Temperature plays a crucial role in the constant interaction between organisms and the environment. It affects development and rates of physiological functions as well as survival of organisms.

We carried out a pilot study of local dispersion and patterns of movement of Golden- ringed dragonfly Cordulegaster boltonii (Odonata: Cordulegasteridae). Cordulegasteridae is a family with many primitive traits present and rather restricted geographical distribution ranges (at least among European species). Their migration seems to be limited despite the body size that predetermines them to high mobility over large spatial scale. Linear habitat (upper parts of narrow forest streams) specialisation along with behavioural ecology (peculiar premating habit of scanning streams for females) is a unique life history, which bring lot of questions. We collected mark-release-recapture data during two adult flight seasons in year 2010 and 2011. We were simultaneously capturing patrolling males along three separate streams (Dračice, Koštěnický and Struha) in total length of 9.9 km in, located in the Natural park Česká Kanada, in the Southern Czech Republic. We captured and marked 440 individuals and recorded 113 recapture events (26 % recapture rate) in year 2010 and 355 individuals were marked, 171 recapture events made (48 % recapture rate) in 2011. Our data suggested high level of stream fidelity (only 10 inter stream dispersal events, 2.8 % dispersal rate). What was as well reflected in a closeness of...

<p>The main cause of environmental disturbance in the Fennoscandian boreal forests today is forestry. Natural disturbances are important to maintain diversity, but anthropogenic disturbance, such as forestry, differs in many ways from the natural ones. Forestry is a big industry in Sweden and only a small remnant of old-growth forest is left. Several studies have shown an initial decrease in e.g. dragonfly diversity a few years after logging, followed by an increase up to numbers comparable with the original species number. In this study I examined whether the new, quite diverse, species composition is similar to the one present before the logging or if some species are disappearing and are replaced with other, maybe opportunistic species. Other factors such as ongoing changes in climate also will be considered. A resampling of 34 (and an additional 4) lakes that also were sampled in 1996-97 was done during summer of 2006. Analyses of data from the two sampling occasions were done. I found that even if the diversity is just temporarily affected (or not affected at all), it is not always the same species involved. This means that the diversity in a single lake can appear to be high, but the total diversity in Sweden, or Scandinavia, is declining. I also found some interesting new species for the area, such as Nehalennia speciosa, Sympecma fusca and Aeshna mixta.</p>

The main cause of environmental disturbance in the Fennoscandian boreal forests today is forestry. Natural disturbances are important to maintain diversity, but anthropogenic disturbance, such as forestry, differs in many ways from the natural ones. Forestry is a big industry in Sweden and only a small remnant of old-growth forest is left. Several studies have shown an initial decrease in e.g. dragonfly diversity a few years after logging, followed by an increase up to numbers comparable with the original species number. In this study I examined whether the new, quite diverse, species composition is similar to the one present before the logging or if some species are disappearing and are replaced with other, maybe opportunistic species. Other factors such as ongoing changes in climate also will be considered. A resampling of 34 (and an additional 4) lakes that also were sampled in 1996-97 was done during summer of 2006. Analyses of data from the two sampling occasions were done. I found that even if the diversity is just temporarily affected (or not affected at all), it is not always the same species involved. This means that the diversity in a single lake can appear to be high, but the total diversity in Sweden, or Scandinavia, is declining. I also found some interesting new species for the area, such as Nehalennia speciosa, Sympecma fusca and Aeshna mixta.

Thesis (Ph.D.)--Antioch University New England, 2010. / Title from PDF t.p. (viewed July 22, 2010). "A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Environmental Studies at Antioch University New England (2010)."--from the title page. Advisor: James Jordan, Ph.D. Includes bibliographical references (p. 97-104).

Thesis (Ph.D.)--Antioch University New England, 2010. / Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Environmental Studies of Antioch University New England, 2010. Includes bibliographical references.

No description available.

Niche and life-history differences in five species of Trithemis were investigated to determine the extent of interspecific competition. Interspecific competition was mostly avoided because species favoured different habitats and microhabitats. There was the possibility of competition between larvae under conditions of lowered food concentration, where they occurred in the same habitat and microhabitat. Larvae of different species preferred specific prey taxa, but chose to feed on a different prey taxon once it was more readily available. Because species were restricted more by food size than taxon, competition for food was unlikely. Interspecific competition may have occurred between adults because the niche breadth of some species became contracted as the density of other species increased. Interspecific competition among larvae was unlikely because individuals of different sizes were present together, allowing for food partitioning. Asynchronous development therefore ensured that competition for food of the same size was reduced. Competition was also reduced by species showing peaks in abundance at different times of the year. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1995.

The south-central United States serves as an important biogeographical link and dispersal corridor between Nearctic and Neotropical elements of western hemisphere odonate faunas. Its species are reasonably well known because of substantial collections, but there has been no concerted effort to document the extent of biodiversity and possible geographic affinities of dragonflies and damselflies of this region. The recent discoveries of Argia leonorae Garrison, Gomphus gonzalezi Dunkle and Erpetogomphus heterodon Garrison from southern and western Texas and northern Mexico suggest that Odonata species remain to be discovered in this area, particularly from far south Texas and northern Mexico. I have documented a total of 12,515 records of Odonata found in 408 counties within the south-central U.S. A total of 73 species of damselflies and 160 species of dragonflies was revealed in the region. The 233 (197 in Texas) Odonata species are distributed among 10 families and 66 genera. Illustrated family, generic, and species-level keys are provided. Since the beginning of this work in the Fall of 1993, one species has been added each to the Louisiana and Oklahoma faunas, and 12 species have been added, previously unreported from Texas, including four new to the U.S. The area of highest Odonata biodiversity overall (161 spp.) is in the Austroriparian biotic province. The greatest degree of faunal similarity between the south-central U.S. and other intra-continental regions was observed for the eastern (64%) United States. Diversity is a function of area, and as expected, the numbers of breeding birds and Odonata, in each contiguous U.S. state are positively correlated (r=0.376, n=33, p=0.031). There is, however, no strong correlation between land area and species diversity within the region, but those natural biotic provinces (Austroriparian, Texan, Balconian) where aquatic systems and topographic heterogeneity are the greatest provide a broader spectrum of potential Odonata habitats and thus support a greater number of Odonata species.

Thesis (PhD)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Dragonflies (Insecta: Odonata) are a valuable tool for assessing aquatic systems and have been used as indicators of ecological health, ecological integrity, and environmental change, including climatic change. In four separate studies I explored the usefulness of dragonflies as surrogates in biomonitoring, site prioritization and indication of global climate change. In the use of dragonflies for biomonitoring, I field-tested a freshwater ecological integrity index, the Dragonfly Biotic Index (DBI), based on dragonfly assemblages at the local scale, and compared the DBI to a standard freshwater benthic macroinvertebrate-based freshwater health index. Overall, dragonflies were more sensitive to changes in river condition than were macroinvertebrates, and the DBI site value and macroinvertebrate scores were highly significantly correlated. I conclude that dragonfly assemblages in the form of a DBI are an excellent tool for environmental assessment and monitoring freshwater biodiversity, with the potential to replace benthic macroinvertebrate-based freshwater quality assessments. In the second study, I used the DBI to prioritize sites for conservation action in South Africa. Using a selected set of top prioritized sites, I compared the DBI’s performance to that of a rarity-complementarity algorithm. Site prioritization using the DBI reveals that CFR sites protect Red Listed taxa rather well. The rarity-complementarity algorithm represents all species, but without greater emphasis on the rare and threatened species. I conclude that the DBI is of great value in selecting biodiversity hotspots, while the algorithm is useful for selecting complementarity hotspots. The third study was made possible by the recent completion of a continental assessment of freshwater biodiversity, which revealed that patterns of richness and threat of four well-studied aquatic taxa largely coincide at the continental scale. Using only dragonflies, I built a protected areas network for Africa using spatial planning software. I then compared the performance of the existing African reserve network and that of known global biodiversity hotspots against the model, and identified sites of conservation concern. Although the current reserve network covers 10.7% of the landscape, the proportional representation of species geographic distributions in reserves is only 1.1%. The reserve network is therefore inefficient, and many areas of conservation priority that are not formally protected remain. The advantage of operating at the fine scale, while covering a large geographic area is that it shifts the focus from the large-scale hotspots to smaller priority areas within and beyond hotspots. In the fourth study, I created species distribution models of dragonflies in an El Niño-prone biodiversity hotspot in South Africa, and predicted the changes in species richness, geographic range and habitat suitability, forty and eighty years from now. According to the model results of two different emissions scenarios, at least three species will be lost from the area by 2050, and four by 2080. The remaining species are predicted to persist with reduced geographical ranges, at generally higher elevations. Most species presented here thrive quite well in artificial environments, that is, engineered ponds or dams. It is therefore unlikely that loss in connectivity will play a role for these species. / AFRIKAANSE OPSOMMING: Naaldekokers (Insecta:Odonata) is waardevolle instrumente om akwatiese sisteme te assesseer, en is al gebruik as aanwysers van ekologiese gesondheid, ekologiese integriteit en omgewingsverandering, insluitend klimaatsverandering. In vier studies het ek die nut van naaldekokers as surrogate in biomonitering, area prioritisering en indikasie van globale klimaatsverandering ondersoek. In die benutting van naaldekokers in biomonitering, het ek ´n varswater ekologiese integriteits indeks, die Dragonfly Biotic Index (DBI), wat gebaseer is op naaldekokergemeenskappe op die plaaslike skaal, getoets en dit vergelyk met ´n standaard bentiese makroinvertebraat-gebaseerde varswater gesondheids index. Naaldekokers was meer sensitief vir veranderinge in riviertoestand as makroinvertebrate, en die DBI lokaliteit waarde en makroinvertebraat telling was beduidend gekorreleer. Die gevolgtrekking was dat naaldekoker gemeenskappe in die vorm van die DBI ‘n uitstekende instrument is vir omgewings assessering en die monitering van varswater biodiversiteit, met die potensiaal om bentiese makroinvertebraat-gebaseerde varswaterkwaliteit assessering te vervang. In die tweede studie, het ek die DBI gebruik om areas te prioritiseer vir bewaringsaksie in Suid Afrika. Met die gebruik van ‘n geselekteerde set top prioriteit areas, het ek die DBI se prestasie vergelyk met die van ‘n rariteit-komplemetariteit algoritme. Area prioritisering met die gebruik van die DBI het aangedui dat CFR areas taxa op die Rooi Lys goed beskerm. Die rariteit-komplementariteit algoritme verteenwoordig alle spesies, maar beklemtoon minder skaars en bedreigde spesies. Die gevolgtrekking was dat die DBI van meer waarde is in die selektering van biodiversiteits ‘hotspots‘, terwyl die algoritme nuttig is vir die selektering van komplementariteits ‘hotspots‘. Die derde studie was moontlik gemaak deur die onlangse voltooiing van ‘n kontinentale assessering van varswater biodiversiteit, wat aangedui het dat patrone van rykheid en bedreiging van vier goed-bestudeerde akwatiese taxa grootliks ooreenstem op die kontinentale skaal. Met die gebruik van naaldekokers, het ek ‘n beskermde area netwerk gebou vir Afrika met ruimtelike beplannings sagteware. Ek het die prestasie van die bestaande Afrika reservaatnetwerk en die van bekende globale biodiversiteit ‘hotspots‘ vergelyk teen die model, en het areas van bewaringsbelang geidentifiseer. Alhoewel die bestaande reservaatnetwerk 10.7% van die landskap dek, is die proporsionele verteenwoordiging van spesies se geografiese verspreiding net 1.1%. Die reservaatnetwerk is dus onvoldoende en baie areas van bewaringsbelang is nie formeel beskerm nie. Die voordeel van op die fyn skaal werk terwyl ‘n groot geografiese are gedek word, is dat dit die fokus van groot skaal ‘hotspots‘ na kleiner prioriteits areas binne en buite ‘hotspots‘ verskuif. In die vierde studie, het ek spesies verspreidingsmodelle van naaldekokers geskep in ‘n El Nino-geneigde biodiversiteits ‘hotspot’ in Suid Afrika, en het veranderinge in spesies rykheid, geografiese verspreiding en habitatsgeskiktheid voorspel, veertig en tagtig jaar van nou af. Volgens die modelresultate van twee verskillende emissie scenarios, sal ten minste drie spesies verlore gaan uit die area teen 2050, en vier teen 2080. Daar word voorspel dat die oorblywende spesies sal voortduur in verkleinde geografiese areas, by groter hoogte bo seespieël. Die meeste spesies hier verteenwoordig floreer in kunsmatige omgewings, soos mensgemaakte damme. Dit is dus onwaarskynlik dat ‘n verlies in konnektiwiteit ‘n rol sal speel vir hierdie spesies.