Forum: Critical Decision Dates for Drought Management in Central and Northern Great Plains Rangelands

Ranchers and other land managers of central and northern Great Plains rangelands face recurrent droughts that negatively influence economic returns and environmental resources for ranching enterprises. Accurately estimating annual forage production and initiating drought decision-making actions proactively early in the growing season are both critical to minimize financial losses and degradation to rangeland soil and plant resources. Long-term forage production data sets from Alberta, Kansas, Montana, Nebraska, North Dakota, South Dakota, and Wyoming demonstrated that precipitation in April, May, and June (or some combination of these months) robustly predict annual forage production. Growth curves from clipping experiments and ecological site descriptions (ESDs) indicate that maximum monthly forage growth rates occur 1 mo after the best spring month (April to June) precipitation prediction variable. Key for rangeland managers is that the probability of receiving sufficient precipitation after 1 July to compensate for earlier spring precipitation deficits is extremely low. The complexity of human dimensions of drought decision-making necessitates that forage prediction tools account for uncertainty in matching animal demand to forage availability, and that continued advancements in remote sensing applications address both spatial and temporal relationships in forage production to inform critical decision dates for drought management in these rangeland ecosystems. (C) 2019 The Author(s). Published by Elsevier Inc. on behalf of The Society for Range Management.

Automated summary

Ranchers and land managers in the central and northern Great Plains are facing recurrent droughts, which negatively impact economic returns and environmental resources for ranching enterprises. Accurate estimation of annual forage production, particularly in the early growing season, is crucial to minimize financial losses and soil degradation. Data sets from various states show that precipitation in April, May, and June robustly predicts annual forage production, with low probability of sufficient precipitation after July 1 to compensate for earlier deficits. It is important for managers to consider uncertainty in matching animal demand to forage availability and utilize remote sensing applications for critical drought management decisions.