Biodiversity’s Holy Grail Is in the Soil

[OKIsItJustMe]

http://www.stri.org/english/about_stri/media/press_releases/PDFs/STRI-PR10_Soil_Biota_release_10.pdf

...

June 25, 2010

...

Biodiversity’s Holy Grail Is in the Soil

Why are tropical forests so biologically rich? Smithsonian researchers have new evidence that the answer to one of life’s great unsolved mysteries lies underground, according to a study published in the journal, Nature.

“We’ve known for a long time that tree seedlings do not grow and survive well under their mothers or other adult trees of the same species,” said Scott Mangan, postdoctoral fellow at the University of Wisconsin—Milwaukee and the Smithsonian Tropical Research Institute in Panama.

“One explanation for the maintenance of the diversity of tropical trees is that adult trees harbor pests and diseases that harm seedlings of their own species more than they do seedlings of other species.” The experiments show that underground organisms are key to the maintenance of species diversity and patterns of tree-species relative abundance. The detrimental effects of soil organisms from adult trees not only explain seedling growth and survival patterns, but moreover that these effects are much more severe for seedlings of rare species than for seedlings of common species.

Mangan planted seedlings of five species under adults of each species in the forest and coupled that experiment with a greenhouse experiment in which he grew seedlings of each species in soil collected around the base of each of the other species. Consistent across experiments, Mangan and colleagues found that the ability of seedlings of a species to survive when grown in soil from the same species actually predicted how common or rare they are as adults.

Their result closely mirrors results presented in Science magazine this week by Liza Comita and colleagues, based on a survey of survival of 30,000 tree seedlings—part of a major effort to understand forest dynamics worldwide sponsored, in part, by the HSBC Climate Partnership.

...

###
Ref. Scott A. Mangan, Stefan A. Schnitzer, Edward A. Herre, Keenan M.L. Mack, Mariana C. Valencia, Evelyn I. Sanchez and James D. Bever. 2010. Negative plant-soil feedbacks predict relative species abundance in a tropical forest. Nature.
http://www.nature.com/nature/journal/vnfv/ncurrent/full/nature09273.html

...