Journal article
Short-term impacts of soil freeze-thaw cycles on roots and root-associated fungi of Holcus lanatus and Calluna vulgaris



Publication Details
Authors:
Andruschkewitsch, M.
Publication year:
2012
Journal:
Plant and Soil
Pages range:
19-31
Volume number:
353
Start page:
19
End page:
31
ISSN:
0032-079X

Abstract
Background and aims 
Soil freeze-thaw cycle (FTC) regimes are altered by climate change and known to influence nutrient cycling and plant growth. Here, we explore mechanistic explanations for the changing plant performance of the grassHolcus lanatusand the dwarf shrubCalluna vulgaris.

Methods 

144 plant-soil mesocosms were subjected to different FTC-regimes in a climate chamber. Root injury, fungal activity and fungal composition (ITS-sequencing) were quantified. Results 

The applied FTC-scenarios increased root injury by 23% on average while no strong differences between scenarios was found. Root damage was greater inC. vulgaristhan inH. lanatus. Fungal activity increased due to the FTC-manipulation and was higher in theC. vulgarissamples, although activity was generally low. No significant shift in the fungal community composition was found immediately after the applied FTCs. A saprobic (Aureobasidium pullulans) and a potentially mycorrhizal fungus (Sebacinales) showed opposing responses to the FTC-manipulation in the different host plants, while a potential phytopathogen (Callophora) decreased in frequency. 

Conclusions

Increased fungal activity within these samples is suggested to be related to an increased dominance of saprobic taxa, but not to a shift in qualitative community composition. Single pathogenic species entering the plants through the observed root injuries subsequent to FTC treatments however, may alter plant performance. While these results suggest the importance of root injury for the response of vegetation to FTCs, fungal activity and pathogenic infection need to be further studied under field conditions over longer time periods.


Keywords
Clone libraries, Freezing-thawing, Frost, Fungal community, ITS rRNA gene, RFLP, Temperature tolerance, Winter ecology

Last updated on 2019-01-11 at 16:04