Effects of Summer Drought on the Fine Root System of Five Broadleaf Tree Species along a Precipitation Gradient

摘要: While much research has addressed the aboveground response of trees to climate warming and related water shortage, not is known about drought sensitivity fine root system, in particular mature trees. This study investigates topsoil (0–10 cm) biomass (FRB), necromass (FRN), morphology five temperate broadleaf tree species (Acer platanoides L., Carpinus betulus Fraxinus excelsior Quercus petraea (Matt.) Liebl., Tilia cordata Mill.) a reduction availability, combining precipitation gradient (nine sites; mean annual (MAP): 920–530 mm year−1) with comparison moist period (average spring conditions) an exceptionally dry summer subsequent year. The extent necromass/biomass (N/B) ratio increase was used as measure species’ belowground deficits. We hypothesized that N/B increases long-term (precipitation gradient) short-term reductions (moist vs. period) while FRB changes only little. In four (exception: A. platanoides), did change MAP, whereas FRN increased toward sites under ample supply Q. petraea). also reduce tip frequency after drought. Different slopes ratio-MAP relation similarly point at lower than other species. After drought, all lost MAP dependence ratio. Thus, mortality more moister drier sites, suggesting generally stands. conclude differ their response. follows most conservative soil exploration strategy smaller drought-tolerant roots, it maintains relatively constant FRB, FRN, across spatial temporal dimensions