Ditch blocking in blanket peatlands is common as part of peatland restoration. The effects of ditch blocking on flow regimes and nearby water tables were examined in a field trial. After an initial 6‐month monitoring period, eight ditches had peat dams installed 10 m apart along their entire length (dammed), four of these ditches were also partially infilled through bank reprofiling (reprofiled). Four ditches were left open with no dams or reprofiling (open). These 12 ditches and the surrounding peat were monitored for 4 more years. An initial five‐fold reduction in discharge occurred in the dammed and the reprofiled ditches with the displaced water being diverted to overland flow and pathways away from the ditches. However, there was a gradual change over time in ditch flow regime in subsequent years, with the overall volume of water leaving the dammed and the reprofiled ditches increasing per unit of rainfall to around twice that which occurred in the first year after blocking. Hence, monitoring for greater than one year is important for understanding hydrological impacts of peatland restoration. Overland flow and flow in the upper ~4 cm of peat was common and occurred in the inter‐ditch areas for over half of the time after ditch blocking. There was strong evidence that topographic boundaries of small ditch catchments, despite being defined using a high‐resolution Light Detection And Ranging‐based terrain model, were not always equivalent to actual catchment areas. Hence, caution is needed when upscaling area‐based fluxes, such as aquatic carbon fluxes, from smaller scale studies including those using ditches and small streams. The effect of ditch blocking on local water tables was spatially highly variable but small overall (time‐weighted mean effect <2 cm). Practitioners seeking to raise water tables through peatland restoration should first be informed either by prior measurement of water tables or by spatial modelling to show whether the peatland already has shallow water tables or whether there are locations that could potentially undergo large water‐table recoveries.

Perennial pools are common natural features of peatlands, and their hydrological functioning and turnover may be important for carbon fluxes, aquatic ecology, and downstream water quality. Peatland restoration methods such as ditch blocking result in many new pools. However, little is known about the hydrological function of either pool type. We monitored six natural and six artificial pools on a Scottish blanket peatland. Pool water levels were more variable in all seasons in artificial pools having greater water level increases and faster recession responses to storms than natural pools. Pools overflowed by a median of 9 and 54 times pool volume per year for natural and artificial pools, respectively, but this varied widely because some large pools had small upslope catchments and vice versa. Mean peat water‐table depths were similar between natural and artificial pool sites but much more variable over time at the artificial pool site, possibly due to a lower bulk specific yield across this site. Pool levels and pool‐level fluctuations were not the same as those of local water tables in the adjacent peat. Pool‐level time series were much smoother, with more damped rainfall or recession responses than those for peat water tables. There were strong hydraulic gradients between the peat and pools, with absolute water tables often being 20–30 cm higher or lower than water levels in pools only 1–4 m away. However, as peat hydraulic conductivity was very low (median of 1.5 × 10−5 and 1.4 × 10−6 cm s−1 at 30 and 50 cm depths at the natural pool site), there was little deep subsurface flow interaction. We conclude that (a) for peat restoration projects, a larger total pool surface area is likely to result in smaller flood peaks downstream, at least during summer months, because peatland bulk specific yield will be greater; and (b) surface and near‐surface connectivity during storm events and topographic context, rather than pool size alone, must be taken into account in future peatland pool and stream chemistry studies.

Accurate estimates of methane (CH 4) fluxes from restored peatlands are needed to inform emission factor estimations and reporting. Flux measurements are usually taken during the daytime but such measurements may provide biased estimates of overall CH 4 emissions if night-time fluxes differ from daytime fluxes. Diurnal variations in CH 4 fluxes have been reported for a range of peatland types, but not for restored raised bogs which are important carbon stores in some countries. To help fill this knowledge gap, we investigated diurnal variations in CH 4 emissions from a restored raised bog. CH 4 fluxes from a restored raised bog were measured in two 24-hr field campaigns using flux chambers. Carbon dioxide (CO 2) fluxes were also monitored, as were a suite of complementary environmental variables. Night-time CH 4 fluxes were significantly greater than daytime fluxes during both campaigns, by 10.4% and 36.1%, respectively. In Campaign 1 air temperature was the best predictor of CH 4 fluxes, whereas in Campaign 2 net ecosystem exchange (NEE) values were the best predictor. This study shows that diurnal variations in CH 4 fluxes exist in a restored peatland and that current approaches biased to daytime measurements will underestimate CH 4 emissions from restored peatlands to the atmosphere. RÉSUMÉ Des estimations précises des flux de méthane (CH 4) à partir de tourbières perturbées sont requises pour informer les estimations de facteurs d'émission et la production de rapports. Les mesures de flux sont généralement prises pendant le jour, mais de telles mesures peuvent fournir des estimations biaisées des émissions totales de CH 4 si les flux nocturnes diffèrent des flux diurnes. Les variations journalières des flux de CH 4 de différent types de tourbières ont déjà été rapportés, mais pas pour les tourbières ombrotrophes restaurées, qui sont d'importants réservoirs de carbone dans certains pays. Pour combler ce manque de connaissances, nous avons évalué les variations journalières des émissions de CH 4 d'une tourbière ombrotrophe restaurée. Les flux de CH 4 ont été mesurés lors de deux campagnes de terrain de 24 heures à l'aide de chambres de débit. Les flux de dioxyde de carbone (CO 2) ont aussi été enregistrés, tout comme une série de variables environnementales complémentaires. Les flux de CH 4 nocturnes étaient significativement plus élevés que les flux diurnes lors des deux campagnes, respectivement par 10,4% et 36,1%. Lors de la Campagne 1, la température de l'air était le meilleur prédicteur des flux de CH 4 , tandis que lors de la Campagne 2, les valeurs d'échanges écosystémiques nets (EEN) étaient le meilleur prédicteur. Cette étude montre que des variations journalières des flux de CH 4 sont présentes dans une tourbière ombrotrophe restaurée et que les approches actuelles basées sur les mesures diurnes sous-estiment les émissions de CH 4 vers l'atmosphère.