Spatial Scales of Pollen and Seed-Mediated Gene Flow in Tropical Rain Forest Trees

University of Michigan Department of Ecology and Evolutionary Biology and Herbarium 830 North University Avenue Ann Arbor MI 48109 USA
Tropical Plant Biology 04/2008; 1(1):20-33. DOI: 10.1007/s12042-007-9006-6

ABSTRACT Gene flow via seed and pollen is a primary determinant of genetic and species diversity in plant communities at different
spatial scales. This paper reviews studies of gene flow and population genetic structure in tropical rain forest trees and
places them in ecological and biogeographic context. Although much pollination is among nearest neighbors, an increasing number
of genetic studies report pollination ranging from 0.5–14km for canopy tree species, resulting in extensive breeding areas
in disturbed and undisturbed rain forest. Direct genetic measures of seed dispersal are still rare; however, studies of fine
scale spatial genetic structure (SGS) indicate that the bulk of effective seed dispersal occurs at local scales, and we found
no difference in SGS (Sp statistic) between temperate (N = 24 species) and tropical forest trees (N = 15). Our analysis did find significantly higher genetic differentiation in tropical trees (F
ST = 0.177; N = 42) than in temperate forest trees (F
ST = 0.116; N = 82). This may be due to the fact that tropical trees experience low but significant rates of self-fertilization and bi-parental
inbreeding, whereas half of the temperate tree species in our survey are wind pollinated and are more strictly allogamous.
Genetic drift may also be more pronounced in tropical trees due to the low population densities of most species.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background and Question: The harvesting of medicinal plants from wild sources is escalating in many parts of the world, compromising the long-term survival of natural populations of medicinally important plants and sustainability of sources of raw material to meet pharmaceutical industry needs. Although protected areas are considered to play a central role in conservation of plant genetic resources, the effectiveness of protected areas for maintaining medicinal plant populations subject to intense harvesting pressure remain largely unknown. We conducted genetic and demographic studies of Nothapodytes nimmoniana Graham, one of the extensively harvested medicinal plant species in the Western Ghats biodiversity hotspot, India to assess the effectiveness of protected areas in long-term maintenance of economically important plant species. Methodology/Principal Findings: The analysis of adults and seedlings of N. nimmoniana in four protected and four non-protected areas using 7 nuclear microsatellite loci revealed that populations that are distributed within protected areas are subject to lower levels of harvesting and maintain higher genetic diversity (H e 50.816, H o 50.607, A518.857) than populations in adjoining non-protected areas (H e 50.781, H o 50.511, A515.571). Furthermore, seedlings in protected areas had significantly higher observed heterozygosity (H o 50.630) and private
    PLoS ONE 12/2014; 9(12):e112769. · 3.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: a b s t r a c t The future of tropical biodiversity in human-dominated landscapes will be conservation and restoration of processes of seed dispersal by birds and mammals. Here the Diversity Storage Hypothesis posits that immense biological diversity resides within skewed species-abundance distributions of tropical trees, and further predicts that many species will adjust to increases of 1.5–3.0 °C anticipated from climate change by 2100. Common and widespread tropical trees (>100,000,000 individuals) may shift ranges but are unlikely to face extinction. Many rare species (e.g. <1000 individuals) have a more precarious future. The latter may be declining species bound for extinction, incipient species adjusting to environmental changes, or relics of past warmer and more seasonal climates that will be resurrected if processes of seed dispersal allow them to persist and spread. In fragmented agricultural landscapes, preserved or planted corridors, buffers and stepping-stone habitat patches around and between forest remnants are more vital than efforts to preserve or create contemporary forest compositions, dominance relations, and species-abundance distributions. An implication of Diversity Storage is that it is more important to facilitate migration into and out of changing landscapes to allow inherent diversity to adjust and coexist with agricultural economies than to resist change. © 2014 The Author. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (
    Global Ecology and Conservation. 11/2014; 2:349-358.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The montane forests of Africa represent some of the Earth's most diverse and threatened ecosystems. In particular, those in West Africa have received comparatively little attention from scientists in terms of understanding the ecology and biodiversity of their species. This thesis wishes to understand genetic and ecological factors that underpin the long-term survival of selected tree species (Cordia millenii, Entandrophragma angolense, Lovoa trichilioides) in the montane forests of the Mambilla Plateau, Nigeria. The results obtained here provide a strong foundation for future work that wishes to preserve the diverse forests of this region.
    01/2014, Degree: MSc Evolutionary Biology, University of Canterbury, Supervisor: Senior supervisor: A/prof Hazel Chapamn, Associate supervisors: Dr Marie Hale & Daniel Stouffer

Full-text (4 Sources)

Available from
May 16, 2014