Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ecology and conservation of fragmented tropical forests

01.08.2002


Panama City, Panama-Today the world’s tropical forests are not only being cleared at an extraordinary rate, they are also increasingly being divided into fragments that can rapidly lose their original rich biodiversity. At the 2002 meetings of the Association for Tropical Biology, hosted by the Smithsonian Tropical Research Institute (STRI), Panama, this conservation crisis was addressed in a symposium bringing together concerned investigators from throughout the tropics.



Organized by William Laurance of STRI and Pierre-Michel Forget of the Museum d’Histoire Naturelle, Paris, the session included 24 presentations that examined the causes, scope, and consequences of fragmentation in studies from 12 countries on five continents. The range of organisms included was equally broad, extending from mosses to forest trees, and from dung beetles to lemurs. The following are a sampling of the results reported at the meeting.

Tom Lovejoy, of H. John Heinz Center for Science, who initiated the first large scale experimental studies of tropical forest fragmentation in the Brazilian Amazon, the Biological Dynamics of Forest Fragments (BDFF) Project, presented an overview of what has been learned so far and suggested directions for the future. He pointed out that although species declines small fragments may be rapid, larger fragments of 100 hectares or more retain their diversity much longer, enabling us to take steps towards restoration before losses become irreversible.


William Laurance described the rapid changes in forest composition that take place in small forest fragments, based on data collected by the BDFF over the past 22 years. These changes are driven by greatly accelerated tree mortality near forest edges, causing species typical of old growth to decline and disturbance-tolerant species to increase. As a result, the composition of different fragments becomes more similar over time, causing a loss of tree diversity in the fragments taken as a whole even though the diversity decline in individual fragments is limited.

In contrast, data from a naturally fragmented forest in India showed that fragments serve as reservoirs for tree genetic diversity. Rajani Kanth of the University of Agricultural Sciences, Bangalore, presented work with collaborators B. Tambat, G. Ravikanth, U. Shankaar, and K.N. Ganeshaiah, demonstrating that although individual small fragments of shola forest in the Western Ghat mountains are low in genetic diversity, collectively they contain more diversity than large fragments, emphasizing the value of small fragments for conservation.

Jean Paul Metzger of the Universidade São Paolo, Brazil, reported on studies of the effects of fragment size and connectivity on species survival, community richness, and regeneration processes in the Atlantic forest of Brazil. Detailed surveys of trees, vertebrates, and butterflies showed fragmentation affected species richness and diversity for all study groups, and also affected important ecological processes, but some of these effects were unexpected. For example, tree communities in small isolated fragments turned out to be richer in than those in larger connected ones.

Surrounding land use can have important effects on species persistence in fragmented landscapes. Luis Miguel Renjifo of the Insituto Alexander von Humboldt, Colombia, compared the relative abundances of 113 species of birds in forest fragments surrounded by either pastures or exotic tree plantations, to those in plots surrounded by continuous forest. More than 65% of the species showed significant differences in abundance depending on the surrounding type of land use. Some species persisted better in patches surrounded by plantations than in those surrounded by pasture, suggesting that such a land use could be used as a management tool as a complement to habitat protection and restoration.

Future climate change due to global warming may have catastrophic effects on species restricted to fragmented habitats. Steve Williams of James Cook University, Australia, presented an analysis of the potential effects of climate change on the vertebrate fauna of the wet tropics of Australia, especially the 72 species endemic to the region. While a conservative scenario of a 1E C temperature rise would result in the direct loss of only one endemic, a perhaps more likely rise of 3.5E could cause the loss of 50% of the endemic fauna.

William F. Laurance | EurekAlert!
Further information:
http://www.si.edu/

More articles from Ecology, The Environment and Conservation:

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

nachricht International network connects experimental research in European waters
21.03.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Periodic ventilation keeps more pollen out than tilted-open windows

29.03.2017 | Health and Medicine

Researchers discover dust plays prominent role in nutrients of mountain forest ecoystems

29.03.2017 | Earth Sciences

OLED production facility from a single source

29.03.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>