Implications of ectomycorrhizal inoculation for drought stress tolerance of Atlas cedar (Cedrus atlantica (Endl.) Carrière) seedlings

Background: Ectomycorrhizal inoculation is a promising strategy to minimise the initial transplant shock and increase plant survival and growth during the first years of out-planting in the field. The aim of this research was to investigate the effect of sporal inoculum of three ectomycorrhizal fungi: Cortinarius cedretorum, Amanita vaginata and Inocybe geophylla on tolerance levels of Atlas cedar (Cedrus atlantica (Endl.) Carrière) seedlings subjected to applied drought stress in nursery conditions. Methods: Carpophores, seeds and organic forest soil were collected under pure stands of Atlas cedar. After fifteen months of growth, seedlings were subjected to drought stress by withholding water for thirty days; we assessed morphological and physiological variables of all seedling batches (inoculated and uninoculated, controlled and stressed seedlings) Results: All roots of inoculated stressed seedlings were mycorrhizal. The mycorrhization rates were 67%, 64.6% and 53.6% for stressed seedlings inoculated with Cortinarius cedretorum, Amanita vaginata, Inocybe geophylla, respectively. This root mycorrhization was accompanied by a significant improvement in seedling growth, especially height and length of the main root (10.2 cm, 52 cm) reached in stressed seedlings inoculated with Cortinarius cedretorum. There was a significant increase in relative water content, total chlorophyll, carotenoids, soluble sugars and starch, superoxide dismutase and ascorbate peroxydase enzyme activities in inoculated stressed seedlings compared with uninoculated seedlings. Conclusions: Inoculation of Atlas cedar seedlings with spores of ectomycorrhizal fungi remains a very effective alternative for improving growth and the morphological and physiological status of seedlings under drought conditions. Cortinarius cedretorum appears to be consistently advantageous followed by Amanita vaginata and Inocybe geophylla.

Diversity and distribution of epiphytic lichens on Cedrus atlantica and Quercus faginea in Mount Babor Forest, Algeria

Belguidoum A, Lograda T, Ramdani M. 2021. Diversity and distribution of epiphytic lichens on Cedrus atlantica and Quercus faginea in Mount Babor Forest, Algeria. Biodiversitas 22: 887-899. Information about lichen diversity in Algeria is limited despite their important role as biological indicators of ecosystem health. The aim of the study was to carry out an inventory of epiphytic lichens in the Mount Babor Forest on two types of phorophytes (host trees), i.e., Cedrus atlantica and Quercus faginea, in varying altitudinal gradients and the diameter of host tree. The similarity of the sampled sites was assessed by the Sorensen index (β). Sixty-six species of epiphytic lichens were identified, which belong to 24 families and 38 genera. C. atlantica hosted a higher number of species than Q. faginea. The majority of lichen on C. atlantica belonged to the Parmeliaceae family, whereas those on Q. faginea belonged to the Physciaceae family. Crustose and foliose lichens were the most common species in the study area. The results showed the existence of a distinct relationship between the parameters of the distribution (i.e., tree diameter, elevation) and the specific lichen richness. The greatest number of lichen species (59 species) was observed on large diameter trunks (41-60 cm). Lichen diversity increased along with the increase in altitude. Sorensen’s similarity index revealed the presence of heterogeneity in the community composition of lichen vegetation.