UC Davis postdoctoral researcher Julie Cridland is working with Santiago Ramirez, assistant professor of evolution and ecology at UC Davis, and Neil Tsutsui, professor of environmental science, policy and management at UC Berkeley, to understand the population structure of honey bees (Apis mellifera) in California. To understand California bees, the researchers realized that they first needed to better understand honey bee populations in their native range in the Old World. There are two major lineages of honey bees in Europe -- C, "Central European," including Italy and Austria and M, including Western European populations from Spain to Norway -- which give rise to most of the honey bees used in agriculture worldwide. The more docile C lineage bees came later, and today many California bees are from the C lineage, but there is still a huge amount of genetic diversity, Ramirez said. "You can't understand the relationships among bee populations in California without understanding the populations they come from," Cridland said.
Where do honey bees come from? A new study clears some of the fog around honey bee origins. The work could be useful in breeding bees resistant to disease or pesticides. Honeybees are essentially to our world and agriculture. In order to have plants grow and prosper we need pollination which the bees help do. https://www.sciencedaily.com/releases/2017/02/170217012456.htm
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In a new study published in Scientific Reports this week, a team led by researchers from Michigan Technological University created the first, truly global inventory for volcanic sulfur dioxide emissions, using data from the Dutch-Finnish Ozone Monitoring Instrument on NASA's Earth Observing System Aura satellite launched in 2004. While this number is higher than the previous estimate made in the late 1990s based on ground measurements, the new research includes data on more volcanoes, including some that scientists have never visited, and it is still lower than human emissions of sulfur dioxide pollution levels. He led the effort to catalog sulfur dioxide emissions sources from human activities and volcanoes and to trace emissions derived from the satellite observations back to their source by using wind data. But the satellite data could allow us to target new ground-based measurements at unmonitored volcanoes more effectively, leading to better estimates of volcanic carbon dioxide emissions." Ground-based data are more detailed, and in areas like Central America where large sulfur dioxide-emitting volcanoes are close together, they better distinguish which specific volcano gas plumes come from. The work highlights the necessity of consistent long-term data, according to co-author Nick Krotkov, an atmospheric scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, which produces the sulfur dioxide data from the Aura satellite.
Volcanoes erupt, they spew ash, their scarred flanks sometimes run with both lava and landslides. But only occasionally. A less dramatic but important process is continuous gas emissions from volcanoes; in other words, as they exhale. A number of volcanoes around the world continuously exhale water vapor laced with heavy metals, carbon dioxide, hydrogen sulfide and sulfur dioxide, among many other gases. Of these, sulfur dioxide is the easiest to detect from space. https://www.sciencedaily.com/releases/2017/03/170309150624.htm Using a library of more than 10,000 deep-sea corals collected by Caltech's Jess Adkins, an international team of scientists has shown that periods of colder climates are associated with higher phytoplankton efficiency and a reduction in nutrients in the surface of the Southern Ocean (the ocean surrounding the Antarctic), which is related to an increase in carbon sequestration in the deep ocean. There is 60 times more carbon in the ocean than in the atmosphere -- partly because the ocean is so big. As such, the ocean is the greatest regulator of carbon in the atmosphere, acting as both a sink and a source for atmospheric CO2. As the sea creatures who consume those sugars -- and the carbon they contain -- die, they sink to the deep ocean, where the carbon is locked away from the atmosphere for a long time. In most parts of the modern ocean, phytoplankton deplete all of the available nutrients in the surface ocean, and the biological pump operates at maximum efficiency. However, in the modern Southern Ocean, there is a limited amount of iron -- which means that there are not enough phytoplankton to fully consume the nitrogen and phosphorus in the surface waters. Because the Southern Ocean flows around Antarctica, all of its waters funnel through that gap -- making the samples Adkins collected a robust record of the water throughout the Southern Ocean. As a result, there is a correlation between the ratio of nitrogen isotopes in sinking organic matter (which the corals then eat as it falls to the seafloor) and how much nitrogen is being consumed in the surface ocean -- and, by extension, the efficiency of the biological pump. As such, the evidence suggests that colder climates allow more biomass to grow in the surface Southern Ocean -- likely because colder climates experience stronger winds, which can blow more iron into the Southern Ocean from the continents.
We know a lot about how carbon dioxide (CO2) levels can drive climate change, but how about the way that climate change can cause fluctuations in CO2 levels? New research from an international team of scientists reveals one of the mechanisms by which a colder climate was accompanied by depleted atmospheric CO2 during past ice ages. Efficient nutrient consumption by plankton in the Southern Ocean drove carbon sequestration in the deep ocean during the ice ages, a new study suggests. https://www.sciencedaily.com/releases/2017/03/170314150916.htm |
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