Diversity Of Dragonflies Research Articles

Diversity and abundance of Dragonflies and Damselflies (Order - Odonata) of Pohara Range in Pohara – Malkhed Reserve Forest, Maharashtra (India)

The present work is aimed to study diversity and abundance of dragonflies and damselflies of Pohara range in Pohara – Malkhed Reserve Forest, Maharashtra. This study has been carried out for one year from June 2012 to May 2013. We observed six families of Dragonflies and Damselflies (Order – Odonata). The most abundant family was Lebellulidae comprising 20 species followed by Coenagrionidae comprising 10 species. The list abundant families were Gomphidae, Ashnidae, Platycenemididae and Lestidae comprise one, two, one and one species respectively. Species richness (S), Relative abundance (P), Species diversity, and Evenness (E) were studied.

Special Ecology Feature: Enhancing the Diversity of Dragonflies in Urban Areas

Special Ecology Feature: Enhancing the Diversity of Dragonflies in Urban Areas

Underground mining can contribute to freshwater biodiversity conservation: Allogenic succession forms suitable habitats for dragonflies

Human-induced changes negatively affect all components of freshwater ecosystems and comprise the major cause of global loss of diversity and the biotic homogenization of freshwater faunas. The high diversity of dragonflies in heavily industrialized areas is therefore paradoxical, to say the least. We compared diversity of dragonflies in three main freshwater habitat types (natural and human-made) occurring in Upper Silesia (Central Europe). We used multivariate methods and diversity indices for a general analysis, comprising both species richness and the species composition of assemblages. We recorded 50 species in mine subsidence pools from the total of 54 sampled species. These included a high proportion of habitat specialists (typically threatened species). We emphasize that secondary habitats (e.g. spontaneously originated mine subsidence pools) should not a priori be regarded as ecological traps, because these often are the available habitats with highest quality. These habitats significantly outweigh ponds in species richness and proportion of habitat specialists. The conservation potential of specific secondary habitats lies in the fact that these habitats can substitute for very rare natural wetlands often restricted to higher elevations. We assume that high diversity in this type of secondary habitats is not random, but rather that it depends on environmental heterogeneity caused by a specific allogenic succession process occurring as a direct consequence of mining.

Abundance and diversity of dragonflies four years after the construction of a reservoir

Few studies have investigated the impacts of river impoundments on reservoir constructions. Reservoir construction deeply changes dragonflies' habitat structures, especially in relation to shoreline vegetation. This study investigated the effects ofthe impoundment of the Guadiana River and its tributaries on dragonflies four years after the construction of a reservoir. A total of 17 dragonfly species (11 Zygoptera and ten Anisoptera), representing six families, were recorded in 21 sites in the years 1999 and 2003. Aeshna mixta, Coenagrion caerulescens, Coenagrion scitulum, Sympetrum foscolombei, Sympetrum meridionale and Sympetrum striolatum were sampled just before the impoundment took place, and Anax parthenope, Onychogomphus forcipatus, Orthetrum coerulescens, Trithemis annulata, Platycnemis acutipennis and Platycnemis latipes were recorded only after the construction of the reservoir. We concluded that the construction of the Alqueva Reservoir four years earlier did not change the dragonfly species richness, possibly because of species overlap, but that the species composition was modified. Changes in marginal vegetation may have been important to new species compositions.

Predicted insect diversity declines under climate change in an already impoverished region

Being ectotherms, insects are predicted to suffer more severely from climate change than warm-blooded animals. We forecast possible changes in diversity and composition of butterflies, grasshoppers and dragonflies in Belgium under increasingly severe climate change scenarios for the year 2100. Two species distribution modelling techniques (Generalised Linear Models and Generalised Additive Models), were combined via a conservative version of the ensemble forecasting strategy to predict present-day and future species distributions, considering the species as potentially present only if both modelling techniques made such a prediction. All models applied were fair to good, according to the AUC (area under the curve of the receiver operating characteristic plot), sensitivity and specificity model performance measures based on model evaluation data. Butterfly and grasshopper diversity were predicted to decrease significantly in all scenarios and species-rich locations were predicted to move towards higher altitudes. Dragonfly diversity was predicted to decrease significantly in all scenarios, but dragonfly-rich locations were predicted to move upwards only in the less severe scenarios. The largest turnover rates were predicted to occur at higher altitudes for butterflies and grasshoppers, but at intermediate altitudes for dragonflies. Our results highlight the challenge of building conservation strategies under climate change, because the changes in the sites important for different groups will not overlap, increasing the area needed for protection. We advocate that possible conservation and policy measures to mitigate the potentially strong impacts of climate change on insect diversity in Belgium should be much more pro-active and flexible than is the case presently.

Species diversity of dragonflies and damselflies (Odonata) at a Manitoba pond

Species diversity of dragonflies and damselflies (Odonata) at a Manitoba pond

Global diversity of dragonflies (Odonata) in freshwater

Larvae of almost all of the 5,680 species of the insect order Odonata (dragonflies and damselflies) are dependent on freshwater habitats. Both larvae and adults are predators. The order is relatively well studied, and the actual number of species may be close to 7,000. Many species have small distributional ranges, and are habitat specialists, including inhabitants of alpine mountain bogs, seepage areas in tropical rain forests, and waterfalls. They are often successfully used as indicators for environmental health and conservation management. The highest diversity is found in flowing waters in rain forests of the tropics, the Oriental and Neotropical regions being the most speciose. This paper discusses diversity, summarises the biogeography of dragonflies in the different biogeographical regions and gives the total number of species and genera per family per biogeographical region. Examples are given of areas of particular diversity, in terms of areas of endemism, presence of ancient lineages or remarkable recent radiations but no well-based review of areas with high endemism of dragonflies is available so far. The conservation status of dragonflies is briefly discussed. Species confined to small remnants of forest in the tropics are most under threat of extinction by human activities.