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Study Finds Ancient Warming Greened Antarctica

By Guest PostJune 20, 2012Environment, Sciencealgae, ancient warming, andrill campaign, antarctic coast, antarctic ice sheet, atmospheric water vapor, aura spacecraft, carbon dioxide, climate system, fossil, frozen continent, greened antarctica, hydrogen isotope ratio, ian raine, jung eun lee, louisiana state university, margins of antarctica, marine organisms, microscopic pores, middle miocene epoch, miocene epoch, model, modern humans, NASA, past climate, plant leaf, plant life, pollen, precipitation, ross ice shelf, sarah j feakins, sediment core, sophie warny, southern mcmurdo sound, vegetation, vegetation on antarctica, wax remnants

PASADENA, Calif. — A new university-led study with NASA participation finds ancient Antarctica was much warmer and wetter than previously suspected. The climate was suitable to support substantial vegetation — including stunted trees — along the edges of the frozen continent.

The team of scientists involved in the study, published online June 17 in Nature Geoscience, was led by Sarah J. Feakins of the University of Southern California in Los Angeles, and included researchers from NASA’s Jet Propulsion Laboratory in Pasadena, Calif., and Louisiana State University in Baton Rouge.

By examining plant leaf wax remnants in sediment core samples taken from beneath the Ross Ice Shelf, the research team found summer temperatures along the Antarctic coast 15 to 20 million years ago were 20 degrees Fahrenheit (11 degrees Celsius) warmer than today, with temperatures reaching as high as 45 degrees Fahrenheit (7 degrees Celsius). Precipitation levels also were found to be several times higher than today. (more…)

800-Year-Old Farmers Could Teach Us How to Protect The Amazon

By Guest PostApril 14, 2012Environmentagriculture, Amazon, amazonian forest, amazonian savannas, archaeologist, cattle ranching, charcoal, climate, columbian encounter, conservation, deforestation, doyle mckey, ecosystem, Environment, european settlers, farming, farmland sustainably, fire, francis mayle, french guiana, global warming, indigenous people, jose iriarte, mitchell power, old world diseases, paleoecologist, phytoliths, plant remains, pollen, raised field, savannas, stephen rostain, sustainable use, university of exeter, university of montpellier

In the face of mass deforestation of the Amazon, we could learn from its earliest inhabitants who managed their farmland sustainably.

Research from an international team of archaeologists and paleoecologists, published in the journal Proceedings of the National Academy of Sciences, shows for the first time that indigenous people, living in the savannas around the Amazonian forest, farmed without using fire.

Led by the University of Exeter, the research could provide insights into the sustainable use and conservation of these globally-important ecosystems, which are being rapidly destroyed. Pressure on the Amazonian savannas today is intense, with the land being rapidly transformed for industrial agriculture and cattle ranching.

By analysing records of pollen, charcoal and other plant remains like phytoliths spanning more than 2,000 years, the team has created the first detailed picture of land use in the Amazonian savannas in French Guiana. This gives a unique perspective on the land before and after the first Europeans arrived in 1492. (more…)

Where Have All the Flowers Gone?

By Guest PostJune 18, 2011Nature, Scienceabraham miller rushing, animal pollinated plants, bees, bumblebees, climate change, colorado mountain meadows, david inouye, davis, elk mountains of colorado, flower species, george aldridge, high mountain wildflower season, hummingbirds, jessica forrest, national science foundation, nectar, petals, pollen, pollinators, rocky mountain biological laboratory, rocky mountains, sub alpine meadows, summer wildflower, tucson, university of california, university of maryland, usa national phenology network, wildflowers, william barr

*High-mountain wildflower season reduced, affecting pollinators like bees, hummingbirds*

It’s summer wildflower season in the Rocky Mountains, a time when high-peaks meadows are dotted with riotous color.

But for how long?

Once, wildflower season in montane meadow ecosystems extended throughout the summer months. But now scientists have found a fall-off in wildflowers at mid-season. (more…)

UF Pine lsland Pollen Study Leads to Revision of State’s Ancient Geography

By Guest PostMarch 3, 2011Scienceavon park formation, calusa indian village, david jarzen, deep injection well, early eocene, evolution of mammals, florida, flowering plants, fort myers, fossils, fredrick rich, geologic history, gray lignitic clay, jonathan bloch, limestone, marine environments, oligocene epoch, paleontologist, phytoplankton, pine island, pollen, sea level

GAINESVILLE, Fla. — A new University of Florida study of 45-million-year-old pollen from Pine Island west of Fort Myers has led to a new understanding of the state’s geologic history, showing Florida could be 10 million to 15 million years older than previously believed.

The discovery of land in Florida during the early Eocene opens the possibility for researchers to explore the existence of land animals at that time, including their adaptation, evolution and dispersal until the present. (more…)

Ancient Forest Emerges Mummified From the Arctic

By Guest PostDecember 17, 2010Environment, Sciencealberta, Arctic, arctic biodiversity, arctic ice, atmosphere, birch, branches, canada, carbon dioxide, david elliot, ellesmere island, ellesmere island national park, global cooling, global warming, joel barker, landslide, melt, melting glacier, methane, mummified forest, North America, ohio state university, organic material, pollen, spruce, tree trunks

SAN FRANCISCO — The northernmost mummified forest ever found in Canada is revealing how plants struggled to endure a long-ago global cooling.

Researchers believe the trees — buried by a landslide and exquisitely preserved 2 to 8 million years ago — will help them predict how today’s Arctic will respond to global warming.

They also suspect that many more mummified forests could emerge across North America as Arctic ice continues to melt. As the wood is exposed and begins to rot, it could release significant amounts of methane and carbon dioxide into the atmosphere — and actually boost global warming. (more…)

The Genetics of Self-Incompatibility

By Guest PostNovember 6, 2010Nature, Scienceantigens, female, fertilization, genes, genetic, immune response, inbreeding, male, offspring, organism, petunia, petunia pistil, petunia pollen, plant, pollen, proteins, rna, rna-destroying enzyme, seiji takayama, sexual organs, t-cell receptors, teh-hui kao

*Petunias show that the mechanisms behind inbreeding prevention are similar to immune response*

About the image: The female part of the petunia flower secretes an enzyme that is designed to deter pollen tube growth, thereby preventing fertilization. However, in the cases that the pollen has come from a genetically different plant, the pollen produces its own protein that combats the pistil’s enzyme. With the enzyme out of the way, the pollen tube can keep growing and fertilization can occur. Image credit: Zina Deretsky, National Science Foundation

Inbreeding is a bad strategy for any organism, producing weak and problematic offspring. So imagine the challenge of inbreeding prevention in a plant where male and female sexual organs grow right next to each other! Such is the genetic conundrum faced by the petunia. (more…)

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