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Rewetting of disturbed peatlands is an important restoration strategy for climate change mitigation. Previous work primarily focuses on the biogeochemical processes altered by rewetting and few studies have investigated the biophysical impacts, which can diminish or amplify biogeochemical effects beyond the ecosystem scale. We used a paired flux tower approach in a restored peatland to collect year‐round eddy covariance data to assess the biophysical impacts of disturbance and management practices. The first site was actively rewetted and is characterized by Sphagnum and white beak‐rush with patches of open water. The second site represents a disturbed ecosystem, which underwent natural regeneration and is dominated by scrub pine, Sphagnum, and low shrubs. We found that the actively restored site had higher net radiation compared to the second site due to more surface water ponding; however, the higher aerodynamic conductance at the passively restored site contributed to enhanced daytime turbulent fluxes, and hence, both sites had similar aerodynamic temperatures during the daytime. The actively restored site experienced warmer nighttime and seasonal aerodynamic temperature as much of the excess radiation during the day was stored in the water column and released at night. To achieve restoration goals, higher water tables are now maintained throughout large sections of the bog. The study implies that water table manipulation has the potential to minimize greenhouse gas emissions from the bog, thereby allowing the biophysical impacts of peatland restoration to enhance the biogeochemical benefits. Therefore, it is important to consider both biophysical and biogeochemical changes in peatland restoration management. Plain Language Summary: Peatland restoration through rewetting influences the climate by altering land‐atmosphere greenhouse gas dynamics and energy and water exchanges. The energy and water exchanges altered by rewetting can influence surface and air temperature, and hence local and regional climate; however, they are understudied. This study analyzed year‐round water and energy exchange measurements at two sites in the Burns Bog peatland in British Columbia, Canada, which represent two different dominant ecosystem types that experienced different restoration strategies. We found that the rewetted site with more open water had warmer nighttime and seasonal surface temperature. The results indicate that water levels and vegetation type influenced by restoration strategies have a strong impact on energy partitioning, surface aerodynamic characteristics, and consequently surface and air temperatures. Peatland restoration management should recognize the implications of both greenhouse gas fluxes and energy and water exchanges to fully understand climatic impacts of restoration. Key Points: Significant surface temperature differences at night between the two restored peatland sites with different surface characteristicsThe warmer nighttime and seasonal temperatures at the actively rewetted site were due to energy stored in standing water during daytimeRestoration management has to consider biophysical impacts in addition to biogeochemical changes [ABSTRACT FROM AUTHOR]

Increases in global temperatures due to climate change threaten to tip the balance between carbon (C) fluxes, liberating large amounts of C from soils. Evidence of warming-induced increases in CO2 efflux from soils has led to suggestions that this response of soil respiration (RS) will trigger a positive land C–climate feedback cycle, ultimately warming the Earth further. Currently, there is little consensus about the mechanisms driving the warming-induced RS response, and there are relatively few studies from ecosystems with large soil C stores. Here, we investigate the impacts of experimental warming on RS in the C-rich soils of a Tasmanian grassy sedgeland and whether alterations of plant community composition or differences in microbial respiratory potential could contribute to any effects. In situ, warming increased RS on average by 28 %, and this effect was consistent over time and across plant community composition treatments. In contrast, warming had no impact on microbial respiration in incubation experiments. Plant community composition manipulations did not influence RS or the RS response to warming. Processes driving the RS response in this experiment were, therefore, not due to plant community effects and are more likely due to increases in below-ground autotrophic respiration and the supply of labile substrate through rhizodeposition and root exudates. CO2 efflux from this high-C soil increased by more than a quarter in response to warming, suggesting inputs need to increase by at least this amount if soil C stocks are to be maintained. These results indicate the need for comprehensive investigations of both C inputs and losses from C-rich soils if efforts to model net ecosystem C exchange of these crucial, C-dense systems are to be successful. [ABSTRACT FROM AUTHOR]