Forest browning trends in response to drought in a highly threatened mediterranean landscape of South America

• Autores: Miranda, Alejandro; Lara, Antonio; Altamirano, Adison; Di Bella, Carlos Marcelo; González, Mauro E.; Camarero, Jesus Julio
• Año de publicación: 2020
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: Ecological Indicators 115 : 10640 (August 2020)
• Materia: Cambio Climático; Sequía; Bosques; Resiliencia; Teledetección; América del Sur; Climate Change; Drought; Forests; Resilience; Remote Sensing; South America
• Institución: Instituto Nacional de Tecnología Agropecuaria

Deforestation is widely studied throughout the world. However, a less evident issue is the effect of climate change and drought on remnants of native forests. The objective of this work was to understand the geographic variations in resistance to drought of the Mediterranean sclerophyllous forests of central Chile. These forests have been historically reduced and fragmented and in recent years were subjected to the most prolonged drought occurred between 2010 and 2017. Using data from the MODIS satellite sensor, temporal trends in the NDVI (Normalized Difference Vegetation Index) were quantified. We related these trends with different environmental variables to understand the effects of geographical variation and forest type as indicators of resistance to drought. We observed a significant direct effect of drought, attributable to the reduced precipitation in central Chile, and a significantly reduced NDVI in near one-third of the region forests (browning). However, NDVI and therefore forest productivity were more stable in some mesic sites such as ravine bottoms, but not on south-facing slopes. This suggests that under a regime of reduced precipitations, a greater available soil humidity would be a more important factor than the fact of receiving less solar radiation. Finally, the highest degree of browning was observed in semi-arid sclerophyllous forest dominated by species tolerant to drought. Our findings emphasize the need to consider topographic site conditions to adequately assess forest productivity and vulnerability where local wet conditions could provide drought refuges. This recent drought may be analogous to forecasted warmer and drier climate conditions with more frequent and severe droughts, so our results may serve as a general framework for climate-smart decisions in highly threatened forest restoration and conservation.
Instituto de Clima y Agua
Fil: Miranda, Alejandro. Universidad de La Frontera. Departamento de Ciencias Forestales. Laboratorio de Ecología del Paisaje y Conservación; Chile. Universidad Austral de Chile. Facultad de Ciencias Forestales y Recursos Naturales. Escuela de Graduados; Chile. Universidad de Chile. Center for Climate and Resilience Research; Chile
Fil: Lara, Antonio. Universidad de Chile. Center for Climate and Resilience Research; Chile. Universidad Austral de Chile. Facultad de Ciencias Forestales y Recursos Naturales. Instituto de Conservación, Biodiversidad y Territorio; Chile
Fil: Altamirano, Adison Universidad de La Frontera. Departamento de Ciencias Forestales. Laboratorio de Ecología del Paisaje y Conservación; Chile. Universidad de La Frontera. Facultad de Ciencias Agropecuarias y Forestales. Butamallin Research Center for Global Change; Chile
Fil: Di Bella, Carlos Marcelo. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Clima y Agua; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Métodos Cuantitativos y Sistemas de Información; Argentina
Fil: González, Mauro E. Universidad de Chile. Center for Climate and Resilience Research; Chile. Universidad Austral de Chile. Facultad de Ciencias Forestales y Recursos Naturales. Instituto de Conservación, Biodiversidad y Territorio; Chile
Fil: Camarero, Jesus Julio. CSIC. Instituto Pirenaico de Ecología; España