ContextThe contribution of forest understory to thetemperate forest carbon sink is not well known,increasing the uncertainty in C cycling feedbacks onglobal climate as estimated by Earth System Models.ObjectivesWe aimed at quantifying the effect ofwoody and non-woody understory vegetation on netecosystem production (NEP) for a forested area of158 km2in the European Alps. RESEARCH ARTICLESubstantial understory contribution to the C sinkof a European temperate mountain forest landscapeT. Dirnbo ̈ck.D. Kraus.R. Grote.S. Klatt.J. Kobler.A. Schindlbacher.R. Seidl.D. Thom.R. KieseReceived: 14 March 2019 / Accepted: 10 December 2019ÓThe Author(s) 2020AbstractContextThe contribution of forest understory to thetemperate forest carbon sink is not well known,increasing the uncertainty in C cycling feedbacks onglobal climate as estimated by Earth System Models.ObjectivesWe aimed at quantifying the effect ofwoody and non-woody understory vegetation on netecosystem production (NEP) for a forested area of158 km2in the European Alps.MethodsWe simulated C dynamics for the period2000–2014, characterized by above-average temper-atures, windstorms and a subsequent bark beetleoutbreak for the area, using the regional ecosystemmodel LandscapeDNDC.ResultsIn the entire study area, woody and non-woody understory vegetation caused between 16 and37% higher regional NEP as compared to a bare soilscenario over the 15-year period. The mean annualcontribution of the understory to NEP was in the sameorder of magnitude as the average annual European(EU-25) forest C sink. After wind and bark beetledisturbances, the understory effect was more pro-nounced, leading to an increase in NEP between 35 nd 67% compared to simulations not taking intoaccount these components.ConclusionsOur findings strongly support theimportance of processes related to the understory inthe context of the climate change mitigation potentialof temperate forest ecosystems. The expectedincreases in stand replacing disturbances due toclimate change call for a better representation ofunderstory vegetation dynamics and its effect on theecosystem C balance in regional assessments andEarth System Models.     «

ContextThe contribution of forest understory to thetemperate forest carbon sink is not well known,increasing the uncertainty in C cycling feedbacks onglobal climate as estimated by Earth System Models.ObjectivesWe aimed at quantifying the effect ofwoody and non-woody understory vegetation on netecosystem production (NEP) for a forested area of158 km2in the European Alps. RESEARCH ARTICLESubstantial understory contribution to the C sinkof a European temperate mountain forest...     »