When drought hits, it’s not just soil moisture that changes—plants change too. However, no two plants are the same in how they deal with dry weather. Understanding the different ways forage species respond to drought conditions can help livestock producers make better grazing decisions, protect pasture productivity, and maintain long-term range health. 

Here are a few different ways plants respond to drought conditions: 

1. Growth Shutdown and Dormancy 

Some grasses respond to drought by essentially shutting down. Cool-season species like smooth bromegrass and Kentucky bluegrass often enter dormancy to conserve energy and moisture.^1,4 While they may look dead, these plants are still alive and capable of regrowth when conditions improve. With the growth stoppage because of drought, there is a reduction in replenishment of carbohydrates (energy) in the grass plants.  This will affect the growth and vigor of the grass plant the following year.  In many cases, the lack of seed production and maturity when early dormancy occurs can result in a higher quality of forage, although quantity is greatly reduced.  

What this means for producers: 

Once plants are fully dormant (no longer actively growing and able to regrow after grazing), grazing can be a strategic way to utilize remaining forage. Because dormant plants aren’t actively growing, grazing has minimal negative impacts—as long as a protective stubble height is maintained to shield crowns and buds. However, it’s important to ensure plants are truly dormant; grazing too early during slowdown can further weaken already stressed plants.  Management during the year following drought should consider the impact of lower energy reserves in the recovering plants. 

2. Early Maturity 

Other species—often warm-season grasses like prairie sandreed or sideoats grama—respond by speeding up their development, shifting energy toward reproduction rather than vegetative growth, which accelerates seed set and reduces forage quality.^1,3 This typically occurs when early moisture allows plants to grow but is followed by a dry spell.  When this happens, forage quality drops fast once seed heads form.  In contrast, when conditions start out dry and maintain a drought cycle, limited moisture more typically results in plants limiting all growth and going dormant (see above) before maturing. 

What this means for producers: 

Fast maturity reduces palatability and nutritional value. Keep an eye on growth stage progression and time grazing to capture these species before quality declines, especially in rotational systems. 

3. Nutrient Reallocation to Roots 

During drought, many perennials slow or stop aboveground growth and divert resources to roots or other underground storage structures sch as rhizomes or crowns. This survival response helps the plant ride out dry conditions and prepares it to regrow once moisture returns. J.E. Weaver’s early 20th century prairie studies at UNL showed how deep-rooted species like big bluestem prioritize root health during drought.^1,2,6 

What this means for producers: 

Grazing during this reallocation phase can compromise plant recovery by draining those stored reserves. Providing growing season recovery—especially following a drought period—supports root recovery and stand longevity. Adjustment of stocking rates to ensure plants already stressed by drought are also not overgrazed is an important first step to limit the damage done during drought. Additionally, adjusting the timing of grazing in pastures can help with maintaining desirable plant growth. For example, deferring pastures that were grazed heavier than expected in the year of the drought to later in the growing season of the following year provides opportunities for recovery.   

4. Short-term Increases in Annual Plants 

Perennial species that have been stressed by drought do not always produce as much surface cover through leaf growth, especially the year following a drought, as they recover. This reduction in competition and canopy cover creates a window of opportunity for opportunistic annual species to establish, often temporarily. Species such as sunflower, ragweed, and kochia respond well to low cover and infrequent precipitation events.⁵ As drought breaks or lessens as some precipitation events occur, large ‘booms’ of annual plants can quickly dominate the landscape. Often as range health improves post drought, native species are able to outcompete annual weeds, resulting in a decrease in those annual plants. 

What this means for producers: 

Annual species have much shorter windows of palatability, compared to the desirable perennial grasses they pop up around. Monitoring rangeland after heavy rainfall events during a drought period can be a good insight into understanding what plants are available for foraging. Rapid buildup and maturity of annual plants can feel alarming, but the build-up of annual species is often temporary.  They often provide a service by giving cover and forage a drought stressed pasture would otherwise lack. Good grazing management will allow perennial species to outcompete annuals and shift back without the need for dramatic weed control measures. 

5. Long-term Species Composition Shifts 

Over time, drought can change what species dominate a pasture. Observational studies and long-term monitoring in the Great Plains have shown that drought-hardy species like blue grama and buffalograss often increase in dominance, while moisture-sensitive grasses such as smooth brome, big bluestem, or indiangrass decline. This is especially true following repeated drought years^.2,3,4” 

What this means for producers: 

By frequently observing and taking note of what species are available in your pastures, you can be better able to see if your pasture composition is shifting. A move toward more drought- and/or grazing-adapted species may suggest that management needs to change.  Using a simple monitoring technique like photo point monitoring can help detect changes in species composition quickly and accurately. Management plans that worked before may need to evolve with your forage base. 

Managing with Drought in Mind 

Understanding how plants respond to drought allows for smarter grazing decisions. Consider these strategies during dry periods: 

• Develop and follow trigger dates to guide stocking and de-stocking decisions based on forage growth progress. 
• Lower stocking rates or adjust rotations when active growth slows or stops. 
• Be careful not to further stress drought impacted plants.  When fully dormant, grazing can have minimal impacts on stand vigor, but stubble height needs to be preserved 
• Delay grazing after rainfall to give plants time to recover and regrow. 
• Time rotations to catch peak forage quality, especially in fast-maturing species. 
• Track species composition over time to identify shifts that may require management changes. 
• Have a simple monitoring protocol in place to help detect changes in forage species. 

From early prairie science to modern grazing research, we’ve learned that plant resilience and adaptive grazing management go hand in hand. Recognizing what plants are doing during drought—and responding accordingly—can help producers protect their forage base and maintain herd performance through dry times. 

For tools, drought planning guides, and forage updates, visit https://beef.unl.edu.   

References 

1. Weaver, J.E. (1954). North American Prairie. University of Nebraska Press. 
   Chapter 4: “Root Habits as Related to Environment.” 
2. Weaver, J.E., & Albertson, F.W. (1936). Effects of drought, dust, and intensity of grazing on vegetation of a prairie region. Ecological Monographs, 6(1), 1–22. 
3. .  Volesky, J. (2021). Grazing and Forage Management During and After Drought. UNL BeefWatch. https://beef.unl.edu/beefwatch/2021/grazing-and-forage-management-during-and-after-drought/ 
4. Derner, J.D., Boutton, T.W., & Briske, D.D. (2006). Grazing and ecosystem carbon storage in the North American Great Plains. Plant and Soil, 280, 77–90. 
5. Peters, D.P.C., Yao, J., & Gosz, J.R. (2018). Changes in grassland ecosystem structure and function due to climate change and disturbance. Global Change Biology, 24(11), 4973–4984. 
6. Peters, D.P.C., Yao, J., Browning, D., & Rango, A. (2014). Mechanisms of grass response in grasslands and shrublands during dry or wet periods. Oecologia, 174, 1323–1334. 

 Article written by: Ben Beckman & Ryan Benjamin, Nebraska Extension Educator, and Jacob Harvey, UNL Barta Brother Manager.