Appropriate prairie management techniques depend upon the objectives of the manager. Prairies can be managed for many purposes, including aesthetics, grazing/haying, recreation, hunting, wildlife habitat, or biological diversity. The information on this website is heavily weighted toward management for biological diversity because a healthy prairie community provides for the other purposes as well.
Most prairies exist today as fragmented landscapes, making thoughtful and vigilant management ever more important. Here we will explore some of those various management techniques and offer some guidance.
When managing a prairie for biological diversity, two things are especially important to keep in mind.
1. Managing a prairie really means managing the competition between prairie species. Plants and other species are always competing with each other. Your job is to manipulate that competition so that the maximum number of native species are able to sustain themselves in the community. Most of the time, management that favors plant diversity will favor insect and wildlife diversity as well. The more you can learn about the plants in your prairies, how to identify them, their growth and reproductive strategies, and how they respond to various management treatments, the better able you will be to design and measure management strategies.
2. Diverse prairies require diverse management treatments. Managing in the same way each year always favors the same plant and animal species – and, by default, manages against other species. Over time, that kind of repetition decreases the number of plant and animal species in a prairie. By altering the timing and frequency of management treatments, and by using multiple strategies (prescribed fire, haying, grazing, rest) in non-repetitive ways, maximum species diversity can be maintained. It’s also important to provide a variety of habitat structure (tall, short, dense, sparse) within the prairie to provide for the needs of all insect and animal species.
Prescribed fire is an important strategy for prairie management, but one that requires a great deal of expertise and experience to conduct safely. Never attempt a prescribed fire without first getting appropriate training or working with others who have that training and equipment. See the resources section below to learn where and how to find training and equipment in Nebraska – both are becoming increasingly available but not to the extent that is needed.
As with all management treatments, it’s important to define specific objectives for what you want to achieve and be thoughtful about how to use fire to achieve those objectives. Burning to turn the ground black is not necessarily productive. Some people attempt to replicate historic fire regimes by burning on a regular schedule of every 3 or 4 years, but that ignores several things. First, an historic average doesn’t mean that prairies historically precisely every t 3 years – rather it means that the average of a widely varied fire frequency turns out to equal about three. Second, today’s climate, landscape, and challenges are vastly different than those in the past, so mimicking historic fire frequencies doesn’t address the needs of prairies today.
Prescribed fire can be a useful tool to accomplish several things:
- Fire removes thatch and litter (previous years’ vegetation) that can stifle plant growth by cooling the soil and shading young plants.
- Fire can help prevent encroachment by trees and other woody vegetation. Eastern red cedar trees can be killed by fires that consume the majority of their leaves – especially when those fires occur early in the spring or late in the fall. Most deciduous trees and shrubs are only top-killed by fires and will resprout from the ground, but repeated fires can still help to suppress their invasion and allow time for other measures to be taken.
- Fire can injure growing plants by defoliating them as they grow, setting them back and giving an advantage to plants that start their growth (or hit their peak growth spurts) after the fire has passed. Late-spring fires (late April to early May) are often used to suppress smooth brome, for example, and to favor warm-season native grasses – which start their growth in early May.
- Fire can increase the attractiveness and palatability of prairie plants (especially grasses) to grazers, including cattle and many native herbivores. Burning a portion of the prairie each year can shift the intensity of that herbivory around the site, providing a mixture of habitat structure and favoring some species in one place and others elsewhere.
As with other management treatments, it’s important to vary the timing and frequency of prescribed fires between years to avoid repetition (see Guiding Principles above). Burning at different times of the season (early spring, late spring, summer, fall) will provide different results and favor different species. Experimenting with those various seasons of fire can be both interesting and important. Likewise, it’s important to alter the frequency of fire so that a set fire regime (every 3 or 4 years) doesn’t shape the prairie by always favoring species that do well under that regime over others that don’t.
It’s important to leave unburned areas of prairie either in your prairie or in adjacent prairies each year. Some species are particularly vulnerable to fire – especially many insects and reptiles – and every fire will affect some of those species negatively. Altering the season of fire so that the same species aren’t affected every year is important, but it’s even more important to leave refuges for those species to survive in – and to recolonize the remaining prairie from. This is especially important when prairies are relatively small and are isolated from other prairies. Burning the entire site can eliminate species that may not have a way to recolonize from elsewhere.
Many prairie enthusiasts are wary of grazing because the prairies they’ve seen that are grazed don’t look very good. It’s important to separate grazing as a management tool from chronic overgrazing – which certainly has very negative impacts on prairies. Grazing by cattle or bison can be an extremely flexible and useful tool for managing both plant diversity and habitat structure. By altering the stocking rate, timing, frequency, intensity, and duration of grazing treatments you can address a wide variety of prairie management challenges – no other management option provides that level of flexibility. On the other hand, grazing presents a number of logistical challenges because you need livestock, fencing, and water. Grazing can be difficult on small prairies (under 20 acres or so) because the amount of infrastructure needed is high for the size of the prairie to be grazed.
You can read a nice introduction to the topic of grazing in prairies here.
Invasive species are a major challenge to prairie managers. Each species requires its own strategies, but there are some general approaches and guidelines that can be helpful as well. Because of the time and resources that invasive species control can require, it’s important to have good system of prioritization. In general highest priority should be given to species that:
- Aren’t yet at the site or are just starting to invade. It’s much easier to stop a new invasion than a species that is well-entrenched. Preventing new species is well worth the time needed to patrol the prairie regularly. Be aware of the species most likely to invade and be vigilant – and act quickly when they show up.
- Are feasible to control. Some species are relatively easy to eradicate, while others take immense resources. Start with the ones you can easily eliminate first. Then work on the others if you have time. Reduce the number of invasive species you have to deal with (but see the next bullet).
- Cause the most damage. Species that affect the objectives you have for your prairies should be given high priority. If a species is non-native but not really causing problems, ignore it until you have time to deal with it.
Once you have your priorities set, be strategic about your attack. Read about a good overall approach to invasive species control here.
Trees, both non-native and native can alter the structure and function of a prairie to the point where it is no longer a prairie. Historically, fire played a large role – along with climate and herbivores – in keeping trees at bay from most of Nebraska’s grasslands. Today, there are so many small and large woodlands around the state that the seed rain from trees overwhelms prairies to the point that fire alone is rarely sufficient to keep them out. Herbicides are necessary for most deciduous tree control – but there are ways to apply those chemicals with minimal effect on other species. Click here to read about a tool that can help apply herbicide to trees quickly and easily.
Successful prairie managers are those that look at what they’ve done, how it worked, and what the next challenges are. Then they synthesize that information and use it to determine what to do next. It’s very important to be willing to change course when something isn’t working. On the other hand, monitoring can be extremely time consuming and expensive, so it’s important to prioritize the kinds of evaluation that will be most feasible and helpful.
RESOURCES:Central Platte NRD–Prescribed fire program for private landowners David Carr 215 N Kaufman Ave. Grand Island, NE 68803 308-385-6282 - Pheasants Forever–Mobile prescribed burn unit. 308-374-5339 Contrasting Approaches to Prairie Management: Leopold, Land Health and Cabbages.
“A Land Ethic” is the concluding essay in Aldo Leopold’s 1949 book, A Sand County Almanac, and is the most powerful and relevant piece of conservation writing I’ve ever read. Leopold’s essay spells out the changes we need to make in the way we view our relationship with the land, and it is both impressive and frustrating that nearly everything in that essay still reads true today. If anyone reading this blog post has never read A Sand County Almanac, please stop reading this, go pick up a copy of the book, and read it.
I’ll wait…read more