Cryptosporidium parvum is a fecal borne protozoan parasite that can be carried by and cause gastrointestinal illness in humans, cattle, and wildlife. The illness, cryptosporidiosis, can be fatal to persons with compromised immune systems. At question is the potential for C. parvum in cattle fecal deposits on rangeland watersheds to contaminate surface water. First, C. parvum oocysts must be rel...

Rangelands essentially comprise geographical regions dominated by grass with or without scattered woody plants. Rangelands are often considered to function primarily as feed for livestock. In this view, conservation and biodiversity issues are secondary. The alternate view involves recognising rangelands as a biome without a specific function, but where there is an implied responsibility for in...

Jack A. Morgan is plant physiologist and Feike Dijkstra is post-doc research ecologist at the Rangeland Resources Research Unit, Ronald F. Follett is research leader and soil scientist and Stephen Del Grosso is a soil scientist and ecologist at the Soil Plant Nutrient Research Unit, USDA Agricultural Research Service Northern Plains Area, Fort Collins, Colorado. Leon Hartwell Allen Jr. is soil ...

Invasive plants reduce the capacity of ecosystems to provide goods and services required by society, alter ecological processes, and can displace desirable species. They can reduce wildlife habitat quality, riparian area integrity, rangeland economic value, and enterprise net returns. The invasion process is regulated by characteristics of the invading plant and the community being invaded. The...

Soil characteristics and functions are critical determinants of rangeland systems and the ecosystem services that they provide. Rangeland soils are extremely diverse, but an emerging understanding is that paradigms developed in more mesic forest ecosystems may not be applicable. Vascular plants, biological soil crusts, and the soil microbial community are the three major functional groups of or...

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We conducted a 5-year study on the impact of nutrients, depending on stream and season. grazing on stream-channel bare ground and erosion, and a © CSA 3-year study of cattle-trail erosion on intermittent stream channels draining grazed oak (Quercus)-woodland 450. Correlations of stocking with the cryptogamic soil watersheds. These studies were conducted on the San crust of a semi-arid rangeland...

The current growing body of evidence for diversity-disturbance relationships suggests that the peaked pattern predicted by the intermediate disturbance hypothesis (IDH) may not be the rule. Even if ecologists could quantify the diversity-disturbance relationship consistent with the IDH, the applicability of the IDH to land management has rarely been addressed. We examined two hypotheses related...