Biology subjects

Rog, I.

Publications and source records attributed to Rog, I..

3 recordsLinked to original sources

bioRxiv2022

Tell me who your neighbors are: The role of spatial location and tree species identity in determining the ectomycorrhizal community composition of saplings and mature trees in a mixed conifer forest

O_LIThe mutualistic interaction between trees and ectomycorrhizal fungi (EMF) can have a major effect on forest dynamics and specifically in seedling establishment. Both intrinsic (i.e., identity of the sapling) and extrinsic (i.e., the identity of mature trees in the vicinity of the sapling) factors can affect the EMF community composition of young saplings. C_LIO_LIHere, we compared the EMF community composition associated with the roots of young saplings and mature trees of two co-habiting Pinaceae: Pinus halepensis and Cedrus deodara growing together in a planted forest plot, using fungal ITS metabarcoding. C_LIO_LIWe found that the differences between the two sapling groups were mostly attributed to changes in the relative abundance of specific fungal species. Moreover, we found that physical proximity to a specific host species had a significant effect on the community composition of young saplings. However, while no significant differences in sapling size were apparent, the sapling shoot structure was affected by the identity of the nearest mature tree and its unique EMF community composition. C_LIO_LISynthesis: These results suggest that the dynamics of the EMF community are greatly determined by extrinsic factors such as the small-scale distribution of mature trees in the forest, with possible cascading effects on the development of young trees. C_LI

ecology↗

bioRxiv2022

Prosperity of the commons: Generalist mycorrhizal species dominate a mixed forest and may promote forest diversity by mediating resource sharing among trees

Mechanisms of host-microbe interactions and their direct impact on both parties have been extensively researched, however, much less is known on the effect of these interactions on the ecology of the host-community. Here we investigate tree-fungi mycorrhizal interactions, focusing on mycorrhizal-mediated resource sharing among trees, while examining the dynamics between specialist and generalist fungi and their implications on the forest ecology. Using genetic meta-barcoding, we identified the fungal community colonizing different trees in a mixed forest, and generated an extensive mapping connecting fungal sequences to their tree hosts. The mycorrhizal fungal community diverged between ectomycorrhizal and arbuscular host trees, but, unexpectedly, multiple ectomycorrhizal species colonized roots of non-ectomycorrhizal host trees. We complemented these findings by a novel computational framework, modeling competition between generalist and specialist mycorrhizal fungi, accounting for fungal-mediated resource sharing among neighboring trees. The analysis of the model revealed that generalist mycorrhizal networks may affect the entire tree community, and contribute to the maintenance of forest diversity in the long run. Furthermore, higher initial spatial mixing of trees can promote the evolution of generalist mycorrhizal species. These novel belowground interactions among trees and fungi may significantly impact forest biodiversity.

ecology↗

bioRxiv2022

Combined drought resistance strategies and the hydraulic limit in co-existing Mediterranean woody species

O_LIWoody species employ various strategies to cope with drought stress. We investigated similarities and differences in response to chronic drought to understand resistance strategies in co-occurring Mediterranean species. C_LIO_LIWe studied five predominant Mediterranean species; Quercus calliprinos, Pistacia palaestina, Pistacia lentiscus, Rhamnus lycioides, and Phillyrea latifolia over two summers at three sites with different aridities. We measured key hydraulic and osmotic traits related to drought resistance, including resistance to embolism ({Psi}50), carbon isotope signature ({delta}13C), pre-dawn ({Psi}PD) and mid-day ({Psi}MD) water potentials, and native ({Psi}s) and full turgor ([Pcy]0) osmotic potentials. C_LIO_LISignificant differences among species appeared in resistance to embolism. The species also showed differences in the water potential plastic response over the dry season. This interspecific variation increased at the end of the dry season and resulted in very narrow hydraulic safety margins (HSM). Consequently, predicted loss of hydraulic conductivity revealed species with significant native embolism. Two of the species also had seasonal changes in osmotic adjustment. C_LIO_LIOur detailed analysis indicates that co-existing Mediterranean woody species combine various drought resistance strategies to minimize mortality risk. However, all of them risk mortality as they approach their hydraulic limit near the dry margin of their distribution. C_LI

plant biology↗