With California's wild Coho salmon populations down to 1% of their former numbers, there's growing evidence that beavers - long reviled as a pest of the waterways - are essential to restore the species, writes Maria Finn. In the process, they raise water tables, recharge aquifers and improve water quality. What's not to love?

Beavers are the single most important factor in determining whether Coho salmon persist in California. They work night and day, don't need to be paid, and are incredible engineers.

Scientists for the first time have simultaneously compared widespread impacts from two of the most common forest insects in the West – mountain pine beetle and western spruce budworm – an advance that could lead to more effective management policies.

By combining data from satellites, airplanes and ground-based crews, the researchers have shown in unprecedented detail how insects affect Western forests over decades.

In the past, forest managers relied on airplane surveys to evaluate insect damage over broad areas.

The activity of the Sun is an important factor in the complex interaction that controls our climate. New research now shows that the impact of the Sun is not constant over time, but has greater significance when the Earth is cooler. There has been much discussion as to whether variations in the strength of the Sun have played a role in triggering climate change in the past, but more and more research results clearly indicate that solar activity - i.e. the amount of radiation coming from the Sun - has an impact on how the climate varies over time.

This post originally was published on WRI.org.

How does bioenergy contribute to a sustainable food and climate future?

A new WRI paper finds bioenergy can play a modest role using wastes and other niche fuelstocks, but recommends against dedicating land to produce bioenergy. The lesson: do not grow food or grass crops for ethanol or diesel or cut down trees for electricity.

Even modest quantities of bioenergy would greatly increase the global competition for land. People already use roughly three-quarters of the world’s vegetated land for crops, livestock grazing and wood harvests. The remaining land protects clean water, supports biodiversity and stores carbon in trees, shrubs and soils -- a benefit increasingly important for tackling climate change. The competition for land is growing, even without more bioenergy, to meet likely demands for at least 70 percent more food, forage and wood.

A study led by atmospheric physicists at the University of Toronto finds that global warming will not lead to an overall increasingly stormy atmosphere, a topic debated by scientists for decades. Instead, strong storms will become stronger while weak storms become weaker, and the cumulative result of the number of storms will remain unchanged. "We know that with global warming we'll get more evaporation of the oceans," said Frederic Laliberte, a research associate at U of T's physics department and lead author of a study published this week in Science. "But circulation in the atmosphere is like a heat engine that requires fuel to do work, just like any combustion engine or a convection engine."

Christmas came early this year for gray wolves thanks to an awesome ruling handed down by a federal judge that immediately reinstated federal protection for them in the Great Lakes region.

The ruling affects wolves in Michigan, Minnesota and Wisconsin, and, unless overturned, will stop these three states from holding any more hunting and trapping seasons, which is expected to protect an estimated 3,700 wolves.

Weddell seals have biological adaptations that allow them to dive deep--as much as of hundreds of meters--while hunting, but also an uncanny ability to find the breathing holes they need on the surface of the ice. Now, researchers supported by the National Science Foundation (NSF) believe they have figured out how they do it--by using the Earth's magnetic field as a natural GPS. "This animal, we think, may be highly evolved with an ability to navigate using magnetic sense in order to find ice holes some distance apart and get back to them safely," explained Randall Davis of the Department of Marine Biology at Texas A&M University. If the hypothesis turns out to be true, it would represent the first evidence of such a trait in a marine mammal.

There are consequences of the successful efforts worldwide to save beavers from extinction. Along with the strong increase in their population over the past 100 years, these furry aquatic rodents have built many more ponds, establishing vital aquatic habitat. In doing so, however, they have created conditions for climate changing methane gas to be generated in this shallow standing water, and the gas is subsequently released into the atmosphere. In fact, 200 times more of this greenhouse gas is released from beaver ponds today than was the case around the year 1900, estimates Colin J. Whitfield of the University of Saskatchewan in Canada. He led a study in Springer's journal AMBIO² about the effect that the growth in beaver numbers in Eurasia and the Americas could be having on methane emissions.

The fur trade of the sixteenth to nineteenth centuries nearly led to the extinction of beaver populations worldwide. After trapping was limited and conservation efforts led to the re-introduction of these animals into their natural ranges, the number of North American (Castor canadensis) and Eurasian (Castor fiber) beavers grew. The North American beaver has also been introduced to Eurasia and South America (specifically the archipelago of Tierra del Fuego); establishment of these populations has, in effect, created an anthropogenic greenhouse gas source in these landscapes.

Princeton University researchers have uncovered a previously unknown, and possibly substantial, source of the greenhouse gas methane to the Earth's atmosphere. After testing a sample of abandoned oil and natural gas wells in northwestern Pennsylvania, the researchers found that many of the old wells leaked substantial quantities of methane. 

Raptors, or birds of prey, some of which are endangered species, typically live in environments that provide natural land cover, such as forests and grasslands. Protecting endangered raptor species helps maintain food chain balance and prevents overpopulation of common raptor prey, such as snakes and rodents. As more businesses are built on the edges of urban areas, land where raptors once lived becomes industrialized, which raises concerns about the consequences of habitat destruction on raptor populations. Now, University of Missouri researchers have found that businesses can contribute to raptor preservation efforts by engaging in less development of lawn areas and increased planting or preservation of native grasslands and woodlots.