986 resultados para CRÍA DE AVES - COLOMBIA


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Recruitment, defined and measured as the incorporation of new individuals (i.e. coral juveniles) into a population, is a fundamental process for ecologists, evolutionists and conservationists due to its direct effect on population structure and function. Because most coral populations are self-feeding, a breakdown in recruitment would lead to local extinction. Recruitment indirectly affects both renewal and maintenance of existing and future coral communities, coral reef biodiversity (bottom-up effect) and therefore coral reef resilience. This process has been used as an indirect measure of individual reproductive success (fitness) and is the final stage of larval dispersal leading to population connectivity. As a result, recruitment has been proposed as an indicator of coral-reef health in marine protected areas, as well as a central aspect of the decision-making process concerning management and conservation. The creation of management plans to promote impact mitigation,rehabilitation and conservation of the Colombian coral reefs is a necessity that requires firstly, a review and integration of existing literature on scleractinian coral recruitment in Colombia and secondly, larger scale field studies. This motivated us to summarize and analyze all existing information on coral recruitment to determine the state of knowledge, isolate patterns, identify gaps, and suggest future lines of research.

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Fringillidae is a large and diverse family of Passeriformes. So far, however, Fringillidae relationships deduced from morphological features and by a number of molecular approaches have remained unproven. Recently, much attention has been attracted to mitochondrial tRNA genes, whose sequence and secondary structural characteristics have shown to be useful for Acrodont Lizards and deep-branch phylogenetic studies. In order to identify useful phylogenetic markers and test Fringillidae relationships, we have sequenced three major clusters of mitochondrial tRNA genes from 15 Fringillidae, taxa. A coincident tree, with coturnix as outgroup, was obtained through Maximum-likelihood method using combined dataset of 11 mitochondrial tRNA gene sequences. The result was similar to that through Neighbor-joining but different from Maximum-parsimony methods. Phylogenetic trees constructed with stem-region sequences of 11 genes had many different topologies and lower confidence than with total sequences. On the other hand, some secondary structural characteristics may provide phylogenetic information on relatively short internal branches at under-genus level. In summary, our data indicate that mitochondrial tRNA genes can achieve high confidence on Fringillidae phylogeny at subfamily level, and stem-region sequences may be suitable only at above-family level. Secondary structural characteristics may also be useful to resolve phylogenetic relationship between different genera of Fringillidae with good performance.

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Yuhina 11 10 StachyrisZosterops Cyt bND3 RNA 12S, 16S 2379bp S. dennistouniS. striataS. whiteheadi Z. japonicusZ. erythropleurusZ. palpebrosus Y. gularis Y. occipitalis Y. flavicollis Y. bakeri Y. everetti Y. castaniceps Staphiada Harrison, 1986a, bY. zantholeuca Erpornis Cibois et al., 2002 5.74Mya 1.66Mya Y. brunneiceps 5.05Mya 51 Y. humilis 2 myoglobin intron 7-fibrinogen intron7, -fibint 7

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Historicamente, a expanso de atividades agropecurias sobre reas naturais considerada uma das principais ameaas biodiversidade. Desmatamentos, uso do fogo, superpastoreio, monocultura, mecanizao intensiva e uso indiscriminado de agrotxicos diminuem a diversidade da flora e da fauna (RAMBALDI; OLIVEIRA, 2003). Por outro lado, muitas reas consideradas de grande valor para a conservao da biodiversidade esto inseridas em um mosaico de fragmentos de remanescentes naturais intercalados em uma matriz predominantemente constituda por reas agrcolas, onde muitas espcies da fauna silvestre encontram recursos necessrios para sua sobrevivncia enquanto outras no conseguem adaptar-se e acabam sofrendo ameaas at serem regionalmente extintas. A incorporao de conceitos e tecnologias inovadoras na agropecuria, como a agricultura orgnica, a reduo e eliminao de agrotxicos e do uso do fogo, alm da manuteno de remanescentes de fragmentos florestais nativos so prticas que poderiam favorecer o incremento da biodiversidade local e, consequentemente, a sustentabilidade ambiental das atividades agrcolas.