Increasing contribution of peatlands to boreal evapotranspiration in a warming climate

Helbig, Manuel; Waddington, J. M.; Alekseychik, Pavel; Amiro, B.D.; Aurela, Mika; Barr, Alan G.; Black, T. Andrew; Blanken, Peter D.; Carey, Sean K.; Chen, Jiquan; Chi, Jinshu; Desai, Ankur R.; Dunn, Allison L.; Euskirchen, Eugénie; Flanagan, Lawrence B.; Forbrich, Inke; Friborg, Thomas; Grelle, Achim; Harder, Silvie; Heliasz, Michal; Humphreys, Elyn; Ikawa, Hiroki; Isabelle, Pierre‐Érik; Iwata, Hiroyasu; Jassal, Rachhpal S.; Korkiakoski, Mika; Kurbatova, Juliya; Kutzbach, Lars; Lindroth, Anders; Löfvenius, Mikaell Ottosson; Lohila, Annalea; Mammarella, Ivan; Marsh, Philip; Maximov, Trofim C.; Melton, Joe R.; Moore, Paul A.; Nadeau, Daniel F.; Nicholls, Erin M.; Nilsson, Mats; Ohta, Takeshi; Peichl, Matthias; Petrone, Richard M.; Petrov, Roman E.; Prokushkin, Anatoly; Quinton, William L.; Reed, David E.; Roulet, Nigel T.; Runkle, Benjamin R. K.; Sonnentag, Oliver; Strachan, I. B.; Taillardat, Pierre; Tuittila, Eeva‐Stiina; Tuovinen, Juha‐Pekka; Turner, J.; Ueyama, Masahito; Varlagin, Andrej; Wilmking, Martin; Wofsy, Steven C.; Zyrianov, Vyacheslav

doi:10.1038/s41558-020-0763-7

Cited by 124 publications

(100 citation statements)

References 68 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…As Sphagnum is considered a keystone species for peat formation (Van Breemen, 1995), there may exist a critical depth threshold that must be exceeded for many locations on the landscape for the production of Sphagnum peat to continue, despite seasonal meteorological drought. With summer water deficits being expected to increase in many peatland dominated regions (e.g., Granath et al, 2016;Helbig et al, 2020) under climate change, this could potentially lead to an ecological shift in peatlands from a Sphagnum dominated system to one dominated by forests (Dang & Lieffers, 1989;Kettridge et al, 2015) or more drought tolerant mosses, such as Polytrichum species (Benscoter & Vitt, 2008;Laine et al, 1995). This then leads to two important ecohydrological ques- An answer to these questions could simply be time, where deep sites initiated earlier than shallow sites.…”

Section: Implications For Peatland Developmentmentioning

confidence: 99%

“…Rydin et al, 2013). There is a concern, however, that Sphagnum mosses and their associated peatland carbon stocks may be vulnerable to future climate change due to enhanced peat decomposition and moss moisture stress (Dorrepaal et al, 2009; Ise et al, 2008), where summer water deficits are predicted to increase substantially within the next century (Granath et al, 2016; Helbig et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Peat depth as a control onSphagnummoisture stress during seasonal drought

Moore

Didemus

Furukawa

et al. 2021

Hydrological Processes

Self Cite

View full text Add to dashboard Cite

Peatlands are globally important long-term sinks of carbon, however there is concern that enhanced peat decomposition and moss moisture stress due to climate change mediated drought will reduce moss productivity making these ecosystems vulnerable to carbon loss and associated long-term degradation. Peatlands are resilient to summer drought moss stress because of negative ecohydrological feedbacks that generally maintain a wet peat surface, but where feedbacks may be contingent on peat depth. We tested this 'survival of the deepest' hypothesis by examining water table (WT) position, near-surface moisture content, and soil water tension in peatlands that differ in size, peat depth, and catchment area during a summer drought. All shallow sites (<40 cm depth) lost their WT (i.e., the groundwater well was dry) for considerable time during the drought period. Near-surface soil water tension increased dramatically at shallow sites following WT loss, increasing~5-7.5× greater at shallow sites compared to deep sites (≥40 cm depth). During a mid-summer drought intensive field survey, we found that 60-67% of plots at shallow sites exceeded a 100 mb tension threshold used to infer moss water stress. Unlike the shallow sites, tension typically did not exceed this 100 mb threshold at the deep sites. Using species dependent water contentchlorophyll fluorescence thresholds and relations between volumetric water content and WT depth, Monte Carlo simulations suggest that moss had nearly twice the likelihood of being stressed at shallow sites (0.38 ± 0.24) compared to deep sites (0.22 ± 0.18). This study provides evidence that mosses in shallow peatland may be particularly vulnerable to warmer and drier climates in the future, but where species composition may play an important role. We argue that a critical 'threshold' peat depth specific for different hydrogeological and hydroclimatic regions can be used to assess what peatlands are especially vulnerable to climate change mediated drought.

show abstract

Section: Implications For Peatland Developmentmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Peat depth as a control onSphagnummoisture stress during seasonal drought

Moore

Didemus

Furukawa

et al. 2021

Hydrological Processes

Self Cite

View full text Add to dashboard Cite

show abstract

“…The slight overestimates in the diurnal change in mixing ratio were apparent in the high range of the diurnal change (Figure 4f). Evapotranspiration in boreal forests was lower than that in boreal peatlands (Helbig et al, 2020) and did not differ between shrubs and woodlands (Beringer et al, 2005) or lakes (McFadden et al, 2003). The surface representativeness of the study sites could be a reason for the overestimates.…”

Section: Discussionmentioning

confidence: 96%

Cooling and Moistening of the Planetary Boundary Layer in Interior Alaska Due to a Postfire Change in Surface Energy Exchange

et al. 2020

Self Cite

View full text Add to dashboard Cite

Boreal forest fires can alter the surface energy exchange due to postfire land cover change, which influences the regional climate through changes in scalar budgets within the planetary boundary layer (PBL). In this study, we estimated the changes in potential temperature and moisture budgets within the convective boundary layer (CBL) associated with postfire changes in surface energy exchange in interior Alaska. We integrated 9 years of paired eddy covariance measurements at mature evergreen and postfire young forests, radiosonde observations, and a mixed-layer slab model. The postfire increase in albedo and decreased Bowen ratio decreased the sensible heat flux and PBL height, resulting in cooling magnitudes in the CBL up to 3-5°C in spring months and smaller cooling magnitudes (0.4°C) in other months. The cooling in the CBL decreased at a rate 0.5°C yr −1 from 8 to 13 years after the fire via vegetation recovery but was still recognizable 13 years after the fire. The postfire change moistened the CBL in summer months due to the decreased PBL height and increased latent heat flux in the postfire young forest. Interactions between fire-induced surface changes and PBL dynamics should be evaluated further for understanding long-term climatic change and ecosystem responses to climate change.

show abstract

“…Although hydrological restoration of peatlands has been implemented throughout Europe and North America (Lamers et al, 2015), rewetted peatlands are under pressure from climate change (Levison et al, 2014). Shifting precipitation patterns and increasing evapotranspiration resulting from global warming may further degrade peatlands (Tarnocai, 2009;Nijp et al, 2015;Helbig et al, 2020). However, the impact of a changing climate on peatland ecohydrology through extreme weather events such as droughts is likely not uniform over different spatial scales and climatic zones.…”

Section: Introductionmentioning

confidence: 99%

Meteorological Controls on Water Table Dynamics in Fen Peatlands Depend on Management Regimes

et al. 2021

View full text Add to dashboard Cite

Fens belong to the most threatened ecosystems in Europe. Maintaining a high water table through rewetting is an effective measure to rehabilitate many of their ecosystem functions. However, the impact of meteorological conditions such as vapor pressure deficit (VPD) and precipitation on water tables is still unclear for rewetted fens. Here, we compare the impact of meteorological factors on water table dynamics in a drained and a rewetted fen, using multiple regression with data from continuous high-resolution (temporal) water level monitoring and weather stations. We find that an increase in the daily mean VPD causes a higher drop in the water table at the drained and degraded fen compared to the rewetted fen. Precipitation contributes to recharge, causing the water table to rise higher at the drained site than at the rewetted site. We attribute the differential influence of meteorological conditions on water table dynamics to different soil specific yield values (i.e., water storage capacity) largely driven by lower water table position at the drained site. Our study underlines the importance of understanding how and why water tables in peatlands vary in response to meteorological factors for management decisions (e.g., rewetting). Continuous monitoring of water table and vegetation development in rewetted fen peatlands is advisable to ensure long-term success especially under climate change conditions and associated drought events.

show abstract

Increasing contribution of peatlands to boreal evapotranspiration in a warming climate

Cited by 124 publications

References 68 publications

Peat depth as a control onSphagnummoisture stress during seasonal drought

Peat depth as a control onSphagnummoisture stress during seasonal drought

Cooling and Moistening of the Planetary Boundary Layer in Interior Alaska Due to a Postfire Change in Surface Energy Exchange

Meteorological Controls on Water Table Dynamics in Fen Peatlands Depend on Management Regimes

Contact Info

Product

Resources

About