Sunday, December 30, 2007

Innovative Model Connects Circuit Theory To Wildlife Corridors

 

Innovative Model Connects Circuit Theory To Wildlife Corridors

ScienceDaily (Dec. 30, 2007) — Scientists at Northern Arizona University and the National  Center for Ecological Analysis and Synthesis have developed a model that borrows from electronic circuit theory to predict gene flow across complex landscapes .  Their approach could help biologists design better wildlife corridors, which are crucial to protecting threatened plant and animal populations.

Innovative Model Connects Circuit Theory To Wildlife Corridors

Sunday, December 23, 2007

Climate Change and Food Security Special Feature: Global fish production and climate change

 

Current global fisheries production of {approx}160 million tons is rising as a result of increases in aquaculture production. A number of climate-related threats to both capture fisheries and aquaculture are identified, but we have low confidence in predictions of future fisheries production because of uncertainty over future global aquatic net primary production and the transfer of this production through the food chain to human consumption. Recent changes in the distribution and productivity of a number of fish species can be ascribed with high confidence to regional climate variability, such as the El NiƱo–Southern Oscillation. Future production may increase in some high-latitude regions because of warming and decreased ice cover, but the dynamics in low-latitude regions are governed by different processes, and production may decline as a result of reduced vertical mixing of the water column and, hence, reduced recycling of nutrients. There are strong interactions between the effects of fishing and the effects of climate because fishing reduces the age, size, and geographic diversity of populations and the biodiversity of marine ecosystems, making both more sensitive to additional stresses such as climate change. Inland fisheries are additionally threatened by changes in precipitation and water management. The frequency and intensity of extreme climate events is likely to have a major impact on future fisheries production in both inland and marine systems. Reducing fishing mortality in the majority of fisheries, which are currently fully exploited or overexploited, is the principal feasible means of reducing the impacts of climate change.

Climate Change and Food Security Special Feature: Global fish production and climate change -- Brander 104 (50): 19709 -- Proceedings of the National Academy of Sciences