Moth outbreaks reduce decomposition in subarctic forest soils
|Author:||Sandén, Hans1; Mayer, Mathias1; Stark, Sari2;|
1Institute of Forest Ecology, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences (BOKU), Peter-Jordan-Straße 82, 1190, Vienna, Austria
2Arctic Centre, University of Lapland, PL 122, 96101, Rovaniemi, Finland
3Institute for Sustainable Plant Production, Department for Soil Health and Plant Nutrition, Austrian Agency for Health and Food Safety (AGES), Spargelfeldstraße 191, 1220, Vienna, Austria
4Norwegian Institute of Bioeconomy Research (NIBIO), Svanhovd, 9925, Svanvik, Norway
5Norwegian Institute for Nature Research (NINA), Framsenteret, P.O. Box 6600, 9296, Langnes, Tromsø, Norway
6Research Unit of Ecology and Genetics, University of Oulu, P.O. Box 8000, 90014, Oulu, Finland
|Online Access:||PDF Full Text (PDF, 1.1 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2020040310317
|Publish Date:|| 2020-04-03
Tree mortality from insect infestations can significantly reduce carbon storage in forest soils. In subarctic birch forests (Betula pubescens), ecosystem C cycling is largely affected by recurrent outbreaks of defoliating geometrid moths (Epirrita autumnata, Operophtera brumata). Here, we show that soil C stocks in birch forests across Fennoscandia did not change up to 8 years after moth outbreaks. We found that a decrease in woody fine roots was accompanied by a lower soil CO₂ efflux rate and a higher soil N availability following moth outbreaks. We suggest that a high N availability and less ectomycorrhiza likely contributed to lowered heterotrophic respiration and soil enzymatic activity. Based on proxies for decomposition (heterotrophic respiration, phenol oxidase potential activity), we conclude that a decrease in decomposition is a prime cause why soil C stocks of mountain birch forest ecosystems have not changed after moth outbreaks. Compared to disturbed temperate and boreal forests, a CO₂-related positive feedback of forest disturbance on climate change might therefore be smaller in subarctic regions.
|Pages:||151 - 163|
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
1172 Environmental sciences
1181 Ecology, evolutionary biology
This study was funded by the European Unions’ FP7 (Grant No. 262693 [INTERACT]), the Austrian Federal Ministry of Education, Science and Research (Project “Gemeinsam für nachhaltige Entwicklung – The Future we Want”) and Douglas L. Godbold, Institute of Forest Ecology, BOKU Vienna. JUJ was supported by the Research Council of Norway (Grant No. 244454) and PRW by the Academy of Finland (Grant No. 138309).
|Academy of Finland Grant Number:||
138309 (Academy of Finland Funding decision)
© 2019 The Author(s). This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.