Alustaimestiku mitmekesisus ja geobotaaniline analüüs Edela-Eesti luitmännikutes

A Thesis for applying for the degree of Doctor of Philosophy in ForestryThis thesis focuses on vascular plants, bryophytes and lichens of forested dunes of various heights in south-west Estonia, with the overall aim to determine the environmental factors that shape ground vegetation communities. To investigate the ecosystems on dunes, five typical dunes were selected in the coastal area of the Baltic Sea in south-west Estonia between Uulu and Häädemeeste; the average distance of the study sites from the Baltic Sea coast was approximately 2–3 km. To study ground vegetation species richness, species composition and horizontal structure, 251 quadrats of 1 m2 in size were established. For all quadrats, descriptions of vascular plants, bryophytes and lichen species were provided, and the total coverages of vascular plants, bryophytes and lichen species as well the coverage of each layer were estimated. In addition, various environmental factors were determined. In total, 133 ground vegetation species were recorded on the five dunes: 42 vascular plant, 43 bryophyte and 48 lichen species. Ground vegetation species richness and composition on the forested dunes were not determined by one or two factors, but rather by a complex system of environmental variables that showed different effects on different ground vegetation life-forms. Vascular plant species richness and composition on forested dunes was also dependent on the absolute dune height, zone and aspect of the slope, soil nitrogen, potassium and phosphorus contents, soil pH and moisture, the cover of the bryophyte-lichen layer and light conditions. Regarding bryophyte and lichen layer species composition, some of the most important factors were the aspect of the dune, vascular plant species cover, light conditions, the thickness of the moderately decomposed organic soil horizon, soil pH, electrical conductivity and volumetric water content. Lichen species richness was highest on the slopes of the dunes, while bryophyte species richness was higher at the bottoms and decreased towards the tops of the dunes. Ground vegetation species richness and species’ horizontal and vertical structure on forested dunes were highly dependent on topography-induced differences, aspect, height and zone of the dunes. The most important factors controlling the complex of ground vegetation were light conditions, soil water content, thickness of the moderately decomposed litter layer and soil potassium and calcium contents.Doktoritöö eesmärk oli uurida luitemetsade alustaimestiku liigilist mitmekesisust ja leida, millised keskkonnatunnused mõjutavad soontaimede, sammalde ning samblike liigirikkust ja liigilist koosseisu luitemetsades. Luitemetsade alustaimestiku liigilise mitmekesisuse ja liigirikkuse uurimiseks valiti Edela-Eestis Uulu ning Häädemeeste vahele jäävalt alalt viis tüüpilist luidet, mille kaugus rannajoonest jäi vahemikku 2—3 km. Soontaimede, sammalde ja samblike liigilise koosseisu ning horisontaalse struktuuri määramiseks rajati kokku 251 ühe ruutmeetri suurust prooviruutu. Prooviruutudel määrati soontaimede, sammalde ja samblike üldkatvus, seal esinevad liigid ning nende katvus ning erinevad kasvukeskkonda iseloomustavad parameetrid. Alustaimestiku liigirikkuse uurimisel nimetati 42 soontaimeliiki, 43 samblaliiki ja 49 samblikuliiki. Töö tulemustest selgub, et keskkonnatingimused, mis määravad metsastunud luidetel alustaimestiku liigirikkuse ja koosluse struktuuri, moodustavad omavahel seotud keerulise süsteemi, mis mõjutab alustaimestiku moodustanud eluvorme erinevalt. Soontaimede liigirikkust ja liikide mitmekesisust luidetel on enim mõjutanud luite topograafilised omadused, nagu luite absoluutne kõrgus, asukoht luitel ja paiknemine ilmakaarte suhtes, samuti substraadi pH, lämmastiku-, fosfori- ja kaaliumisisaldus, mullaniiskus ning valgustingimused. Soontaimede puhul on oluline näitaja ka sambla- ja samblikurinde üldkatvus. Lämmastiku üha suureneva depositsiooni tingimustes kerkib esile oluline fakt, et luitemetsade soontaimede liigirikkus väheneb märgatavalt suurenenud lämmastikuhulga korral. Sambla- ja samblikurinde liigilist koosseisu ning struktuuri määravad luite kõrgus, paiknemine ilmakaarte suhtes, asukoht luitel, lisaks valgustingimused, mulla pH ja lahustuvate soolade ioonide kontsentratsioon mullalahuses, mullaniiskus, soontaimede üldkatvus ja mõõdukalt lagunenud kõdukihi tüsedus. Kui sammalde liigirikkus püsis kogu luite piires suhteliselt stabiilsena, olles suurim luidete jalamitel, siis samblike liigirikkus oli suurim luidete nõlvadel, kus maapinnale jõudvat valgust oli kõige enam ja mullaniiskus väikseim. Analüüsides uuritud luitemetsade alustaimestikku tervikuna ja koosluse liigilist koosseisu mõjutavaid tegureid, ilmnes, et statistiliselt olulised on luite kõrgus ja paiknemine ilmakaarte suhtes, mõõdukalt lagunenud kõduhorisondi tüsedus, mulla pH, mullaniiskus, mulla kaaliumi- ja kaltsiumisisaldus ning luite valgustingimused.Publication of this dissertation is supported by the Estonian University of Life Sciences and by the Doctoral School of Earth Sciences and Ecology created under the auspices of European Social Fun

Effect of environmental factors on the composition of terrestrial bryophyte and lichen species in Scots pine forests on fixed sand dunes

Aim of the study: To investigate terrestrial bryophyte and lichen species richness and environmental factors affecting the composition of species.Area of the study: Four Boreal zone fixed dunes were selected in the coastal area of the Baltic Sea in southwest Estonia.Material and methods: Non-metric multidimensional scaling was performed to analyse distribution patterns and environmental factors like canopy cover, photosynthetically active radiation, soil organic horizon thickness and decomposition rates, soil volumetric water content, soil pH and electrical conductivity and soil nutrients correlated with bryophyte and lichen species composition.Main results: Thirty bryophytes and 22 lichens were found on 232 sample plots, the most frequent species were Pleurozium schreberi (Willd. ex Brid.) Mitt., Hylocomium splendens (Hedw.) Schimp., Dicranum polysetum Sw. ex anon., Cladonia arbuscula (Wallr.) Flot. and Cladonia furcata (Huds.) Schrad. The lichen species richness was highest on the slopes of the dunes and decreased towards the bottoms and tops; bryophyte species richness was higher on the bottoms and decreased towards the tops of the dunes.Research highlights: The composition of bryophytes and lichens is significantly influenced by the aspect and the location on the dune, light conditions, soil pH, soil salinity (measured as electrical conductivity) and volumetric water content, thickness of moderately decomposed organic horizon and vascular plant species cover.KeywordsInland dunes; terrestrial bryophyte and lichen communities; environmental factors; topography

Effect of environmental factors on the composition of terrestrial bryophyte and lichen species in Scots pine forests on fixed sand dunes

Aim of the study: To investigate terrestrial bryophyte and lichen species richness and environmental factors affecting the composition of species.Area of the study: Four Boreal zone fixed dunes were selected in the coastal area of the Baltic Sea in southwest Estonia.Material and methods: Non-metric multidimensional scaling was performed to analyse distribution patterns and environmental factors like canopy cover, photosynthetically active radiation, soil organic horizon thickness and decomposition rates, soil volumetric water content, soil pH and electrical conductivity and soil nutrients correlated with bryophyte and lichen species composition.Main results: Thirty bryophytes and 22 lichens were found on 232 sample plots, the most frequent species were Pleurozium schreberi (Willd. ex Brid.) Mitt., Hylocomium splendens (Hedw.) Schimp., Dicranum polysetum Sw. ex anon., Cladonia arbuscula (Wallr.) Flot. and Cladonia furcata (Huds.) Schrad. The lichen species richness was highest on the slopes of the dunes and decreased towards the bottoms and tops; bryophyte species richness was higher on the bottoms and decreased towards the tops of the dunes.Research highlights: The composition of bryophytes and lichens is significantly influenced by the aspect and the location on the dune, light conditions, soil pH, soil salinity (measured as electrical conductivity) and volumetric water content, thickness of moderately decomposed organic horizon and vascular plant species cover.KeywordsInland dunes; terrestrial bryophyte and lichen communities; environmental factors; topography

Changes in the canopies of Pinus sylvestris and Picea abies under alkaline dust impact in the industrial region of Northeast Estonia

Studies were carried out in 1999, 2005 and 2007 in the area of Kunda cement plant in Northeast Estonia on sample plots 3 km W and 2.5 and 5 km E of Kunda. As control stands, two plots for pine and spruce were established in Lahemaa National Park (34–38kmWof Kunda). The selected pine and spruce stands were 75–85-year-old Myrtillus site type, of 0.7–0.8 density and II quality class, with moderately dense or sparse understorey. The values concerning needle density and number of needle scars were higher for shoots formed in the period of higher pollution than for the shoots grown under a considerably lower pollution load. Although the cement dust pollution has notably decreased from year to year, the number of needle pairs per 1 cm of the shoot was 1.8–2.1 times greater in the shoots formed in 1998 than in those formed in 2003, whereas the changes were statistically reliable. Possibly the low temperatures at the time of shoot and needle formation affected the density of needles on all sample plots, and thus the number of needles on shoots formed in 2003 was many times smaller. After the significant fall in the pollution load since 1996 the length growth of needles intensified around Kunda cement plant, at the same time no changes occurred in the length growth of needles in the control area. As compared to the data from 1998, the length growth of pine needles had improved, especially 2.5 and 5 km E from the cement plant, needles being respectively 1.5 and 1.1cm longer than 6 years ago. The stimulation of the growth of pine and spruce needles 2.5 and 5 km E of the cement plant may be a sign of a positive effect of reduced doses of cement dust in soil. The greater length of pine and spruce needles is the reason for the larger biomass of the needlesVytauto Didžiojo universitetasŽemės ūkio akademij