Thickets and patches: woody plants are changing water availability in dry landscapes

Featured Image: Sparse woody plant encroachment, known as xerification, occurs here in the Chihuahuan Desert north of Coyame, in Chihuahua, Mexico. Source: Ricraider / CC BY-SA via Wikimedia Commons.

Paper: Woody Plant Encroachment has a Larger Impact than Climate Change on Dryland Water Budgets

Authors: A.P. Schreiner-McGraw, E.R. Vivoni, H. Ajami, O.E. Sala, H.L. Throop, and D.P.C. Peters

Almost half of the land on Earth is arid, with little precipitation. Arid lands are home to roughly 20% of the world’s human population, and to much of the world’s livestock as well. Arid lands are changing rapidly, both with respect to land cover and water availability. While the effects of climate change on arid places have attracted a lot of attention, the encroachment of woody plants into grasslands is also rapidly transforming arid landscapes. New research shows that the effects of woody plant encroachment are even more important than climate change for the water budget of arid ecosystems.

Continue reading “Thickets and patches: woody plants are changing water availability in dry landscapes”

Humans most likely drove Madagascar’s megafaunal extinction

Featured image: Deforestation in Madagascar, image credit: Gregoire Dubois, CC BY-NC-SA 2.0, on Flickr.

Paper: Relationships between climate change, human environmental impact, and megafaunal extinction inferred from a 4000-year multi-proxy record from a stalagmite from northwestern Madagascar
Authors: L. B. Railsback, L. A. Dupont, F. Liang, G. A. Brook, D. A. Burney, H. Cheng., and R. L. Edwards

Madagascar is so large and ecologically unique that it has been dubbed a continent in its own right. It wasn’t occupied by humans until 3,000 years ago and the island’s megafauna died out comparatively recently. Just 1000 years ago sloth lemurs the size of pandas, 10-foot tall elephant birds, and a puma-like predator called the giant fossa roamed the island.

Continue reading “Humans most likely drove Madagascar’s megafaunal extinction”

Climate records written on the seafloor

Featured image: A perspective view of the seafloor at the East Pacific Rise, 9N. Made with GeoMapApp (www.geomapapp.org, CC-BY), and GMRT topography data (Ryan et al. 2009, CC-BY).

Paper: Do sea level variations influence mid-ocean ridge magma supply? A test using crustal thickness and bathymetry data from the East Pacific Rise
Authors: B. Boulahanis, S. M. Carbotte, P. J. Huybers, M. R. Nedimovic, O. Aghaei, J. P. Canales, and C. H. Langmuir

Many of our records of past sea level come from local measurements from coastal towns logged over decades or centuries, or are estimated from ice or sediment cores spanning the last few thousand years, but new research suggests that much longer records can be found in an unlikely place: imprinted deep underground in the oceanic crust.

Continue reading “Climate records written on the seafloor”

Sediment riding on ice to the rescue of vulnerable salt marshes

Featured image by Jennifer Crowder from Pixabay.

Paper: Enhanced, climate-driven sedimentation on salt marshes
Authors: D.M. FitzGerald, Z.J. Hughes, I.Y. Georgiou, S. Black, A. Novak
Journal: Geophysical Research Letters

Accelerated sea level rise threatens to drown many of the world’s salt marshes, but sediment riding on ice rafts might be coming to the rescue. Continue reading “Sediment riding on ice to the rescue of vulnerable salt marshes”

Do melting glaciers release extra sediment?

Featured image: Pitztal Glacier, Austria by annca on Pixabay

Paper: Increased Subglacial Sediment Discharge in a Warming Climate: Consideration of Ice Dynamics, Glacial Erosion, and Fluvial Sediment Transport
Authors: Ian Delaney and Surendra Adhikari

The world’s glaciers are shrinking, sending great quantities of water downstream in a geologic instant. But new research shows a lesser-known effect of climate warming: a large increase in sediment released from melting glaciers that might rearrange the shape of Earth’s surface. Continue reading “Do melting glaciers release extra sediment?”

How Algae Emissions Could Affect the Weather

Featured image by Jesse Allen and Robert Simmon, Public Domain

Paper: Unprecedented DMSP Concentrations in a Massive Dinoflagellate Bloom in Monterey Bay, CA
Authors: Ronald P. Kiene, Brent Nowinski, Kaitlin Esson, Christina Preston, Roman Marin III, James Birch, Christopher Scholin, John Ryan, and Mary Ann Moran

Tiny marine organisms have been showing up in higher and higher numbers in bodies of water. These organisms also emit sulfur-containing compounds – and if they emit enough sulfur, their emissions could affect the climate. Continue reading “How Algae Emissions Could Affect the Weather”