Lenz-Ruckli, Regina. The invasive plant Impatiens glandulifera affects mycorrhizal fungi, plant and invertebrate diversity in deciduous forests. 2013, PhD Thesis, University of Basel, Faculty of Science.
Official URL: http://edoc.unibas.ch/diss/DissB_11527
Aboveground gastropod richness and abundance were found to be higher in invaded plots than in control plots. The presence of I. glandulifera also altered the composition of gastropod species. Belowground fewer types of ectomycorrhiza were found on root systems of F. sylvatica saplings. Moreover, in plots with I. glandulifera the composition of ectomycorrhiza morphotypes was shifted. Considering mycorrhizal colonisation on fine roots saplings of both tree species, the presence of the invasive plant resulted in a reduction of ectomycorrhizal colonisation of F. sylvatica saplings and of arbuscular mycorrhiza colonisation on A. pseudoplatanus. Thus, disruption of mycorrhizal symbiosis probably led to a lower biomass and survival rate in saplings of both species grown in invaded plots. Additional results showed that soil moisture, soil pH, available phosphorus and microbial activity were increased in invaded plots.
Increased gastropods abundance and richness could be explained by higher soil moistures and damped soil temperature in invaded plots. However, measured changes in soil conditions did not affect mycorrhizal colonisation and performance of both sapling species. Therefore allelopatic effects of I. glandulifera on mycorrhizal symbioses were also examined. Allelopatic compounds are known to contribute to the spread of some invasive plant species and can disrupt mycorrhizal symbiosis. I identified the allelopathic compound 2-methoxy-1,4-naphtoquinone (2-MNQ) in plant organs of I. glandulifera, in soil of its proximity and in rain water rinsed from its leaves. Specific bioassays using shoot and root extracts of I. glandulifera as well as synthetic 2-MNQ revealed strong inhibitory effects on mycelium growth of ectomycorrhiza fungi and on the germination of native forest herbs. This finding indicates that the release of 2-MNQ may contribute to the invasion success of I. glandulifera.
Health, function and diversity of forest ecosystems are closely linked to the abundance and richness of mycorrhizal fungi. This study demonstrates that the spread I. glandulifera into deciduous forest ecosystem resulted in lower mycorrhizal colonisation of saplings. Thus, forest regeneration might be strongly affected by I. glandulifera. Moreover, changes in soil chemistry and soil conditions induced by I. glandulifera caused shifts in above- and belowground communities. Therefore ecosystem services and functions of forest habitats can be affected. Removal or stopping the preceding spread of I. glandulifera may be an investment for the conservation of native species and may prevent potential losses in timber production.
|Advisors:||Baur, Bruno and Erhardt, Andreas|
|Faculties and Departments:||05 Faculty of Science > Departement Umweltwissenschaften > Institut für Natur- Landschafts- und Umweltschutz > Naturschutzbiologie (Baur)|
|Bibsysno:||Link to catalogue|
|Number of Pages:||1 Online-Ressource|
|Last Modified:||26 Sep 2016 14:56|
|Deposited On:||26 Sep 2016 14:48|
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