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Darwin's naturalization conundrum posits that the alien species either succeed in the introduced region because they are phylogenetically related to the native species and thus tend to have niches similar to those of native species, or they are phylogenetically dissimilar to native species and thus occupy unfilled niches. This conundrum has received a lot of attention, but the findings regarding these two hypotheses have been contradictory. To reconcile the two seemingly contradictory hypotheses, we assessed the phylogenetic relationship of a highly widespread and invasive species, Anthemis cotula L. (focal species), separately with the native species and all its co‐occurring species (including native and non‐native species) along an elevation gradient. Our results show that the abundance of A. cotula declined continuously with an increase in elevation and with an increase in the number of both all co‐occurring and native species only. The phylogenetic distance between the focal species and the native species based on weighted mean pairwise distance (MPDaw) declined with elevation as well as native species richness. Our study also revealed that soil nutrients strongly influence the abundance of A. cotula; however, their effect on the phylogenetic distance between the focal and other species is negligible. These findings suggest a strong role of microecological factors and spatial heterogeneity in the abundance distributions of invasive species and community assembly. Thus, it could be concluded that the phylogenetic relationship of A. cotula with co‐occurring all or only native species varies with elevation and species richness, adding another layer of complexity to the resolution of Darwin's naturalization conundrum. [ABSTRACT FROM AUTHOR]

We assessed the impact of road disturbances on the dominant mycorrhizal types in ecosystems at the global level and how this mechanism can potentially lead to lasting plant community changes. We used a database of coordinated plant community surveys following mountain roads from 894 plots in 11 mountain regions across the globe in combination with an existing database of mycorrhizal–plant associations in order to approximate the relative abundance of mycorrhizal types in natural and disturbed environments. Our findings show that roadside disturbance promotes the cover of plants associated with arbuscular mycorrhizal (AM) fungi. This effect is especially strong in colder mountain environments and in mountain regions where plant communities are dominated by ectomycorrhizal (EcM) or ericoid‐mycorrhizal (ErM) associations. Furthermore, non‐native plant species, which we confirmed to be mostly AM plants, are more successful in environments dominated by AM associations. These biogeographical patterns suggest that changes in mycorrhizal types could be a crucial factor in the worldwide impact of anthropogenic disturbances on mountain ecosystems. Indeed, roadsides foster AM‐dominated systems, where AM‐fungi might aid AM‐associated plant species while potentially reducing the biotic resistance against invasive non‐native species, often also associated with AM networks. Restoration efforts in mountain ecosystems will have to contend with changes in the fundamental make‐up of EcM‐ and ErM plant communities induced by roadside disturbance. [ABSTRACT FROM AUTHOR]

In view of the mutualistic facilitation of invasive plants, we examined the mycorrhizal status of 469 species, including 335 alien and 134 native to the region of Kashmir Himalaya, India. Data on the mycorrhizal status and altitudinal range of the target species were obtained using some peer reviewed primary published and web based sources. One sample Z score test and regression analysis were performed to workout the relative proportion of mycorrhizal and non-mycorrhizal plants in different altitudinal belts and relationship of mycorrhizal symbiosis with increasing altitude, respectively. With increasing altitude, the mycorrhizal association of both the alien and native plant species showed a decreasing trend, although alien plant species showed much stronger negative values than native species do. Both aliens and native species showed significantly higher proportion of mycorrhizal species compared to non-mycorrhizal counterparts in all the vegetation zones (Temperate, Montane, Sub-alpine and Alpine). Interestingly, in none of the vegetation zones do aliens and natives differ in terms of their mycorrhizal and non-mycorrhizal species fractions, suggesting that change in mycorrhizal symbioses along any elevational gradient occurs more due to restrictions on mycorrhizal fungi survival than due to the identity of the species concerned. These trends call for further studies at wider geographical scales to better understand the mechanisms and implications of mycorrhizal associations for managementof alien plant invasion in such eco-climatically sensitive regions, especially in the context of climate change. Keywords AMF * Alien species * Natives * Alpine * Vegetation zone * Kashmir Himalaya, Introduction Community and ecosystem wide effects of alien plant invasion, although lately recognised, are serious in view of the huge economic loses inflicted and the ecosystem services impaired thereof (Vila [...]

An important factor in the performance of out-planted conifers is the association of plant roots with ectomycorrhizal (EcM) fungi. However, limited information is available about the diversity of root-associated EcM fungi of Pinus wallichiana A.B. Jackson, a coniferous species endemic to Himalayan forests that has hampered the reforestation programs in the area. The study was carried at three major forest areas of the Kashmir Himalaya believed to be pure stands of P. wallichiana. Fine root tips harbouring EcM fungi were collected and processed for extraction of fungal DNA, which was subsequently subjected to ITS rDNA targeted PCR-RFLP profiling. DNA sequencing analysis of the overlapping ITS amplifications followed by global nucleotide BLAST analyses of the assembled nuclear ribosomal DNA (rDNA) revealed a total of 33 fungal taxa associated with P. wallichiana of which 23 species were EcM fungi. Of the 10 non-EcM fungi, we found a peculiar saprophytic wood decaying fungus, Chalara microchona, associated with P. wallichiana for the first time. The study not only reveals the species richness of fungi associated with this conifer but also documents new fungal associations with it, which have not been reported so far. The results in the study set a baseline for the broad association of ectomycorrhizal fungi with P. wallichiana, which may serve as guiding cue to design reforestation programs in the Kashmir Himalaya. Key words: ectomycorrhizae, Kashmir Himalaya, PCR-RFLP, ITS region, Pinus wallichiana. Resume: Un facteur important pour la performance des plantations de coniferes est l'association des racines des plants avec des champignons ectomycorhiziens (EcM). Cependant, il y a peu d'information disponible concernant la diversite des champignons EcM associes a Pinus wallichiana A.B. Jackson, une espece de conifere endemique dans les forets himalayennes, ce qui a nui aux programmes de reboisement dans la region. L'etude a ete realisee dans trois regions forestieres importantes du Cachemire dans l'Himalaya, occupees par des peuplements vraisemblablement purs de P. wallichiana. Des apex de racines fines infectees par des champignons EcM ont ete collectes et traites pour en extraire l'ADN fongique qui a par la suite ete soumis a un profilage de la region ITS de l'ADNr par techniques de PCR et RFLP. L'analyse de sequencage de l'ADN provenant de l'amplification des regions ITS chevauchantes suivie d'analyses BLAST globales de la sequence nucleotidique de l'ADN ribosomique nucleaire assemble (ADNr) a revele la presence d'un total de 33 taxons fongiques associes a P. wallichiana, parmi lesquels 23 especes etaient des champignons EcM. Parmi les 10 champignons non EcM, nous avons trouve un saprophyte particulier pour la premiere fois : Chalara microchona, un champignon de carie du bois associe a P. wallichiana. L'etude revele non seulement la richesse en especes de champignons associes a ce conifere, mais documente de nouvelles associations fongiques avec cette espece, qui n'ont pas ete rapportees jusqu'a maintenant. Les resultats de l'etude etablissent les bases de l'association generale des champignons EcM avec P. wallichiana, qui peuvent servir de ligne directrice pour concevoir des programmes de reboisement au Cachemire himalayen. [Traduit par la Redaction] Mots-cles: ectomycorhizes, Cachemire himalayen, PCR-RFLP, region ITS, Pinus wallichiana., Introduction Forests provide ecological, economic, social, and aesthetic services to natural systems and mankind (Hassan et al. 2005). Even though many Himalayan areas have registered a net positive change in [...]