The decreasing range between dry- and wet- season precipitation over land and its effect on vegetation primary productivity

PLoS One. 2017 Dec 28;12(12):e0190304. doi: 10.1371/journal.pone.0190304. eCollection 2017.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ecosystem*
  • Plant Development*
  • Rain*
  • Seasons*

Grants and funding

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.