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Neotropical dragonflies ( I nsecta: O donata) as indicators of ecological condition of small streams in the eastern A mazon
Author(s) -
OliveiraJunior José Max Barbosa,
Shimano Yulie,
Gardner Toby Alan,
Hughes Robert M.,
Marco Júnior Paulo,
Juen Leandro
Publication year - 2015
Publication title -
austral ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.688
H-Index - 87
eISSN - 1442-9993
pISSN - 1442-9985
DOI - 10.1111/aec.12242
Subject(s) - streams , riparian zone , ecology , ecosystem , indicator species , vegetation (pathology) , biology , range (aeronautics) , aquatic ecosystem , odonata , habitat , medicine , computer network , materials science , pathology , computer science , composite material
Sensitive and cost‐effective indicators of aquatic ecosystem condition in A mazon streams are necessary to assess the effects of anthropogenic disturbances on those systems in a viable and ecologically meaningful manner. We conducted the present study in the municipality of P aragominas, state of P ará, northern B razil, where we sampled adult dragonflies in 50 100‐m‐long wadeable stream sites in 2011. We collected 1769 specimens represented by 11 families, 41 genera and 97 species. The suborder Z ygoptera contributed 961 individuals and A nisoptera 808. Among the 97 recorded species, nine were classified as useful indicators of ecological condition, with four species being associated with more degraded streams (three A nisoptera, one Z ygoptera) and five with more preserved streams (all were Z ygoptera). A nisoptera (dragonflies) tend to provide more useful indicators of more degraded environments because they have more efficient homeostatic mechanisms and are more mobile, enabling them to tolerate a wider range of environmental conditions. By contrast, Z ygoptera (damselflies) tend to provide a more useful role as indicators of more preserved environments and high levels of environmental heterogeneity because of their smaller body sizes and home ranges and greater ecophysiological restrictions. We conclude from our assessment of this low‐order A mazonian stream system that (i) the occurrence of specific odonate species is strongly associated with the configuration of riparian vegetation, (ii) agricultural activities appear to be the main factor determining changes in the composition of odonate assemblages and (iii) these insects can act as useful indicators of the ecological consequences of riparian habitat loss and disturbance. Because generalist species invade moderately degraded areas, those areas may have high species richness but host few species of Z ygoptera. Therefore, preserving dense riparian vegetation is necessary to maintain aquatic ecological condition, and that condition can be rehabilitated by planting new trees. Both require enforcing existing environmental regulations, various types of incentives and educating local communities.