Impacts of alkaline dust pollution on biodiversity of plants and lichens: from communities to genetic diversity
Date
2016-10-20
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Abstract
Õhusaaste ohustab oluliselt looduslikku mitmekesisust, avaldades mõju erinevatel bioloogilistel tasemetel – alates rakulisest tasemest kuni ökosüsteemide tasemeni. Tolmusaaste on Eestis alati olnud märkimisväärne keskkonnaprobleem, kuna paljude aastate vältel moodustasid Eesti tööstusettevõtete poolt õhku paisatud saastest suure osa just tahked aluselised heitmed. Käesolev töö on keskendunud aluselistele jämedatele tolmuosakestele, mis vabanevad keskkonda lubjakivi kaevandamise käigus, tsemenditööstusest ja kruusateedelt. Selleks, et leevendada õhusaastest tekitatud kahju keskkonnale, on vajalik hinnata ja jälgida õhusaaste mõjusid ning otsida uusi võimalikke bioindikaatoreid täiendamaks õhuseirejaamade andmeid. Selle töö eesmärkideks oligi uurida eri päritoluga pikaajalise aluselise tolmusaaste toimet boreaalsetele metsakooslustele, sambliku-, sambla- ja vetikakooslustele mändidel ning ühe samblikku moodustava seeneliigi populatsioonide geneetilisele mitmekesisusele. Leidsin, et pikaajaline tolmusaaste on avaldanud neutraliseerivat toimet mulla keemilistele omadustele ning männi ja kuuse koorele; mulla ja puukoore pH on tõusnud tolmusaaste mõju piirkondades ja vähenes tolmusaaste allikate kaugenedes. Selgus, et tolmusaaste hävitas looduslikke kooslusi ning põhjustas uudsete koosluste tekkimist tolmureostuse mõjupiirkondades, näiteks happelembeste/happettaluvate liikide järk-järgulist asendumist neutrofiilsete ja seejärel kaltsifiilsete liikidega. Huvitav on see, et aluseline tolmusaaste mõjub looduslikele kooslustele “parapositiivselt” aidates looduslike koosluste häirimise kõrval ajutiselt kaasa haruldaste ja kaitstavate liikide levikule. Oma töös pakkusin välja mitmed uued tolmusaaste indikaatorliigid mändidel, näiteks härma-kiiriksamblik, piir-kärnsamblik või rohevetikas Trentepohlia umbrina. Näitasime esmakordselt aluselise tolmusaaste negatiivset mõju tavalise ja laialt levinud sambliku, vars-habesambliku populatsioonide geneetilisele mitmekesisusele.
Air pollution is a consequential global threat to overall biodiversity, affecting different biological levels – from cellular to ecosystem level. The dust pollution has always been essential environmental issue in Estonia since over the years the large part of industrial pollution was formed by alkaline dust. The current thesis is focused on alkaline coarse dust particles, which are released to the environment through cement industry, limestone quarries and directly from unpaved gravel roads by traffic. In order to monitor and mitigate damages caused by dust pollution, the influence of pollution on different levels of biodiversity should be estimated and the potential sources of pollution and their extension detected. Therefore, the aim of the thesis was to study the response of pine forest ecosystems, epiphytic communities (algae, lichens, bryophytes) on pines, and genetic diversity of populations of a common lichen-forming fungus to changed environmental conditions induced by a long-term alkaline pollution. The results showed that long-term dust pollution had a neutralizing effect on soil properties, pine and spruce barks: the pH value of soil and tree barks decreased along an increasing distance from the sources of pollution. The alkaline pollution has caused destruction of natural communities and formation of novel communities in the vicinity of pollution sources, for example invasion of non-typical and pollution-tolerant species for local communities occurred, including calcicolous species and species characteristic for nutrient-rich habitats. Interestingly, dust pollution revealed a kind of ‘parapositive’ impact on natural communities, suggesting that pollution might, besides disturbing communities, temporarily also contribute to the distribution of rare and protected species. Finally, alkaline pollution had a negative impact on the genetic variation of Usnea subfloridana populations, a common species of lichen-forming fungi.
Air pollution is a consequential global threat to overall biodiversity, affecting different biological levels – from cellular to ecosystem level. The dust pollution has always been essential environmental issue in Estonia since over the years the large part of industrial pollution was formed by alkaline dust. The current thesis is focused on alkaline coarse dust particles, which are released to the environment through cement industry, limestone quarries and directly from unpaved gravel roads by traffic. In order to monitor and mitigate damages caused by dust pollution, the influence of pollution on different levels of biodiversity should be estimated and the potential sources of pollution and their extension detected. Therefore, the aim of the thesis was to study the response of pine forest ecosystems, epiphytic communities (algae, lichens, bryophytes) on pines, and genetic diversity of populations of a common lichen-forming fungus to changed environmental conditions induced by a long-term alkaline pollution. The results showed that long-term dust pollution had a neutralizing effect on soil properties, pine and spruce barks: the pH value of soil and tree barks decreased along an increasing distance from the sources of pollution. The alkaline pollution has caused destruction of natural communities and formation of novel communities in the vicinity of pollution sources, for example invasion of non-typical and pollution-tolerant species for local communities occurred, including calcicolous species and species characteristic for nutrient-rich habitats. Interestingly, dust pollution revealed a kind of ‘parapositive’ impact on natural communities, suggesting that pollution might, besides disturbing communities, temporarily also contribute to the distribution of rare and protected species. Finally, alkaline pollution had a negative impact on the genetic variation of Usnea subfloridana populations, a common species of lichen-forming fungi.
Description
Väitekirja elektrooniline versioon ei sisalda publikatsioone.
Keywords
tolm, õhu saastamine, metsakooslused, metsataimestik, samblikud, taimekooslused, bioloogiline mitmekesisus, geneetiline mitmekesisus, dust, air pollution, forest communities, forest flora, lichens, plant communities, biodiversity, genetic diversity