Genetic Variation and Comparison of Effective Dispersal Distances of Two Miconia Species

Gonzalo Rivas, University of Missouri, St. Louis

The present study seeks to quantify local patterns of genetic variation and seed dispersal for two plant species, the tree Miconia calvescens and the shrub Miconia nervosa, in their native Ecuadorian habitats. M. nervosa is widely distributed in Neotropical wet forests and can be found within Yasuní National Park and, thus, at the Tiputini Biodiversity Station, (TBS) where all field work for this species has been performed. For the dispersal analysis at TBS, the field work was concentrated in a core area of 18-ha within the Harpia plot, a one 100-ha plot (~1 km x 1 km) established in upland forest of TBS during 2001 by Drs. Bette Loiselle and John Blake. On the other hand, M. calvescens occurs at higher elevations in the Amazonian highlands (from ~600 to 1400 m.a.s.l), where the same field work effort and methodology will be carried out for this species.

The comparison of genetic variation and effective seed dispersal distances of the two Miconia species in Ecuador will form the main part of Gonzalo Rivas’ Masters thesis at the University of Missouri-Saint Louis, UMSL. This thesis is one stage of a larger project that seeks to compare the ecological and genetic variation of the two target species between the native -Ecuadorian- and introduced -Australian- habitats. Both plant species produce fleshy-fruited berries with seeds dispersed by birds. The plants differ in the size of their disperser assemblages both within and between regions. Field ecological methods and molecular genetic analyses will be used to measure effective dispersal distances and genetic variability by linking established seedlings and saplings with their respective parental plants.

The results will provide baseline data that will help to answer fundamental questions such as how is the genetic structure and effective dispersal of plants in native and invasive habitats influenced by different frugivore assemblages? and how do seed dispersal processes vary between habitats when plants are introduced to new environments with different ecological conditions? One of the overall objectives is to increase our knowledge about the role that animal dispersers play in defining the abundance and genetic variation in plant populations and, potentially, contributing to understanding the process involved in the invasive spread of plants in novel environments. In the long term this study will also assist in management efforts based on scientific methods to control the expansion of invasive plant species, which is one of the main threats to global biodiversity. For the comparison of the larger study (e.g. dispersal analyses in introduced habitats), field research will be conducted in lowland tropical rain forests of northern Queensland, Australia. This work will be performed in coordination with the Commonwealth Scientific and Industrial Research Organization CSIRO, Australia.

 

 

Acknowledgments:

Many thanks to the Missouri Botanical Garden staff, the TBS staff, Universidad San Francisco de Quito, CSIRO staff, and the University of Missouri- Saint Louis for the logistics and human resources help provided. Juan Guevara, Denise Hardesty, Kimberly Holbrook, Julia Salvador, and Carmen Ulloa, provided amazing help in the field and valuable feedback throughout the preparation and preliminary implementation of the present project. This project is funded in the preliminary stage by a University of Missouri- Saint Louis Research Board Award to Bette Loiselle, and a Parker-Gentry Tropical Research Fellowship of the Whitney R. Harris World Ecology Center awarded to Gonzalo Rivas. This project is supported in part by the Commonwealth Scientific and Industrial Research Organization CSIRO, Australia.

For more information:

Bette Loiselle: loiselle@umsl.edu
Gonzalo Rivas: gonzalo.rivas@umsl.edu