Research Bites – Page 17

July 17, 2020July 17, 2020

Great Success with Mixed Perennial Grasses for Bioenergy Crops

Paper: Climate Benefits of Increasing Plant Diversity in Perennial Bioenergy Crops
Authors: Yi Yang, Evelyn C. Reilly, Jacob M. Jungers, Jihui Chen, Timothy M. Smith

An Advanced Bioenergy plant.
*Source: Ammodramus / CC BY-SA via Wikimedia Commons.*

Climate change, primarily caused by fossil-fuel-based CO₂ emissions, could trigger disastrous consequences, including extreme weather and mass species extinctions. Bioenergy (a renewable energy derived from plants) can reduce greenhouse gas emissions by replacing fossil fuel with biomass. Atmospheric carbon is consumed via photosynthesis by bioenergy crops, such as wood, grain crops, and perennial grasses. Perennial grasses are good candidates for bioenergy crops because they can be directly combusted or converted to ethanol.

July 17, 2020July 17, 2020

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.

July 16, 2020December 12, 2020

Tiny but Mighty! Nanosized Drivers of Explosive Volcanism

Paper: Can nanolites enhance eruption explosivity?

Authors: F. Cáceres, F. B. Wadsworth, B. Scheu, M. Colombier, C. Madonna, C. Cimarelli, K-U. Hess, M. Kaliwoda, B. Ruthensteiner, D. B. Dingwell

Explosive volcanic eruptions have punctuated our planet’s geological record for millions of years. The explosive nature of these eruptions can lead to thousands of cubic kilometers (that’s a billion Olympic swimming pools) of material travelling hundreds of miles across our landscapes and into our atmosphere. Approximately 630,000 years ago, the most recent eruption from the Yellowstone volcanic center sent ash and dust from Wyoming to southern Texas, USA. More recently, the 1815 eruption of Mt. Tambora, Indonesia, led to 1816 being historically known as the “Year Without a Summer”. The “Year without a summer” was started when volcanic materials entered the atmosphere and induced a volcanic winter, which led to extreme weather, agricultural stresses, and food shortages across the globe.

July 15, 2020July 15, 2020

Pioneering plants tell us when volcanoes last erupted

Featured image: vegetated lava flows on Le Grand Brûlé, with the profile of Piton de la Fournaise behind. Image credit: Mickaël Douineau on Flickr (CC BY-NC-ND 2.0).

Paper : Dating young (<1000 yr) lava flow eruptions of Piton de la Fournaise volcano from size distribution of long-lived pioneer trees Authors: Sébastien Albert, Olivier Flores, Laurent Michon and Dominique Strasberg

A newly formed lava flow may appear to be a sterile environment: devoid of vegetation and humus. But within years, the rocky wasteland erupts into life as a host of tenacious plants take hold. The size of plants rooted on solidified lava is now being used by volcanologists working on Piton de la Fournaise, a shield volcano on the Indian Ocean island of Réunion, to date past eruptions.

July 9, 2020July 9, 2020

Tiny wobbles foreshadow big earthquakes

Featured image: A GPS station in the Sawtooth National Forest near Ketchum, Idaho. Photo by Scott Haefner (USGS).

Paper: Months-long thousand-kilometre-scale wobbling before great subduction earthquakes
Authors: J. R. Bedford, M. Moreno, Z. Deng, O. Oncken, B. Schurr, T. John, J. C. Báez, M. Bevis

We’re always on the lookout for earthquake precursors, indicators that the Earth might be gearing up for some shaking, and geophysicists think they might have found a new one: a small but measurable back-and-forth “wobble” of the land starting several months before very big earthquakes hit.

June 26, 2020June 26, 2020

How does dust from African and Asian deserts affect rainfall over California?

Featured image: Sand Dunes by Free-Photos on Pixabay

Paper: Dusty Atmospheric Rivers: Characteristics and Origins

Authors: Kara K. Voss, Amato T. Evan, Kimbery A. Prather, and F. Martin Ralph

Atmospheric rivers, narrow plumes of highly concentrated water vapor in the atmosphere, can cause heavy rain over the coastal western United States and southwest Canada. In fact, up to half of California’s annual rainfall comes from atmospheric rivers, and while this rain helps replenish California’s water sources, it can also cause flooding and mudslides. A new study sheds light on how dust kicked up from deserts halfway around the world in Africa and Asia may influence these atmospheric rivers and control California’s rain patterns.

June 23, 2020June 23, 2020

Small Sediment’s Big Impact on Flash Floods

Featured image by Hans from Pixabay.

Paper: Modeling the Effects of Sediment Concentration on the Propagation of Flash Floods in an Andean Watershed

Authors: María Teresa Contreras and Cristían Escauriaza

Climate change has altered weather patterns around the world and has even led to increased heavy rainfall in some regions. This, combined with El Niño – a weather pattern produced by unusual winds that can cause some regions to experience heavier than normal rainfall – has led to high numbers of catastrophic flash floods in populated areas near the Andes mountains. To add insult to injury, climate models predict increases in heavy rainfall events in the future, further worsening the chance for flash floods. New research from scientists working in Chile and the United States aims to model the impact of these floods on communities by simulating realistic flash flood conditions with different amounts of sediment, a potentially dangerous component of flash floods in mountainous regions.

June 11, 2020July 26, 2020

Unexpected consequence of permafrost thaw: potentially less methane released into the atmosphere

Paper: Thaw Transitions and Redox Conditions Drive Methane Oxidation in a Permafrost Peatland

Authors: Clarice R. Perryman, Carmody K. McCalley, Avni Malhotra, M. Florencia Fahnestock, Natalie N. Kashi, Julia G. Bryce, Reiner Giesler, Ruth K. Varner

Permafrost is a blanket of soil that is frozen for more than two years and can trap its contents for hundreds to thousands of years. Now that permafrost soil is thawing. This is particularly significant in peatland permafrost because these wetlands sequester high amounts of carbon. As peatland permafrost degrades, methane emissions are expected to increase as the water table rises and provides a suitable environment for methane production by microbes.

June 9, 2020June 10, 2020

Whose Faces do we See in Geology Textbooks?

Student standing on textbooks in library

Author’s Note: The last few weeks have left us grappling with the profound effects of systemic racism, as seen in the wake of the recent protests and violence all over the USA and the world, as well as the disproportionate effect of COVID-19 on Black communities. This week’s post is dedicated to exploring the impact of another effect of systemic racism: lack of representation in educational spaces, made apparent in geology textbooks.

June 4, 2020February 2, 2021

Rivers of Memory: India

Paper: Evolution of modern river systems: an assessment of ‘landscape memory’ in Indian river systems

Authors: Vikrant Jain, Sonam, Ajit Singh, Rajiv Sinha, S. K. Tandon

“A river cuts through rock not because of its power, but because of its persistence.”
James N Watkins

In geomorphology, the persistence of rivers is etched into the very landscape – a memory of the forces that once shaped it, and continue to do so, slowly, and inexorably. Landscape memory, as Gary John Brierley once wrote, is the imprint of the past upon contemporary landscapes, which include geologic, climatic, and anthropogenic factors.

The rivers of the Indian subcontinent bear witness to forces that shaped them over millennia – and a recent publication in the Journal of International Geosciences traces the evolution of India’s river systems at different time scales.