Is forest management a significant source of monoterpenes into the boreal atmosphere?

[摘要] Volatile organic compounds (VOCs) including terpenoids are emitted into theatmosphere from various natural sources. Damaging the plant tissue is knownto strongly increase their monoterpene release. We measured the terpenoidemissions caused by timber felling, i.e. those from stumps and loggingresidue. The emissions from stumps were studied using enclosures and thosefrom the whole felling area using an ecosystem-scale micrometeorologicalmethod, disjunct eddy accumulation (DEA). The compounds analyzed wereisoprene, monoterpenes and sesquiterpenes. Strong emissions of monoterpeneswere measured from both the stumps and from the whole felling area. Theemission rate decreased rapidly within a few months after the logging. Inaddition to fresh logging residue, the results suggest also other strongmonoterpene sources may be present in the felling area. These could includepre-existing litter, increased microbial activity and remaining undergrowth.In order to evaluate the possible importance of monoterpenes emittedannually from cut Scots pine forests in Finland, we conducted a roughupscaling calculation. The resulting monoterpene release was approximated tobe on the order of 15 kilotonnes per year, which corresponds to about onetenth of the monoterpene release from intact forests in Finland.

[学科分类] 地球化学与岩石