Vegetation productivity under climate change depends on landscape complexity in tropical drylands: Fid-Bau Portal

Vegetation productivity under climate change depends on landscape complexity in tropical drylands

de Araujo, Helder F. P. / Machado, Célia C. C. / Alves, Ana Carolina Flores / da Costa Lima, Mônica / da Silva, José Maria Cardoso

Abstract

Abstract Models suggest that extreme drought events induced by climate change can reduce the vegetation productivity of drylands and negatively influence millions of people living in these areas. However, the complexity of landscapes can moderate how much such events impact their vegetation productivity. Accordingly, more complex landscapes are expected to be less likely to experience drought-induced vegetation productivity loss than less complex landscapes. Understanding the relationship between loss of vegetation productivity and the landscape complexity during drought events is fundamental to designing sound adaptation policies and practices for dryland societies. We evaluated the effects of variation in annual precipitation and complexity on the vegetation productivity of 33 landscapes in the Caatinga, the largest region of tropical dry forests in South America, before, during, and after one of the region’s worst drought events the past 30 years. We combined field measurements, satellite images, and modeling to quantify the vegetation productivity and landscape complexity. In general, our results show that the vegetation productivity of more complex landscapes was always higher than in less complex landscapes throughout the study period. However, the difference in vegetation productivity between landscapes with different complexities was more pronounced during the drought years. In addition, we found that the landscape complexity positively influenced vegetation productivity in all years, but that precipitation had no effect on vegetation productivity during the driest and wettest years. Our results indicate that maintaining more complex landscapes is the best adaptive strategy to guarantee drylands vegetation productivity during extreme climatic events.