Looking beyond the grasses
September 9, 2009
When I think about rangeland vegetation I’m inclined to think primarily about the grasses and forbs that dominate the uplands. Because grasses are the dominant component of most rangelands in the Northern Great Plains, they often are the focus of most livestock producers as well. Two recent experiences reminded me that there’s more to rangelands than grass.
A graduate student is beginning a project which will focus on invasive plants in rangelands in southwestern South Dakota. One of the most serious invaders is salt cedar. A trip to locate some of the areas where salt cedar control was in progress reminded me of the contrast present in our rangelands and the importance and value of the riparian areas. We spent our time traversing moderate and small waterways, because that’s the habitat that salt cedar favors. I was encouraged by the success apparent where survey and control efforts have been underway before salt cedar invasions become intractable. Early detection and control was producing substantial progress. While battling invasive weeds will require persistence and vigilance, it was gratifying to see success.
As we examined the vegetation in these streamside areas, I was impressed by their productivity! Yes, it’s been a good year for moisture, but the composition of the vegetation didn’t occur overnight – and it’s been through a long term dry spell. Three species that I expect to see further east where precipitation is higher were abundant. American licorice, switchgrass and prairie cordgrass were present at every site we examined, including the bed of an intermittent stream that was currently dry. Perhaps even more striking was the occurrence and vigor of these plants immediately adjacent to extremely arid sites. Within a distance of 20 feet or less, vegetation changed from the tall switchgrass and cordgrass to sites dominated by blue grama.
For many reasons, conservation of these productive riparian areas should be a high priority in any comprehensive ranch plan. Conservation will include being alert to the introduction of invaders like salt cedar and include a control strategy. It will be equally important to preserve the value of these productive areas as a grazing resource. These areas can and should be grazed, but the penalty for overgrazing and lost production underlines the need to be intentional and precise about how they are grazed. Proximity to water provides a major challenge in controlling and allocating access by grazing livestock.
Another recent trip took me to the USDA Plant Materials Center in Bismarck, ND. Scientists at the Bismarck PMC are responsibility for the development of plants useful for conservation, particularly in North and South Dakota and Minnesota. While a large number of adapted and productive grass populations important to our rangelands have been released, I was impressed by the variety of other plants they are working with. Both trees and shrubs receive considerable attention at the PMC. Personnel coordinate collection, propagation and evaluation of these woody species which by their nature is a long term process. Plantings across the region are made to evaluate adaptation, often in cooperation with local conservation districts.
Green ash and Russian Olive have both contributed to large acreages of tree belts and windbreaks across the plains. Efforts are underway to identify satisfactory substitutes for both plants. Green ash is likely to be subject to spread of the Emerald Ash borer and Russian Olive has threatened habitats where it has become invasive.
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On a personal level, I found the plantings of chokeberry (different than chokecherry) quite impressive. This shrub is well adapted to our region and I find both the foliage and fruit very attractive. The variety ‘McKenzie’ was released by the PMC in Bismarck and several cooperating institutions and agencies last year. This shrub is useful in wildlife plantings and would serve well as the shrub row in multirow plantings. The fruit has even received interest and attention because of the high concentration of nutritionally beneficial antioxidants.
Join me in looking beyond the grasses when you next pause to appreciate our rangelands. Forbs, shrubs and trees are vital to the diversity and habitats that make our plains so precious. Develop an appreciation as well for the immense value of riparian habitats – they contribute much more than their extent might imply.