The 2004 Tsunami took the lives of 230,000 coastal residents in Asia, but mangrove forests saved thousands more.
Chandra Giri, a land change scientist with the U.S. Geological Survey, was intrigued.
“I watched TV news reports six years ago showing lives and property saved by mangroves during the tsunami,” said Giri. “These trees really do have a role to play as a protective barrier against some natural disasters.”
Mangroves, or salt-tolerant coastal forests, provide food, habitat and carbon storage, but their ability to safeguard against hurricanes, tsunamis and floods is less clear.
Giri set out to assess the protective value of mangrove forests, but a lack of distribution data sent his team of international scientists looking at where mangrove forests are rather than what they do.
The team’s high-resolution satellite-based map of global mangrove distribution, which was published in the Journal of Global Ecology and Biogeography this summer, is the first of its kind. It shows mangroves on about 53,000 square miles of earth’s surface—12 percent less than previously thought.
This reduction, coupled with increasing threats to mangroves, is cause for conservation concern. According to Giri, “Thirty five percent of mangrove ecosystems disappeared between 1980 and 2000…due to agricultural expansion, urban development and shrimp farming.”
Stress typically has negative effects on human health, but stress in plants may actually prove beneficial to the health of the planet as well as its human inhabitants.
Based on observation, genetic studies and computer modeling, a group of scientists from the National Center for Atmospheric Research (NCAR) published a paper in Science Express Thursday stating that deciduous plants worldwide absorb about 36 percent more polluting chemicals, or oVOCs, than previously thought.
“Plants clean our air to a greater extent that we had realized,” said Thomas Karl, an NCAR scientist and the lead author of the study. “They actively consume certain types of air pollution.”
Oxygenated volatile organic compounds, or oVOCs, are a type of air polluting chemical with negative effects on both human health and the environment.
When the plants in the study were under stress, in the form of physical wounds or exposure to irritants such as ozone pollution, they absorbed more oVOCs from the atmosphere.
“As a response to various types of stress,” said Chhandak Basu, one of the study’s scientists from the University of Northern Colorado, “plants can actually adjust their metabolism and increase their uptake of atmospheric chemicals.”
The price tag on a forest in today’s global market is a reflection of the lumber or paper it can produce.
According to Daniel Bunker, though, a forest’s value should also include the ecological services it provides: clean water, climate regulation, biomedical prospects and wildlife protection, among others.
“Because these latter services are typically not bought and sold,” said Bunker, an assistant professor in the New Jersey Institute of Technology’s Federated Department of Biology, “their value is often ignored by landowners and policymakers.”
Bunker is one of 16 leading biodiversity scientists working to change this.
The team’s most recent paper, “Ecosystem Services for 2020,” was published in Science magazine Friday, and encourages recognition of these ecological service values under the Convention on Biological Diversity (CBD).
“By placing value on these and all services that biodiversity produces,” says Bunker, “we will be better positioned to conserve the biodiversity that we so clearly rely upon for human well- being."
The scientists hope their recommendations will encourage signatory nations at the 10th Conference of the Parties—the meeting of CBD’s governing body in Nagoya, Japan this week—to make ambitious and achievable goals for their 2020 CBD targets.
As our climate warms, scientists expect evapotranspiration to follow suit. On a global scale, though, this apparently is not the case.
In an article published in Nature on Sunday, scientists said evapotranspiration—the movement of water from the land to the atmosphere—increased during the 80s and 90s, as warmer temperatures increased ocean evaporation and precipitation.
But beginning in 1998, evapotranspiration actually slowed or stopped in much of the southern half of the globe. Soils in these areas have become drier and consequently release less water. The affected areas include both historically dry regions and tropical rainforests.
"We didn't expect to see this shift in evapotranspiration over such a large area of the Southern Hemisphere," said Beverly Law, a professor of global change forest science at Oregon State University and co-author of the study.
Scientists do not have enough historical data to determine if the change is due to natural variability or a long-term global trend, but the latter implies serious consequences.
Less evapotranspiration means less global cooling, as well as more frequent and intense heat waves. This will also increase drought stress, lowering the productivity and carbon absorption of plants.
“Car. Bun. Seek. West. Race. Shun.”
Both phrases say the same thing, but the latter is far more efficient.
Similarly, both ordinary plants and genetically modified plants sequester carbon, but scientists at the Lawrence Berkeley and Oak Ridge National Laboratories assert that the latter can now be far more efficient.
The UN defines carbon sequestration as “the process of removing carbon from the atmosphere and storing it in a reservoir. “
Plants are a natural carbon reservoir. During photosynthesis they incorporate atmospheric carbon into their biomass. This long-lived form of carbon eventually ends up in the soil and can remain out of circulation for hundreds of years.
The study was published Friday in the October issue of BioScience, and included four strategies for boosting biological carbon sequestration through the genetic modification of plants:
1. Improving the light absorption efficiency of plants
2. Increasing the amount of carbon plant sends to their roots
3. Improving stress-resistance, allowing plants to grow on marginal land
4. Increasing crop and bioenergy yields
With such improved efficiency, scientists anticipate the removal of several billion tons of additional carbon from the atmosphere annually, which may slow the accumulation of greenhouse gases and mitigate global warming.