Realizing the potential of British grasslands: some problems and possibilities

Grass is easily the most important crop in Britain and an analysis is made of the factors affecting its yield and quality. There follows some mention of grass utilization, and of the concept of Metabolizable Energy which enables feed value of forage to be related to nutrient requirements of ruminant animals. Grassland output could be doubled if known technology on herbage production and utilization were implemented nationwide, and an analysis is included of why the crop is presently so under-used. Prospects for milk and meat production are assessed and the importance of improving grassland management stressed, both to maintain the farmer's living standards and to increase market competitiveness. Major research objectives are highlighted and the need for close contact between the researcher, adviser and farmer emphasized to achieve full exploitation of grassland at least cost.     

An archaeology of fear and environmental change in Philadelphia

This paper examines how mechanisms of social control function to mediate human-environment relations and processes of environmental change in the city. Using the Fairmount Park System of Philadelphia as a case study, I argue that a history of social control mechanisms, both formal and informal, maintained viable socio-environmental urban relationships. Their decline over the last several decades has produced a legacy of fear towards the city’s natural environment that has had, and continues to have, profound socio-spatial and ecological implications. I argue that these changes have their origin in a set of racially motivated decisions made during the volatile years of the late 1960s and early 1970s and that African American women, in particular, have been impacted disproportionately by their consequences. Fear of crime in the natural environment and suspicion of environmental change have resulted in the exclusion of local women and children from what was, historically, a politically and socially viable public space. In this context, urban ecological change is locally understood as more an issue of social control than one of environmental concern.     

Modeling effects of climate change on Yakima River salmonid habitats

We evaluated the potential effects of two climate change scenarios on salmonid habitats in the Yakima River by linking the outputs from a watershed model, a river operations model, a two-dimensional (2D) hydrodynamic model, and a geographic information system (GIS). The watershed model produced a discharge time series (hydrograph) in two study reaches under three climate scenarios: a baseline (1981–2005), a 1-°C increase in mean air temperature (plus one scenario), and a 2-°C increase (plus two scenario). A river operations model modified the discharge time series with Yakima River operational rules, a 2D model provided spatially explicit depth and velocity grids for two floodplain reaches, while an expert panel provided habitat criteria for four life stages of coho and fall Chinook salmon. We generated discharge-habitat functions for each salmonid life stage (e.g., spawning, rearing) in main stem and side channels, and habitat time series for baseline, plus one (P1) and plus two (P2) scenarios. The spatial and temporal patterns in salmonid habitats differed by reach, life stage, and climate scenario. Seventy-five percent of the 28 discharge-habitat responses exhibited a decrease in habitat quantity, with the P2 scenario producing the largest changes, followed by P1. Fry and spring/summer rearing habitats were the most sensitive to warming and flow modification for both species. Side channels generally produced more habitat than main stem and were more responsive to flow changes, demonstrating the importance of lateral connectivity in the floodplain. A discharge-habitat sensitivity analysis revealed that proactive management of regulated surface waters (i.e., increasing or decreasing flows) might lessen the impacts of climate change on salmonid habitats.