Vector and Disease Management Research to Reduce the Effects of Pierce’s Disease in California’s Vineyards

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By Natalie Swinhoe, Anthropology and Evolution, Ecology, and Biodiversity, 2015 Pierce’s Disease in grapevines is a major threat to California’s viticultural economy. Caused by the bacterial strain Xylella fastidiosa, the disease blocks water transfer in the xylem of stems, leading to water stress and eventual death. Until the 1990s, the only carriers for the disease were native Blue-Green Sharpshooters, Graphocephala atropunctata. However, between 1994 and 2000, a devastating outbreak occurred in Southern California, destroying more than 1000 acres of vineyards (Ringenberg et al., 2014). This epidemic was caused by a new nonnative vector- the Glassy-Winged Sharpshooter, Homalodisca vitripennis (Tumber et al, 2013). Compared to the Blue-Green Sharpshooter, the Glassy-Winged Sharpshooter has a much greater capacity to spread Pierce’s Disease because it can fly further and feed on a larger variety of plant parts (Alston et al., 2013, Baccari and Lindow, 2010).

Learning from Drought in California: Past and Present

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By Marisa Sanchez, Molecular and Cellular Biology, ’15 The most current drought in California is considered to be one of the worst droughts in the past century, and many wonder if this severity is due to climate change. However, California has had a long history of unpredictable weather fluctuations, and is familiar with severe droughts. Many droughts can have devastating effects, particularly in the agricultural industry and the hydropower industry. Most Californians have also experienced the effects of a drought first-hand, such as having enforced water rationing. Even though, California’s history has shown that most droughts have devastating effects, droughts can also great learning experiences.

When the Last Frog Croaks

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By Renata Vidovic, Evolution and Ecology ’15 To some, the phrase climate change evokes images of dry lakes, melting icebergs, and rising oceans. However, the effects of global warming are not simply cataclysmic geological changes. There are links between all biotic and abiotic features of an ecosystem. Unsurprisingly, climate change has an immense impact on frog populations around the world. Home range, abundance, breeding cycles, pathogen epidemics, and physical degradation in frogs are all affected by the changing climate.

“No Ecosystem is an Island”

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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, […]

Grass-fed or grain-fed?

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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.

Climate Engineering: Worth the Risk?

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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.