TY - JOUR AB - With climate change, the frequency of severe droughts is predicted to increase globally, resulting in increased forest dieback. Although fine-root systems and their associated fungi are considered crucial for tree nutrient exchange after a drought period and consequently for tree recovery, post-drought dynamics remain poorly understood. We rewatered mature European beech and Norway spruce after a 5-year experimental summer drought to shed light on belowground recovery processes. Therefore, we tracked the fine-root parameters growth, vitality, and mycorrhization in monospecific rooting zones with intraspecific root contact and mixed rooting zones with interspecific root contact of both tree species during the first 3 months of recovery, and we analyzed compositions of their root-associated fungal communities by DNA- and RNA-ITS2 sequencing. During recovery, the fine-root parameters differed between both tree species, with only minor effects of the tree rooting zone. Root-associated fungal communities showed no significant response to irrigation within 3 months after drought release. The rooting zone was the dominating factor affecting the root-associated fungal diversity, the abundance of trophic modes, and the response of individual saprotrophic and ectomycorrhizal (ECM) species. Furthermore, an analysis of the most abundant fungal species revealed that for ECM fungi, drought tolerance was common and for saprotrophs, a facultative, root-associated lifestyle. These results suggest that tree species-specific fungal communities are stable despite previous long-term drought and are closely associated with tree species-specific response patterns related to root survival and recovery. Moreover, an association between saprotrophic fungi and roots might be a strategy to support fungal drought survival. AU - Danzberger, J. AU - Werner, R. AU - Mucha, J.* AU - Pritsch, K. AU - Weikl, F. C1 - 68351 C2 - 53633 CY - Avenue Du Tribunal Federal 34, Lausanne, Ch-1015, Switzerland TI - Drought legacy effects on fine-root-associated fungal communities are modulated by root interactions between tree species. JO - Front. For. Glob. Change VL - 6 PB - Frontiers Media Sa PY - 2023 SN - 2624-893X ER - TY - JOUR AU - Ghirardo, A. AU - Blande, J.D.* AU - Ruehr, N.K.* AU - Balestrini, R.* AU - Kuelheim, C.* C1 - 64325 C2 - 52059 CY - Avenue Du Tribunal Federal 34, Lausanne, Ch-1015, Switzerland TI - Editorial: Adaptation of trees to climate change: Mechanisms behind physiological and ecological resilience and vulnerability. JO - Front. For. Glob. Change VL - 4 PB - Frontiers Media Sa PY - 2022 SN - 2624-893X ER - TY - JOUR AB - Phosphorus (P) solubilization is an important process for P acquisition by plants and soil microbes in most temperate forests. The abundance of inorganic P solubilizing bacteria (PSB) is affected by the P concentration in the soil and the carbon input by plants. We used a girdling approach to investigate the interplay of root-derived C and initial P content on the community composition of gcd-harboring bacteria as an example of PSB, which produce gluconic acid. We hypothesized that gcd-harboring PSB communities from P-poor sites are more vulnerable to girdling, because of their lower diversity, and that a shift in gcd-harboring PSB communities by girdling is caused by a response of few, mostly oligotrophic, taxa. We used a high-throughput metabarcoding approach targeting the gcd gene, which codes for the quinoprotein glucose dehydrogenase, an enzyme involved in the solubilization of inorganic P. We compared the diversity of gcd-harboring PSB in the mineral topsoil from two temperate beech forests with contrasting P stocks, where girdling was applied and compared our data to the respective control plots with untreated young beech trees. At both sites, gcd-harboring PSB were dominated by Proteobacteria and Acidobacteria, however, with differences in relative abundance pattern on the higher phylogenetic levels. The P-poor site was characterized by a high relative abundance of Kaistia, whereas at the P-rich site, Dongia dominated the gcd-harboring bacterial communities. Girdling induced an increase in the relative abundance of Kaistia at the P-poor site, whereas other bacterial groups of the family Rhizobiaceae were reduced. At the P-rich site, major microbial responders differed between treatments and mostly Bradyrhizobium and Burkholderia were positively affected by girdling in contrast to uncultured Acidobacteria, where reduced relative abundance was found. Overall, these effects were consistent at different time points analyzed after the introduction of girdling. Our data demonstrate that plant-derived carbon influences community structure of gcd-harboring bacteria in temperate beech forest soils. AU - Michas, A. AU - Pastore, G.* AU - Chiba, A. AU - Grafe, M. AU - Clausing, S.* AU - Polle, A.* AU - Schloter, M. AU - Spohn, M.* AU - Schulz, S. C1 - 62613 C2 - 50918 TI - Phosphorus availability alters the effect of tree girdling on the diversity of phosphorus solubilizing soil bacterial communities in temperate beech forests. JO - Front. For. Glob. Change VL - 4 PY - 2021 SN - 2624-893X ER - TY - JOUR AU - Nosenko, T. AU - Hanke-Uhe, M.* AU - Heine, P.A.* AU - Shahid, A.* AU - Dübel, S.* AU - Rennenberg, H.* AU - Schumacher, J.* AU - Winkler, J.B. AU - Schnitzler, J.-P. AU - Hänsch, R.* AU - Kaufholdt, D.* C1 - 62153 C2 - 50670 TI - Plant defense proteins as potential markers for early detection of forest damage and diseases. JO - Front. For. Glob. Change VL - 4 PY - 2021 SN - 2624-893X ER - TY - JOUR AU - Schroeder, H.* AU - Nosenko, T. AU - Ghirardo, A. AU - Fladung, M.* AU - Schnitzler, J.-P. AU - Kersten, B.* C1 - 62707 C2 - 50977 TI - Oaks as beacons of hope for threatened mixed forests in Central Europe. JO - Front. For. Glob. Change VL - 4 PY - 2021 SN - 2624-893X ER - TY - JOUR AB - The emission of biogenic volatile organic compounds (BVOCs) is usually thought to depend on species-specific emission capacities that vary with seasonal and phenological conditions. Actual—so called constitutive—emissions are then calculated from prevailing temperature and radiation. However, various abiotic and biotic stressors such as ozone, extreme radiation and temperature conditions, as well as wounding e.g., from insect feeding, can lead to de-novo emissions of stress-induced BVOCs (sBVOCs) that may excel constitutive emissions by more than an order of magnitude. These emissions often have a considerable different compound composition and are short-lived but can prolong under continuous stress for quite some time. Thus, they may easily have a large impact on overall regional BVOC emissions. However, sBVOCs are generally not considered in models since up to date no consistent mechanism has been proposed. This manuscript suggests a new mechanism based on the finding that sBVOCs originate from a handful of biosynthetic pathways which synthesize compounds in the groups of monoterpenes, sesquiterpenes, and green leave volatiles, as well as methyl salicylate, ethanol/acetaldehyde, methanol/formaldehyde, and acetone. Isoprene is also considered but since it is often constitutively emitted, the specific role of stress induction is difficult to determine for this compound. A function is proposed that describes the production of all de-novo sBVOCs sufficiently well and scales with stress intensity. It is hypothesized that the response delay and the form of the function is specific for the production pathway and valid for ozone as well as wounding (herbivory) induced stress. Model parameters are then derived from pooled literature data based on a meta-analysis of suitable induction-response measurements of different plant species. The overall emission amount derives from the intensity and frequency of the stress impulse. We present a number of literature studies that are used to parameterize the new model as well as a selection of evaluations for single- and multiple-stress inductions. Furthermore, coupling and interaction with constitutive emission models as well as limitations and possible further developments are discussed. AU - Grote, R.* AU - Sharma, M. AU - Ghirardo, A. AU - Schnitzler, J.-P. C1 - 56659 C2 - 47128 TI - A new approach for estimating abiotic and biotic stress-induced de novo emissions of biogenic volatile organic compounds from plants. JO - Front. For. Glob. Change PY - 2019 SN - 2624-893X ER -