Methane dynamics in northern wetlands: Significance of vascular plants

Research output: ThesisDoctoral Thesis (compilation)

Abstract

The studies presented in Papers I to VI illustrate several different aspects of the impact of vascular plants on methane emissions from northern natural wetlands. The subject has been approached on different scales, ranging from the study of microbial substrates in the vicinity of a single plant root, to an attempt to extrapolate some of the results to the entire northern hemisphere north of 50°N. The main overall conclusions from the papers are that vascular plants affect net methane emissions 1) by offering an efficient route of transport to the atmosphere so that methane oxidation in oxic surface soils is avoided, and 2) by being sources of methanogenic substrate.

The degree to which vascular wetland plants affect methane emissions seems to be dependent on species-specific differences in both the capacity to act as gas conduits and the exudation of labile carbon compounds to the soil. An intimate coupling between vascular plant production and methane emission was found in an Arctic tundra wetland, although other environmental variables (water table, temperature) also contributed significantly to the explained variation in methane exchange. Studies of vascular plant exudation of organic acids suggest that the available pool of methanogenic substrates is both qualitatively and quantitatively correlated to vascular plant production (photosynthetic rate).

On global scales, vascular plant production as a single factor does not seem to be sufficient to explain the majority of variation in methane flux patterns. Based on comparable experiments at five different sites in the northewestern Eurasian and Greenlandic North, we suggest that mean seasonal soil temperature is the best predictor of methane exchange on broad spatial and temporal scales.

Details

Authors
  • Anna Joabsson
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Ecology

Keywords

  • aquatic ecology, marine biology, Hydrobiology, Växtekologi, Plant ecology, climate change, arctic wetlands, northern wetlands, plant-microbe interactions, methane emission, vascular plants, limnology, Marinbiologi, limnologi, akvatisk ekologi, Ecology, Ekologi
Original languageEnglish
QualificationDoctor
Awarding Institution
Supervisors/Assistant supervisor
  • [unknown], [unknown], Supervisor, External person
Award date2001 Oct 18
Publisher
  • Department of Ecology, Lund University
Print ISBNs91-7105-158-9
Publication statusPublished - 2001
Publication categoryResearch

Bibliographic note

Defence details Date: 2001-10-18 Time: 10:00 Place: The Ecology Building External reviewer(s) Name: Crill, Patrick M. Title: Prof Affiliation: [unknown] --- The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Plant Ecology and Systematics (Closed 2011) (011004000)