• Poisonous Plants and Plant Toxins That Are Likely to Contaminate Hay and Other Prepared Feeds in the Western United States

      Stegelmeier, B. L.; Panter, K. E. (Society for Range Management, 2012-04-01)
      Livestock poisoning by toxic plants is a relatively common problem in pastures and rangelands and it is estimated to annually cost the livestock industry more than $200 million. However, these estimates are for grazing animals and the total cost is probably much greater because many animals are poisoned by contaminated feeds. Many poisonous plants are accessible to grazing livestock, but they are generally avoided and are not eaten, or they are eaten at doses that they do not produce detectable disease. In such cases toxic plants may not be more than a problem of displacing desirable nutritious plants. However, this is not always the case, especially when toxic plants contaminate prepared feeds. Poisonous plants incorporated in preserved forages, such as hay and silage, are much more likely to be eaten. This may occur because of increased competition from herd mates or by increased feeding pressure as prepared feeds are most often used in winter when alternative food sources are exhausted. Alternatively, the plants may become more palatable as they are diluted with palatable feed or the previously distasteful plant components are altered during forage preparation or storage. In addition, normally safe forages, under certain conditions, can produce and accumulate toxins. Identifying these toxic contaminates and understanding when forages may be toxic is critical in reducing poisoning and ensuring quality animal products. Our objectives of this review are to present basic principles of identifying contaminated feeds and sampling forages, introduce several common forages that under certain conditions can be toxic, present a brief description of plants that we have found contaminating feed in the western United States, and review how to treat or avoid such poisonings. 
    • To Burn or Not to Burn: Ecological Restoration, Liability Concerns, and the Role of Prescribed Burning Associations

      Toledo, David; Kreuter, Urs P.; Sorice, Michael G.; Taylor, Jr., Charles A. (Society for Range Management, 2012-04-01)
      Fire suppression in ecosystems that have evolved in the presence of fire, together with the occurrence of other natural and anthropogenic processes, has resulted in the conversion of many grasslands and savannas to woodlands. From an ecological perspective, eliminating fire in areas that evolved with fire inhibits natural processes that limit woody plant expansion and, consequently, promotes ecosystem degradation. From an economic perspective, brush encroachment associated with fire suppression has led to reduced livestock carrying capacity and destruction of property by catastrophic fires that occur when accumulated fuel loads ignite under hot dry conditions. By contrast, research results suggest many ecological and economic benefits to using prescribed fire. This leaves social constraints as the primary hurdle to applying periodic fire on the landscape. Prescribed fire has not been adopted widely as a management and/or restoration tool primarily because of perceived safety and legal concerns. In this paper we discuss the benefits and risks of using prescribed fire and how prescribed burn associations have mitigated these risks, resulting in an increase of prescribed fire application, including extreme restoration burns that are ignited under wildfire-like conditions. 
    • Using Homestead Records and Aerial Photos to Investigate Historical Cultivation in the United States

      Morris, Lesley R. (Society for Range Management, 2012-04-01)
      Without consideration of prior cultivation history, we may misinterpret the results of a study or the success of management practices in rangelands. Cultivation involves plowing the soil, seeding, and harvesting a crop annually. The long-lasting impacts, known as “land-use legacies,” from these disturbances on soils and native plant communities have been observed in ecosystems worldwide for decades, centuries, and even millennia after cultivation ceases. In sagebrush ecosystems, cultivation can be one of the most drastic disturbances, with recovery taking well over 90 years in some places. These legacies include altered vegetation, soils, and hydrology. The reestablishment of native species in formerly cultivated areas is typically slowed, if not halted, due to loss of native seedbanks, limited dispersal, and loss of establishment niches. In contrast, exotic and invasive species are often quick to establish and dominate formerly cultivated land. Cultivation can also modify soil structure, texture, and nutrient content. Plowing breaks up soil structure, making it more susceptible to erosion and loss of soil organic matter and nutrients. Plowing also can lead to soil compaction, which affects primary hydrological processes like soil water-holding capacity, run off, and infiltration. These legacies are important because they represent fundamental changes in the structure and function of ecosystems. Unfortunately, the influence of this historical land use is often overlooked in ecological studies, research design, and management implementation.