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Elumeeva T.G.,CAS Chengdu Institute of Biology | Tekeev D.K.,Teberda State Biosphere Reserve | Wu Y.,CAS Chengdu Institute of Biology | Wang Q.,CAS Chengdu Institute of Biology | Onipchenko V.G.,Moscow State University
Plant Biosystems | Year: 2014

Alpine plants of the eastern Qinghai-Tibetan plateau (Sichuan, China) are developed under long-lasting grazing by wild and domestic yaks. Among morphological features of plants, life forms may reflect their adaptation to grazing. We studied life-form composition of four typical communities within the alpine belt (3930–3960 m a.s.l.) subjected to grazing of various intensity: alpine fen (heavily grazed), alpine shrub meadow (heavily grazed), Spiraea alpina thicket (grazed), and Rhododendron thicket (practically not grazed). The following morphological traits were studied: (1) life form according to Raunkiaer, (2) life form according to Serebryakov, (3) canopy structure, and (4) rate of lateral spreading. We derived life-form spectra based on (1) the number of species per life form and (2) the cumulative abundance of species which have the same life form. One-way ANOVA and nonparametric ANOVA were run to test for significance of differences between spectra. The studied communities differed significantly by the proportion of different life forms. The main life forms are caudex and short rhizome hemicryptophytes, nonclonal species, or species with a low rate of lateral spreading. Therophytes made up 10–11% of the communities except in Rhododendron thickets, where such were absent. These life forms can indicate grazing in the study area. © 2013, © 2013 Società Botanica Italiana. Source

Adzhiev R.K.,Moscow State University | Onipchenko V.G.,Moscow State University | Tekeev D.K.,Teberda State Biosphere Reserve
Zhurnal Obshchei Biologii | Year: 2012

The experiment with seeds buried in soil has been carried out for 63 alpine plant species from the Northwest Caucasus. Seeds were mixed with native soils and placed in soil at the depth of 8-10 cm for five years. After excavation, seeds of 45 species did not germinate at all. Viability of eight species, four Carex species among them, exceeded 10%. These species are typical of Geranium-Hedysarum meadows and alpine snowbeds and form the main part of soil seed banks in these communities. Source

Elumeeva T.G.,Moscow State University | Onipchenko V.G.,Moscow State University | Egorov A.V.,State University of South Dacota | Khubiev A.B.,Karachai Cherkessian Ud Aliev State University | And 3 more authors.
Alpine Botany | Year: 2013

We studied long-term (25-31 years) dynamics of alpine communities at the Teberda Reserve, NW Caucasus, Russia, to test the following hypotheses: (1) lower altitude species increase and high altitude species decrease their abundance as a consequence of climate warming; (2) such changes in abundance are more significant in communities with short growth season (due to persistent snow cover) compared to exposed communities; (3) species with similar changes in abundance have similar functional traits. Four alpine communities with different positions in relief were considered in order of winter snow cover: alpine lichen heaths (ALH), Festuca varia grasslands (FVG), Geranium-Hedysarum meadows (GHM), and snowbed communities (SBC). The altitudinal distribution of species significantly predicted the direction and degree of changes in species abundance in GHM (p < 0.001), SBC (p < 0.02) and FVG (p < 0.05) with high altitude species decreasing and low altitude species increasing their abundance. Mean altitudes of significantly decreasing species exceeded that of increasing species by ca. 100-130 m in FVG, GHM and SBC. There were no species traits or trait combinations that consistently predicted their changing abundance in ALH, FVG and SBC. In GHM increasing species tended to have leaves with higher SLA (i.e. softer leaves) and lower root nitrogen content. The observed dynamic processes may be caused partly by recent climate warming, although slow recovery from historic grazing pressure may also play a role. Regardless of the causes driving the plant species' upward shift, communities experiencing high snow accumulation (SBC, GHM) seem to be more vulnerable to changes in structure and composition. © 2013 Swiss Botanical Society. Source

Soudzilovskaia N.A.,VU University Amsterdam | Soudzilovskaia N.A.,Leiden University | Soudzilovskaia N.A.,Louis Bolk Institute | van der Heijden M.G.A.,Institute for Sustainability science | And 8 more authors.
New Phytologist | Year: 2015

A significant fraction of carbon stored in the Earth's soil moves through arbuscular mycorrhiza (AM) and ectomycorrhiza (EM). The impacts of AM and EM on the soil carbon budget are poorly understood. We propose a method to quantify the mycorrhizal contribution to carbon cycling, explicitly accounting for the abundance of plant-associated and extraradical mycorrhizal mycelium. We discuss the need to acquire additional data to use our method, and present our new global database holding information on plant species-by-site intensity of root colonization by mycorrhizas. We demonstrate that the degree of mycorrhizal fungal colonization has globally consistent patterns across plant species. This suggests that the level of plant species-specific root colonization can be used as a plant trait. To exemplify our method, we assessed the differential impacts of AM : EM ratio and EM shrub encroachment on carbon stocks in sub-arctic tundra. AM and EM affect tundra carbon stocks at different magnitudes, and via partly distinct dominant pathways: via extraradical mycelium (both EM and AM) and via mycorrhizal impacts on above- and belowground biomass carbon (mostly AM). Our method provides a powerful tool for the quantitative assessment of mycorrhizal impact on local and global carbon cycling processes, paving the way towards an improved understanding of the role of mycorrhizas in the Earth's carbon cycle. © 2015 New Phytologist Trust. Source

Soudzilovskaia N.A.,VU University Amsterdam | Soudzilovskaia N.A.,University of Amsterdam | Douma J.C.,Center for Crop System Analysis | Akhmetzhanova A.A.,Teberda State Biosphere Reserve | And 7 more authors.
Global Ecology and Biogeography | Year: 2015

Aim: Most vascular plants on Earth form mycorrhizae, a symbiotic relationship between plants and fungi. Despite the broad recognition of the importance of mycorrhizae for global carbon and nutrient cycling, we do not know how soil and climate variables relate to the intensity of colonization of plant roots by mycorrhizal fungi. Here we quantify the global patterns of these relationships. Location: Global. Methods: Data on plant root colonization intensities by the two dominant types of mycorrhizal fungi world-wide, arbuscular (4887 plant species in 233 sites) and ectomycorrhizal fungi (125 plant species in 92 sites), were compiled from published studies. Data for climatic and soil factors were extracted from global datasets. For a given mycorrhizal type, we calculated at each site the mean root colonization intensity by mycorrhizal fungi across all potentially mycorrhizal plant species found at the site, and subjected these data to generalized additive model regression analysis with environmental factors as predictor variables. Results: We show for the first time that at the global scale the intensity of plant root colonization by arbuscular mycorrhizal fungi strongly relates to warm-season temperature, frost periods and soil carbon-to-nitrogen ratio, and is highest at sites featuring continental climates with mild summers and a high availability of soil nitrogen. In contrast, the intensity of ectomycorrhizal infection in plant roots is related to soil acidity, soil carbon-to-nitrogen ratio and seasonality of precipitation, and is highest at sites with acidic soils and relatively constant precipitation levels. Main conclusions: We provide the first quantitative global maps of intensity of mycorrhizal colonization based on environmental drivers, and suggest that environmental changes will affect distinct types of mycorrhizae differently. Future analyses of the potential effects of environmental change on global carbon and nutrient cycling via mycorrhizal pathways will need to take into account the relationships discovered in this study. © 2015 John Wiley & Sons Ltd. Source

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