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Title: DISPERSAL OF EUGLOSSINE BEES BETWEEN FRAGMENTS OF THE BRAZILIAN ATLANTIC FOREST

Author
item TONHASCA, A - UENF,CAMPOS BRAZIL
item ALBUQUERQUE, G - UENF,CAMPOS BRAZIL
item BLACKMER, JACQUELYN

Submitted to: Journal of Tropical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2002
Publication Date: 1/31/2003
Citation: TONHASCA, A.J., ALBUQUERQUE, G.S., BLACKMER, J.L. DISPERSAL OF EUGLOSSINE BEES BETWEEN FRAGMENTS OF THE BRAZILIAN ATLANTIC FOREST. JOURNAL OF TROPICAL ECOLOGY. 2003. pp. 100-102

Interpretive Summary: The Brazilian Atlantic Forest is one of the 'hot spots' for conservation. After centuries of deforestation, most of the remaining Atlantic Forest exists as small fragments. Pollination may be impaired in these fragments because isolation often negatively influences insect dispersal. To determine if fragmentation in the Atlantic Forest limits dispersal of euglossine bees, we conducted a study at two sites near the town of Conceição de Macabu, Rio de Janeiro State, Brazil. The sites are part of a landscape of forest fragments and pastures surrounding the Desengano mountain range, and were comprised of two adjacent fragments of at least 50 ha. Euglossine bees were sampled simultaneously at two stations located on opposite sides of a pasture that divided the fragments. Direct routes between some stations were blocked by a hill. Bees arriving at baits were captured and marked on the thorax with non-toxic marking pens and then released. A different color was used at each station. Our recaptures indicated that cleared areas did not prevent some euglossine bee species from moving between patches of the Atlantic Forest. Also, steep hills did not prevent the bees from locating baits on the opposite side from where they were released. In the Biological Dynamics of Forest Fragments Project in the Amazon, researchers observed a decline in the number of bees in isolated fragments. This study is frequently cited as evidence for the negative effect of fragmentation on euglossine bees dispersal and consequently their pollinating services. However, these studies were conducted shortly after fragmentation occurred, which could have affected temporarily the local euglossine bee populations. In the Desengano area, where long-established fragments surround the primary forest, euglossine bees were able to move within and between forest patches.

Technical Abstract: The Brazilian Atlantic Forest is one of the world's 'hot spots' for conservation because of its high level of endemism and number of endangered species. After centuries of deforestation, most of the remaining Atlantic Forest is scattered as small fragments on private land. Pollination could be impaired in these fragments because isolation often negatively influences insect dispersal. To determine if fragmentation in the Atlantic Forest limits dispersal of euglossine bees, we conducted a study at two sites near the town of Conceição de Macabu, Rio de Janeiro State, Brazil. The sites are part of a landscape of forest fragments, pastures and areas under regeneration surrounding Desengano mountain range, and are comprised of two adjacent forest fragments of at least 50 ha. Euglossine bees were sampled simultaneously at two stations located on opposite sides of the pasture that divided the fragments. Direct routes between some stations were blocked by a hill. Bees arriving at baits were captured and marked on the thorax with non-toxic marking pens and then released. A different color was used at each station. Our recaptures indicated that cleared areas did not prevent some euglossine bee species from moving between patches of the Atlantic Forest, even to and from very small forest fragments. Also, steep hills did not prevent the bees from locating baits on the opposite side from where they were released. In the Biological Dynamics of Forest Fragments Project in the Amazon, researchers observed a decline in the number of bees in isolated fragments. This study is frequently cited as evidence for the negative effect of fragmentation on euglossine bees dispersal and consequently their pollinating services. However, these studies were conducted shortly after fragmentation occurred, which could have affected temporarily the local euglossine bee populations. In the Desengano area of the Atlantic Forest, where long-established fragments surround the primary forest, euglossine bees were able to move within and between forest patches.