Absorbing Roots of Invasive Woody Plants Apparently Have a Thicker Cortex Parenchyma Compared to Native Species

Invasive plants are usually fast-growing species with a high rate of physiological processes. However, the relative growth rate has not been estimated for many invasive species, including Acer negundo L. (Sapindaceae) and Amelanchier spicata (Lam.) K. Koch (Rosaceae); this hampers the understanding of the reasons for the success of their invasion. The authors compared the absorbing roots of A. negundo and A. spicata with respect to mycorrhizal colonization with two native woody species of the same families, Acer platanoides L. and Sorbus aucuparia L. The samples were collected from several sites in the Central Urals and analysed using standard morphological and anatomical methods. The abundance of arbuscular mycorrhiza,dark septate endophytes and root hairs did not differ between the invasive and native species. Nevertheless, the roots of the invasive species were shown to have a thicker cortex parenchyma formed by larger cells. We suggest that this could contribute to invasion success, but a higher growth rate of the roots of invasive species has not yet been proven. Keywords: Acer negundo, Amelanchier spicata, invasive plants, absorbing roots, arbuscular mycorrhiza, root cortex, parenchyma &nbsp

The Richness and Cover of Alien Plants in the Undergrowth and Field Layer of Urbanized Southern Taiga Forests

The aim of the work is to compare the richness (the number of species in 400 m2)and cover of alien plants in the undergrowth and field layer of a large city forest. The research was carried out in 2016–2017 in the southern taiga subzone of the Eurasian boreal zone, specifically in the urban forests of the industrial city of Ekaterinburg(the Central Urals, Russia) and the area around it. 235 plots have been analyzed. The number and cover of alien species in the undergrowth and field layer are contrastively different. The richness and cover of alien herbaceous species are much less than the richness and cover of alien woody plants (shrubs and trees) in the undergrowth. Thus, the undergrowth layer has transformed much more comprehensively as a result ofalien plant invasions than the field layer. This conclusion is valid both for analysis on the scale of individual plots and for the analysis of complete species lists in urban and suburban forests. This statement is also true for the analysis of the cover of alien plants. This result appears to be unexpected. Keywords: plant invasions, invasiveness of communities, urban forests, woody plants, herbaceous plant

Root structure syndromes of four families of monocots in the Middle Urals

The present article tests the following general assumption: plant taxa with different specializations towards mycorrhizal interactions should have different root syndromes. Roots of 61 species common in boreal zone were studied: 16 species of Poaceae, 24 species of Cyperaceae, 14 species of Orchidaceae, and 7 species of Iridaceae. Using a fixed material of 5 individuals of each species, the following was determined: number of orders of branching roots; transverse dimensions of root, stele and cortex; number of primary xylem vessels and exodermis layers; length of root hairs; abundance of mycorrhiza. Species of each family had well-defined syndromes. Roots of Orchidaceae and Iridaceae were thick with a large stele and developed exodermis. Orchidaceae had no branching roots and had long root hairs. In Iridaceae, roots were branched, and root hairs were short. Roots of Poaceae and Cyperaceae were thin with a relatively thin stele. Root hairs were short in Poaceae and long in Cyperaceae. Our finding that root syndromes of four families of monocots differed is a new and unexpected discovery. The high specificity of root syndromes in Cyperaceae, Iridaceae, Poaceae, and Orchidaceae indicates that species of these families use different strategies to obtain water and soil nutrients. © 2023 Kunming Institute of Botany, Chinese Academy of SciencesRussian Academy of Sciences, РАН; Ural Branch, Russian Academy of Sciences, UB RAS: 122021000092–9The authors would like to express their deepest gratitude to A.N. Sozontov (Institute of Plant and Animal Ecology, Ural Branch, Russian Academy of Sciences) for performing PERMANOVA analysis. The work of D.V. Veselkin is a part of the research project of the Institute of Plant and Animal Ecology, Ural Branch, Russian Academy of Sciences (№122021000092–9)

δ15N in Birch and Pine Leaves in the Vicinity of a Large Copper Smelter Indicating a Change in the Conditions of Their Soil Nutrition

δ13C and δ15N were analyzed in the leaves of Pinus sylvestris L. and Betula spp. under the conditions of severe heavy metal (Zn, Cu, Cd, and Pb) contamination. Twenty-seven plots located near the Karabash copper smelter (Russia) were studied. No reliable correlation of 13C in tree leaves with the level of pollution was observed. δ15N, both in Pinus sylvestris and Betula spp., increased similarly in polluted areas. δ15N was increased by 2.3‰ in the needles of Pinus sylvestris and by 1.6‰ in the leaves of Betula spp. in polluted plots compared to the background ones. The probable reasons for the increase in δ15N were estimated using multiple regression. The regression model, which includes two predictors: δ15N in the humus horizon and the occurrence of roots in the litter, explains 33% of the total variability of δ15N in leaves. Thus, in ecosystems polluted with heavy metals, the state of trees is determined not only by the direct toxic effects of heavy metals but also by indirect ones associated with the features of plant mineral nutrition. This fact opens the way to the search for opportunities to control the state of plants in disturbed ecosystems by regulating the content of mineral nutrition elements. © 2022 by the authors

Ecol1103004BetekhtinaLO.fm

Abstract-The prevalence of arbuscular mycorrhizas and abundance of mycorrhizal fungi in the roots of her baceous plants with different types of Grime-Ramenskii's ecological strategies (competitors, ruderals, and stress tolerators) have been studied in the Middle Urals. The closest association with arbuscular fungi has been observed in species with a competitive strategy. Compared to them, stress tolerant species are charac terized by lower abundance of mycorrhizal fungal hyphae in the root system, while ruderal plants include a relatively large proportion of nonmycotrophic species showing no interaction with arbuscular fungi

Absorbing Roots of Invasive Woody Plants Apparently Have A Thicker Cortex Parenchyma Compared to Native Species

Invasive plants are usually Fast-growing species with a high rate of physiological processes. However, the relative growth rate has not been estimated for many invasive species, including Acer negundo L. (Sapindaceae) and Amelanchier spicata (Lam.) K. Koch (Rosaceae); this hampers the understanding of the reasons for the success of their invasion. The authors compared the absorbing roots of A. negundo and A. spicata with respect to mycorrhizal colonization with two native woody species of the same families, Acer platanoides L. and Sorbus aucuparia L. The samples were collected from several sites in the Central Urals and analysed using standard morphological and anatomical methods. The abundance of arbuscular mycorrhiza,dark septate endophytes and root hairs did not differ between the invasive and native species. Nevertheless, the roots of the invasive species were shown to have a thicker cortex parenchyma formed by larger cells. We suggest that this could contribute to invasion success, but a higher growth rate of the roots of invasive species has not yet been proven. Keywords: Acer negundo, Amelanchier spicata, invasive plants, absorbing roots, arbuscular mycorrhiza, root cortex, parenchyma &nbsp

THE FINE STRUCTURE ОF THE ABSORPTIVE ROOTS ОF NATIVE АND INVASIVE WOODY PLANTS

We compared the fine structure of the absorptive roots and mycorrhizal abundance between two invasive, Acer negundo and Amelanchier spicata, and two native, Acer platanoides and Sorbus aucuparia, woody plants belonging to the same family. The roots of invasive species were shown to be thicker: 304 ± 21 μm in diameter in Acer negundo vs 284 ± 15 μm in Acer platanoides and 273 ± 9 μm in Amelanchier spicata vs 241 ± 10 μmin Sorbus aucuparia. Mycorrhizal abundance, abundance of dark septate endophytes and root hairs did not differ between invasive and native species. Our findings only partly support the data obtained in previous studies.Работа выполнена при поддержке РФФИ № 15-04-07770