On the influence of provenance to soil quality enhanced stress reaction of young beech trees to summer drought

Abstract

Climate projections propose that drought stress will become challenging for establishing trees. The magnitude of stress is dependent on tree species, provenance, and most likely also highly influenced by soil quality. European Beech (Fagus sylvatica) is of major ecological and economical importance in Central European forests. The species has an especially wide physiological and ecological amplitude enabling growth under various soil conditions within its distribution area in Central Europe. We studied the effects of extreme drought on beech saplings (second year) of four climatically distinct provenances growing on different soils (sandy loam and loamy sand) in a full factorial pot experiment. Foliar δ13C, δ15N, C, and N as well as above‐ and belowground growth parameters served as measures for stress level and plant growth. Low‐quality soil enhanced the effect of drought compared with qualitatively better soil for the above‐ and belowground growth parameters, but foliar δ13C values revealed that plant stress was still remarkable in loamy soil. For beeches of one provenance, negative sandy soil effects were clearly smaller than for the others, whereas for another provenance drought effects in sandy soil were sometimes fatal. Foliar δ15N was correlated with plant size during the experiment. Plasticity of beech provenances in their reaction to drought versus control conditions varied clearly. Although a general trend of declining growth under control or drought conditions in sandy soil was found compared to loamy soil, the magnitude of the effect of soil quality was highly provenance specific. Provenances seemed to show adaptations not only to drought but also to soil quality. Accordingly, scientists should integrate information about climatic pre‐adaptation and soil quality within the home range of populations for species distribution modeling and foresters should evaluate soil quality and climatic parameters when choosing donor populations for reforestation projects.

The Future of European Beech in Northern Germany—Climate Change Vulnerability and Adaptation Potential

“…Our findings of only limited acclimation contrast with dendrochronological results from larger (continent-wide) studies which found a lower drought sensitivity of mature beech trees in dry-marginal beech populations as compared to more mesic central populations, pointing at successful drought adaptation of these genetically more distant populations [67][68][69]. Similarly, many common garden experiments with beech seedlings and saplings of different European origins revealed a higher drought resistance and/or faster drought recovery of populations from drier and warmer sites [9,70,71], which seems to contrast with our results. That the beech populations of the drier sites of our study were not successful in maintaining growth under increasingly stressful climatic conditions might be a consequence of the relatively small genetic distances found between our populations [53] and perhaps insufficient genetic adaptation to the rapid climate aridification in recent time.…”

Summer drought exposure, stand structure, and soil properties jointly control the growth of European beech along a steep precipitation gradient in northern Germany

“…Our results seem to contradict studies that indicated a lower drought sensitivity of beech in dry‐marginal southern populations, where local drought adaptation in these genetically more distant populations is likely (Cavin & Jump, 2017; Magri et al, 2006; Muffler et al, 2020). In fact, many common garden drought experiments with beech seedlings and saplings of different provenances demonstrate that populations originating from drier sites in most cases showed signs of higher drought tolerance and/or faster recovery from drought stress than moister origins (Buhk et al, 2016; Leuschner, 2020; Thiel et al, 2014). Overall, population differentiation was apparently more often described in morphological, phenological and growth‐related traits (such as leaf size and thickness) than in physiological properties (as embolism resistance) (Frank et al, 2017; García‐Plazaola & Becerril, 2000; Knutzen et al, 2015).…”

Intra-annual stem size variations converge across marginal populations of European beech

“…Intra-specific gradients of beech are commonly available in the literature (Stojnić et al 2017;Cocozza et al 2016;Bolte et al 2016;Ježík et al 2016;Buhk et al 2016;Harter et al 2015). However, the majority of them focus on the southern, western, and/or northern margins of beech distribution range.…”