DOI: 10.5061/dryad.600vs50
title: Data from: Testing the benefits of conservation set-asides for improved habitat connectivity in tropical agricultural landscapes

description: 1. Habitat connectivity is important for tropical biodiversity
 conservation. Expansion of commodity crops, such as oil palm, fragments
 natural habitat areas, and strategies are needed to improve habitat
 connectivity in agricultural landscapes. The Roundtable on Sustainable
 Palm Oil (RSPO) voluntary certification system requires that growers
 identify and conserve forest patches identified as High Conservation Value
 Areas (HCVAs) before oil palm plantations can be certified as sustainable.
 We assessed the potential benefits of these conservation set-asides for
 forest connectivity. 2. We mapped HCVAs and quantified their forest cover
 in 2015. To assess their contribution to forest connectivity, we modelled
 range expansion of forest-dependent populations with five dispersal
 abilities spanning those representative of poor dispersers (e.g.,
 flightless insects) to more mobile species (e.g., large birds or bats)
 across 70 plantation landscapes in Borneo. 3. Because only 21% of HCVA
 area was forested in 2015, these conservation set-asides currently provide
 few connectivity benefits. Compared to a scenario where HCVAs contain no
 forest (i.e., a no-RSPO scenario), current HCVAs improved connectivity by
 ~3% across all dispersal abilities. However, if HCVAs were fully
 reforested, then overall landscape connectivity could improve by ~16%.
 Reforestation of HCVAs had the greatest benefit for poor to intermediate
 dispersers (0.5-3 km per generation), generating landscapes that were up
 to 2.7 times better connected than landscapes without HCVAs. By contrast,
 connectivity benefits of HCVAs were low for highly mobile populations
 under current and reforestation scenarios, because range expansion of
 these populations was generally successful regardless of the amount of
 forest cover. 4.Synthesis and applications. The RSPO requires that HCVAs
 be set aside to conserve biodiversity, but HCVAs currently provide few
 connectivity benefits because they contain relatively little forest.
 However, reforested HCVAs have the potential to improve landscape
 connectivity for some forest species (e.g., winged insects), and we
 recommend active management by plantation companies to improve forest
 quality of degraded HCVAs (e.g., by enrichment planting). Future revisions
 to the RSPO’s Principles and Criteria (P&C) should also ensure
 that large (i.e., with a core area &gt;2 km2) HCVAs are reconnected to
 continuous tracts of forest to maximise their connectivity benefits.
description: Data and R code for
 running IFM simulationsZip folder containing
 raw data and R code for running Incidence Function Model (IFM)
 simulations. The 'LoopedIFM_SetupScript.R' script runs the IFM
 simulations in a loop for the 70 New Planting Procedure (NPP) plantation
 landscapes. Model parameters (e.g., dispersal distance and population
 density) can be changed in this script. The set-up script also loads the
 raw data (raster) files ('FinalRaster70NPPsBuffer.tif' and
 'FinalRaster70NPPsCurrentBuffer.tif'), which are converted into
 a dataframe before the IFM simulations are run. The set-up script calls
 three functions: the 'IFM2_Function.R' script, which is the IFM
 simulation code, as well as two 'Cardinal Points function'
 scripts ('CardinalPoints_WithHCVFunctionParallel.R' and
 'CardinalPoints_WithNoHCVFunctionParallel.R'), which set up the
 modeled landscapes over which to run the simulations. Finally, the
 'NPP70Centroids.csv' file is required to run the loop and
 provides NPP plantation IDs and X/Y coordinates of each plantation
 centroid.Connectivity_simulations.zipData and R code for logistic regression analysesZip folder containing data and R code for running the logistic regression analyses. The 'LogisticRegression_FinalScript.R' script contains R code for the General Additive Models (GAMs) and the Generalized Linear Mixed Models that were used to analyse the Incidence Function Model (IFM) simulation results. The summarised IFM simulation outputs used in the statistical analyses are contained within the 'SuccessGLMDataNew.csv' file. Definitions of column headings within this file are provided in the R script.Logistic_regression.zipHCVA and NPP plantation summary dataZip folder containing three Excel spreadsheets with summary information for the 70 New Planting Procedure (NPP) plantations and associated High Conservation Value Areas (HCVAs) used in our study. The 'SummaryData_ForHistograms.xlsx' file contains the data used for Fig. 3 in the main text, and includes the area and forest cover of HCVAs within each NPP plantation. It also includes the size of each NPP plantation estate and the area of non-HCVA forest cover within each NPP plantation. The 'SummaryData_HCVAPatchSize.xlsx' file contains the size of all spatially discrete HCVA patches within each NPP plantation and the 'SummaryData_HCVAType.xlsx' contains the size and forest cover of all spatially discrete HCVA patches within each NPP plantation that could be identified to Type (e.g., HCV 1-6). Descriptions of column headings are provided in the Excel files.HCVA_summary_data.zip