Taxonomy term

Errant asteroids and toxic emissions from volcanic eruptions are the usual suspects in mass extinctions. But during the Ordovician, it was a million-year stretch of cooling ushered in by proliferating algae that triggered a worldwide glaciation and extinction event, according to a new study.

Calculations of the planet’s nitrogen balance have always been off: plants and soils seem to sequester far more nitrogen than expected. The atmosphere has long been thought of as the only major source of nitrogen, but a new study indicates an additional source: as much as a quarter of Earth’s terrestrial nitrogen may be supplied by eroding bedrock.

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.

Mangrove trees, which today thrive in tropical and subtropical climates in the low and midlatitudes, grew in the high Russian Arctic about 56 million years ago, scientists reported in Geology. It’s the northernmost occurrence of mangrove trees ever documented.