Peatland vegetation composition and phenology drive the seasonal trajectory of maximum gross primary production.

Gross primary production (GPP) is a key driver of the peatland carbon cycle. Although many studies have explored the apparent GPP under natural light conditions, knowledge of the maximum GPP at light-saturation (GPP) and its spatio-temporal variation is limited. This information, however, is crucial since GPP essentially constrains the upper boundary for apparent GPP.

Partitioning of the net CO exchange using an automated chamber system reveals plant phenology as key control of production and respiration fluxes in a boreal peatland.

The net ecosystem CO exchange (NEE) drives the carbon (C) sink-source strength of northern peatlands. Since NEE represents a balance between various production and respiration fluxes, accurate predictions of its response to global changes require an in depth understanding of these underlying processes. Currently, however, detailed information of the temporal dynamics as well as the separate biotic and abiotic controls of the NEE component fluxes is lacking in peatland ecosystems.

Hydrology-driven ecosystem respiration determines the carbon balance of a boreal peatland.

The carbon (C) balance of boreal peatlands is mainly the sum of three different C fluxes: carbon dioxide (CO2), methane (CH4) and dissolved organic carbon (DOC). Intra- and inter-annual dynamics of these fluxes are differentially controlled by similar factors, such as temperature and water-table. Different climatic conditions within and between years might thus result in varying absolute and relative contributions of each flux to net ecosystem productivity (NEP).