Increasing synergistic effects of habitat destruction and hunting on mammals over three decades in the Gran Chaco

ROMERO-MUÑOZ, ALFREDO; BENÍTEZ-LÓPEZ, ANA; ZURELL, DAMARIS; BAUMANN, MATTHIAS; CAMINO, MICAELA; DECARRE, JULIETA; CASTILLO, HUGO; GIORDANO, ANTHONY J.; GÓMEZ?VALENCIA, BIBIANA; LEVERS, CHRISTIAN; NOSS, ANDREW J.; QUIROGA, VERÓNICA; THOMPSON, J. JEFFREY; TORRES, RICARDO; VELILLA, MARIANELA; WEILER, ANDREA; KUEMMERLE, TOBIAS

ECOGRAPHY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2020

0906-7590

Habitat destruction and overexploitation are the main threats tobiodiversity and where they co-occur, their combined impact is oftenlarger than their individual one. Yet, detailed knowledge of the spatialfootprints of these threats is lacking, including where they overlap andhow they change over time. These knowledge gaps are real barriers foreffective conservation planning. Here, we develop a novel approach toreconstruct the individual and combined footprints of both threats overtime. We combine satellite-based land-cover change maps, habitatsuitability models, and hunting pressure models to demonstrate ourapproach for the community of larger mammals (48 species >1 kg)across the 1.1 million km² Gran Chaco region, a global deforestationhotspot covering parts of Argentina, Bolivia, and Paraguay. This providesthree key insights. First, we find that the footprints of habitat destructionand hunting pressure expanded considerably between 1985 and 2015,across ~40% of the entire Chaco ? twice the area affected bydeforestation. Second, both threats increasingly acted together withinthe ranges of larger mammals in the Chaco (17% increase on average,±20% SD, cumulative increase of co-occurring threats across 465,000km2), suggesting large synergistic effects. Conversely, core areas ofhigh-quality habitats declined on average by 38%. Third, we identifiedremaining priority areas for conservation in the northern and centralChaco, many of which are outside the protected area network. We alsoidentify hotspots of high threat impacts in central Paraguay and northernArgentina, providing a spatial template for threat-specific conservationaction. Overall, our findings suggest increasing synergistic effectsbetween habitat destruction and hunting pressure in the Chaco, asituation likely common in many tropical deforestation frontiers. Ourwork highlights how threats can be traced in space and time tounderstand their individual and combined impact, even in situationswhere data are sparse