2,107 research outputs found

    Prolific fruit output by the invasive tree Bellucia pentamera Naudin (Melastomataceae) is enhanced by selective logging disturbance

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    Selective logging in tropical rain forests may promote population growth of invasive plants. The ability of invaders to respond, specifically in reproductive traits, to increase in resource abundance may allow them to increase their presence in the seed rain of recipient communities. The invasive pioneer tree Bellucia pentamera (Melastomataceae) is currently spreading within Gunung Palung National Park in West Kalimantan, Indonesia. The park has also experienced periods of illegal, small‐scale, selective logging that seem to have facilitated population growth and spread of this invader. We first used fruiting frequency as a proxy for fruit output to make comparisons between B. pentamera and the native tree community of over 200 genera. We then constructed two Generalized Linear Autoregressive Moving Average (GLARMA) models using 13 months of phenology data to predict both fruiting frequency and crop size of B. pentamera under selective logging versus natural treefall disturbance regimes. Bellucia pentamera fruited at considerably higher frequency than all 200 native genera considered. This invader also responded positively to selective logging with both odds of being in fruit and crop sizes at least doubling in logged plots. Prolific seed output of B. pentamera is especially problematic within the lottery competition of tropical rain forest gap tree communities, in which prominence in the seed rain is particularly important. Furthermore, the reproductive response of B. pentamera to selective logging suggests that this harvesting practice may have a considerable role in facilitating this invasion in Southeast Asia.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/144654/1/btp12545.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144654/2/btp12545_am.pd

    The Digital Herbarium: Solutions for Data Collection and Identification of Indonesian Plant Diversity

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    Indonesia is one of the world’s biodiversity hotspots. It is estimated to be the home of 9.5% flowering plant species, making it the seventh country with the highest biodiversity. Plant data collection is necessary to ascertain the level of plant biodiversity, as such data help in conservation efforts and long-term management. One of the methods applied is the collection of plants, with the purpose to acquire as much data about its biological resources. The collected specimen are then gathered and processed into a herbarium to be used as an information source in managing biological resources. Unfortunately, there are some difficulties related to the making and management of a herbarium. This study aims to assess the advantages and disadvantages of photo-specimens (digital herbarium) for documenting plant biodiversity in Indonesia. The methods need steps including biological recording, specimen preparing, macro-mode capturing, and last stage identification. About 2149 plants have been gathered from Borneo, Seram, Waigeo, Flores and Sulawesi which consisted of 152 family, 512 genus, and 1,832 species, with a total of 30391 pictures of plant parts. From the experiment conducted on 672 specimens, it achieved 98.8 % accuracy on the family level and 80.1 % accuracy on the genus level, while the species level reached 78.8%. The results showed that digital herbarium can be used to conduct identification and data collection of plant biodiversity. Furthermore, this method is simple, cheap and relatively easier to conduct. The output is a catalog of plant species in specific areas, which provides better understanding about plant identification and biodiversity, enhances conservation practices, and provides better long-term protection for Indonesian plant biodiversity

    Plant DNA Barcodes, Taxonomic Management and Species Discovery in Tropical Forests

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    DNA barcodes have great potential for species identification and taxonomic discovery in tropical forests. This use of DNA barcodes requires a reference DNA library of known taxa with which to match DNA from unidentified specimens. At an even more basic level, it presupposes that the species in the regional species pool have Latin binomials. This is not the case in species-rich tropical forests in which many species are new to science or members of poorly circumscribed species complexes. This chapter describes a work- flow geared toward taxonomic discovery, which includes the discovery of new species, distribution records, and hybrid forms, and to management of taxonomic entities in forest inventory plots. It outlines the roles of laboratory technicians, field workers and herbarium-based taxonomists, and concludes with a discussion of potential multilocus nuclear DNA approaches for identifying species in recently evolved clades.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94302/1/Dick&Webb2012.pdf8

    The Great American Biotic Interchange: Dispersals, Tectonics, Climate, Sea Level and Holding Pens

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    The biotic and geologic dynamics of the Great American Biotic Interchange are reviewed and revised. Information on the Marine Isotope Stage chronology, sea level changes as well as Pliocene and Pleistocene vegetation changes in Central and northern South America add to a discussion of the role of climate in facilitating trans-isthmian exchanges. Trans-isthmian land mammal exchanges during the Pleistocene glacial intervals appear to have been promoted by the development of diverse non-tropical ecologies

    Interpolated wave functions for nonadiabatic simulations with the fixed-node quantum Monte Carlo method

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    Simulating nonadiabatic effects with many-body wave function approaches is an open field with many challenges. Recent interest has been driven by new algorithmic developments and improved theoretical understanding of properties unique to electron-ion wave functions. Fixed-node diffusion Monte Caro is one technique that has shown promising results for simulating electron-ion systems. In particular, we focus on the CH molecule for which previous results suggested a relatively significant contribution to the energy from nonadiabatic effects. We propose a new wave function ansatz for diatomic systems which involves interpolating the determinant coefficients calculated from configuration interaction methods. We find this to be an improvement beyond previous wave function forms that have been considered. The calculated nonadiabatic contribution to the energy in the CH molecule is reduced compared to our previous results, but still remains the largest among the molecules under consideration.Comment: 7 pages, 3 figure

    Linear enamel hypoplasia and historical change in a central Australian community

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    The document attached has been archived with permission from the Australian Dental Association. An external link to the publisher’s copy is included.Background: The current study extends the use of linear enamel hypoplasia (LEH) to examine the historical changes in living conditions encountered by Aboriginal people at Yuendumu who were born between 1890 and 1960. LEH provides health information beyond written records and gives insight into the relationship between individual health and living conditions during initial and ongoing contact with Europeans. Materials and Methods: The dental casts of 446 people, collected as part of the University of Adelaide longitudinal study of growth and development, were recorded for the presence of hypoplastic defects. Defects were recorded according to the Development Defects of the Enamel (DDE) standards and assigned to developmental units based on their crown position. Results: The frequency of LEH on the permanent dentitions increased five-fold from the 1890-1929 birth cohort to the 1955-1960 cohort. LEH also affected earlier developing enamel units. Deciduous defects did not show a strong temporal trend but overall prevalence was comparable to other disadvantaged groups. Conclusion: The changes in permanent LEH frequency and age distribution correspond to altered living conditions with the worst hypoplasia recorded after settlement of Aboriginal people at Yuendumu. Prior to that period LEH was comparable to precontact Australian populations indicating that resettlement had a dramatic impact on childhood morbidity.J Littleton and GC Townsen
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