Figure 1.

Mean CH₄ emission rates from peat mesocosms with different plant species, under unsealed conditions and after sealing the soil surface with agar. Black error marks on top show standard error for unsealed emissions and white error marks inside the bars show standard error for sealed emissions. Small and capital letters above the error bars indicate significant differences in CH₄ emission rates relative to mesocosms with bare soil only, for low water and high water treatments, respectively. Note that all (white, grey and black) bars start at zero, these are not cumulative bars. High water table means the soil was kept saturated up to surface level throughout the experiment; under the low water table treatment, water table was kept constant at five centimetres below the soil surface. Percent values below each bar indicate the chimney effect caused by each species under that particular treatment i.e. the proportion of total emission being transported via plant. BS: Bare soil (non-plant control), CP: Caltha palustris, MA: Mentha aquatica, LE: Lycopus europaeus, RH: Rumex hydrolapathum, AO: Anthoxanthum odoratum, CR: Carex rostrata, EA: Eriophorum angustifolium, GM: Glyceria maxima. Graph shows the original data while the significant differences are based on the statistical analysis of log-transformed data.