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Sahlén, Göran
Publications (10 of 43) Show all publications
Renner, S., Périco, E., Dalzochio, M. S. & Sahlén, G. (2019). Ecoregions within the Brazilian Pampa biome reflected in Odonata species assemblies. Austral ecology (Print), 44(3), 461-472
Open this publication in new window or tab >>Ecoregions within the Brazilian Pampa biome reflected in Odonata species assemblies
2019 (English)In: Austral ecology (Print), ISSN 1442-9985, E-ISSN 1442-9993, Vol. 44, no 3, p. 461-472Article in journal (Refereed) Published
Abstract [en]

Based on vegetation composition, previous studies of the Pampa biome in southern Brazil have defined seven ecoregions within the area. Here, we test this ecoregion approach studying the semi-aquatic insect group Odonata in five of these regions, aiming at comparing the ecoregions to the more traditional environmental predictors of water quality and land cover. Based on a data set of occupancy comprising 99 species distributed between 131 localities, a one-way Permutational Multivariate Analysis of Variance was used to compare differences in the species composition between the ecoregions, followed by a Principal Component Analysis to visualize the variation. The composition varied significantly between all groups tested, and the ordination explained 61.8% of the variance. A partial redundancy analysis of ecoregions, land cover and water quality variables explained 71% of the variance in Odonata community structure. Ecoregion was the most important predictor, followed by water quality and land cover. Within these species assemblies, we could select certain species that were representative of a given ecoregion, to which their distribution within the Pampa biome was entirely or mainly confined. Of 24 representative species 41.7% were rare, while the rest were more abundant and, hence, easier to detect. We suspect that the differences found between the Pampa ecoregions might be due to geology, as such factors may be strong determinants of biodiversity. Specific ecological requirements at the family and genus levels also seemed to act selectively on the species compositions within the ecoregions. Today, the Pampa is highly fragmented due to agricultural activities such as rice cultivation, extensive cattle farming and forest plantations. We suggest that an ecoregion-based approach to the implementation of conservation measures may be the best way to help these distinct species assemblies survive. © 2018 Ecological Society of Australia

Place, publisher, year, edition, pages
Richmond: Wiley-Blackwell, 2019
Keywords
biodiversity, biogeography, ecology, Neotropics, species distribution
National Category
Ecology
Identifiers
urn:nbn:se:hh:diva-38357 (URN)10.1111/aec.12680 (DOI)2-s2.0-85056744020 (Scopus ID)
Available from: 2018-11-17 Created: 2018-11-17 Last updated: 2019-04-12Bibliographically approved
Dalzochio, M. S., Périco, E., Renner, S. & Sahlén, G. (2018). Description of the final stadium larva of Erythrodiplax media (Odonata: Libellulidae) with preliminary key to known South American larvae in the genus. International Journal of Odonatology, 21(2), 93-104
Open this publication in new window or tab >>Description of the final stadium larva of Erythrodiplax media (Odonata: Libellulidae) with preliminary key to known South American larvae in the genus
2018 (English)In: International Journal of Odonatology, ISSN 1388-7890, Vol. 21, no 2, p. 93-104Article in journal (Refereed) Published
Abstract [en]

The larva of Erythrodiplax media is described and illustrated based on two exuviae of reared larvae and one final stadium larva collected in Xangri-lá, State of Rio Grande do Sul, Brazil. The larva of E. media can be distinguished from other species of Erythrodiplax by the presence of lateral spines on S8 and S9, the number of premental setae (n = 22), palpal setae (n = 7) and by the mandibular formula. We also provide a preliminary key to known South American larvae in the genus. © 2018 Worldwide Dragonfly Association.

Place, publisher, year, edition, pages
Abingdon: Taylor & Francis Group, 2018
Keywords
Brazil, coastal wetlands, dragonfly, exuvia, Anisoptera
National Category
Biological Systematics
Identifiers
urn:nbn:se:hh:diva-36717 (URN)10.1080/13887890.2018.1462260 (DOI)2-s2.0-85048851963 (Scopus ID)
Note

This research was supported by CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) through a postdoctoral fellowship (to MSD) and a Professor Visitante do Exterior (PVE) cooperation program between UNIVATES and Halmstad University [88881.068147/2014-01 #1] and by FAPERGS (Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul, [PROBIC/2016, #2]).

Available from: 2018-05-03 Created: 2018-05-03 Last updated: 2018-07-02Bibliographically approved
Schmidt Dalzochio, M., Périco, E., Renner, S. & Sahlén, G. (2018). Effect of tree plantations on the functional composition of Odonata species in the highlands of southern Brazil. Hydrobiologia, 808(1), 283-300
Open this publication in new window or tab >>Effect of tree plantations on the functional composition of Odonata species in the highlands of southern Brazil
2018 (English)In: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 808, no 1, p. 283-300Article in journal (Refereed) Published
Abstract [en]

Changes in biodiversity have mainly been assessed using taxonomical diversity indices. Although these approaches contribute to the scientific understanding of species richness and composition patterns, trait-based metrics may be more useful for detecting responses to land use change. We used odonates as a model system to compare traits composition in mixed ombrophilous forest (MOF) and tree plantations: exotic species (Pinus sp.) and native species (Araucaria angustifolia). Our goal was to understand and compare how each vegetation type affects the selection of species traits, and which factors are responsible for the presence of the species in the environment. We recorded 36 Odonata species distributed across 14 functional groups. The functional composition varied between MOF and exotic tree plantations and was similar between these two habitats and native tree plantations. Native forest favoured specialist traits. Our results suggest that the conversion of MOF to tree plantations, especially exotic ones, results in a shift to less specialized Odonata communities with altered functional group composition. This result highlights the negative impact associated with the conversion of native forests into exotic plantations. Our results show that odonates with specialist traits are limited to natural forest sites, which makes the conservation of such areas crucial. © 2017 Springer International Publishing AG, part of Springer Nature

Place, publisher, year, edition, pages
Dordrecht: Springer Netherlands, 2018
Keywords
Anisoptera, Biological traits, Exotic plantations, Zygoptera
National Category
Ecology
Identifiers
urn:nbn:se:hh:diva-35383 (URN)10.1007/s10750-017-3431-9 (DOI)2-s2.0-85033433702 (Scopus ID)
Available from: 2017-11-09 Created: 2017-11-09 Last updated: 2018-03-23Bibliographically approved
Kohli, M. K., Sahlén, G., Kuhn, W. R. & Ware, J. L. (2018). Extremely low genetic diversity in a circumpolar dragonfly species, Somatochlora sahlbergi (Insecta: Odonata: Anisoptera). Scientific Reports, 8, 1-10, Article ID 15114.
Open this publication in new window or tab >>Extremely low genetic diversity in a circumpolar dragonfly species, Somatochlora sahlbergi (Insecta: Odonata: Anisoptera)
2018 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, p. 1-10, article id 15114Article in journal (Refereed) Published
Abstract [en]

We present the first empirical treatment of the northernmost breeding dragonfly, Somatochlora sahlbergi. We sequenced populations from United States, Canada, Finland, Sweden and Norway for cytochrome oxidase I (COI) and D2 region of 28s. We found that, despite geographic barriers across its vast arctic range, S. sahlbergi is a single species. Not only does it appear to interbreed across its entire range, there also seems to be almost no variation among European and North American populations in their COI gene fragment (the barcode gene), which is usually extremely variable. We further found that characters thought to be diagnostic for the larvae of S. sahlbergi were absent in our European samples. We review and re-describe the habitat of this species based on new findings from recent field observations. Finally, we report for the first time the likely presence of this species in Japan. We hope our findings will encourage further study of this species and other under-studied insect taxa that inhabit the remote Arctic.

Place, publisher, year, edition, pages
London: Nature Publishing Group, 2018
National Category
Genetics
Identifiers
urn:nbn:se:hh:diva-38143 (URN)10.1038/s41598-018-32365-7 (DOI)
Funder
Carl Tryggers foundation , 13-396
Available from: 2018-10-11 Created: 2018-10-11 Last updated: 2018-10-19Bibliographically approved
Pires, M. M., Périco, E., Renner, S. & Sahlén, G. (2018). Predicting the effects of future climate change on the distribution of an endemic damselfly (Odonata, Coenagrionidae) in subtropical South American grasslands. Journal of Insect Conservation, 22(2), 303-319
Open this publication in new window or tab >>Predicting the effects of future climate change on the distribution of an endemic damselfly (Odonata, Coenagrionidae) in subtropical South American grasslands
2018 (English)In: Journal of Insect Conservation, ISSN 1366-638X, E-ISSN 1572-9753, Vol. 22, no 2, p. 303-319Article in journal (Refereed) Published
Abstract [en]

Climate change is predicted to affect the distribution of freshwater taxa, and stronger impacts are expected on endemic species. However, the effects of future climates on freshwater insects from the Neotropical region have been generally overlooked. In this study, the distribution of a damselfly (Cyanallagma bonariense, Odonata, Coenagrionidae) endemic to the subtropical South American grasslands (Pampa) was modelled in relation to future scenarios of high greenhouse gas emissions (RCP 8.5) for 2050 and 2070. For this purpose, ecological niche models were developed based on assumptions of limited dispersal and niche conservatism, and the projected distribution of C. bonariense was contrasted with the location of current protected areas (PAs) in the Pampa. A broad potential distribution of C. bonariense was indicated throughout the Pampa, and projections predicted a predominance of range contractions rather than range shifts in climatically suitable areas for C. bonariense in 2050 and 2070. Projections of suitable areas overlapped in central Argentina and southernmost Uruguay in these periods. Our results indicated a potential resilience of C. bonariense to future climate change, which is likely related to the low restrictions in habitat use of C. bonariense. In every projection, however, most PAs were expected to lose effectiveness, as by 2070 most PAs fall outside the range of the predicted distribution of C. bonariense. Thus, the creation or enlargement of PAs in these areas is recommended and these results represent an important information for the conservation of endemic freshwater insects under global warming scenarios in an overlooked Neotropical landscape. © Springer International Publishing AG, part of Springer Nature 2018

Place, publisher, year, edition, pages
Dordrecht: Springer Netherlands, 2018
Keywords
Aquatic insects, Ecological niche modelling, Pampa, Zygoptera, Protected areas, Species range, Habitat suitability
National Category
Ecology
Identifiers
urn:nbn:se:hh:diva-36722 (URN)10.1007/s10841-018-0063-y (DOI)000433233900013 ()2-s2.0-85046471903 (Scopus ID)
Note

Funding: CAPES (Coordination of Improvement of Higher Level Personnel). Grant number 88881.068147/2014-01.

Available from: 2018-05-04 Created: 2018-05-04 Last updated: 2018-06-29Bibliographically approved
Korkeamäki, E., Elo, M., Sahlén, G., Salmela, J. & Suhonen, J. (2018). Regional variations in occupancy frequency distributions patterns between odonate assemblages in Fennoscandia. Ecosphere, 9(4), Article ID e02192.
Open this publication in new window or tab >>Regional variations in occupancy frequency distributions patterns between odonate assemblages in Fennoscandia
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2018 (English)In: Ecosphere, ISSN 2150-8925, E-ISSN 2150-8925, Vol. 9, no 4, article id e02192Article in journal (Refereed) Published
Abstract [en]

Odonate (damselfly and dragonfly) species richness and species occupancy frequency distributions (SOFD) were analysed in relation to geographical location in standing waters (lakes and ponds) in Fennoscandia, from southern Sweden to central Finland. In total, 46 dragonfly and damselfly species were recorded from 292 waterbodies. Species richness decreased to the north and increased with waterbody area in central Finland, but not in southern Finland or in Sweden. Species occupancy ranged from 1 up to 209 lakes and ponds. Over 50% of the species occurred in less than 10% of the waterbodies, although this proportion decreased to the north. In the southern lakes and ponds, none of the species occurred in all lakes, whereas in the north many species were present in all of the studied waterbodies. The dispersal ability of the species did not explain the observed species occupancy frequencies, but generalist species with a large geographical range occurred in a higher percentage of the waterbodies. At Fennoscandian scale, we found that the unimodal satellite pattern was predominant. However, at smaller scale, we found geographical variations in odonate species SOFD patterns. The most southern communities followed the unimodal satellite-dominant pattern, whereas in other regions communities fitted best with the bimodal core - satellite patterns. It seems that the richer species pool in the southern locations, and the larger distribution range of the northern species, skewed the unimodal pattern into a bimodal satellite dominant pattern. © 2018 The Authors.

Place, publisher, year, edition, pages
Washington: Ecological Society of America, 2018
Keywords
Core-satellite species patterns, damselfly, dragonfly, freshwater lake, pond, Odonata, species richness
National Category
Ecology
Identifiers
urn:nbn:se:hh:diva-36459 (URN)10.1002/ecs2.2192 (DOI)2-s2.0-85046004563 (Scopus ID)
Note

This study was supported by Finnish Biodiversity Research Programme (FIBRE), the Academy of Finland (JuS) and Ministry of Environment (JuS), Maj and Tor Nessling Foundation (JuS), the Finnish Cultural Foundation (Häme) (JSu), the Finnish Entomological Society (JSa), and Kone Foundation (ME) for financing our study. This study was funded by Academy of Finland: Finnish Centre of Excellence Programme (2000–2005).

Available from: 2018-03-16 Created: 2018-03-16 Last updated: 2018-06-12Bibliographically approved
Renner, S., Périco, E., Schmidt Dalzochio, M. & Sahlén, G. (2018). Water body type and land cover shape the dragonfly communities (Odonata) in the Pampa biome, Rio Grande do Sul, Brazil. Journal of Insect Conservation, 22(1), 113-125
Open this publication in new window or tab >>Water body type and land cover shape the dragonfly communities (Odonata) in the Pampa biome, Rio Grande do Sul, Brazil
2018 (English)In: Journal of Insect Conservation, ISSN 1366-638X, E-ISSN 1572-9753, Vol. 22, no 1, p. 113-125Article in journal (Refereed) Published
Abstract [en]

The biogeographical region known as the Pampa biome in southern Brazil, was originally mainly covered with open fields or grassland, with areas of riparian forest surrounding the water bodies. Today this landscape appears highly fragmented due to agricultural activities such as rice cultivation, extensive cattle farming, and forest plantations. Studies have shown that the Pampa biome has high levels of biodiversity and endemism, but with regard to invertebrates, this biome is still one of the least known in Brazil. We therefore designed a study comparing the dragonfly (Odonata) communities to environmental and landscape features in this area, measuring diversity by species richness, relative abundance and Shannon index. Our results showed that the Pampa is a biome very rich in odonates, and that the species communities are highly dependent on the environmental conditions of the area. Habitats such as Rivers/Streams, bordered by native grasslands and riparian forests, were shown to harbour communities that were ecologically more complex and sensitive than other habitat types. Man-made lakes and agricultural areas displayed lower levels of biodiversity and odonate communities dominated by generalist species. By combining data on the communities of Odonata and other taxa, our analyses may be instrumental in determining priority areas for future conservation measures within the area. © 2018, Springer International Publishing AG, part of Springer Nature.

Place, publisher, year, edition, pages
Dordrecht: Springer, 2018
Keywords
Landscape ecology, Conservation, Grasslands, Macroinvertebrates
National Category
Ecology
Identifiers
urn:nbn:se:hh:diva-38315 (URN)10.1007/s10841-017-0042-8 (DOI)000427390500010 ()2-s2.0-85040050570 (Scopus ID)
Note

Funding Agency:

Capes (Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior)

UNIVATES

Halmstad University Grant Number: 88881.068147/2014-01 

Available from: 2018-11-14 Created: 2018-11-14 Last updated: 2018-11-15Bibliographically approved
Al Jawaheri, R. & Sahlén, G. (2017). Negative impact of lake liming programmes on the species richness of dragonflies (Odonata): a study from southern Sweden. Hydrobiologia, 788(1), 99-113
Open this publication in new window or tab >>Negative impact of lake liming programmes on the species richness of dragonflies (Odonata): a study from southern Sweden
2017 (English)In: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 788, no 1, p. 99-113Article in journal (Refereed) Published
Abstract [en]

Liming programmes aiming to restore fish populations are being implemented in many acidified aquatic systems in northern Europe. We studied Odonata communities in 47 forest lakes in SW Sweden, 13 that are currently being limed, and 8 that have previously been limed. Thirty-one species were recorded, with the highest mean number in untreated lakes, followed by previously treated lakes and currently treated lakes. Species communities differed between untreated and limed lakes, but only few rare species found in the untreated lakes were absent in the treated lakes. Likewise, species known to thrive in acid environments were either rare or showed no preferences. Comparing the number of records of odonate species within a large regional area to the proportion of lakes inhabited in our study, we found that seven of the most commonly observed species occurred less frequently in limed lakes than in the untreated ones, including two of the three most common taxa. Reduced species numbers in limed lakes might be due to conditions on other trophic levels, including fish predation. We argue that Odonata should be considered when developing new biological indices of water quality, although the causes of the observed occurrence patterns need to be studied further. © 2016 Springer International Publishing Switzerland

Place, publisher, year, edition, pages
Dordrecht: Springer Netherlands, 2017
Keywords
Community structure, Macroinvertebrates, pH, Regional abundance, Tolerance
National Category
Ecology
Identifiers
urn:nbn:se:hh:diva-32451 (URN)10.1007/s10750-016-2990-5 (DOI)000392386500009 ()2-s2.0-84988649421 (Scopus ID)
Available from: 2016-11-18 Created: 2016-11-18 Last updated: 2018-03-23Bibliographically approved
Renner, S., Périco, E., Ely, G. & Sahlén, G. (2017). Preliminary dragonfly (Odonata) species list from the Pampa biome in Rio Grande do Sul, Brazil, with ecological notes for 19 new records for the state. Biota Neotropica, 17(4), Article ID e20170374.
Open this publication in new window or tab >>Preliminary dragonfly (Odonata) species list from the Pampa biome in Rio Grande do Sul, Brazil, with ecological notes for 19 new records for the state
2017 (English)In: Biota Neotropica, ISSN 1806-129X, E-ISSN 1676-0611, Vol. 17, no 4, article id e20170374Article in journal (Refereed) Published
Abstract [en]

An inventory of Odonata was carried out in the southern half of the state of Rio Grande do Sul, Brazil, in the Pampa biome. Originally, this biogeographical region was covered mostly by open fields and grassland, with sections of higher vegetation surrounding water bodies and rocky hills. Today the landscape is fragmented due to agricultural activities, mainly cattle farming, rice crops and forest plantations. Our survey was conducted in three municipalities from this region, between March 2015 and April 2016. Aiming at a general overview of the species composition, our sampling sites were selected on a wide basis, including lakes, bogs, temporary water bodies, small streams and river sections. Eighty two species of Odonata were collected comprising 40 genera and seven families. The dominant families were Libellulidae (56,1%), Coenagrionidae (24,5%) and Aeshnidae (7,3%). We found a diverse odonate assemblage, adding 19 new species records for the state of Rio Grande do Sul.

Abstract [pt]

Um inventário de Odonata foi desenvolvido na metade Sul do estado do Rio Grande do Sul, Brasil, no Bioma Pampa. Originalmente, esta região biogeográfica era coberta principalmente por campos abertos e pastagens, com seções de vegetação mais alta nas imediações de corpos d’água e elevações rochosas. Atualmente a paisagem se encontra fragmentada devido a atividade agrícola, entre as principais, a criação de gado, cultivo de arroz e silvicultura. A pesquisa foi desenvolvida em três municípios da região, entre Março de 2015 e Abril de 2016. Buscando uma visão geral da composição de espécies, os locais de amostragem selecionados incluíram lagos, banhados, corpos d’água temporários e seções de rio. Oitenta e duas espécies foram coletadas compreendendo 40 gêneros e 7 famílias. As famílias dominantes foram Libellulidae (55,1%), Coenagrionidae (24,5%) e Aeshnidae (7,3%). Nós encontramos uma grande diversidade nas comunidades de Odonata, adicionando 19 novos registros de espécies para o estado do Rio Grande do Sul.

Place, publisher, year, edition, pages
Campinas: Centro de Referencia em Informacao Ambiental, 2017
Keywords
Anthropogenic threats, ecology, grassland, Neotropics, southern fields, Ameaças antropogênicas, ecologia, pastagens, região neotropical, campos sulinos
National Category
Ecology
Identifiers
urn:nbn:se:hh:diva-35430 (URN)10.1590/1676-0611-bn-2017-0374 (DOI)
Note

Funding: UNIVATES

Available from: 2017-12-07 Created: 2017-12-07 Last updated: 2017-12-14Bibliographically approved
Troast, D., Suhling, F., Jinguji, H., Sahlén, G. & Ware, J. (2016). A Global Population Genetic Study of Pantala flavescens. PLoS ONE, 11(3), Article ID e0148949.
Open this publication in new window or tab >>A Global Population Genetic Study of Pantala flavescens
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2016 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, no 3, article id e0148949Article in journal (Refereed) Published
Abstract [en]

Among terrestrial arthropods, the dragonfly species Pantala flavescens is remarkable due to their nearly global distribution and extensive migratory ranges; the largest of any known insect. Capable of migrating across oceans, the potential for high rates of gene flow among geographically distant populations is significant. It has been hypothesized that P. flavescens may be a global panmictic population but no sufficient genetic evidence has been collected thus far. Through a population genetic analysis of P. flavescens samples from North America, South America, and Asia, the current study aimed to examine the extent at which gene flow is occurring on a global scale and discusses the implications of the genetic patterns we uncovered on population structure and genetic diversity of the species. This was accomplished using PCR-amplified cytochrome oxidase one (CO1) mitochondrial DNA data to reconstruct phylogenetic trees, a haplotype network, and perform molecular variance analyses. Our results suggested high rates of gene flow are occurring among all included geographic regions; providing the first significant evidence that Pantala flavescens should be considered a global panmictic population. © 2016 Troast et al.

Place, publisher, year, edition, pages
San Francisco: Public Library of Science, 2016
National Category
Evolutionary Biology
Identifiers
urn:nbn:se:hh:diva-30795 (URN)10.1371/journal.pone.0148949 (DOI)000371724200013 ()26934181 (PubMedID)2-s2.0-84960941873 (Scopus ID)
Available from: 2016-04-21 Created: 2016-04-21 Last updated: 2018-03-22Bibliographically approved
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