36 pages

Caddisfly (Insecta, Trichoptera) diversity of Lithuania and impacts of environmental factors on their distribution and abundance ; Lietuvos apsiuvų (Insecta, Trichoptera) įvairovė ir aplinkos veiksnių įtaka jų paplitimui ir gausumui

Obtenez un accès à la bibliothèque pour le consulter en ligne
En savoir plus

Description

INSTITUTE OF ECOLOGY OF NATURE RESEARCH CENTRE VILNIUS UNIVERSITY Giedrė Višinskien ė CADDISFLY (INSECTA, TRICHOPTERA) DIVERSITY IN LITHUANIA AND IMPACTS OF ENVIRONMENTAL FACTORS ON THEIR DISTRIBUTION AND ABUNDANCE Summary of doctoral dissertation Biomedical Sciences, Ecology and Environmental Science (03 B) Vilnius, 2010 The dissertation was prepared during 2003–2010 at the Institute of Ecology of Nature Research Centre External defense of the dissertation. Consultant Supervisor: Dr K ęstutis Arba čiauskas (Institute of Ecology of Nature Research Centre, Biomedical Sciences, Ecology and Environmental Sciences – 03 B) The defence of doctoral dissertation is held at the Vilnius University Ecology and Environmental Research Council: Chairman: Prof. Dr Sigitas Pod ėnas (Vilnius University, Biomedical Sciences, Zoology – 05 B) Members: Prof. Dr Habil. Sergej Olenin (Klaip ėda University, Biomedical Sciences, Ecology and Environmental Science – 03 B) Dr Habil. Janina Šyvokien ė (Institute of Ecology of Nature Research Centre, Biomedical Sciences, Ecology and Environmental Science – 03 B) Doc. Dr Zita Gasi ūnait ė (Klaip ėda University, Biomedical Sciences, Ecology and Environmental Science – 03 B) Dr Tomas Virbickas (Institute of Ecology of Nature Research Centre, Biomedical Sciences, Ecology and Environmental Science – 03 B) Opponents: Doc.

Sujets

Informations

Publié par
Publié le 01 janvier 2010
Nombre de lectures 81

INSTITUTE OF ECOLOGY OF NATURE RESEARCH CENTRE
VILNIUS UNIVERSITY










Giedrė Višinskien ė





CADDISFLY (INSECTA, TRICHOPTERA) DIVERSITY IN LITHUANIA AND
IMPACTS OF ENVIRONMENTAL FACTORS ON THEIR DISTRIBUTION
AND ABUNDANCE






Summary of doctoral dissertation


Biomedical Sciences, Ecology and Environmental Science (03 B)












Vilnius, 2010 The dissertation was prepared during 2003–2010 at the Institute of Ecology of Nature
Research Centre
External defense of the dissertation.


Consultant Supervisor:
Dr K ęstutis Arba čiauskas (Institute of Ecology of Nature Research Centre,
Biomedical Sciences, Ecology and Environmental Sciences – 03 B)



The defence of doctoral dissertation is held at the Vilnius University Ecology and
Environmental Research Council:

Chairman:
Prof. Dr Sigitas Pod ėnas (Vilnius University, Biomedical Sciences, Zoology – 05 B)

Members:
Prof. Dr Habil. Sergej Olenin (Klaip ėda University, Biomedical Sciences, Ecology
and Environmental Science – 03 B)
Dr Habil. Janina Šyvokien ė (Institute of Ecology of Nature Research Centre,
Biomedical Sciences, Ecology and Environmental Science – 03 B)
Doc. Dr Zita Gasi ūnait ė (Klaip ėda University, Biomedical Sciences, Ecology and
Environmental Science – 03 B)
Dr Tomas Virbickas (Institute of Ecology of Nature Research Centre, Biomedical
Sciences, Ecology and Environmental Science – 03 B)

Opponents:
Doc. Dr Darius Daunys (Klaip ėda University, Biomedical Sciences, Ecology and
Environmental Science – 03 B)
Prof. Dr Virginijus Sruoga (Vilnius Pedagogical University, Biomedical Sciences,
Zoology – 05B)



The official defence of the dissertation will be held at the public meeting of the Council
at the Institute of Ecology of Nature Research Centre on 01 October 2010, at 14:00.
Address: Akademijos 2, LT – 08412, Vilnius, Lithuania
Phone: + 370 5 2729257, fax. + 370 5 2729352


The summary of the doctoral dissertation was distributed on 31 August 2010
The dissertation is available in the libraries of Vilnius University and the Institute of
Ecology of Nature Research Centre

GAMTOS TYRIM Ų CENTRO EKOLOGIJOS INSTITUTAS
VILNIAUS UNIVERSITETAS










Giedrė Višinskien ė





LIETUVOS APSIUV Ų (INSECTA, TRICHOPTERA) ĮVAIROV Ė IR APLINKOS
VEIKSNI Ų ĮTAKA J Ų PAPLITIMUI IR GAUSUMUI






Daktaro disertacijos santrauka


Biomedicinos mokslai, ekologija ir aplinkotyra (03 B)












Vilnius, 2010 Disertacija rengta 2002–2010 metais Gamtos tyrim ų centro Ekologijos institute
Disertacija ginama eksternu


Mokslinis konsultantas:
Dr. K ęstutis Arba čiauskas (Gamtos tyrim ų centro Ekologijos institutas,
biomedicinos mokslai, ekologija ir aplinkotyra – 03 B)



Disertacija ginama Vilniaus universiteto Ekologijos ir aplinkotyros krypties
taryboje:

Pirmininkas:
Prof. dr. Sigitas Pod ėnas (Vilniaus universitetas, biomedicinos mokslai, zoologija –
05 B)

Nariai:
Prof. habil. dr. Sergej Olenin (Klaip ėdos universitetas, biomedicinos mokslai,
ekologija ir aplinkotyra – 03 B)
Habil. dr. Janina Šyvokien ė (Gamtos tyrim ų centro Ekologijos institutas,
biomedicinos mokslai, ekologija ir aplinkotyra – 03 B)
Doc. dr. Zita Gasi ūnait ė (Klaip ėdos universitetas, biomedicinos mokslai, ekologija ir
aplinkotyra – 03 B)
Dr. Tomas Virbickas (Gamtos tyrim ų centro Ekologijos institutas, biomedicinos
mokslai, ekologija ir aplinkotyra – 03 B)

Oponentai:
Doc. dr. Darius Daunys (Klaip ėdos universitetas, biomedicinos mokslai, ekologija ir
aplinkotyra – 03 B)
Prof. dr. Virginijus Sruoga (Vilniaus pedagoginis universitetas, biomedicinos
mokslai, zoologija – 05 B)


Disertacija bus ginama viešame Ekologijos ir aplinkotyros mokslo krypties tarybos
pos ėdyje 2010 m. spalio m ėn. 01 d. 14 val. Gamtos tyrim ų centro Ekologijos instituto
sal ėje.
Adresas: Akademijos 2, LT – 08412, Vilnius, Lietuva
Tel. + 370 5 2729257, fax. + 370 5 2729352


Disertacijos santrauka išsiuntin ėta 2010 m. rugpj ūčio m ėn. 31 d.
Disertacij ą galima peržiūr ėti Gamtos tyrim ų centro Ekologijos instituto ir Vilniaus
universiteto bibliotekose.
Introduction

Relevance of the study. The loss of biodiversity is now one of the most important
environmental problems in the world. Aquatic ecosystems are particularly important for
biodiversity and productivity of the biosphere. They are sensitive to various
environmental changes. For the assessment and conservation of biological diversity it is
important to estimate the influence of environmental factors on aquatic invertebrate
species distribution and abundance, on their community structure, and also to predict
community alternations in the conditions of global and local changes.
Caddisflies (Insecta, Trichoptera) are one of the most important groups of benthic
macroinvertebrates in freshwater ecosystems. They are sensitive to changes of physical
and chemical parameters in water bodies, so often used to assess the ecological status of
the water body (Kiss et al. 2002; Czachorowski, Buczy ński 2004; Kownacki, Soszka
2004). The highest diversity of caddisfly larvae usually is in rapid, cold-water rivers of
different size. Information about distribution of caddisfly species in Lithuania, their
importance in benthic invertebrate communities, influence of environmental factors on
larval distribution and abundance and other ecological characteristics of caddisflies in
river habitats is incomplete. Caddisfly species rarity in our country has not been
analyzed. All this is important in assessing biological diversity and ecological status in
Lithuania or particular regions of the country, protected areas, in different water bodies.
It is also important in examining current ecological processes in river communities and
in predicting possible alterations under global environmental change.

Objective and tasks of the study.
The main objective of this work is to investigate the caddisfly (Trichoptera)
fauna, diversity, species distribution and rarity in Lithuania, to evaluate the influence of
environmental factors on the distribution and abundance of caddisflies in different
habitats of Lithuanian rivers.
The following tasks were defined to achieve the main objective:
1. To evaluate Lithuanian caddisfly species rarity, to assess rarity categories and
interrelation between caddisfly distribution and abundance;
2. To update checklist of Lithuanian caddisfly and to estimate distribution of
caddisfly species;
3. To estimate the seasonal dynamics of caddisfly adults flight activity and factors
affecting the number of generations;
4. To assess the influence of environmental factors on distribution and abundance
of caddisfly larvae (at family, genus and species taxonomic ranks) in
Lithuanian rivers;
5. To evaluate the significance of caddisflies in the structure of benthic
invertebrate communities in different Lithuanian rivers;
6. To evaluate caddisfly bioindicative value for assessment of ecological status in
Lithuanian rivers.
Novelty of the study.
In this study following aspects were investigated for the first time:
1. Lithuanian caddisfly rarity and the relationship between caddisfly distribution
and abundance were determined;
52. New species of caddisfly were discovered and the checklist of Lithuanian
caddisfly was updated;
3. Patterns of seasonal flight of caddisfly adults were established, and the factors
affecting the number of generations were estimated;
4. The environmental factors impacting the distribution and abundance of
caddisfly larvae (at family, genus and species taxonomic ranks) in Lithuanian
rivers were estimated;
5. The significance of caddisflies in the communities of benthic invertebrates of
different Lithuanian rivers was evaluated;
6. The bioindicative properties of selected caddisfly taxa in Lithuanian running
waters were specified and recommendations for improvement of assessment of
ecological status were proposed.
Scientific and practical significance:
1. The results obtained supplement the knowledge of diversity, distribution, and
abundance of caddisflies and other benthic macroinvertebrates of Lithuanian
rivers;
2. The determined patterns of caddisfly distribution and abundance are important
in optimizing biodiversity conservation measures;
3. The results are important for improvement of methods for biotic assessment of
ecological status of Lithuanian rivers.
Defended statements:
1. The distribution and abundance of caddisfly species are interrelated: widespread
species are more abundant;
2. Caddisfly species could be divided into 5 rarity categories in Lithuania;
3. Four types of seasonal flight are characteristic of caddisfly adults; the dynamics
of seasonal flight depends on species identity and variation in air temperature;
4. Distribution and abundance of particular caddisfly family, genus and species in
Lithuanian rivers depends upon different environmental factors that
importance varies between the taxonomic ranks. The main factors for the most
caddisfly taxa are current velocity, water temperature regime, river discharge,
bottom structure, and oxygen saturation.
5. The ecological status indices in which caddisflies are used are recommended to
be adjusted with regard to information obtained in the current study on the
impacts of environmental factors on caddisfly larvae distribution and
abundance in Lithuanian rivers.

Presentation and approval of results. Results of this study have been published
in 31 publications: 23 articles and 8 abstracts of scientific conference reports. The
material of the dissertation was presented at 15 conferences: of young hydro-
ecologists ‘Biodiversity and Functioning of Aquatic Ecosystems’ (Plateliai, Lithuania,
th th2002), the 2 and 4 international conf. ‘Research and Conservation of Biological
Diversity in Baltic Region‘ Daugavpils, Latvia, 2003, 2007), national conf. ‘Lithuanian
Biodiversity (Status, Structure, Protection)’ (Vilnius, Lithuania, 2003), international
Baltic conf. ‘Long-term Ecological Research‘ 2004),
conf. ‘The Relevance of Ecology, Social and Economy Research in Forestry and
Environmental Science‘ (Kaunas, Lithuania, 2004), regional conf. ‘Biodiversity and
Functioning of Aquatic Ecosystems in the Baltic Sea Region‘ (Palanga, Lithuania,
62004), national (2003–2005) and international (2006–2009) conf. ‘Man and Nature
Protection‘ (Kaunas, Lithuania), international conf. ‘Biodiversity, Protection and
Prospects of Baltic Seashore Habitats‘ (Klaip ėda, Lithuania, 2009).
Dissertation structure and scope. The dissertation is presented in the following
chapters: Introduction, Literature Review, Material and Methods, Research Results
(consisting of 5 subchapters), Discussion of the Results, Conclusions, References, List of
Author‘s Publications, and Appendices. All the material is presented in 229 pages; The
list of references includes 298 sources. The list of the author‘s publications contains 31
entries. The dissertation is written in Lithuanian with summaries in English and
Lithuanian. The text contains 19 tables, 58 figures, and 6 appendices.
Acknowledgements. I would like to express my heartfelt gratitude to the
scientific supervisor Dr K ęstutis Arba čiauskas for care, patience, fellowship, tolerance,
understanding, valuable advice and assistance during dissertation preparation. I thank my
colleague and friend Dr Rasa Bernotien ė for fellowship, tolerance and all assistance in
collecting and analyzing the material. I thank my colleagues Daiva Kalytyt ė and
Vytautas Rakauskas for friendship, discussions and assistance. I am sincerely grateful to
all staff of the Laboratory of Entomology for their patience, understanding and help in
gathering material. I sincerely thank prof. Dr H. Malicky (Austria), prof. Dr S.
Czachorowski, Dr P. Buczy ński, Dr M. Przewo źny (Poland) for valuable advices and
help with the identification of aquatic invertebrates.
I am especially grateful to my family, dear husband Vytautas and daughter Gerda
for their love, understanding, patience and support.
There are many other friends and colleagues not mentioned herein, my heartfelt
thanks to all of them.

LITERATURE REVIEW

This part of the dissertation presents a historical summary of caddisfly
investigations related to the topic of this work and conducted in Europe and Lithuania.
The bioindicative significance of caddisfly larvae in benthic invertebrate communities
and criteria for the assessment of ecological statues of rivers are discussed.

MATERIAL AND METHODS

Research material. The material of caddisfly larvae and other benthic
invertebrates was collected in 33 Lithuanian rivers (B ūka, Dysna, Dubysa, Elm ė,
Grabuosta, Graisupis, Grūda, Juodupis, L ėvuo, Merkys, Mus ė, M ūša, M ūšia, Nemunas,
Nemun ėlis, Rieš ė, Sasna, Siesartis, Skroblus, Sudervė, Susiena, Šelmenta, Širvinta,
Šventoji, Paj ūrio Šventoji, Ūla-Pelesa, Varius, Venta, Verk ė, Vilnia, Virinta, Vyžuona,
Žeimena) in 2003–2004 and 2006–2008. Single and seasonal investigations of caddisfly
adults were performed by the author and other persons in 115 study sites in Lithuania
during 1987–2008. In total, 254 quantitative samples of benthic invertebrates and 238
quantitative samples of caddisfly adults were collected during the studies in 193
localities (Fig. 1). The collected material is deposited in the Institute of Ecology of
Nature Research Centre (Akademijos str. 2, Vilnius).
Methods of research. The physical and chemical environmental parameters were
taken from literature or, when relevant, measured at each study site: river size, discharge,
7depth at study site, current velocity, water temperature regime, bottom structure, bottom
coverage by aquatic vegetation and deposits of coarse and fine particulate organic
matter, site illumination (shading), amounts of nitrites, nitrates and phosphates, dissolved
oxygen, water hardness, pH, oxygen saturation, amount of organic matter (ChDSMn).
For statistical analysis, some factors were divided into categories.

Fig.1. Study sites of caddisflies and benthic macroinvertebrates
1 pav. Apsiuv ų ir bentoso makrobestuburi ų tyrim ų vietos

The samples of benthic macroinvertebrates were collected by standard kick-
sampling in a particular biotope (microhabitat) or by taking multihabitat samples
collected over the 10 minutes period with a hydrobiological dip net from all possible
biotopes at each study site (LAND 57–2003, Arba čiauskas 2009). In laboratory, the
collected samples were picked out, separated and preserved in 70% ethyl alcohol.
Specimen animals were identified to the lowest possible taxon, all individuals were
counted and usually weighted.
Entomological net and light traps of different construction were used for caddisfly
imago sampling. Adults were placed in the tubes dried or fixed in alcohol, further fixed
on entomological pins and preserved in the collections. Genital structures used for insect
description were prepared in 5% KOH solution, analyzed and preserved in glycerin.
Analysis of the material. The individuals of each species (or higher taxon) were
counted and weighed separately; their abundance and biomass were recalculated as per
-2 -2square meter and provided as ind. m and g m . Species dominance (D) was evaluated
with respect to their share (%) in the community. Diversity was estimated using
Shannon-Wiener species diversity index. Species occurrence frequency (F), assessed as
proportion of study sites where species was present, was used for species separation
between rarity categories. Whereas different research methodologies were used for
different life cycle stages, the rarity of caddisflies was estimated for adults and larvae
separately. The rarity of species was estimated according to caddisfly imago occurrence
in 40 localities and larvae occurrence in 26 localities. Sampling localities were
considered to be representative of species richness if more than 10 caddisfly species
were identified at a site. The quantitative data from 8 light-traps were used to estimate
the species abundance (ind. per flight season) per site and further the mean species
8abundance in different rarity categories was evaluated. Analogically, the mean species
-2of larvae (ind. m ) in different rarity categories was also calculated.
Differences in abundance between rarity categories were analysed using Kruskal-Wallis
ANOVA and a multiple comparison test.
For the assessment of the ecological status of investigated rivers in accordance
with the composition of benthic invertebrates, different biotic indices were used: EPT,
abundance proportion of trophic groups of invertebrates, BMWP, BMWP–PL,
(Biological Monitoring Working Party score system), ASPT (Average Score Per Taxon),
DSFI (Danish Stream Fauna Index). The calculations were carried out in accordance
with methodical guidelines (Appendix 1, Arba čiauskas 2009) or using program Asterics
3.1.1. The analysis of variance (one-way ANOVA) was used to assess the relation
between quality classes in river sites according to these indices and annual average of
organic matter. Spearman Rank Correlation (r ) was used to assess relationship of trophic s
groups, EPT index values and abundance of taxa with biotic indices of ecological status.
The amount of data used in statistical analysis depended on the hypothesis to be
tested. To estimate the significance of variation differences between distinguished
categories after checking statistical analysis presumptions, the analysis of variance
(ANOVA), Kruskal-Wallis analysis and multiple comparison (post hoc) tests (Tukey
HSD, Unequal N HSD) were used. For analysing the impact of environmental factors on
the distribution of caddisflies in Lithuanian rivers correlation analysis and analysis of
variance were used. The number of caddisfly taxa and abundance of analysed taxa were
log transformed before analysis. The correlation analysis, multifactor analysis of
variance and multiple regression were used for establishment of important environmental
factors influencing caddisfly families, genera and species distribution and abundance in
the rivers. The repeated measures ANOVA and Tukey HSD tests were used to test the
air temperature effect on the number of caddisfly generations. The Bray–Curtis Index of
Similarity was used for the comparison of benthic communities. The data were processed
employing Microsoft Excel, Statistica 7.0 and BioDiversity software programmes.

RESEARCH RESULTS AND DISCUSSION

Fauna of Lithuanian caddisflies. 152 species and 1 subspecies of caddisflies
were recorded in 193 localities during the studies. 22 caddisfly taxa (21 species and 1
subspecies) were found in Lithuania for the first time. The current checklist also includes
20 species, which were defined before 1969 (Ulmer et al. 1917; Racięcka 1931, 1937;
Kazlauskas 1960; Spuris 1969), and one recently reported new species (Pli ūrait ė 2001;
Pli ūrait ė, Kesminas 2004; Virbickas, Pliūrait ė 2002) that has not been observed during
the current study. The general distribution of all these species in Europe supports the
possibility of their occurrence in Lithuania. Currently, the caddisfly species list
comprises 173 species and 1 subspecies representing 18 families and 71 genera. 33% (58
species) of Lithuanian caddisfly fauna belongs to Limnephilidae family. Other families
constitute no more than 19% of caddisfly fauna. The most common Lithuanian caddisfly
species (founded in >25% of study sites) belonged to Limnephilidae (Limnephilus
flavicornis F., L. rhombicus L., L. griseus L., Glyphotaelius pellucidus Retz.),
Phryganeidae (Phryganea grandis L.) and Hydropsychidae families (Hydropsyche
pellucidula Curt.). Eighteen rarest species (founded in a single locality) belonged to
Hydroptilidae, Polycentropodidae, Ryacophylidae, Hydropsychidae, Phryganeidae,
9Leptoceridae, and Limnephilidae families. Only Apatania wallengreni McL. and
Limnephilus centralis Curt. were registered in larva stage, the remaining species were
identified in adult stage. This fact confirms a more accurate species identification of
adults and a more detailed evaluation of species diversity in the study area by
encompassing investigations into all caddisfly stages. When investigating caddisflies in
the habitats of water bodies, we estimated biological diversity and ecological status of
the particular body. However, the fauna of temporary water bodies, canals,
marshes and other water bodies suitable for particular caddisfly species becomes
accessible, which is hardy accessible for investigation by hydrobiological methods.
Nevertheless, 174 caddisfly taxa should not be considered a complete species list
in Lithuania. Some other species such as Hydroptila cornuta Mos., Oxyethira frici Klap.,
Molanna albicans Zett., Beraea maurus Curt., Ernodes articularis Pict., Potamophylax
cingulatus Steph., Limnephilus hirsutus Pict. could also be expected in our country
because of their wide distribution in Europe and occurrence in Poland, Latvia and/or
Belarus (Barnard, Malicky 2007). Currently, 145 caddisfly species are known in Belarus
(Γигиняк 2009), 196 species in Latvia (Kalni ņš, Spuņģis 2002), and 288 species in
Poland (Czachorowski, Pietrzak 2003).
Caddisfly species rarity in Lithuania. Caddisfly species rarity becomes
important for biodiversity investigations in different localities, from small water bodies,
protected areas in Lithuania to species distribution in Europe. Some authors recommend
using only species presence/absence data, while others also use species abundance,
frequency and distribution data (Nógrádi, Uherkovich 1995, 1999; Schmera 2001). Until
now, however, classification of Lithuanian caddisflies into rarity categories has not been
attempted, although such categorization is of particular interest in evaluating the status of
the country, separate regions or water bodies, examining the current and future
ecological processes in river communities. It is also important, because some caddisfly
species definitely need protection status. The Lithuanian Red Data Book currently lists
only two caddisflies species (Holostomis phalaenoides L. and Philopotamus montanus
Don.) (Rašomavi čius et al. 2007); however, data on the current status of these species
are not quite clear. Red Data Lists of neighbouring countries include a larger number of
rare and protected caddisfly species (Czachorowski et al. 2004).
Hanski’s Rule states that common species are more abundant than rare (Krebs
2001). If this rule applies to caddisflies, the abundance of caddisfly species (estimated as
the mean number of adult specimens per flight season in a site or as the mean abundance
-2of individuals per area unit (ind. m ) in an aquatic habitat) should be associated with
species rarity.
The majority caddisfly species were detected during adult caddisfly studies, i.e.
143 species and 1 subspecies from 40 localities, have been used for the assessment of
species rarity. On the basis of species frequency (F), caddisfly imago were classified into
5 rarity categories: 1) very rare, ≤2% (species which are present in 1–2 localities per 100
studied localities should be included into this category; as in this study data on caddisfly
adults were available from 40 localities, we classified as very rare those species which
were detected at only one locality); 2) rare, 3–10%; 3) common, 11–50%, 4) very
common, >50%; and 5) locally abundant, ≤5%, but abundance of specimens exceeds 150
individuals per locality. According to collected data, 23, 36, 70, 13 and 2 species were
categorized as very rare, rare, common, very common and locally abundant,
correspondingly. The most frequent species according to imago occurrence were
10