Taxonomy term

sarah derouin

Surveying forests from afar

Traditional surveys of forest health and diversity take hours of hiking and sampling by scientists who can only cover relatively small areas. Satellites, meanwhile, can survey large swaths of land, collecting information about forests in a fraction of the time that a ground survey might take. But the resolution and types of satellite data available don’t always allow for detailed studies. Now, a team of ecologists is staking out the middle ground by developing airborne laser scanning techniques to create high-resolution maps of tree species diversity to monitor changes in forest ecosystems.

22 Mar 2018

Meteorite impacts may have kick-started ancient subduction

Earth in the Hadean Eon, between 4.56 billion and 4 billion years ago, was much too hot to support active plate tectonics as we know it today, where cold, established plates slowly march around Earth. Yet some evidence, including from tiny zircon crystals dating to the Hadean, has suggested that a form of plate tectonics was active by about 4.1 billion years ago — about a billion years before many researchers think modern plate tectonics started. The mechanisms that could have initiated and sustained early tectonics are unclear, but according to a new study, constant bombardment of early Earth by meteorites could have triggered temporary bursts of early tectonism.

22 Feb 2018

Beavers preserve wetlands in water-stressed areas

Once considered detrimental to ecosystems and nuisances where, for example, dams flooded farmland, beavers have been rhetorically touted in recent years as a potential boon for wetland health and water conservation. Anecdotal accounts and qualitative findings have suggested beavers improve water quality and availability in drought-stressed ecosystems, but just how much influence they have was not known. In new research, scientists have examined two creeks in Nevada to directly measure how effective beaver dams are at slowing water flows and storing water through the dry summer months.

30 Jan 2018

Unexpected nanoparticles trace coal pollution

Coal burning produces an array of chemicals and particulates that, when released into the atmosphere, contribute to pollution, poor air quality and threats to public health. Measurements of particulate air pollution typically focus on particles called PM2.5, which have diameters of 2.5 micrometers or less. This group includes nano-sized particles, although these bits of minerals, dust and organics often go undetected because of their tiny size. In a new study, researchers sampling a coal ash spill have unearthed a type of nanoparticle not previously known to be produced by burning coal. While the particles might be useful in detecting pollution problems, they may also have consequences for human and environmental health.

24 Jan 2018

Down to Earth With: Wildfire meteorologist Craig Clements

Not many people are able to combine their work and hobbies the way Craig Clements, a meteorologist at San Jose State University in California, has. “I was always interested in mountain weather,” he says. “I got into meteorology through my interest in mountaineering and climbing.”

19 Jan 2018

Predators may have spurred evolution of ancient brittle stars

Threats to species can encourage evolution, leading to animals with harder shells or other defensive adaptations. In a recent study in the Journal of Systematic Palaeontology, researchers found that while some ancient brittle stars — relatives of starfish with long, whip-like arms — evolved in the face of threats, some adapted a different approach: they moved.

10 Jan 2018

Western wildfires affect water quality

Wildfires have burned increasing acreage in recent decades, a trend that’s expected to continue with global climate change. In the U.S. West, the frequency of fires has implications for water availability — both water used to fight wildfires and municipal water supplies, which can be contaminated by loosened debris from eroding, fire-burned slopes.

09 Jan 2018

Impact signature in rock produced by lightning strikes

When a meteorite smashes into Earth’s rocky surface, the immense temperatures and pressures created can melt rock into glass and leave signatures of the impact behind. Impacts produce tell-tale planar features in quartz grains called shock lamellae — picture a scrambled television signal, with repeating horizontal lines chopping and distorting the image into layers — that scientists have thought were produced only by meteorites.

05 Jan 2018

Nautical charts reveal coral decline around Florida Keys

Coral reef cover is known to have decreased over the past few decades, but longer term estimates of coral cover have been difficult to reconstruct. In a new study, researchers used high-resolution historical nautical maps from the 18th century to determine changes to reefs in the Florida Keys.

26 Dec 2017

19th-century discovery now reveals modern human arrival in Sumatra

Modern humans began journeying out of Africa by at least 75,000 years ago, eventually expanding across the planet. Evidence of these early human travels, including fossils and artifacts, is typically spotty and difficult to find. But one such discovery more than a century ago has shed new light on the appearance of humans in Southeast Asia.

19 Dec 2017