Absence of Elephants and Rhinoceroses Reduces Biodiversity in Tropical Forests

ScienceDaily

A recent study published in the 'Biotropica' journal has revealed that megaherbivores, such as elephants and rhinoceroses, are essential in maintaining the biodiversity of the tropical rainforests of South-East Asia, suggesting they be protected and even reintroduced into areas where have disappeared due to illegal human activity.  The megaherbivores’ ability to disperse seeds from the flora they consume far exceeds the abilities of smaller seed-dispersing herbivores, making them an important factor contributing to the structural integrity of the rainforest and the variety found within that type of environment.   The tight quarters due to the density of plant species within the rainforest make it difficult for the plants to disperse their seeds themselves so they rely on animals to aide in their dispersal.  But plants, such as the mango tree, whose seeds are very large cannot rely on smaller animals to distribute their seeds.  Elephants and rhinos are special in that they ingest the whole fruit, seeds and all, and digest them slowly and inefficiently.  So, when they poop (it always comes back to poop!), most of the seeds come out and they come out virtually unharmed.  This allows them to disperse the seeds across the forests, helping to solve the forest’s own density issue.  

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The underlying message of the study is to stop illegal hunting.  The International Union for Conservation of Nature (IUCN) says that the elephants of South-East Asia are in “danger of extinction” and the two rhinoceros species are “critically endangered”.  Elephant and rhino populations world-wide, not just in Asia, are drastically decreasing.  The Western Black Rhino of Africa was officially declared extinct on November 10, 2011 with the Northern White Rhino of central Africa “possibly extinct” in the wild and the Javan Rhino in Vietnam “probably extinct” (MSNBC).  It is heart wrenching that within the last year we have seen three species of Megafauna go extinct.  Every animal has a profound effect on the environment in which they live; otherwise, they wouldn’t have adapted to be there.  It’s a shame we have to “discover” why they are important to find it necessary to preserve them.