FORCES BEHIND FOREST LOSS

As the first seven sections of this site have described, tropical rainforests are incredibly rich ecosystems that play a fundamental role in the basic functioning of the planet. Rainforests are home to probably 50 percent of the world's species, making them an extensive library of biological and genetic resources. In addition, rainforests help maintain the climate by regulating atmospheric gases and stabilizing rainfall, protect against desertification, and provide numerous other ecological functions.

However, these precious systems are among the most threatened on the planet. Although the precise area is debated, each day at least 80,000 acres (32,300 ha) of forest disappear from Earth. At least another 80,000 acres (32,300 ha) of forest are degraded. Along with them, the planet loses as many as several hundred species to extinction, the vast majority of which have never been documented by science. As these forests fall, more carbon is added to the atmosphere, climactic conditions are further altered, and more topsoil is lost to erosion.

Despite increased awareness of the importance of these forests, deforestation rates have not slowed. Analysis of figures from the Food and Agriculture Organization of the United Nations (FAO) shows that tropical deforestation rates increased 8.5 percent from 2000-2005 when compared with the 1990s, while loss of primary forests may have expanded by 25 percent over the same period. Nigeria and Vietnam's rate of primary forest loss has doubled since the 1990s, while Peru's rate has tripled.

Overall, FAO estimates that 10.4 million hectares of tropical forest were permanently destroyed each year in the period from 2000 to 2005, an increase since the 1990-2000 period, when around 10.16 million hectares of forest were lost. Among primary forests, annual deforestation rose to 6.26 million hectares from 5.41 million hectares in the same period. On a broader scale, FAO data shows that primary forests are being replaced by less biodiverse plantations and secondary forests. Due to a significant increase in plantation forests, forest cover has generally been expanding in North America, Europe, and China while diminishing in the tropics. Industrial logging, conversion for agriculture (commercial and subsistence), and forest fires—often purposely set by people—are responsible for the bulk of global deforestation today.

Taken from:
mongabay

Frogs species discovered living in elephant dung.

Three different species of frogs have been discovered living in the dung of the Asian elephant in southeastern Sri Lanka. The discovery—the first time anyone has recorded frogs living in elephant droppings—has widespread conservation implications both for frogs and Asian elephants, which are in decline.

"I found the frogs fortuitously during a field study about seed dispersal by elephants," Ahimsa Campos-Arceiz, a research fellow from the National University of Singapore, told Monagaby.com. "I thought it was an interesting phenomenon and commented it with some colleagues, experts on elephant and amphibian ecology. None of them had heard about such a thing before. Local people in the study area…seemed also unaware of it."

Mushroom growing out of dung pile. Photo by Campos-Arceiz.

Campos-Arceiz examined 290 elephant dung piles and found six frog individuals in five dung piles, representing three species: the ornate narrow-mouthed frog Microhyla ornata, another narrow-mouthed species Microhyla rubra, and a frog species in the Sphaerotheca genus.

While Campos-Arceiz is uncertain why the frogs were residing in the elephant dung, he speculates that "elephant dung provides a good shelter. I found the frogs in an arid area during the dry season. Under such conditions and in the absence of litter, elephant dung is probably a good alternative to spend the day in. Elephants digest food very poorly. Their feces contain a large proportion of undigested material and are highly fibrous. When fresh, elephant dung is humid and probably cooler than the environment during the day. Moreover, frogs could eat some of the many invertebrates present in elephant dung."

"Elephants (and their dung!) can play a facilitative role for other organisms," Campos-Arceiz says explaining the many roles elephant dung plays in the larger forest ecosystem. "For plants, elephant dung provides a suitable germination environment after being dispersed by elephants. Fungi are also dispersed by elephants and some are extremely common growing in elephant dung. Invertebrates are extremely common as well. I was indeed impressed with the quantity and diversity of invertebrates in some dung piles…Vertebrates like jungle fowls and land monitors pick elephant dung to feed on these invertebrates; others like small birds and mammals can consume undigested material from the dung, sometimes acting as secondary seed dispersers. Elephant dung plays some role in nutrient cycling as well, moving nutrients from the vegetation to the soil. Elephants are capable of controlling the availability of resources for other organisms modifying the physical environment acting thus as ecosystem engineers."

To test the importance of elephant dung regarding forest biodiversity, Campos-Arceiz searched through an additional 180 dung piles of free-ranging cows and buffaloes and found no frogs and far less diversity of invertebrates.

Classified as Endangered by the IUCN Red List, Asian elephants are threatened by the illegal ivory trade and habitat degradation and loss. Their range has shrunk significantly over the last centuries, and many researchers worry it will contract further.

Taken from:

mongabay.com