The decreasing range between dry- and wet- season precipitation over land and its effect on vegetation primary productivity.
Public Library of Science
Copyright: © 2017 Murray-Tortarolo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
One consequence of climate change is the alteration of global water fluxes, both in amount and seasonality. As a result, the seasonal difference between dry- (p < 100 mm/month) and wet-season (p > 100 mm/month) precipitation (p) has increased over land during recent decades (1980-2005). However, our analysis expanding to a 60-year period (1950-2009) showed the opposite trend. This is, dry-season precipitation increased steadily, while wet-season precipitation remained constant, leading to reduced seasonality at a global scale. The decrease in seasonality was not due to a change in dry-season length, but in precipitation rate; thus, the dry season is on average becoming wetter without changes in length. Regionally, wet- and dry-season precipitations are of opposite sign, causing a decrease in the seasonal variation of the precipitation over 62% of the terrestrial ecosystems. Furthermore, we found a high correlation (r = 0.62) between the change in dry-season precipitation and the trend in modelled net primary productivity (NPP), which is explained based on different ecological mechanisms. This trend is not found with wet-season precipitation (r = 0.04), These results build on the argument that seasonal water availability has changed over the course of the last six decades and that the dry-season precipitation is a key driver of vegetation productivity at the global scale.
This work was supported by the Dirección General de Asuntos del Personal Académico, Universidad Nacional Autónoma de México, and Consejo Nacional de Ciencia y Tecnología to Dr. Guillermo N. Murray-Tortarolo. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
This is the author accepted manuscript. The final version is available from Public Library of Science via the DOI in this record.
Vol. 12 (12), pp. e0190304 -
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