How much biomass grows in the savannah?
February 16, 2017 09:49 AM - Friedrich-Schiller-University Jena
Savannahs form one of the largest habitats in the world, covering around one-fifth of the Earth's land area. They are mainly to be found in sub-Saharan Africa. Savannahs are home not only to unique wildlife, including the 'Big Five' - the African elephant, rhinoceros, Cape buffalo, leopard and lion - but also to thousands of endemic plant species such as the baobab, or monkey bread tree.
Monarch Butterflies Just Lost Another Third of Their Population
February 16, 2017 07:02 AM - Alicia Graefi, Care2
While international efforts are underway to protect iconic monarch butterflies from disappearing, the latest population count has found their numbers have dropped by nearly one-third since last year.
According to the Xerces Society for Invertebrate Conservation, in the 1990s, an estimated one billion monarchs embarked on an epic annual migration. Their journey takes them from sites in Canada and the U.S. to wintering grounds in California and Mexico, where they find shelter and warmth among oyamel fir trees in the winter.
New Methods Further Discern Extreme Fluctuations in Forage Fish Populations
February 15, 2017 04:34 PM - NOAA Fisheries West Coast Region
California sardine stocks famously crashed in John Steinbeck’s “Cannery Row.” New research, building on the pioneering work of Soutar and Isaacs in the late 1960’s and others, shows in greater detail that such forage fish stocks have undergone boom-bust cycles for centuries, with at least three species off the U.S. West Coast repeatedly experiencing steep population increases followed by declines long before commercial fishing began.
Natural population fluctuations in Pacific sardine, northern anchovy and Pacific hake off California have been so common that the species were in collapsed condition 29 to 40 percent of the time over the 500-year period from A.D. 1000 to 1500, according to the study published today in Geophysical Research Letters. Using a long time series of fish scales deposited in low-oxygen offshore sedimentary environments off southern California, the authors from NOAA Fisheries and the University of Michigan described such collapses as “an intrinsic property of some forage fish populations that should be expected, just as droughts are expected in an arid climate.”
Newly engineered material can cool roofs, structures with zero energy consumption
February 15, 2017 04:24 PM - Trent Knoss via University of Colorado at Boulder
A team of University of Colorado Boulder engineers has developed a scalable manufactured metamaterial — an engineered material with extraordinary properties not found in nature — to act as a kind of air conditioning system for structures. It has the ability to cool objects even under direct sunlight with zero energy and water consumption.
When applied to a surface, the metamaterial film cools the object underneath by efficiently reflecting incoming solar energy back into space while simultaneously allowing the surface to shed its own heat in the form of infrared thermal radiation.
Extraordinary Levels of Pollution Found in the Deepest Part of the Sea
February 15, 2017 03:01 PM - Alicia Graef, Care2
Since the Mariana Trench is the deepest part of the ocean, you might guess that it is safe from the impact of humans, but you would be wrong. Scientists have found that, despite its depth and remoteness, the deep sea contains levels of toxins that match some of the most polluted marine systems on earth.
How temperature guides where species live and where they'll go
February 15, 2017 02:59 PM - Morgan Kell
For decades, among the most enduring questions for ecologists have been: "Why do species live where they do? And what are the factors that keep them there?" A Princeton University-based study featured on the February cover of the journal Ecology could prove significant in answering that question, particularly for animals in the world's temperate mountain areas.
Global Ocean De-Oxygenation Quantified
February 15, 2017 02:15 PM - GEOMAR Helmholtz Centre for Ocean Research Kiel
The ongoing global change causes rising ocean temperatures and changes the ocean circulation. Therefore less oxygen is dissolved in surface waters and less oxygen is transported into the deep sea. This reduction of oceanic oxygen supply has major consequences for the organisms in the ocean. In the international journal Nature, oceanographers of GEOMAR Helmholtz Centre for Ocean Research Kiel have now published the most comprehensive analysis on oxygen loss in the world's oceans and their cause so far.
NASA Study Identifies New Pathway for Greenland Meltwater to Reach Ocean
February 15, 2017 11:57 AM - NASA / Goddard Space Flight Center
Cracks in the Greenland Ice Sheet let one of its aquifers drain to the ocean, new NASA research finds. The aquifers, discovered only recently, are unusual in that they trap large amounts of liquid water within the ice sheet. Until now, scientists did not know what happened to the water stored away in this reservoir -- the discovery will help fine tune computer models of Greenland’s contribution to sea level rise.
Researchers Catch Extreme Waves with High-Resolution Modeling
February 15, 2017 10:55 AM - Lawrence Berkeley National Laboratory
Surfers aren’t the only people trying to catch big waves. Scientists at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) are trying to do so, too, at least in wave climate forecasts.
Intergalactic unions more devastating than we thought
February 15, 2017 10:49 AM - Moscow Institute of Physics and Technology
Scientists from MIPT, the University of Oxford, and the Lebedev Physical Institute of the Russian Academy of Sciences estimated the number of stars disrupted by solitary supermassive black holes in galactic centers formed due to mergers of galaxies containing supermassive black holes. The astrophysicists found out whether gravitational effects arising as two black holes draw closer to one another can explain why we observe fewer stars being captured by black holes than basic theoretical models predict. In their study published in The Astrophysical Journal, the researchers looked into the interplay of various dynamic mechanisms affecting the number of stars in a galaxy that are captured per unit time (tidal disruption rate). (Spoiler Alert! An advanced theoretical model yielded results that are even more inconsistent with observations, leading the team to hypothesize that the disruption of stars in galactic nuclei may occur without our knowledge.)