BG
Biogeosciences

Coffee break biogeosciences

Coffee break biogeosciences–high resolution δ18O record from bivalves

Coffee break biogeosciences–high resolution δ18O record from bivalves

Much like trees, clam shells have growth rings. The chemistry of these rings can be used as a proxy for ocean chemistry. Recently, an international team of scientists used the growth rings found in shells of Arctica islandica to produce an annual absolutely dated marine δ18O record for the last millennium which was published in Nature Communications. The record represents the first fine scale archive longer than ~100 years.   Additionally, it has higher resolution, and less age uncertainty than δ18O records produced from sediment cores.

To read more into what this record means, and the full results of the study see D.J. Reynolds et al, 2016.

Coffee break biogeosciences–in situ sub-millimeter scale resolution imaging of benthic environments

Coffee break biogeosciences–in situ sub-millimeter scale resolution imaging of benthic environments

Coral reefs and other benthic marine ecosystems play a very important role in the biogeochemical cycles of our oceans. However, laboratory based study of these environments ranges from being difficult to actually impossible. In order to look at the microscopic-scale processes that occur in the benthic environment a team of scientists developed the Benthic Underwater Microscope (BUM). The device, which can be deployed by a diver in situ allows for imaging and filming microscopic processes occurring on corals reefs. The microscope can be used to observe coral polyp behavior, and the behavior of symbiotic organisms living inside the coral. Scientists have also found that it can be used to observe the recolonization of bleached corals by micro algae.
To read more about this new imaging device see the original paper by Mullen et al., 2016, and here is the device in action.

Coffee break biogeosciences – climate change affects mountain plant’s sex ratios

Coffee break biogeosciences – climate change affects mountain plant’s sex ratios

As climate change progresses, widespread changes in phenotypes in many plant populations are bing observed by scientists around the world. For instance in alpine areas, dominant plant species on lower altitude are shifting towards higher altitude as they adapt to increasing temperatures, thereby competing with high-altitude native plant species. In a recent study by Petry et al. (2016) it was shown that responses to climate change in the plant Valeriana edulis (valerian) are strongly sex-specific, thereby reducing pollen limitation and increasing seedset under climate change scenarios. By comparing the presence of female and male valerian plants at different elevations (from 2500 to 3600m) along slopes in the Rocky Mountains of Colorado, they found that climate change is impacting the sex ratio of plants along their elevation range, with a higher presence of female plants high on the mountain as compared to male plants. As these ratios of female to male plants are changing faster than species are moving uphill, they might be a much more rapid trait to detect responses of plant communities to climate change than migration patterns.

To read more about this research on how warming alters mountain plant´s sex rations in the Rocky mountains, check out the article by Petry et al. (2016).

Coffee break biogeosciences–The oldest known fossilized active root meristem

Coffee break biogeosciences–The oldest known fossilized active root meristem

Meristems are groups of undifferentiated cells found in growth zones of plants. Active meristem zones have a different cellular organization than inactive zones, and up until recently no fossilized active root meristem had been found. A team of scientists recently found and described the fossilized remains of an actively growing root meristem dating from the Carboniferous. The fossil, named Radix carbonica, was determined to have been actively growing at the time of fossilisation based on the size and number of cells which radiate outwards from the root tip. The organization of stem cells and differentiating cells found within the fossilized root tip is dramatically different from modern root types and the authors conclude that distinct root types present in the fossil record are now extinct.

To read more about this work read the article by Hetherington et al (2016).

Coffee break biogeosciences–Urban bees found to feed on flowers

Coffee break biogeosciences–Urban bees found to feed on flowers

Honey bees, a highly important pollinator, have suffered a number of declines and population collapses in recent years. The growth of urban centers has contributed to a loss of foraging habitat and an introduction of new food sources. A recent study conducted across the rural-urban boundary of Raleigh, North Carolina, USA examined the feeding sources of urban and rural honey bees using δ13C measurements. This type of measurement can be used because bees which feed on human produced sugars are isotopically heavier than those which feed on flowering plants. The study found that both wild urban and rural honey bees have similar δ13C, therefore urban bees are likely supported by urban flowers rather than human food sources. Managed hived in both rural and urban areas had higher δ13C measurements associated with being fed sugar syrups.

To read more about this work read the article by Penick et al (2016).

Coffee break biogeosciences – New coral reef at Amazon river mouth discovered

Coffee break biogeosciences – New coral reef at Amazon river mouth discovered

At the Amazon river mouth, a huge 9,300 sq km coral reef system has been found below the muddy waters off the mouth of the river Amazon. As corals mostly thrive in clear, sunlit, salt water, and the waters near the mouth of the Amazon are some of the muddiest in the world, the discovery of this almost 2000 km long reef leaves scientists puzzled about the potential extent of coral reefs worldwide.

To find out more about the coral reef at the Amazon river mouth, read  the article by Moura et al. (2016).

 

 

Coffee break biogeosciences – using truffle dogs for science!

Coffee break biogeosciences –  using truffle dogs for science!

Coffee break biogeosciences, your bi-weekly biogeoscience cake to accompany your coffee…

Do you remember your last scientific conference? Did you also find the scientific coffee break discussion as interesting as the scientific talks? If yes, these short blog posts will allow you to keep the interesting coffee break discussions going as we´ll give you on a bi-weekly basis your scientific biogeoscience cake to accompany your coffee…

Mushrooms are considered perfect bio-indicators of environmental pollution. For instance, some forest mushrooms can accumulate high levels of radioactivity if the soil is contaminated with radioactive nuclides like caesium-137 (137Cs) and 90-strontium (90Sr). In a recent paper published in Biogeosciences (Büntgen et al., 2016), an open access journal of the European Geoscience Union, Swiss and German researchers analyzed truffles collected at different spots in central Europe and found that they contained insignificant amounts of 137Cs, hence being fit for human consumption.

In 1986, the Chernobyl nuclear disaster in Ukraine released substantial quantities of radioactive particles, especially 137Cs. Transported by winds and deposited by heavy rainfall, 137Cs polluted large parts of the European continent, leaving much of the continent’s topsoil layers still radioactively contaminated 30 years later. To date it remained unclear whether truffles accumulate radioactivity at a harmful level comparable to other fungal species. The researchers collected with the help of trained dogs Burgundy truffles in several natural habitats and plantations in Switzerland, Germany, France and Italy. The collected truffles contained negligible amounts of radioactivity, with 137Cs values ranging below the detection limit of 2 becquerels per kilogram (Bq kg -1). This is far below the tolerance value of 600 Bq kg-1, meaning the truffles are safe for consumption, at least in the areas the researchers sampled from. Therefore, if you´re having a headache after eating truffles in your local Italian restaurant, don´t blame the truffles but rather suspect the waiter, who overcharged you for a plate of pasta with fungi (on top of the bottle of Chianti wine).

Citation:
Büntgen, U., Jäggi, M., Stobbe, U., Tegel, W., Sproll, L., Eikenberg, J., and Egli, S.: All-clear for gourmets: truffles not radioactive, Biogeosciences, 13, 1145-1147, doi:10.5194/bg-13-1145-2016, 2016.

http://www.biogeosciences.net/13/1145/2016/