Muutused vihmaussikooslustes sõltuvalt majandamisviisist
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Kuupäev
2012
Kättesaadav alates
ainult raamatukogus, only in library
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Abstrakt
Käesolevas töös uuriti vihmausside arvukust mõjutavaid tegureid, kuna vihmaussid on olulised
mulla saastatuse ja kurnatuse indikaatoriteks. Töö eesmärgiks oli uurida kirjanduse põhjal,
kuidas mõjutavad vihmausside arvukust erinevad mulla omadused, mullaharimistööd ning
majandamisviisid. Eestis on senini leitud 13 vihmaussiliiki. Dominantliigiks on harilik mullauss
(Aporrectodea caliginosa), kes võib kogu vihmaussikooslustest moodustada 65− 95%.
Tulemuseks leiti, et vihmausside arvukus on mõjutatud väga paljude tegurite poolt.
Harimisviisidest mõjutab vihmausside arvukust enim kündmine, vähem pindmine
mullaharimine. Keskmiselt leidub põllumuldades alla 100 isendi m2 kohta. Rohke orgaanilise
aine sisaldus mullas mõjutab vihmausse positiivselt ning samuti ka orgaaniliste väetiste lisamine
mulda. Herbitsiidide kasutamise puhul ei leitud, et nende kasutamine osutaks erilist mõju.
Looduslikest teguritest mõjutab vihmausside arvukust mulla lõimis, niiskuse sisaldus ja
temperatuur. On leitud, et saviliiv mullas on vihmausside arvukus kõrgem. Liigne mulla niiskuse
sisaldus pärsib vihmausside arengut ning ajutiselt liigniisketes muldades on domineerivamad
liigid, kes eelistavad niiskemaid muldi. Pikk põuaperiood suvel enamasti mõjutab vihmausside
arvukust negatiivselt, kui mullas pole piisav niiskusevaru.
In this thesis, the factors affecting the abundance of earthworms as important indicators of soil pollution were studied. The aim of research was to study how the soil properties, cultivation and management practices affects earthworms. 13 earthworm species have been found in Estonia so far. Dominant specie is Aporrectodea caliginosa, which may constitute 60− 95% of earthworm community in Estonia. It was shown that the abundance of earthworms is influenced by a number of different factors. Ploughing affects earthworm’s more than surface cultivation. On the average about 100 individuals are found per m2 in agricultural soils. Higher organic matter content in soils affects earthworms positively, as well as adding organic fertilizers to the soil. The use of herbicides does not have a significant effect on earthworm abundance. Natural factors that affect earthworms are soil texture, moisture content and temperature. Excessive moisture content in soils decreases earthworm abundance. However in hydromorphic soils the dominant species are those who prefer moister soils. A long period of drought mostly affects earthworm abundance negatively if there the soil moisture content is not sufficient.
In this thesis, the factors affecting the abundance of earthworms as important indicators of soil pollution were studied. The aim of research was to study how the soil properties, cultivation and management practices affects earthworms. 13 earthworm species have been found in Estonia so far. Dominant specie is Aporrectodea caliginosa, which may constitute 60− 95% of earthworm community in Estonia. It was shown that the abundance of earthworms is influenced by a number of different factors. Ploughing affects earthworm’s more than surface cultivation. On the average about 100 individuals are found per m2 in agricultural soils. Higher organic matter content in soils affects earthworms positively, as well as adding organic fertilizers to the soil. The use of herbicides does not have a significant effect on earthworm abundance. Natural factors that affect earthworms are soil texture, moisture content and temperature. Excessive moisture content in soils decreases earthworm abundance. However in hydromorphic soils the dominant species are those who prefer moister soils. A long period of drought mostly affects earthworm abundance negatively if there the soil moisture content is not sufficient.
Kirjeldus
Märksõnad
vihmaussid, indikaatorid, mullaharimine, orgaanilised ained, bakalaureusetööd