disturbance effect
 of anthropogenic disturbance vectors: human population, infrastructure,
 grazing, logging, and fire (For detailed description of variables and your
 weights used in each vector see Table S1 - Supplementary Material of
 Antongiovanni et al. (2020).  The five anthropogenic
 disturbance vectors are:<br> Human population: was composed by human
 population density, distance to settlements, and distance to urban
 localities.<br> Infrastructure: was composed by distance to paved
 roads, distance to unpaved roads, distance to transposition channels,
 distance to wind turbines, distance to railroads, and distance to energy
 transmission lines.<br> Grazing: was composed by ovine density,
 caprine density and bovine density.<br> Logging: was composed by
 distance to charcoal-based industries.<br> Fire: was composed by
 fire density  All
 14 primary surfaces of disturbance (raster format) were expressed as
 distance or density and all disturbance variables surfaces were
 standardized by their maximum value (i.e., max = 100). The projection of
 the spatial data was Albers Equal Area Conic and the pixel size for all
 raster surfaces was 90 meters. All the spatial analyses were performed in
 ArcGis 10.1. The
 relative importance of each primary variable was defined by assigning it a
 relative weight (wi), varying from 0 to 1 see Table S1 - Supplementary
 Material of Antongiovanni et al. (2020). The CDI surface was calculated as
 the weighed sum of the 14 primary variables considering their relative
 importance, standardized by the maximal weighted sum recorded for in the
 landscape, including the anthropogenic matrix. Furthermore, in order to
 understand the spatial heterogeneity of different disturbance components,
 we also calculated the standardized weighted sum for the five disturbance
 vectors: human population, infrastructure, grazing, logging, and fire. The
 pixel values in these five surfaces were standardized according to the
 maximum value of each vector. 
description: All surfaces names are the
 same as described in the article and in supplementary material by
 Antongiovanni (2020) published in J. Apllied Ecology. The detailed
 description of the data source and the derivation of each vector and the
 CDI is also described in detail in the article and in the supplementary
 material by Antongiovanni (2020).