An article has just been published in the “Plant science” journal on the water uptake depths of sessile oak and Scots pine growing in mixed stands during a severe drought. The data were collected in 2016 on the OPTMix plots. To determine the water uptake depths, isotopic signatures (oxygen) of wood and soil during the water stress period were compared. The results show that during a severe drought Sessile Oak and Scots Pine growing in mixed stands have different water uptake depths.
Bello, J., N. J. Hasselquist, P. Vallet, A. Kahmen, T. Perot and N. Korboulewsky (2019). « Complementary water uptake depth of Quercus petraea and Pinus sylvestris in mixed stands during an extreme drought. » Plant and Soil. doi: 10.1007/s11104-019-03951-z
Aims: The growing demand from forest managers is to identify silvicultural practices to overcome projected water scarcity during the next decades. One solution is to mix tree species in the same stand, thereby increasing resource partitioning and minimizing competition for limited soil water. This study investigates the mixture approach for Quercus petraea (Matt.) Liebl. and Pinus sylvestris L. during an extreme summer drought event.
Methods: During the summer drought event in 2016, we analyzed the isotopic signatures of large- and small-tree xylem and soil water throughout the soil profile to assess the depth of water uptake for both tree species. We also measured predawn leaf water potentials (PLWP) to assess water availability for individual tree species.
Results: When grown in pure stands, both species primarily utilized soil water near the surface. In contrast, partial niche complementarity for limited water resources