1,255,060 research outputs found

    The Dynamics of Species Composition Stand Structure and Above Ground Biomass of Undisturbed Forest in East Kalimantan

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    Dinamika Komposisi Spesies Struktur Pohon dan Biomasa di Hutan Terganggu di Kalimantan Timur. Kajian dinamika komposisi spesies dan biomasanya dilakukan selama 4,3 tahun (Desember 2004 - April 2009) di hutan terganggu Kalimantan Timur. Untuk melakukan kajian di gunakan 6 plot permanen (100x100 m2), yang berada di hutan penelitian Samboja. Semua pohon berdiameter > 10 cm dbh (diukur pada posisi 1,3 m diatas tanah). Pada Desember 2004,tercatat 2143 pohon tersebar di plot tersebut terdiri dari 39 famili, 82 genus dan 111 spesies. Pada pengamatan April 2009 tercatat 2466 pohon terdiri dari 40 famili, 86 genus dan 123 jenis.Sebagian besar spesies yang mendominasi adalah Garcinia nervosa dan Trigonostemon laevigatus tetapi setelah pengamatan pada tahun 2009, keduanya tidak lagi mendominasi. Selama kurun 4,3 tahun terjadi penambahan kepadatan 15,1%, basal area 12,9% dan biomasa 11,6%. Penambahan kepadatan tercatat meningkat dari 357 menjadi 411 pohon/ha. Basal area meningkat mulai dari 20,09 menjadi 22,67 m2 ha-1, sedangkan biomasa meningkat dari 286,3 menjadi 319,4 ton ha-1

    Species Composition of Glass Eels (Anguilla Spp.) Recruiting to the Palu River, Central Sulawesi [Komposisi Spesies Glass Eels (Anguilla Spp.) Yang Beruaya Di Muara Sungai Palu, Sulawesi Tengah]

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    Demand for tropical eel seed has been increased and many tropical eel populations are under pressure. To conserve eel biodiversity and manage eel populations sustainably, it is necessary to identify eel species and their recruitment patterns at regional and watershed scales. The research objective was to determine the species composition and temporal recruitment patterns of glass eels recruiting to Palu River in Central Sulawesi. Glass eels sampling were conducted in January-April 2009, May-November 2010 and April-December 2011. Identification under anaesthetic (15-17.5 ppm clove oil solution) was based mainly on the number of ano-dorsal vertebrae (ADV). Species composition was dominated by two commercially species, Anguilla marmorata and A. bicolor pacifica with substantial variation and no clear temporal patterns. Specimens of other species that important from conservation and biodiversity aspects were present at each month but cannot be accurately identified using the ADV method. DNA analysis method is required to identify these specimens

    Changes in Species Richness and Composition of Tiger Moths (Lepidoptera: Erebidae: Arctiinae) among Three Neotropical Ecoregions

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    Paraná, Yungas and Chaco Serrano ecoregions are among the most species-richterrestrial habitats at higher latitude. However, the information for tiger moths, one of the most speciose group of moths, is unknown in these ecoregion. In this study, we assess the species richness and composition on these three ecoregion. Also we investigated whether tiger moths species composition is influenced by climatic factors and altitude. Tiger moths species were obtained with samples from 71 sites using standardized protocols (21 sites were in Yungas, 19 in Paraná and 31 in Chaco Serrano). Rarefaction-extrapolation curves, non-parametric estimators for incidence and sample coverage indices were performed to assess species richness in the ecoregions studied. Non metric multidimensional scaling and adonis test were performed to compare the species composition of tiger moths among ecoregions. Permutest analysis and Pearson correlation were used to evaluate the relationship among species composition and annual mean temperature, annual temperature range, annual precipitation, precipitation seasonality and altitude. Among ecoregions Paraná was the richest with 125 species, followed by Yungas with 63 species and Chaco Serrano with 24 species. Species composition differed among these ecoregions, although Yungas and Chaco Serrano were more similar than Paraná. Species composition was significantly influenced by climatic factors and altitude. This study showed that species richness and species composition of tiger moths differed among the three ecoregions assessed. Furthermore, not only climatic factors and altitude influence the species composition of tiger moths among ecoregions, but also climatic seasonality at higher latitude in Neotropical South America region becomes an important factor.Fil: Beccacece, Hernán Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Zeballos, Sebastián Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Zapata, Adriana Inés. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Diversidad Animal I; Argentin

    Tropical rainforest bird community structure in relation to altitude, tree species composition, and null models in the Western Ghats, India

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    Studies of species distributions on elevational gradients are essential to understand principles of community organisation as well as to conserve species in montane regions. This study examined the patterns of species richness, abundance, composition, range sizes, and distribution of rainforest birds at 14 sites along an elevational gradient (500-1400 m) in the Kalakad-Mundanthurai Tiger Reserve (KMTR) of the Western Ghats, India. In contrast to theoretical expectation, resident bird species richness did not change significantly with elevation although the species composition changed substantially (<10% similarity) between the lowest and highest elevation sites. Constancy in species richness was possibly due to relative constancy in productivity and lack of elevational trends in vegetation structure. Elevational range size of birds, expected to increase with elevation according to Rapoport's rule, was found to show a contrasting inverse U-shaped pattern because species with narrow elevational distributions, including endemics, occurred at both ends of the gradient (below 800 m and above 1,200 m). Bird species composition also did not vary randomly along the gradient as assessed using a hierarchy of null models of community assembly, from completely unconstrained models to ones with species richness and range-size distribution restrictions. Instead, bird community composition was significantly correlated with elevation and tree species composition of sites, indicating the influence of deterministic factors on bird community structure. Conservation of low- and high-elevation areas and maintenance of tree species composition against habitat alteration are important for bird conservation in the southern Western Ghats rainforests.Comment: 36 pages, 5 figures, two tables (including one in the appendix) Submitted to the Journal of the Bombay Natural History Society (JBNHS

    Prime Graphs and Exponential Composition of Species

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    In this paper, we enumerate prime graphs with respect to the Cartesian multiplication of graphs. We use the unique factorization of a connected graph into the product of prime graphs given by Sabidussi to find explicit formulas for labeled and unlabeled prime graphs. In the case of species, we construct the exponential composition of species based on the arithmetic product of species of Maia and M\'endez and the quotient species, and express the species of connected graphs as the exponential composition of the species of prime graphs.Comment: 30 pages, 7 figures, 1 tabl

    Fatty acid composition of forage herb species

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    Diet composition of fish species from the southern continental shelf of Colombia

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    The diet composition of 30 fish species belonging to 16 families from the Pacific Coast of Colombia is described. Benthic crustaceans (37.5%) and bony fishes (23.7%, chiefly demersal) were the most important food items for the fish species analyzed. Data on diet composition of the fish species are presented for the first time which can be a source of information for trophic modeling

    Plant succession on gopher mounds in Western Cascade meadows: consequences for species diversity and heterogeneity

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    Pocket gophers have the potential to alter the dynamics of grasslands by creating mounds that bury existing vegetation and locally reset succession. Gopher mounds may provide safe sites for less competitive species, potentially increasing both species diversity and vegetation heterogeneity (spatial variation in species composition). We compared species composition, diversity and heterogeneity among gopher mounds of different ages in three montane meadows in the Cascade Range of Oregon. Cover of graminoids and forbs increased with mound age, as did species richness. Contrary to many studies, we found no evidence that mounds provided safe sites for early successional species, despite their abundance in the soil seed bank, or that diversity peaked on intermediate-aged mounds. However, cover of forbs relative to that of graminoids was greater on mounds than in the adjacent meadow. Variation in species composition was also greater within and among mounds than in adjacent patches of undisturbed vegetation, suggesting that these small-scale disturbances increase heterogeneity within meadows

    Analysis of soil and species composition

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    Measurements were made during May to October, 1987 and June to August, 1989 over a tallgrass prairie near Manhattan, Kansas. Soil at the experimental site is predominantly Dwight silty clay loam. The prairie was burned on 16 April 1987 and on 28 April 1989 to improve the mix of grasses and forbs. The experimental area was not grazed during 1986 - 1989. A summary of results are given for soil moisture and plant growth; momentum flux and canopy aerodynamic characteristics; evapotranspiration, components of energy balance and canopy conductance; modeling canopy stomatal conductance; canopy photosynthesis, photosynthetic efficiency and water use efficiency; modeling canopy photosynthesis; the carbon dioxide budget in a temperate grassland ecosystem; and photosynthesis and stomatal conductance related to reflectance on the canopy scale
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