Techniques for Plant Establishment in Arid Ecosystems

harsh desert sites. Recognition of the need forecosystem restoration is growing in arid lands. Increasing use of deserts has resulted in plant and soil degradation which can be reversed by reestablishing native plants. Without intervention, desert areas disturbed by human activities such as offroad vehicle recreation and mining may take decades or centuries to recover (Bainbridge and Virginia, 1990). Conditions favorable for seed germination and seedling establishment are infrequent and unpredictable in the desert, making direct seeding an ineffective restoration strategy (Cox et al., 1982; Barbour, 1968). Fortunately, many desert shrubs are easy to grow in a nursery and respond well to transplanting. But in harsh desert climates, intense solar radiation, high temperatures, high winds, low rainfall, low soil fertility, and intense herbivore pressure can limit transplant success unless plants are prepared carefully and protected after planting. Our research in the Mojave and Sonoran Deserts of California has identified nursery production techniques and seedling protection methods that improve survival. In this article we provide an overview of successful desert revegetation practice~, which should also prove useful to many workers in less severe environments. It begins with a review of containers and soil mixes for transplant preparation, followed by a discussion of strategies for protecting transplants from environmental stress. Container Types and Soil Mixes One of the most important choices in developing a planting program on an arid site is understanding the bureaucratic, biological, and physical constraints on the restoration project and, with these in mind, choosing containers that can deliver survivors in the field at minimum cost. This overview reflects almost ten years of experience in this area, and concludes with some general recommendations for restorationists working in arid environments.