Uzay Uğur Sezen B.S. 1995, M.S. 1998, Department of
Biology, Middle East Technical University, Ankara, Turkey PhD 2007, Department of
Ecology & Evolutionary, University of Connecticut, Storrs, Connecticut |
Gene flow, parentage analysis, tropical ecology, population genetics.
Parentage analysis of the
canopy palm Iriartea deltoidea
in a tropical second-growth forest: Research conducted with my advisor,
Robin L. Chazdon, examines the recolonization of a second-growth forest by an animal dispersed
canopy palm tree (Iriartea deltoidea) in Caribbean lowlands of Costa Rica.
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Me (holding a modified crossbow used for sampling tall canopy tree leaves) and
my field assistant Rigoberto G. Vargas posing in front of a downed Iriartea leaf frond for DNA extraction at
La Selva Biological Field Station, Costa Rica. |
Click
here to see a video of sampling from tall palm trees. |
Recolonization of
tropical second-growth forests: Despite a long history of international
and local efforts old growth tropical forests are still under intense human pressure.
Second-growth forests are naturally recovering abandoned fields after complete or near
complete logging of old-growth forest vegetation. Today, second-growth forests cover
more area than primary forests in many tropical countries and represent the forests of
the future. Regeneration of diverse secondary forests requires successful seed dispersal
events and we have no accurate information
about the sources of seeds colonizing these areas. Parentage analysis on established
trees is a powerful tool to reveal patterns of successful seed dispersal events.
Reconstruction of parent-offspring relationships with the use of molecular genetic
markers can provide accurate information about different phases of recolonization
into a young forest stand by analysing distinct demographic classes of founders.
Contribution of nearby parents to the gene pool of founder trees in second-growth forest
has important implications for restoration/rehabilitation and conservation of such
valuable world resource.
My research focus is on parentage analysis of an abundant neo-tropical palm Iriartea deltoidea, to determine patterns of successful seed dispersal into a regenerating second-growth forest in Costa Rica. Iriartea has a high dispersal ability. It has strong association with a suite of animal dispersers including the chestnut mandibled toucan (Ramphastos swainsonii). It also has a very wide geographic distribution from Nicaragua in north to Bolivia in south, from western Amazon basin of Brazil in east to Venezuela in west. It is found along an elevational gradient between lowland and montane rainforest up to 1300m. Palms are structurally and functionally important components of tropical rainforests worldwide and therefore are particularly informative group to understand genetic aspects of recolonization in second-growth forests. |
1. Geographic distribution of Iriartea deltoidea. |
2. Location of La Selva Biological Field Station at the northern tip of Braulio Carrillo National Park (Heredia province, Costa Rica). |
3. 1977 Aerial photo
of my study site just before the abandonement of the land. Red rectangle is 30 ha plot (1 km x 300 m).
Shown in yellow is the boundary between old-growth forest and cleared pasture. Black dots are grid
tubes of La Selva coordinate system.
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4. Map of
reproductively mature Iriartea trees in 35 ha study area. I extended the old-growth
portion of the study area by 5 ha during the fall 2004. Shown in red are newly sampled trees.
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"Genetic consequences of tropical second-growth forest regeneration" Science Vol.307 p.891 (2005)
Abstract
News about this article:
American Scientist
New Scientist
Voice of America(VoA)
UCONN Advance
ATLAS Magazine, Turkey
Radikal, Turkey
La Nacion Costa Rica
Folha de Sao Paolo Brasil
"Multigenerational genetic analysis of tropical secondary forest regeneration" Ecology Vol.88 pp. 3065-3075 (2007)