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The semiarid rangelands of South Texas and Northern Mexico are much less productive than they were 100 to 150 years ago. A small percentage of this area only requires improved grazing management practices for greater productivity. Rangelands dominated by the most persistent and productive plant species only require harvest strategies that maintain healthy and productive plants. Moderately degraded rangelands may require brush management, but the most damaged rangelands require revegetation. The most degraded rangelands have microenvironments where plants require more water, but receive less. The worst of these areas simply get worse with time, even with careful management. Within the last 20 years, ecologists recognized that some damaged rangelands do not necessarily recover, just because management improves (Friedel 1991). Damaged hydrologic processes, harsh microenvironments, and few natural seed sources create barriers to natural improvement.
Although improved grazing management must be part of any long-term management plan, it is unlikely to significantly improve severely degraded ecosystems. Even complete removal of livestock does not insure secondary succession leading toward recovery. Unfortunately, the expense and risk of revegetation has limited its use. Most rangelands are less productive because they have damaged ecosystem processes and/or are dominated by species that do not contribute to management objectives. The most significant challenge of revegetating semiarid rangelands is to repair damaged processes, improve microenvironments, and establish plants that will continue recovery processes. Thus, although revegetating semiarid rangelands requires numerous important considerations, I will focus on practices that address hydrologic problems and improve microenvironments. These techniques include seedbed preparation, water harvesting, the use of mulches, and interseeding.