Seeds Suffer in Rainforest Fragments
11/16/99
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RELAYED TEXT STARTS HERE:
Title: Seeds Suffer in Rainforest Fragments
Source: Science Daily Magazine, University Of California, Davis
(http://www-news.ucdavis.edu/PubComm/)
http://www.sciencedaily.com/releases/1999/11/991116055536.htm
Status: Copyright 1999, contact source for permission to reprint
Date: November, 16, 1999
In a finding that could have important implications for rainforest
preservation, a researcher from the University of California, Davis,
reports that seeds that fall to the ground in small fragments of
tropical rainforests are three to seven times less likely to sprout
than those that fall in larger, continuous forests.
"Rainforest fragments are subject to many conditions, called 'edge
effects,' that make them less hospitable to germinating seeds," said
Emilio Bruna, a doctoral student in the UC Davis Population Biology
Graduate Group. "Fragments are hotter and drier, and have more light
penetrating the canopy to the forest floor, than continuous forests
do. Those aren't the conditions that rainforest plants are adapted
to, and these new results suggest that the seeds simply can't
survive."
What's more, Bruna said, other research has suggested that plants in
fragments could become inbred, which could make their seeds less
likely to germinate in the first place. Such inbreeding, coupled with
edge effects, could push the reproduction rate so low that the
populations in forest fragments would eventually die away.
Bruna's research was conducted at the Biological Dynamics of Forest
Fragments Project in Manaus, Brazil, which is administered
cooperatively by the Smithsonian Institution and Brazil's National
Institute for Research in the Amazon. It was funded by UC Davis, the
Smithsonian Institution and the U.S. National Science Foundation. His
report was published in the Nov. 11 issue of the journal Nature as a
peer-reviewed "Brief Communication."