Somewhere in Cameroon and 25 to 30 kilometers in from the
nearest dirt road is a spot once inhabited by the lone tent of Tom
Smith, director of the UCLA Center for Tropical Research.
For more than a decade, Smith made his second home in a tent
studying birds as models for ecological biodiversity and
speciation.
Now, in his Hershey Hall office, Smith is working to get the
appropriate and updated scientific knowledge to where it is needed:
the conservation decision-making tables of governmental and
non-governmental organizations.
The need for such a center became especially evident when he was
researching in South Africa and realized that conservationists were
using 10- to 15-year-old data for policy making, Smith said.
Smith’s motivation for founding the center was to answer
questions that many lawmakers, biologists and environmentalists
ask.
Simply put: How do we preserve biodiversity efficiently? Which
ecosystems are most threatened and would be most responsive to
conservation efforts?
“Up until recently, conservationists have protected areas
of high biodiversity and of high threat to human
disturbance,” Smith said.
Scientists and lawmakers have long concentrated their resources
and time to protect highly threatened places of abundant
biodiversity, such as rainforests.
To most people, this doesn’t seem unreasonable or
unexpected because rainforests have been long known as a biozone
declining rapidly due to deforestation.
“On the order of around 100 species are going globally
extinct each day due to rainforest deforestation,” said
Richard Vance, professor of ecology and evolutionary biology.
Smith agrees, but adds that the rainforests may not be the only
place where conservation efforts should be directed.
“Transitional habitats, known as ecotones, are regions
between the grasslands and rainforest and are areas which need to
be prioritized,” Smith said.
Inspired by a scientist in the 1920s to study the importance of
transitional habitats, Smith began his research by finding regions
which were necessary to speciation, and ultimately important to
biodiversity.
A long-standing theory since the 1940s, speciation states that
new species arise through genetic mutations when two populations of
the same species are separated by physical barriers, according to
Steve Nadis in an article he wrote titled, “The Land where
Species are Born.”
This theory counters the long-standing view of scientists that
refugia, zones which had isolated species during the Ice Age, were
key to speciation.
“To me, the refugia hypothesis just didn’t add
up,” Smith said.
So in 1997, he and his colleagues decided to test his refugia
and ecotones hypotheses by spending years trapping and studying
birds with bird nets in a pristine region of Cameroon.
Mist nets are thin, almost invisible nets which birds
inadvertently fly through and become caught.
The scientists would test the trapped birds morphologically and
genotypically and then set them free.
Namely, they took measurements of the birds’ wing spans,
leg length and weight, and beak sizes. In addition, they collected
blood samples to test for gene flow patterns of the species.
“The results indicated that there was great adaptive
biodiversity in the area,” Smith said. In the ecotone, new
species arise when forest species adapt savannah, and vice
versa.
The unique ecotone, rainforest and savannah elevational gradient
contains physical barriers which separate two populations of the
same species to make future speciation possible.
For example, the Cameroon’s little greenbul (Andropadus
virens) of the ecotone region was discovered to sing at a different
pitch than the greenbul in the rainforest.
These conclusions were distinct to years of conservationist
policy, which hardly considered ecotones as potential national
parks and areas of biodiversity. But the most significant outcome
of Smith’s research has been the World Bank’s creation
of the first ecotone national park, titled the million-acre Mbam
Djerem National Park, where Smith himself researched.
In addition, the National Science Foundation gave Smith’s
research team a grant in 1999 to look into ecotones in Africa,
South America and Australia.
“There is good support that these overlapping ecosystems
are essential for speciation,” said Smith.