Secondary production of the central rangeland region of the United States.

Rangelands are the dominant land use across a broad swath of central North America where they span a wide gradient, from <350 to >900 mm, in mean annual precipitation. Substantial efforts have examined temporal and spatial variation in aboveground net primary production (ANPP) to precipitation (PPT) across this gradient. In contrast, net secondary productivity (NSP, e.

Integrated Crop-Livestock Systems and Water Quality in the Northern Great Plains: Review of Current Practices and Future Research Needs.

Integrated crop-livestock systems hold potential to achieve environmentally sustainable production of crop and livestock products. Although previous studies suggest that integrated crop-livestock systems improve soil health, impacts of integrated crop-livestock systems on water quality and aquatic ecosystems are largely unknown. This review (i) summarizes studies examining surface water quality and soil leachate for management practices commonly used in integrated crop-livestock systems (e.

Regional grassland productivity responses to precipitation during multiyear above- and below-average rainfall periods.

There is considerable uncertainty in the magnitude and direction of changes in precipitation associated with climate change, and ecosystem responses are also uncertain. Multiyear periods of above- and below-average rainfall may foretell consequences of changes in rainfall regime. We compiled long-term aboveground net primary productivity (ANPP) and precipitation (PPT) data for eight North American grasslands, and quantified relationships between ANPP and PPT at each site, and in 1-3 year periods of above- and below-average rainfall for mesic, semiarid cool, and semiarid warm grassland types.

Phenology of perennial, native grass, belowground axillary buds in the northern mixed-grass prairie.

Premise Of The Study: Vegetative reproduction from belowground bud banks is the primary driver of grassland systems. Despite the importance of bud banks, the timing of recruitment and the crucial link between formation and maintenance is unknown.

Methods: We assessed patterns of belowground bud development, dormancy, and mortality associated with three perennial native grasses in the northern Great Plains.

Crop Species Diversity Changes in the United States: 1978-2012.

Anecdotal accounts regarding reduced US cropping system diversity have raised concerns about negative impacts of increasingly homogeneous cropping systems. However, formal analyses to document such changes are lacking. Using US Agriculture Census data, which are collected every five years, we quantified crop species diversity from 1978 to 2012, for the contiguous US on a county level basis.