By Daniel Friedman, Genetics ’14
For years, ecologists have modeled the biodiversity of natural forests as if they were oceanic islands, adrift in an unlivable sea of humanity. However, research published in April in Nature by C. Mendenhall et al. suggest that this is not the most accurate or predictive way to think about these pockets of nature. By comparing bat diversity on countrysides and oceanic islands, they find that fragmented land ecosystems behave markedly different than their oceanic counterparts. They find that forest “islands” maintain species at higher overall levels of biodiversity than ocean islands, and also gain/lose species in unique patterns. This has relevance to humanity’s actions to support biodiversity on land, and suggests the need for new models, metrics, and strategies of conservation.
Mendenhall, C., Karp, D., Meyer, C., Hadly, E., Daily, G., “Predicting biodiversity change and averting collapse in agricultural landscapes”, Nature, 2014.
Image from Abu Shawka, 2009. Creative Commons.
By Jenny Cade, Biochemistry & Molecular Biology ’15
Eating grass-fed beef and pasture-raised chicken is the eco-friendly thing to do–right? Maybe not, according to a recent paper published in the Proceedings in the National Academy of Science. The study proposes that intensifying livestock production by transitioning from pure grazing to mixed systems–where animals are fed high-energy food like grains–could reduce livestock greenhouse gas emissions by 23% by 2030. Currently, livestock account for 14.5% of all anthropogenic greenhouse gas emissions, so such a reduction would be significant.
In contrast, a comment piece that appeared in Nature last month calls for increasing grazing to make livestock systems more sustainable. Of eight strategies that the authors outline to reduce the environmental and economic costs of raising livestock, “Feed animals less human food” is number one.
Continue reading Grass-fed or grain-fed?
By Ashley Chang, Genetics ’15
Researchers at the GEOMAR Helmhotltz Centre for Ocean Research Kiel are studying the long-term effects of “climate engineering” methods that could help to preserve the climate and protect from rising temperatures. This winter every part of the world except the eastern United States reported record breaking high temperatures. Although political agreements have been made to reducing greenhouse gas emissions, the effects may be too slow as levels of CO2 and other greenhouse gases continue to rise. This is especially important as populous countries, such as China and India, become increasingly industrialized and consequentially raise their greenhouse gas emissions. Continue reading Climate Engineering: Worth the Risk?