Agroclimatology in grasslands

Agroclimatology in grasslands

Grasslands occupy nearly half the world’s ice-free land and provide forage for livestock and native herbivores on almost one-third of the world’s ice-free land. They are generally located in drier regions (arid and semiarid) with large diurnal temperature variations and high interannual rainfall variability. Rainfall is a key driver of pasture and livestock production, and managing drought is a common and challenging experience for pastoral managers. Here we examine the agroclimatic association of the worlds grasslands, looking specifically at grasslands in Australia, South America (Uruguay), and South Africa as examples of important grassland communities. These grazing regions are all affected by more than one climate driver, and the influence of the different drivers on rainfall varies geographically across the world. These climate drivers operate on scales from seasonal to interdecadal, but understanding of the El Niño–Southern Oscillation (ENSO ) has provided the most widespread application of climate science into pastoral decision-making. Although ENSO is the most predictable climate driver, the reliability is limited to the austral spring and summer periods in years with strong ENSO anomalies, and even so, the reliability is moderate at best. Nonetheless, information on current conditions and seasonal forecasts have been generated and disseminated on national scales for decades (Australia late 1980s, Uruguay 1997, and South Africa early 1990s) but the uptake by agricultural decision-makers has been modest (one in three in Australia), and use by governments has largely been limited to crisis management during droughts. There has been little evidence and motivation by governments to manage the hydrological and hydro-illogical cycles by preparing pastoralists for drought by implementing strong policy platforms around early warning, preparedness, and national alerts. Despite the modest uptake of seasonal forecasts, there is evidence that their use in decision-making can increase productivity, profitability, and resource sustainability of pastoral enterprises in some parts of the world. These modest adoption rates have been attributed to poor presentation, lack of understanding of terminology, failure to show value and match forecast scale with decision-making at the value chain level, short lead times, poor reliability, and inappropriate dissemination methods. There is evidence of higher adoption rates at the regional scale where a combination of the following arrangements are most likely to contribute to more widespread use of climate forecasts in the future: (i) strong integration and support from institutions that generate and disseminate forecasts, (ii) information is customized for the region and industry, (iii) trust is built between the institutions and decision-makers, (iv) regional climate champions provide support and training in understanding and use of forecasts, and (v) institutions provide a climate service that delivers climate literacy and regionally relevant decision- and discussion-support tools. Incorporating climate science into climate-integrated agricultural models, decision support tools, training, and education and extension packages has made a valuable contribution to agricultural decision-making for governments, institutions, businesses, and pastoralists, but greater understanding is required to improve application and adoption for beneficial outcomes in both developing and developed world grassland communities.

Published online: 24 January 2020. Copyright © 2019 by American Society of Agronomy.