资源环境科技发展态势分析平台

Extreme weather events represent a large risk to food production systems. In this study, we evaluated the impacts of the 2011-2012 drought in Mexico, the worst in the last 70years, on free-ranged livestock populations to link extreme weather events and production. We also considered the potential prevalence of recurring droughts under two contrasting future climate scenarios to examine what could happen over this century. Our results showed that cattle and goat stocks decreased about 3% in response to the drought countrywide. Regionally, the changes in cattle and goat populations generally mimicked the precipitation anomaly, with the strongest reductions across the driest areas in central and northern Mexico. Our work showed that the biophysical and management components of livestock production interact depending on the regions and the type of livestock, leading to a mosaic of spatial responses. It seems that the management of large herds limits the economic viability of drought crisis management options such as the importation of fodder and water, or by moving the animals to other pastures. Sheep herds were much less affected since more than 50% of the total sheep stock is raised in wetter states, which showed a relatively small (similar to-10%) precipitation anomaly during the drought. Under the severe climate change scenario, a greater frequency of extremely dry years (once every 3years) would have negative impacts on livestock production regionally. Climate change together with already existing trends in overgrazing and soil erosion could further increase the sensitivity of livestock production across the country.