Subalpine Meadows Research Articles

Contributions to the Phytocoenological Study of Oligo-Mesotrophic Peat Bogs / Marshy Meadows in the Vlădeasa Mountains, Western Carpathians, Romania

The purpose of this research consists in the development of a floristic, phytocoenological, ecological, cytogenetic, syndamic, economic and environmentally-friendly study of the marshy meadows located in the subalpine peats of the Vlădeasa Mountains. A total of nine phytocoenological surveys were conducted in the most representative sample areas of the phytocenoses of the Eriophoro vaginati-Sphagnetum recurvi association, in order to find adequate answers to the five proposed objectives of the study. The species found as a result of the floristic inventory were included in an association synthetic table by affinity criteria for coenotaxa: alliance, order, class to which they are subordinate. In the results chapter, the phytocoenoses of the association's meadows were analysed statistically based on tables, histograms, diagrams, by weight in ecological categories of bioforms, phytogeographical elements, cytogenetic elements and the ecological behaviour of the species in relation to edaphic moisture, air temperature, and chemical reaction of the soil. The phytocoenoses of the association, the economic and scientific value and the measures of sustainable management and environmentally friendly management of the subalpine meadows were also studied syndamically. The results thus obtained were compared with two reference works belonging to authors who carried out similar research in different geographical regions. We formulate seven findings in which the results of the research are summarized.

МЕЗОТРОФНЫЕ ДОЛИННЫЕ БОЛОТА НА СЕВЕРНОМ МАКРОСКЛОНЕ ЦЕНТРАЛЬНОГО КАВКАЗА

Alpine swamps, among other wetlands, are of particular interest due to their relict nature, some peculiarities of their origin, functioning and dynamics, as well as due to their poor knowledge. The object of our study was a cascade swamp complex, consisting of three communicating baths and a lake, located at different heights in the Karasu river valley, in Upper Balkaria at an altitude of about 2 thousand meters above sea level. On the basis of our field descriptions, an analysis of the relief and vegetation of the mesotrophic and lowland bogs which constitute the complex was carried out. It was revealed that the basis of the plant communities of mesophytic segments is sphagnum and three types of sedge (marsh, urchin-hairy, and spout). There are communities of subalpine meadows and forests on the slopes around the wetland complex. It is assumed that the complex has some underground supply, in addition to rain and snow supply and runoff from the neighboring mountain massif.

Herbivory damage but not plant disease under experimental warming is dependent on weather for three subalpine grass species

Abstract Both theory and prior studies predict that climate warming should increase attack rates by herbivores and pathogens on plants. However, past work has often assumed that variation in abiotic conditions other than temperature (e.g. precipitation) do not alter warming responses of plant damage by natural enemies. Studies over short time periods span low variation in weather, and studies over long time‐scales often neglect to account for fine‐scale weather conditions. Here, we used a 20+ year warming experiment to investigate if warming affects on herbivory and pathogen disease are dependent on variation in ambient weather observed over 3 years. We studied three common grass species in a subalpine meadow in the Colorado Rocky Mountains, USA. We visually estimated herbivory and disease every 2 weeks during the growing season and evaluated weather conditions during the previous 2‐ or 4‐week time interval (2‐week average air temperature, 2‐ and 4‐week cumulative precipitation) as predictors of the probability and amount of damage. Herbivore attack was 13% more likely and damage amount was 29% greater in warmed plots than controls across the focal species but warming treatment had little affect on plant disease. Herbivory presence and damage increased the most with experimental warming when preceded by wetter, rather than drier, fine‐scale weather, but preceding ambient temperature did not strongly interact with elevated warming to influence herbivory. Disease presence and amount increased, on average, with warmer weather and more precipitation regardless of warming. Synthesis. The effect of warming over reference climate on herbivore damage is dependent on and amplified by fine‐scale weather variation, suggesting more boom‐and‐bust damage dynamics with increasing climate variability. However, the mean effect of regional climate change is likely reduced monsoon rainfall, for which we predict a reduction in insect herbivore damage. Plant disease was generally unresponsive to warming, which may be a consequence of our coarse disease estimates that did not track specific pathogen species or guilds. The results point towards temperature as an important but not sufficient determinant and regulator of species interactions, where precipitation and other constraints may determine the affect of warming.

Relative stable interannual variation in plant–plant pollen transfer rather than the plant–pollinator network of a subalpine meadow

AbstractPrevious studies have shown that plant–pollinator mutualistic interactions experience highly interannual variation. Given that pollinators often move across multiple plant species, the plant–plant interactions that take place via heterospecific pollen (HP) transfer may also vary temporally, which could have important implications for floral evolution and community assembly. Here, we evaluated the interannual variation in plant–pollinator networks and plant–plant heterospecific pollen transfer (HPT) networks of a subalpine meadow community in Southwest China for three consecutive years. The interactions largely varied among years for both network types. The composition of donor-species HP deposited on the plants varied less than did the visit composition of the pollinators, suggesting that HP could be transferred from identical donor species to recipient species through different shared pollinators among years. The plant species were at more similar positions in the HPT network than they were in the plant–pollinator network across years. Moreover, the more generalized plant species in the plant–pollinator network tended to export their pollen grains and more strongly influence HPT. We evaluated the relatively stable structure of the HPT network compared with the plant–pollinator network, which represents an important step in the integration of plant–pollinator and plant–plant interactions.

Effects of different rest grazing periods on the reproduction and root characteristics of Carex capillifolia in subalpine meadow

Carex capillifolia is a dominant subalpine meadow plant species with considerable ecological and economic value. We studied the effects of different springtime rest grazing periods on C. capillifolia reproduction and the root characteristics. The rest grazing periods were established according to the soil thawing depth, plant regreening, and the local traditional rest grazing period. We set up five plots from the critical period of soil thawing (T1), the late period of soil thawing (T2), the early period of grass reviving (T3), the late period of grass growing (T4), and the local traditional rest grazing period (T5) to the start of the rest grazing. The end of the rest grazing in each plot was the plant withering period. Results showed that the sexual reproduction effort of T1 was 64.3% higher than that of T5. The root biomass of T5 was significantly lower than that of all the other treatments. The plant height, ear length, number of seeds per ear, reproductive branch density, and the seed yield of T1 were significantly higher than those of all the other plots. The reproductive branch density was significantly positively correlated with the seed yield. The seed yield of T1 was 200.0%, 349.1%, and 340.4% higher than those of T3, T4, and T5, respectively. The root length, surface area, and volume were the highest for T3. The root phenotypic traits and the nutrient storage content indirectly affected each other and jointly formed part of risk diversification strategies. A grey correlation analysis demonstrated that rest grazing during the critical soil thawing period (T1) was conducive to the growth of C. capillifolia. Therefore, springtime rest grazing should start from the critical soil thawing period in subalpine meadows.

Растения Красной книги России в коллекции флоры Кавказа ГБС РАН

For 77 years, 77 species included in the Red Book of Russia, that is, almost 15% of all species included in it, have been introduced at the exposition of the flora of the Caucasus of the Main Botanical Garden RAS. According to the results of the test, rare species were identified, the most promising for preservation in culture in the agro-climatic conditions of Moscow. The promising species are those confined to mountain forests, subalpine tall grass and intrazonal and riverine meadows of the Caucasus. Some of them are able to naturalize in the conditions of the Central part of Russia. Only if special agricultural techniques are observed, the species of alpine meadows and carpets, subalpine meadows, high-altitude rocks and scree, meadow-steppes, steppes and subtropical Colchian and Talysh forests are stable in Moscow. Rare species of arid habitats (upland xerophytes, arid woodlands) and thermophilic coastal plants are not promising for ex situ conservation. The majority of the studied species of the Orchidaceae family belong to the category of unstable, which is due to the difficulty of their cultivation. Keywords: RED BOOK OF RUSSIA, RARE PLANT SPECIES, BIODIVERSITY CONSERVATION, CAUCASUS FLORA, MAIN BOTANICAL GARDEN, MOSCOW

Растения Красной книги России в коллекции флоры Кавказа ГБС РАН

For 77 years, 77 species included in the Red Book of Russia, that is, almost 15% of all species included in it, have been introduced at the exposition of the flora of the Caucasus of the Main Botanical Garden RAS. According to the results of the test, rare species were identified, the most promising for preservation in culture in the agro-climatic conditions of Moscow. The promising species are those confined to mountain forests, subalpine tall grass and intrazonal and riverine meadows of the Caucasus. Some of them are able to naturalize in the conditions of the Central part of Russia. Only if special agricultural techniques are observed, the species of alpine meadows and carpets, subalpine meadows, high-altitude rocks and scree, meadow-steppes, steppes and subtropical Colchian and Talysh forests are stable in Moscow. Rare species of arid habitats (upland xerophytes, arid woodlands) and thermophilic coastal plants are not promising for ex situ conservation. The majority of the studied species of the Orchidaceae family belong to the category of unstable, which is due to the difficulty of their cultivation. Keywords: RED BOOK OF RUSSIA, RARE PLANT SPECIES, BIODIVERSITY CONSERVATION, CAUCASUS FLORA, MAIN BOTANICAL GARDEN, MOSCOW

Paleochannel of the Yellow River within the Zoige Basin and its environmental significance on the NE Tibetan Plateau

Paleochannel sedimentary sequences can provide abundant information on regional environmental changes. A typical paleochannel (paleo-oxbow lake type) section of the Yellow River was identified within the Zoige Basin on the NE Tibetan Plateau. A multi-index approach was used to accurately identify sediments of different genetic types, such as riverbed deposits of the Yellow River, paleo-oxbow lake deposits, and overbank flood deposits (OFD) in the section. Based on optically stimulated luminescence (OSL) and AMS 14C dates, we examined the environmental evolution recorded by the section. The results show that: (1) The section is a record of environmental change since 4.17 ± 0.49 ka. During 4.17 ± 0.49 to 3.24 ± 0.26 ka, the ancient Yellow River occupied the channel. At 3.24 ± 0.26 ka, the paleochannel experienced a neck cutoff, and the fluvial environment began to change into the oxbow lake environment. After 2.45 ± 0.11 ka, the paleo-oxbow lake gradually disappeared. Subalpine meadow soil has developed at this site since 1.31 ± 0.05 ka. (2) Paleoenvironmental proxies indicate that the Zoige Basin was warmer and wetter before ~3.00 ka, and became drier and colder after ~3.00 ka, which may be mainly related to the weakening of the East Asian summer monsoon (EASM) and the strengthening of the Westerlies. (3) Two episodes of extreme overbank flooding occurred at 2.96 ± 0.24 to 2.87 ± 0.27 ka and 1.84 ± 0.20 to 1.70 ± 0.16 ka, correlated with climate shift period from the mid-Holocene climatic optimum to the late Holocene and the Dark Age Cold Period (DACP), respectively. Due to the relatively cold and dry climate in these periods, glaciers generally advanced on the Tibetan Plateau, and the contribution of snow and ice meltwater weakened. Therefore, the strong rainfall caused by the abnormal atmospheric circulation may be the main cause of these extreme overbank flooding.

Why does overgrazing promote nitrifiers and denitrifiers abundance and the resultant soil N2O emissions?

AbstractOvergrazing by livestock is a global environmental problem, influencing global warming via soil N2O emissions. However, it remains unknown why overgrazing leads to increased N2O emissions. Here, we used a paired design of subalpine meadows in undisturbed and overgrazed sites at four different elevations (from 3000 to 3600 m) located over an area of ~200 km2 in the Qinghai‐Tibetan Plateau (QTP), China, to evaluate relationships among plant diversity, soil ammonium and nitrate N, the abundance of soil nitrifiers (AOA and AOB) and denitrifiers (nirK, nirS and the N2O reductase gene [nosZ]) and soil N2O emissions. Using a generalized linear mixed effects modeling framework with Poisson error, we found that the influence of overgrazing on increased abundance of soil nitrifiers and denitrifiers and associated increased soil N2O emission was a general phenomenon in QTP. More importantly, by using forward selection analysis and structural equation models, we showed overgrazing decreased plant richness, and this resulted in decreased ammonium N, but increased nitrate N at all elevations. Accordingly, decreased ammonium N, but increased nitrate N led to increased abundance of soil nitrifiers (AOA and AOB) and denitrifiers (nirK and nirS), but decreased nosZ abundance, which finally gave rise to increased soil N2O emission at all the elevations. Our results highlight the key role of plant diversity in regulating soil N2O emissions from soils. Thus, performing active ecological restoration to recover native plant species in overgrazed sites may help mitigate the influence of overgrazing on global warming.

Degradation‐induced microbiome alterations may aggravate soil nutrient loss in subalpine meadows

AbstractGrassland degradation has become a serious environmental problem worldwide. However, the link between grassland degradation and soil functional microorganisms remains unclear. Here, we investigated the effects of subalpine meadow degradation on the taxonomic and functional communities of the soil microbiome on Mount Wutai on the eastern margin of the Loess Plateau, China, using shotgun metagenomic sequencing. The results showed that vegetation degradation decreased most soil nutrients (e.g., soil organic carbon [SOC, −48.9%], total nitrogen [TN, −15.2%] and carbon [TC, −38.3%]), leading to significant changes in the taxonomic (r = 0.892, p < 0.001) and functional compositions (r = 0.972, p < 0.001) of the microbial communities (explaining 66.6% and 64.5% of the variance, respectively). The structural equation model (SEM) showed that variations in the soil nutrient status and plant parameters caused by degradation resulted in changes in the microbial community structure and function. The variations in the plant and microbial communities during degradation altered carbon (C) and nitrogen (N) cycling separately or interactively. Among the C degradation‐related genes, the relative abundances of cellulose degradation, sugar utilization and chitin degradation genes in moderately degraded (MD) and heavily degraded (HD) meadows were significantly higher than those in nondegraded (ND) meadows (p < 0.05). The abundance of denitrification genes (nirK, nirS, norB and norC) and nitrification genes (pmoA/amoA, pmoB/amoB, pmoC/amoC and hao) was higher in all degraded meadows, which increased the risk of soil N loss. Our findings revealed the negative feedback of microbes due to subalpine meadow degradation, during which metabolically active microbes tended to accelerate soil nutrient loss.

Soil warming during winter period enhanced soil N and P availability and leaching in alpine grasslands: A transplant study.

Alpine meadows are strongly affected by climate change. Increasing air temperature prolongs the growing season and together with changing precipitation patterns alters soil temperature during winter. To estimate the effect of climate change on soil nutrient cycling, we conducted a field experiment. We transferred undisturbed plant-soil mesocosms from two wind-exposed alpine meadows at ~2100 m a.s.l. to more sheltered plots, situated ~300-400 m lower in the same valleys. The annual mean air temperature was 2°C higher at the lower plots and soils that were normally frozen at the original plots throughout winters were warmed to ~0°C due to the insulation provided by continuous snow cover. After two years of exposure, we analyzed the nutrient content in plants, and changes in soil bacterial community, decomposition, mineralization, and nutrient availability. Leaching of N and P from the soils was continuously measured using ion-exchange resin traps. Warming of soils to ~0°C during the winter allowed the microorganisms to remain active, their metabolic processes were not restricted by soil freezing. This change accelerated nutrient cycling, as evidenced by increased soil N and P availability, their higher levels in plants, and elevated leaching. In addition, root exudation and preferential enzymatic mining of P over C increased. However, any significant changes in microbial biomass, bacterial community composition, decomposition rates, and mineralization during the growing season were not observed, suggesting considerable structural and functional resilience of the microbial community. In summary, our data suggest that changes in soil temperature and snow cover duration during winter periods are critical for altering microbially-mediated processes (even at unchanged soil microbial community and biomass) and may enhance nutrient availability in alpine meadows. Consequently, ongoing climate change, which leads to soil warming and decreasing snow insulation, has a potential to significantly alter nutrient cycling in alpine and subalpine meadows compared to the current situation and increase the year-on-year variability in nutrient availability and leaching.

Metabarcoding of fungal assemblages in Vaccinium myrtillus endosphere suggests colonization of above-ground organs by some ericoid mycorrhizal and DSE fungi

Plants harbor in their external surfaces and internal tissues a highly diverse and finely structured microbial assembly, the microbiota. Each plant compartment usually represents a unique ecological niche hosting a distinct microbial community and niche differentiation, which may mirror distinct functions of a specialized microbiota, has been mainly investigated for bacteria. Far less is known for the fungal components of the plant-associated microbiota. Here, we applied a metabarcoding approach to describe the fungal assemblages in different organs of Vaccinium myrtillus plants (Ericaceae) collected in a subalpine meadow in North-West Italy, and identified specific taxa enriched in internal tissues of roots, stems, leaves and flowers. We also traced the distribution of some important fungi commonly associated with plants of the family Ericaceae, namely the ericoid mycorrhizal (ErM) fungi and the dark septate endophytes (DSE), both playing important roles in plant growth and health. Operational taxonomic units attributed to established ErM fungal species in the genus Hyaloscypha and to DSE species in the Phialocephala-Acephala applanata complex (PAC) were found in all the plant organs. Mycorrhizal fungi are thought to be strictly associated with the plant roots, and this first observation of ErM fungi in the above-ground organs of the host plant may be explained by the evolutionary closeness of ErM fungi in the genus Hyaloscypha with non mycorrhizal fungal endophytes. This is also witnessed by the closer similarities of the ErM fungal genomes with the genomes of plant endophytes than with those of other mycorrhizal fungi, such as arbuscular or ectomycorrhizal fungi.

Responses of Soil Fungal Communities to Subalpine Meadow Degradation in Mount Wutai

Grassland degradation has become a worldwide ecological problem. Although soil microorganisms, as the main participants in the process of grassland degradation, play a key role in maintaining ecosystem function and improving soil productivity, little is known about the changes in microbial communities caused by grassland degradation and their relationship with soil properties and plant communities. In this study, we used Illumina MiSeq sequencing to analyze the soil fungal communities of subalpine meadow soil at four different degradation stages[i.e., non-degraded (ND), lightly degraded (LD), moderately degraded (MD), and heavily degraded (HD)] on Mount Wutai. The results showed that Ascomycota, Basidiomycota, and Zygomycota were the dominant phyla of soil fungi in the subalpine meadow, regardless of degradation stage. LEfSe showed that the subalpine meadows with different degradation degrees were enriched with different biomarkers. Compared with ND, MD and HD were enriched with more pathogenic fungi. Moreover, HD apparently decreased the richness and Shannon indexes of soil fungal communities compared with those of ND. Non-metric multidimensional scaling (NMDS) and similarity analysis (ANOSIM) indicated that the compositions and structures of fungal communities were significantly different among meadows with different degradation degrees (P<0.05). Redundancy analysis (RDA) showed that soil water content, total nitrogen, plant richness, and ammonium nitrogen were significantly correlated with the compositions and structures of fungal communities (P<0.05). There were significant correlations between α diversity and β diversity between plant and fungal communities (P<0.05), indicating strong coupling. The results of our study provide a theoretical basis for further research on the changes in soil fungal communities and their driving mechanism in different degradation stages of subalpine meadows.

A new species of the genus Scoparia Haworth, 1811 (Lepidoptera: Pyraloidea, Crambidae) from the Transcaucasia

Scoparia sinevi Streltzov, sp. n. is described from the Republic of Southern Ossetia. The new species is very similar in its appearance to the Central Asian S. juldusella (Caradja, 1916) but distinctly differs from latter by the male genitalia with cornutus consisting of three large spines (cornutrus with one large spine in S. juldusella). The moths of the new species were collected from forb subalpine meadows in the Rachinsky Range.

Links between leaf anatomy and leaf mass per area of herbaceous species across slope aspects in an eastern Tibetan subalpine meadow.

Leaf anatomy varies with abiotic factors and is an important trait for understanding plant adaptive responses to environmental conditions. Leaf mass per area (LMA) is a key morphological trait and is related to leaf performance, such as light‐saturated photosynthetic rate per leaf mass, leaf mechanical strength, and leaf lifespan. LMA is the multiplicative product of leaf thickness (LT) and leaf density (LD), both of which vary with leaf anatomy. Nevertheless, how LMA, LT, and LD covary with leaf anatomy is largely unexplored along natural environmental gradients. Slope aspect is a topographic factor that underlies variations in solar irradiation, air temperature, humidity, and soil fertility. In the present study, we examined (1) how leaf anatomy varies with different slope aspects and (2) how leaf anatomy is related to LMA, LD, and LT. Leaf anatomy was measured for 30 herbaceous species across three slope aspects (south‐, west‐, and north‐facing slopes; hereafter, SFS, WFS, and NFS, respectively) in an eastern Tibetan subalpine meadow. For 18 of the 30 species, LMA data were available from previous studies. LD was calculated as LMA divided by LT. Among the slope aspects, the dominant species on the SFS exhibited the highest LTs with the thickest spongy mesophyll layers. The thicker spongy mesophyll layer was related to a lower LD via larger intercellular airspaces. In contrast, LD was the highest on NFS among the slope aspects. LMA was not significantly different among the slope aspects because higher LTs on SFS were effectively offset by lower LDs. These results suggest that the relationships between leaf anatomy and LMA were different among the slope aspects. Mechanisms underlying the variations in leaf anatomy may include different solar radiation, air temperatures, soil water, and nutrient availabilities among the slope aspects.

Nitrogen deposition magnifies destabilizing effects of plant functional group loss

Terrestrial ecosystems are under threat by the co-occurring biodiversity loss and nitrogen (N) deposition. Awareness is growing that the stabilizing effects of plant diversity on productivity depend on environmental context, but it remains unknown about how the loss of plant functional groups and N deposition interactively influence species richness and community stability. Here we carried out an eight-year experiment of plant functional groups removal and N addition experiment in subalpine meadow. We found that the removal of plant functional groups and N addition interactively affected averaged plant species richness and community stability. Without N addition, the absence of forbs, but not other functional groups, significantly decreased average species richness and community stability through decreasing species asynchrony (i.e., asynchronous dynamics among species under fluctuating conditions). Under N addition, the absence of forbs, grasses and legumes all led to significant declines in average species richness, causing a decrease in community stability by decreasing species asynchrony, among which the absence of forbs had the greatest negative effects on community stability. Moreover, N addition reinforced the destabilizing effects caused by the loss of functional groups. Our findings show that the diverse forbs maintain plant community stability through asynchronous dynamics among species, especially under N deposition scenario. Therefore, we suggest that conservation and restoration of plant communities and their stability would benefit from a functional-group specific strategy by considering the largely ignored forb species, while helps guide conservation management efforts to reduce temporal variability for ecosystem service in the face of uncertain species extinction and N deposition scenarios.

Biochemical composition and function of subalpine shrubland and meadow soil microbiomes in the Qilian Mountains, Qinghai-Tibetan plateau, China.

Microorganisms participate in the soil biogeochemical cycle. Therefore, investigating variations in microbial biomass, composition, and functions can provide a reference for improving soil ecological quality due to the sensitivity of microorganisms to vegetation coverage changes. However, the differences in soil microorganisms between shrubland and meadow have not been investigated in ecologically vulnerable subalpine areas. This study aimed to investigate the biochemical composition and functions of the soil microbial community under two shrublands and a meadow at high altitudes (3,400–3,550 m). Three sites under two shrublands, Rhododendron thymifolium (RHO) and Potentilla fruticosa (POT), and one meadow dominated by Kobresia myosuroides (MEA), were selected on the southern slope of the Qilian Mountains on the northeastern edge of the Qinghai–Tibetan Plateau, China. Soil physicochemical properties, the microbial community composition expressed by the phospholipid fatty acid (PLFA) biomarker, and enzyme activities were analyzed as well as their relationships. The results showed that water holding capacity and the soil carbon, nitrogen, and potassium content in RHO and POT were higher than those in the MEA. Moreover, the soil active carbon, dissolved organic carbon, total nitrogen, and dissolved total nitrogen content in RHO were higher than those in POT. The abundance of total PLFAs, bacteria, and fungi beneath the shrublands was considerably higher than that in the MEA. The PLFA abundance in RHO was significantly higher than that in POT. The fungal-to-bacterial ratio of RHO and POT was significantly higher than that in the MEA. The activities of β-glucosidase, cellobiohydrolase, and leucine aminopeptidase were the highest in RHO among the three vegetation types, followed by POT and MEA. The redundancy analysis indicated that the biochemical composition of the soil microorganisms and enzyme activities were driven by total nitrogen, dissolved organic carbon, water holding capacity, and soil organic carbon. Therefore, shrublands, which have higher biomass, can improve soil moisture status, increase soil carbon and nitrogen content (especially active carbon and active nitrogen), and further increase the abundance of total PLFAs, bacteria, and fungi. The increase of microbial biomass indirectly enhances the activity of relevant soil enzymes. The variations in PLFA abundance and enzyme activities can be attributed to shrub species, especially evergreen shrubs, which create more favorable conditions for soil microorganisms. This study provides a theoretical basis for investigating the soil biogeochemical cycle and a scientific basis for soil management and vegetation restoration in the subalpine regions.

Effects of an introduced mustard, Thlaspi arvense, on soil fungal communities in subalpine meadows

The subalpine meadows of the Rocky Mountains, USA, are at the advancing front of global change; however, little is known about the sensitivities of high-elevation soil fungal communities to ongoing ecological changes. Soil fungi are sensitive to abiotic and biotic environmental stressors, including climate change, soil disturbance, and the presence of introduced, non-native plants. Invasive plants in the Brassicaceae (mustard family) are known to alter fungal community structure, suppress arbuscular mycorrhizal fungi, and change their relationship with native plant hosts in forest ecosystems, but these phenomena have not been studied in the subalpine zone where non-native mustard plants are becoming established. Here, we investigated whether the presence of the introduced mustard plant, Thlaspi arvense , is associated with distinct properties of the whole fungal and arbuscular mycorrhizal fungal communities in subalpine meadow ecosystems. We observed clear differences in the composition, relative abundance of core taxa, and mean taxon relatedness of soil fungal communities in plots with T. arvense relative to those with only native vegetation. A suite of novel fungi were associated with T. arvense , and overall patterns of AMF phylogenetic diversity were drastically reduced in association with its presence. Our results suggest that T. arvense introduction impacts the soil fungal community, with potential implications for native plant communities and soil nutrient cycling in high elevation meadows of the Rocky Mountains.

Monitoring of Fragile Ecosystems with Spectral Indices Using Sentinel-2A MSI Data in Shahdagh National Park

Studying ecosystems using remote sensing technologies is very relevant since it checks the accuracy of the results of modern research. This study aims to monitor environmental changes in ecosystems of the Shahdagh National Park and its surrounding areas in Azerbaijan using Sentinel 2A MSI data. The study aimed to examine and monitor changes in vegetation, water resources, and drought conditions of the study area in recent years. For analyzing and observing these ecosystems Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), and Normalized Difference Drought Index (NDDI) were calculated using multi-band methods. Obtained indices were compared and changes were investigated analyzing satellite-derived methods. For proper monitoring and assessment of relevant ecosystems, there had been determined 3,825 fishnet points for the study area. This made it possible to compare and coordinate the results of the indices more accurately. After linking fishnet points to raster indices, classification had been made for measuring ecosystems indicators. Vegetation assessments revealed a partial expansion of sparse vegetation or bare rocks, river valleys, as well as nival, subnival, and partial subalpine meadows from 15.1% to 18.1%. Another growth indicator is a significant increase of dense forest ecosystems from 2.3% to 9.2%. According to the results decreases are observed in sparse forests, arable lands, pastures, and shrubs, which are more sensitive to anthropogenic factors. Monitoring of the indices shows that low-humidity areas increase as droughts intensify, especially in plain areas. Finally, the study revealed that the introduction of a specially protected regime within the national park makes ecosystems more sustainable.

Intraspecific Variation in Responses of a Montane Grass, Festuca thurberi, to Simulated Biological Invasion

High elevation plant populations, such as those found in sub-alpine meadows, are at the forefront of climate change and likely to experience novel interactions with migrating plants from lower elevations, including non-native species. Some of these non-native plants, particularly members of the Brassicaceae, produce secondary metabolites that have been shown to inhibit root fungi in other ecosystems. We conducted a growth experiment with plant leachates in order to evaluate the degree to which the dominant high elevation grass species, Festuca thurberi would be affected by future novel interactions with the non-native mustard, Thlaspi arvense, relative to a native mustard (Noccaea fendleri). We assessed growth, chlorophyll content, biomass, mortality, and percent colonization of arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) in different genotypes of F. thurberi exposed to leachates from native and non-native mustards as well as F. thurberi leachate and a deionized (DI) water control. New growth and mortality varied more by genotype than by treatment with leachate of F. thurberi, T. arvense, and N. fendleri. Treatment, genotype, and the treatment × genotype interaction all had significant effects on chlorophyll content, with N. fendleri treatments demonstrating higher relative greenness levels than control treatments. Percent of fine roots with dark septate endophytes was significantly affected by individual genotype and treatment × genotype interaction, but there were no effects of treatment, genotype, or their interaction on percent root colonization by arbuscules or vesicles. Overall, we show that performance of a dominant high-altitude grass species varies in its response to the presence of an expanding, non-native plant, which may become increasingly common due to climate change.