APIRS PicksParticularly interesting new items in the APIRS database.
Selections by reader/cataloger, Mary Langeland; elaborated by Karen Brown.
The population of Myriophyllum quitense (Haloragaceae) at Laguna Toro in the high Andes of Bolivia was noteworthy for possessing some unusual characteristics. Numerous individuals (ca. 5-10% of the population) were noted with leaves arrayed in 5-merous whorls. By contrast, M. quitense typically possesses leaves in 4-merous (occasionally 3-merous) whorls (Orchard 1981). Leaves in 5-merous whorls have only been reported for the species from a single herbarium specimen from North America (Orchard 1981), and, more recently, from Cochabamba's Laguna Alalay (Ritter and Crow 1998).
Ritter, N.P. 2000. Biodiversity and Phytogeography of Bolivia's Wetland Flora. Ph.D. Thesis, University of New Hampshire, 399 pp.
Where the species [Nelumbo lutea] occurs in pure stand the rhizomes form a complex underground network which totals a length of 45 miles per acre. The rate of colonization is phenomenal since a small patch was observed to extend itself radially an average of 45 feet in one growing season. This represents a growth rate of 0.23 feet per day for the entire summer. On this basis six properly spaced patches of lotus (10 feet across) would produce an acre of lotus during one growing period.
Hall, T.F., and Penfound, W.T. 1944. The Biology of the American Lotus, Nelumbo lutea (Wild.) Pers. American Midland Naturalist 31(3):744-758.
Management of nonindigenous species is a crucial aspect of maintaining native biodiversity and normal ecosystem functions. We attempt to guide researchers in developing projects that will be of use to conservation practitioners, tangibly improving applied conservation measures. We advocate a directed approach for conservation research to aid in prioritizing nonindigenous species for intervention by resource managers. This approach includes outlining what needs to be known to make such relative judgments about the impacts of nonindigenous species and the most promising methods by which to obtain such information. We also address active measures that should be taken once priorities have been set, highlighting the roles of risk assessment and research in improving control efforts. Ultimately, a better match between research and practical conservation needs should result in more effective reduction of the effects of nonindigenous species on native species.
Byers, J.E., Reichard, S., Randall, J.M., et al. 2002. Directing Research to Reduce the Impacts of Nonindigenous Species. Conservation Biology 16(3):630-640.
We present the results of a 14-year common garden experiment with the Chinese Tallow Tree (Sapium sebiferum) from its native range (Asia), place of introduction to North America (Georgia) and areas colonized a century later (Louisiana and Texas). Invasive genotypes, especially those from recently colonized areas, were larger than native genotypes and more likely to produce seeds but had lower quality, poorly defended leaves. Our results demonstrate significant post-invasion genetic differences in an invasive plant species. Post-introduction adaptation by introduced plants may contribute to their invasive success and make it difficult to predict problem species.
Siemann, E., Rogers, W.E. 2001. Genetic Differences in Growth of an Invasive Tree Species. Ecology Letters 4:514-518.
In an effort to help modernize neo-tropical plant studies and to make GIS more accessible to botanists, The New York Botanical Garden has developed a digital base map of the Americas with multiple registered map layers that can be superimposed in any combination and may be used to create digital distribution maps from collection lists for dissemination and analysis. The Americas Base Map may be utilized by any botanist affiliated with a nonprofit institution and with access to ArcView®, and it is available on CD or in electronic form by request.
Bletter, N., Janovec, J., Brosi, B., et al. 2003. A Digital Basemap for Studying the Neotropical Flora, The New York Botanical Garden.
We report that an eelgrass bed Zostera marina L. at the Aland Islands, northern Baltic Sea, is dominated by a single genotype which extends over an area of approximately 160x40 m. . . To our knowledge, it represents the largest marine plant identified thus far. Based on estimates of horizontal rhizome growth rates, this clone may be more than 1000 years old. The remarkable phenotypic plasticity of a single genotype which dominates this site illustrates that there is no simple one-to-one relationship between genetic diversity and population persistence in changing and stressful environments.
Reusch, T.B.H., Bostrom, C., et al. 1999. An Ancient Eelgrass Clone in the Baltic. Marine Ecology Progress Ser. 183:301-304.
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