Assessing CH₄ and CO₂ emissions from wetlands in the Drenthe Province, the Netherlands: a modelling approach

Abstract

Assessment of land use related greenhouse gas (GHG) emissions on larger spatial scales is usually achieved by modelling. Surface flux measurements are expensive and measurement locations too widely scattered to serve as spatially reliable flux estimates. Here we assess CO2 and CH4 fluxes from wetland nature reserves in the Dutch province of Drenthe, using the PEATLAND-VU model. Since surface flux observations in the province are absent and cannot be obtained in a short (<1 year) time frame, we extrapolated model validation from elsewhere to the research area. In this way a cost-effective methodology is developed for landuse-related greenhouse gas emission assessments, which can be applied by local governments at a subnational scale.Nature development and restoration in the Netherlands involves usually the restoration of high water tables in former agricultural areas and extensivation or abandonment of agricultural activities. Wet peat soils are known to emit considerable quantities of CH4, while drained agricultural soils emit CO2 from decomposition of the soil organic matter. Therefore, these landuse changes may affect GHG emissions and an assessment of their effects is useful for environmental policy.The PEATLAND-VU Model was used to simulate the CH4 and CO2 emissions for the years 2005-2007 and for May/June 2008. Previous field validation of the model elsewhere was checked for local validity with CH4 and CO2 flux measurements in short field campaigns in May/June 2008, at two locations, Visvliet and Balloërveld. These sites represent respectively eutrophic and oligotrophic peat and peaty soils, and showed large differences in fluxes. These flux differences were simulated correctly by the model by adapting the vegetation net primary production and methane oxidation parameters. Next, model simulations were run for eight combinations of vegetation and soil type. Using the simulated fluxes and the areal extent of the soil combinations, a GIS-based upscaling over all nature reserves was made.This study shows that river valley floors with mesotrophic and eutrophic peat soils dominate the greenhouse fluxes of the area. CH4 fluxes are high in wet terrain, while the CO2 fluxes are high when water table is lower. The fluxes from oligotrophic peat soils are comparatively low. Nature development can contribute to a decrease of the total greenhouse gas flux from peat soils and to conservation of soil organic matter.

Sensitivity analysis of a wetland methane emission model based on temperate and Arctic wetland sites

“…Predictive models may contribute to a better understanding of feedbacks between climate and CH 4 emission, or the effects of wetland management on CH 4 emission (e.g. , Petrescu et al, 2009a, Petrescu et al, 2009b, Hendriks et al, 2007. However, to reduce modelling uncertainty extensive sensitivity testing and uncertainty analysis is required, in particular when models are scaled up from a local to regional or global scale.…”

“…Larger scale modelling of CH 4 fluxes always requires aggregated and simplified information on vegetation and soil and are more difficult to validate. However, to properly understand interactions of wetland CH 4 emission with climate or wetland management, large scale modelling of these emissions and coupling to climate or hydrological models is highly important (Petrescu et al, 2009b). For that purpose it is necessary to know at which level of detail processes need to be modelled to represent the interactions between climate or management correctly.…”

“…VU is a process-based, plot scale model of CO 2 and CH 4 emission from peat soils at various climate scenarios. The model has been used by Van denBos et al (2003) andPetrescu et al (2009b) for regional scale simulation of CO 2 and CH 4 fluxes in the Netherlands.…”

Environmental Impacts—Terrestrial Ecosystems

“…However, some climate change effects will exacerbate the impact of human activities such as drainage, grazing, burning and peat mining (e.g. Petrescu et al 2009). …”

Regionalizing ecological moisture levels and groundwater levels in grassland areas using thermal remote sensing

“…Site specific soil moisture and groundwater levels are considered key parameters in grassland ecosystems (Klijn and Witte 1999). Together with other parameters, they form a basis for estimating site-dependent potential yield and vegetation development and greenhouse gas emissions (Lai 2009;Petrescu et al 2009). Data availability, however, is a problem when comprehensive regional data are required.…”