Agricultural production and bird conservation in complex landscapes of the dry Chaco

MACCHI, L; GRAU, HR; PHALAN, B

Journal of Land Use Science

Taylor & Francis

Año: 2016

The South American dry Chaco is a mosaic of woody vegetation and grasslands withhigh deforestation rates in recent decades. Considering forests and grasslands as themain natural habitats, we assessed the trade-offs between bird populations and agriculturalproduction to compare the potential consequences of different land usestrategies (?sharing?, ?sparing?, and intermediate) for populations of bird speciessensitive to agriculture, while attaining a regional production target. We evaluatedhow populations responded to scenarios with different proportions of forest and grasslands,considering three reference states (100% forest, 80:20% and 50:50% forest andgrasslands, respectively); and scenarios capable of meeting three after-farming scenarios,with land destined to reach a regional production target with three variations offorest:grasslands within spared land. We fitted curves to relate bird abundance toagricultural yield along a gradient of meat production intensity; and we classifiedbird species as ?losers? (if their populations were lower than the baseline population inthe reference state, at any level of production) and ?winners? (if their current populationswere higher than the baseline population). At the ?current? (c. 2010) level ofregional agricultural production, we found a similar number of loser species maximizedby land-sparing and land-sharing strategies; while intermediate strategies werethe least favourable to balance production and bird populations. Under the mostprobable scenarios of increases in regional meat production, most loser bird speciespopulations were maximized by a land-sparing strategy, suggesting that if meatproduction targets are going to increase in the region, this can be more efficientlyachieved by combining well-protected forests and grasslands, and high-yieldingmechanized agriculture (e.g. soybean). Our results highlight the importance of assessingall the important natural habitats (e.g. forests