11 research outputs found
Negative Impacts of Human Land Use on Dung Beetle Functional Diversity
The loss of biodiversity caused by human activity is assumed to alter ecosystem
functioning. However our understanding of the magnitude of the effect of these
changes on functional diversity and their impact on the dynamics of ecological
processes is still limited. We analyzed the functional diversity of
copro-necrophagous beetles under different conditions of land use in three
Mexican biosphere reserves. In Montes Azules pastures, forest fragments and
continuous rainforest were analyzed, in Los Tuxtlas rainforest fragments of
different sizes were analyzed and in Barranca de Metztitlán two types of
xerophile scrub with different degrees of disturbance from grazing were
analyzed. We assigned dung beetle species to functional groups based on food
relocation, beetle size, daily activity period and food preferences, and as
measures of functional diversity we used estimates based on multivariate
methods. In Montes Azules functional richness was lower in the pastures than in
continuous rainforest and rainforest fragments, but fragments and continuous
forest include functionally redundant species. In small rainforest fragments
(<5 ha) in Los Tuxtlas, dung beetle functional richness was lower than in
large rainforest fragments (>20 ha). Functional evenness and functional
dispersion did not vary among habitat types or fragment size in these reserves.
In contrast, in Metztitlán, functional richness and functional dispersion
were different among the vegetation types, but differences were not related to
the degree of disturbance by grazing. More redundant species were found in
submontane than in crassicaule scrub. For the first time, a decrease in the
functional diversity in communities of copro-necrophagous beetles resulting from
changes in land use is documented, the potential implications for ecosystem
functioning are discussed and a series of variables that could improve the
evaluation of functional diversity for this biological group is proposed
Biodiversity, Disparity and Evolvability
A key problem in conservation biology is how to measure biological diversity. Taxic diversity (the number of species in a community or in a local biota) is not necessarily the most important aspect, if what most matters is to evaluate how the loss of the different species may impact on the future of the surviving species and communities. Alternative approaches focus on functional diversity (a measure of the distribution of the species among the different 'jobs' in the ecosystem), others on morphological disparity, still others on phylogenetic diversity. There are three major reasons to prioritize the survival of species which provide the largest contributions to the overall phylogenetic diversity. First, evolutionarily isolated lineages are frequently characterized by unique traits. Second, conserving phylogenetically diverse sets of taxa is valuable because it conserves some sort of trait diversity, itself important in so far as it helps maintain ecosystem functioning, although a strict relationships between phylogenetic diversity and functional diversity cannot be taken for granted. Third, in this way we maximize the "evolutionary potential" depending on the evolvability of the survivors. This suggests an approach to conservation problems focussed on evolvability, robustness and phenotypic plasticity of developmental systems in the face of natural selection: in other terms, an approach based on evolutionary developmental biology
Factors affecting the development of precipitating antibodies in workers exposed to contaminated humidifiers
Ecological Diversity in South American Mammals: Their Geographical Distribution Shows Variable Associations with Phylogenetic Diversity and Does Not Follow the Latitudinal Richness Gradient
Evaluation and selection of functional diversity metrics with recommendations for their use in life cycle assessments
Environmental Biolog