The progressive disappearance of seed-dispersing animals like elephants and rhinoceroses puts the structural integrity and biodiversity of the tropical forest of South-East Asia at risk. With the help of Spanish researchers, an international team of experts has confirmed that not even herbivores like tapirs can replace them.
"Megaherbivores act as the 'gardeners' of humid tropical forests: They are vital to forest regeneration and maintain its structure and biodiversity", as was explained to SINC by Ahimsa Campos-Arceiz, the lead author of the study that was published in the 'Biotropica' journal and researcher at the School of Geography of the University of Nottingham in Malaysia.
In these forests in East Asia, the large diversity of plant species means that there is not enough space for all the trees to germinate and grow. As well as the scarce light, seed dispersion is made more complicated by the lack of wind due to the trees that are up to 90 metres high. Plant life is then limited to seeds dispersed by those animals that eat pulp. They either scatter seeds by dropping their food, regurgitating it or by defecating later on.
The Asian elephant (Elephas maximus) occupies just 5% of its historical range and its range will likely continue to shrink as more forests get cut down.
With the input of hundreds of experts worldwide, the primate review provides scientific data to show the severe threats facing animals that share virtually all DNA with humans. In both Vietnam and Cambodia, approximately 90 percent of primate species are considered at risk of extinction. Populations of gibbons, leaf monkeys, langurs and other species have dwindled due to rampant habitat loss exacerbated by hunting for food and to supply the wildlife trade in traditional Chinese medicine and pets.
A team of researchers from Singapore, Australia, Switzerland, the UK and the USA has carried out a comprehensive assessment to estimate the impact of disturbance and land conversion on biodiversity in tropical forests. In a recent study published in Nature, they found that primary forests – those least disturbed old-growth forests – sustain the highest levels of biodiversity and are vital to many tropical species.
As the human population grows toward 9 billion people and Asia continues to industrialize habitat loss is going to drive many more species to extinction.
|Share |||Randall Parker, 2012 May 16 10:35 PM Environment Species Loss|