Theme 1
Project 1043

Feedbacks on vegetation change to surface energy balance and seasonal thawing of permafrost
Project leader: Prof. dr. F. Berendse
Researcher(s): Dr. D. Blok
Starting date: 15-mrt-07

Terrestrial ecosystems affect climate through fluxes of energy, water and greenhouse gases. Changes in community composition and vegetation structure alter these fluxes, thereby potentially altering climate. Such vegetation feedback could contribute considerably to futre regional climate warming in the Arctic. Recent research mainly focused on vegetation-atmosphere interactions using eddy correlation to compare the surface energy balance among arctic ecosystems. However, vegetation-soil interactions which influence thawing depth have been much less studied, while permafrost thawing has the risk of releasing massive amounts of CO2 and CH4 into the atmosphere. We expect that a shift from moss- to shrub-dominated vegetation, which is already widely occurring in tundra ecosystems, will lead to a positive feedback further increasing local warming and permafrost thawing. In this project we will determine the effects of plant functional types, such as mosses, shrubs and grasses, on the surface energy balance and permafrost thawing. This requires a combination of field observations and experiments in order to disentangle vegetation effects from soil/climate effects. The resulting knowledge of the direct effects of vegetation changes will be incorporated in the ecosystem model NUCOM. This is a further step towards a regional vegetation-permafrost-climate model to explain past and predict future climate-vegetation feedbacks.

Blok D, Heijmans MMPD, Schaepman-Strub G, Kononov AV, Maximov TC, Berendse F (2010). Shrub expansion may reduce summer permafrost thaw in Siberian tundra. Global Change Biology
Darwin Center authors: Berendse F., Blok D., Heijmans M. M. P. D

Daan Blok, Ute Sass-Klaassen, Gabriela Schaepman-Strub, Monique Heijmans, Pascal Sauren and Frank Berendse (2011). What are the main climate drivers for shrub growth in Northeastern Siberian tundra?. Biogeosciences8: 1169-1179.
Darwin Center authors: Berendse F., Blok D., Heijmans M. M. P. D

Daan Blok, Monique Heijmans, Gabriela Schaepman-Strub, Jasper van Ruijven, Frans-Jan Parmentier, Trofim Maximox, Frank Berendse (2011). The Cooling Capacity of Mosses: Controls on Water and Energy Fluxes in a Siberian Tundra Site. Ecosystemsin press:
Darwin Center authors: Berendse F., Blok D., Heijmans M. M. P. D, Parmentier F. J. W.

Blok D, Schaepman-Strub G, Bartholomeus H, Heijmans MMPD, Maximov TC, Berendse F (2011). The response of Arctic vegetation to the summer climate: relation between shrub cover, NDVI, surface albedo and temperature. Environmental Research Letters6:
Darwin Center authors: Berendse F., Blok D., Heijmans M. M. P. D

Blok D (2011). Shrubs in the cold: interactions between vegetation, permafrost and climate in Siberian tundra.
Darwin Center authors: Blok D.

Myers-Smith I, Forbes BC, Wilmking M, Hallinger M, Lantz T, Blok D, Tape KD, Macias-Fauria M, Sass-Klaassen U, Lévesque E, Boudreau S, Ropars P, Hermanutz L, Trant A, Siegwart Collier L, Weijers S, Rozema J, Rayback SA, Martin Schmidt N, Schaepman-Strub G, Wipf S, Rixen C, Ménard C, Venn S, Goetz S, Andreu-Hayles L, Elmendorf S, Epstein HE, Welker J, Grogan P, Hik, D (2011). Shrub expansion in tundra ecosystems: Dynamics, impacts and research priorities. Environmental Research Letters6:
Darwin Center authors: Blok D.

Heijmans, M.M.P.D.; Nauta, A.L.; Blok, D. (2012). Vegetation-soil-permafrost interactions in Siberian tundra: on-going field experiments.
Darwin Center authors: Blok D., Heijmans M. M. P. D

Nauta AL, Heijmans MMPD, Blok D, Limpens J, Elberling B, Gallagher A, Li B, Petrov RE, Maximov TC, van Huissteden J, Berendse F (2014). Permafrost collapse after shrub removal shifts tundra ecosystem to a methane source. Nature Climate ChangeDOI: 10.1038/NCLIMATE2446:
Darwin Center authors: Berendse F., Heijmans M. M. P. D, van Huissteden J., Li B.