Subalpine Meadows Research Articles

Constructing more comprehensive pollination networks: integrating diurnal and nocturnal pollen data with visitation in a subalpine wetland community.

Sampling for describing plant-pollinator interaction networks has been performed using techniques that either focus on the plants (with flower-visit data) or the animals (with analyzing pollen on the body surface of flower visitors). The differences in the structure of the networks obtained using these methods likely influences our understanding of the contribution of nocturnal pollinators, yet this key finding has yet to be the focus of study. In this study, we conducted an intensive diurnal field survey in the subalpine meadows of the Dajiuhu Wetland and supplemented the data with an analysis of diurnal and nocturnal pollen data to examine the changes in pollination networks. We observed 41 plant and 154 pollinator species, corresponding to 665 specific interactions. Visitation and pollen analyses showed significant differences in the composition and interaction between network plants and pollinators, resulting in important structural changes in the network. Given that the diurnal pollen data showed new links that were preferentially attached to highly connected nodes, the level of asymmetric specialization did not decrease; however, nestedness increased 1.3-fold, and mean pollinator connectivity from 3.1 to 5.1. As the behaviors of nocturnal pollinators tended to be more specialized, the inclusion of nocturnal pollen data led to an increase in the number of extreme-specialist pollinator species. Consequently, nestedness decreased 0.8-fold, but mean plant connectivity went from 14.2 to 16.2. These findings suggest that the structure of pollination networks is influenced by the sampling methods and the level of detail of the investigation. Our study has strong implications for the development of monitoring schemes for plant-pollinator interactions. Due to the practical difficulties of nocturnal field visitation, when conducting research, combining diurnal field visitation with both diurnal and nocturnal pollen analyses is the most convenient and realistic method to capture the full complexity of these networks.

Cytotoxic diterpenoids from the roots of Euphorbia jolkinii Boiss against human pancreatic cancer SW1990 cells by regulating the expressions of Bcl-2, Bax, and Caspase-3 proteins

Sixteen undescribed diterpenoids were identified from Euphorbia jolkinii Boiss, a widespread invasive plant in the grassland ecosystem of subalpine meadows in southwest China, through a combination of spectroscopic data analysis. These included two casbane diterpenoids (1 and 2), two ent-atisane diterpenoids (3 and 4), and twelve ent-isopimarane diterpenoids (5–16). All isolates were evaluated the cytotoxicity on pancreatic cancer SW1990 cells in which compounds 1 and 9 exhibited obvious bioactivities against the tumor cells with the IC50 values of 26.50 ± 6.36 and 21.09 ± 5.98 μM respectively. Moreover, compounds 1 and 9 were found to promote the pre-apoptosis of SW1990 cells and regulate the expressions of Bcl-2, Bax, and Caspase-3 proteins to display anti-tumor abilities. Compounds 1 and 9 were subjected to Bcl-2 protein via molecular ducking to reveal their anti-tumor mechanism further. The druggability prediction showed that they possessed good drug properties with development and utilization scenarios.

Pan Trapping and Malaise Trapping: A Comparison of Bee Collection Techniques in Subalpine Meadows

Public lands, managed for multiple uses such as logging, mining, grazing, and recreation, also support vital environmental services like wild bee pollination. A trending decline in wild bees has heightened interest in documenting these key pollinators in their native habitats. Accurate assessment of pollinator community diversity is crucial for population monitoring and informing land management practices. In this study, we evaluate the efficiency of Malaise traps and pan traps in sampling wild bees over three growing seasons in subalpine meadow communities in central Utah. Sixteen trapping sites were established, each with a Malaise trap and an array of blue, white, and yellow pan traps, nine at each site. Weekly collections were made through summer months and a comparison of their effectiveness in capturing bee abundance and species richness was made. Malaise traps captured significantly greater abundance of bees on average, though this was species-dependent. Malaise traps were especially effective at capturing Bombus spp. and larger species. Pan traps were generally more effective with smaller species such as Hylaeus spp. White pan traps outperformed yellow and blue pan traps in terms of abundance and only yellow pan traps in terms of richness. Both methods contributed unique species to the overall collection effort, suggesting that a combination of trapping methods provides a more comprehensive understanding of bee communities. Species accumulation curves indicate that species existing within the community went unencountered in our samples and that more time or perhaps additional methods could aid in best describing the entire community.

Sodium-enriched nectar shapes plant-pollinator interactions in a subalpine meadow.

Many plants have evolved nutrient rewards to attract pollinators to flowers, but most research has focused on the sugar content of floral nectar resources. Concentrations of sodium in floral nectar (a micronutrient in low concentrations in nectar) can vary substantially both among and within co-occurring species. It is hypothesized that sodium concentrations in floral nectar might play an important and underappreciated role in plant-pollinator interactions, especially because many animals, including pollinators, are sodium limited in nature. Yet, the consequences of variation in sodium concentrations in floral nectar remain largely unexplored. Here, we investigate whether enriching floral nectar with sodium influences the composition, diversity, and frequency of plant-pollinator interactions. We experimentally enriched sodium concentrations in four plant species in a subalpine meadow in Colorado, USA. We found that flowers with sodium-enriched nectar received more visits from a greater diversity of pollinators throughout the season. Different pollinator species foraged more frequently on flowers enriched with sodium and showed evidence of other changes to foraging behavior, including greater dietary evenness. These findings are consistent with the "salty nectar hypothesis," providing evidence for the importance of sodium limitation in pollinators and suggesting that even small nectar constituents can shape plant-pollinator interactions.

A review of the Cochylimorpha perfusana (Guenée, 1845) species group (Lepidoptera, Tortricidae) in Europe, with the description of a new species from the Southern Carpathians (Romania)

European species of the Cochylimorpha perfusana (Guenée, 1845) species group are revised. Four species are recognized, all closely related to C. perfusana (Guenée, 1845) with which they have previously been confused. Based on morphological differences and DNA barcode data, C. callosana (Herrich-Schäffer, 1856), sp. rev. and C. dorsimaculana (Preissecker, 1908), sp. rev., are re-instated to their original species rank. Inconsistencies in their taxonomy leading to their synonymy are shown and corrected. Cochylimorpha bucegiana Z. Kovács, S. Kovács & P. Buchner, sp. nov. is described from the subalpine meadows of the Bucegi and Făgăraș Mountains (Southern Carpathians, Romania), and the other three species are redescribed. Adults and genitalia of both sexes of all four, and the habitat of three taxa are figured. The geographic distribution of each species is re-evaluated based on the examined material and a critical analysis of the literature. Literature data for which no material could be found for examination are treated as doubtful and in need of confirmation. Cochylimorpha perfusana is widely distributed in mountain areas of Europe (Alps, Carpathians and Pirin Mountains), C. callosana is widespread only in the north-western Balkan Peninsula and north-eastern Italy, and local in eastern France, Corsica and Hungary, the other two seem to be endemics, C. dorsimaculana to Wachau and Retz in Lower Austria and C. bucegianasp. nov. to the Southern Carpathians in Romania. Cochylimorpha perfusana is recorded for the first time from Bulgaria; the first confirmed records of C. callosana from Slovenia and Hungary are given; and in the north-eastern Italian fauna C. callosana replaces C. perfusana. Records of C. perfusana from Ukraine, the Czech Republic, Slovenia, and north-western Italy require confirmation.

Does pollination interact with the abiotic environment to affect plant reproduction?

Abiotic and biotic components of the environment both limit plant reproduction, but how they interact with one another in combination is less understood. Understanding these interactions is especially relevant because abiotic and biotic environmental components respond differently to various global change drivers. Here we aim to understand whether the effects of pollination (biotic component) on plant reproduction depend on soil moisture (abiotic component), two factors known to affect plant reproduction and that are changing with global change. We conducted pollen supplementation experiments for two plant species, Delphinium nuttallianum and Hydrophyllum fendleri, in subalpine meadows in the Western USA across four years that varied in soil moisture. In a separate one-year field experiment, we factorially crossed water addition with pollen supplementation. We measured proportion fruit set, seeds per fruit, and seeds per plant, in addition to stomatal conductance, to determine whether plant physiology responded to watering. In the four-year study, only H. fendleri reproduction was pollen limited, and this occurred independently of soil moisture. Experimental water addition significantly increased soil moisture and stomatal conductance for both species. The effect of pollen addition on reproduction depended on the watering treatment only for H. fendleri fruit production. Reproduction in D. nuttallianum was not significantly affected by pollen addition or water addition, but it did respond to interannual variation in soil moisture. Although we find some evidence for the effect of a biotic interaction depending on abiotic conditions, it was only for one aspect of reproduction in one species, and it was in an unexpected direction. Our work highlights interactions between the abiotic and biotic components of the environment as an area of further research for improving our understanding of how plant reproduction responds to global change.

Study on the Effect of Soil Moisture on Soil Organic Carbon During the Growing Period of Plants in the Subalpine Meadows Zone of Qilian Mountains, China

Study on the Effect of Soil Moisture on Soil Organic Carbon During the Growing Period of Plants in the Subalpine Meadows Zone of Qilian Mountains, China

Flower visits and pollinator pollen load networks reveal the effects of pollinator sharing on heterospecific pollen transfer in a subalpine plant community.

The mutualistic network of plant-pollinator also involves interspecific pollination caused by pollinator sharing. Plant-pollinator networks are commonly based on flower visit observations, which may not adequately represent the actual pollen transfer between co-flowering plant species. Here, we compared the network structure of plant-pollinator interactions based on flower visits (FV) and pollen loads (PL) on the bodies of pollinators and tested how the degree of pollinator sharing in the two networks affected heterospecific pollen transfer (HPT) between plant species in a subalpine meadow. The FV and PL networks were largely overlapped. PL network included more links than FV network. The positions of plant and pollinator species in the FV and PL networks were positively correlated, indicating that both networks could detect major plant-pollinator interactions. The degree of pollinator sharing, based on either the FV or the PL network, positively influenced the amount of heterospecific pollen transferred between plant species pairs. However, the degree of pollinator sharing had a low overall explanatory power for HPT, and the explanatory powers of the FV and PL networks were similar. Overall, our study highlights the importance of FV and PL for understanding the drivers and outcomes of plant-pollinator interactions, as well as their relevance to HPT.

Monitoring and influencing factors of grassland livestock overload in Xinjiang from 1982 to 2020.

It is crucial to estimate the theoretical carrying capacity of grasslands in Xinjiang to attain a harmonious balance between grassland and livestock, thereby fostering sustainable development in the livestock industry. However, there has been a lack of quantitative assessments that consider long-term, multi-scale grass-livestock balance and its impacts in the region. This study utilized remote sensing and empirical models to assess the theoretical livestock carrying capacity of grasslands. The multi-scale spatiotemporal variations of the theoretical carrying capacity in Xinjiang from 1982 to 2020 were analyzed using the Sen and Mann-Kendall tests, as well as the Hurst index. The study also examined the county-level grass-livestock balance and inter-annual trends. Additionally, the study employed the geographic detector method to explore the influencing factors. The results showed that: (1) The overall theoretical livestock carrying capacity showed an upward trend from 1982 to 2020; The spatial distribution gradually decreased from north to south and from east to west. In seasonal scale from large to small is: growing season > summer > spring > autumn > winter; at the monthly scale, the strongest livestock carrying capacity is in July. The different grassland types from largest to smallest are: meadow > alpine subalpine meadow > plain steppe > desert steppe > alpine subalpine steppe. In the future, the theoretical livestock carrying capacity of grassland will decrease. (2) From 1988 to 2020, the average grass-livestock balance index in Xinjiang was 2.61%, showing an overall increase. At the county level, the number of overloaded counties showed an overall increasing trend, rising from 46 in 1988 to 58 in 2020. (3) Both single and interaction factors of geographic detectors showed that annual precipitation, altitude and soil organic matter were the main drivers of spatiotemporal dynamics of grassland load in Xinjiang. The results of this study can provide scientific guidance and decision-making basis for achieving coordinated and sustainable development of grassland resources and animal husbandry in the region.

The impacts of interannual climate variation on pollination network structure of a sub-alpine meadow: from 2008 to 2021

The impacts of interannual climate variation on pollination network structure of a sub-alpine meadow: from 2008 to 2021

Subalpine Meadow Vegetation of Talish Highlands of Azerbaijan

Subalpine meadow vegetation of Talish highlands has been spread over the subalpine zone of Lankaran highlands at lawny mountain-meadow soils at the height of 1800 m to 2500 m above sea level. During the carried out ecological-geobotanical research, it has been determined 7 formation classes, 12 formation groups and 20 associations. In parallel with the study of type composition and structure of phytocenosis found in the area of investigation, it has been also determined endemic species, productivity of formations, and intensification of degradation at soil-plant coverage of some lawny subalpine meadows, decrease in abundance and productivity of forage crop. Currently, for the purpose of the improvement of natural phytocenosis productivity, crop quality, protection of their genetic reserve and landscapes, as well as the vegetation study for solution of protection problems on the base of scientific means is of a great importance.

DISTRIBUTION REGULATIONS AND LIFE FORMS OF THE SPECIES OF THE BERBERIDACEAE JUSS. FAMILY WHICH ARE DISTRIBUTED IN THE NAKCHIVAN AUTONOMOUS REPUBLIC OVER ALTITUDE ZONES

Nakhchivan Autonomous Republic, which is part of Azerbaijan, has unique physical and geographical conditions. The total length of the border lines of the autonomous republic, located in the south west of the Lesser Caucasus, is 398 km. The main plain of the Autonomous Republic, 2/3 of which is mountainous and 1/3 is plain, is Araz-Long Plain, which in turn is divided into Ordubad, Nakhchivan, Sharur, Sadarak and other small Plains. Due to the fact that the territory of Nakhichevan Autonomous Republic consists of mountainous and lowland areas, the vegetation cover was formed in accordance with these conditions. The north-eastern territories of the autonomous republic, being part of the high mountain belt, cover heights of more than 2500 meters, and the Alpine and subalpine meadows of the Zangazur and Daralayaz ranges included here cover large areas. Plants belonging to the family Berberidaceae Juss. are distributed mainly in the middle and lower mountain belts, sometimes in the upper mountain belt, Alpine and subalpine belts on dry slopes, clayey, salty soils, Stony-gravel areas, as well as in arable land, field and grounds. In the article berberidaceae juss. The distribution of plants belonging to the family in the height zones, life forms have been studied and it has been determined that the species belonging to this family are most common in the middle and low mountain zones. Keywords: low mountain belt, barberry, height belts, shrub, Berberis vulgaris L., biological spectrum, distribution pattern.

Spring rest-grazing time affected soil organic carbon stability and storage in subalpine meadows of Carex

Scientific grazing management is essential to maintain soil organic carbon (SOC) stability in subalpine meadows on the Qinghai-Tibet Plateau (QTP). We studied the stability of SOC in Carex subalpine meadows in QTP with five rest-grazing treatments. (ST1: soil surfaces started thawing; ST2: soil thawing depth > 10 cm; RG1: re-greening coverage reached 30–40%; RG2: re-greening coverage reached 80%; CK: local traditional rest-grazing time). The results showed that rest-grazing at different times in spring affected the active SOC composition by affecting the stability of physical structure. The underground organic carbon storage was dominated by the root carbon storage, while the active organic carbon component had a significant correlation with the litter content. Compared with the traditional rest-grazing, ST1, ST2, RG1 and RG2 increased the topsoil SOC storage by 5.87%, 7.24%, 13.55%, 2.17%, and the topsoil root carbon storage by 32.77%, 36.25%, 9.91%, −0.79%. Rest-grazing at ST1 promoted the production of soil macro-aggregates, increased the hydrolase activity and active SOC contents in topsoil, and promoted the soil nutrient cycling. Continuing grazing after the plant re-green increased the physical structure stability and oxidase activity but decreased the active SOC and SOC storage. Although a late rest-grazing in spring has increased the SOC stability, it reduced soil carbon use efficiency and sequestration. It is necessary to rest-grazing subalpine QTP Carex meadows before soil thaw, which can promote SOC accumulation and nutrient cycling, and transport plant carbon into the deep soil through roots, which is beneficial for grassland productivity and grassland carbon sequestration.

Detecting Floral Resource Availability Using Small Unmanned Aircraft Systems

Floral resources for native pollinators that live in wildland settings are diverse and vary across and within growing seasons. Understanding floral resource dynamics and management is becoming increasingly important as honeybee farms seek public land for summer pasture. Small Unmanned Aircraft Systems (sUASs) present a viable approach for accurate broad floristic surveys and present an additional solution to more traditional alternative methods of vegetation assessment. This methodology was designed as a simplified approach using tools frequently available to land managers. The images of three subalpine meadows were captured from a DJI Phantom 4 Pro drone platform three times over the growing season in 2019 in Sanpete County, Utah. The images were composited using Pix4D software 4.5.6 and classified using a simple supervised approach in ENVI 4.8 and ArcGIS Pro 2.4.3 These same meadows were assessed using two traditional ocular methods of vegetation cover–meter-squared quadrats and macroplot estimation. The areas assessed with these methods were compared side by side with their classified counterparts from drone imagery. Classified images were not only found to be highly accurate when detecting overall floral cover and floral color groups (76–100%), but they were also strongly correlated with quadrat estimations, suggesting that these methods used in tandem may be a conducive strategy toward increased accuracy and efficiency when determining floral cover at broad spatial scales.

Plant stoichiometric hierarchical responses to nutrient enrichment can enhance understanding regarding the process of biodiversity loss

In this study, our objective was to determine whether plant stoichiometry following nitrogen (N) and phosphorous (P) enrichments can enhance understanding regarding biodiversity loss processes. Thus, we conducted a field experiment involving N, P, and N + P enrichments in a sub-alpine meadow on the northeast of Qinghai-Tibet Plateau within the 2009–2014 period. Plant stoichiometric patterns were investigated using six exemplar species, four functional group levels, as well as the community level. The hierarchical responses of species richness, dominance, plant height, and plant ecological stoichiometry to nutrient addition were investigated. Further, step-wise regression analysis was performed and a structural equation model (SEM) was constructed to assess the linkages between ecological performances and plant stoichiometric characteristics. The model was also used to quantify the contributions of stoichiometric characteristics as drivers of changes in species richness. Our results indicated that N-only and N + P enrichments significantly reduced species richness at community-level, while enhancing grass richness and dominance. Furthermore, only the responses of the N:P ratio, P-related stoichiometry (P concentration, C:P ratios, and N:P ratio), and plant C:N:P stoichiometry to N, P, and N + P fertilizations, at community level could be mirrored at functional group and species levels. Additionally, the responses of the plant N contents and C:N ratios of different species and functional groups showed 28% similarity following nutrient addition. However, at functional group level, only 10% of these responses were similar to those observed at community level, and only in grasses and at community level did the stoichiometric responses show any convergence. We also observed that the major factors affecting ecological performance at different levels included plant N contents and C:N ratios. The species dominance of Elymus nutans (E.n) and the functional group dominance of grasses increased with increasing plant N concentration, and in terms of species richness, species, functional group, and community level stoichiometric traits could fully explain 43% of the observed species richness trend. Further, the effect of the community C:N ratio on species richness was significantly positive. Those results indicated stoichiometric responses to N and P fertilization did not entirely show scale-independence. Moreover, in a N-limited community, plant differences with respect to nitrogen content flexibility and nitrogen use efficiency can serve as key drivers in explaining ecological performance. Community C:N ratios showed suitability for used in the prediction of species richness trends, and to clarify changes in biodiversity, it is necessary to investigate stoichiometric traits at functional group level.

Flowering phenology differs among wet and dry sub-alpine meadows in southwestern China.

The effect of floral traits, floral rewards and plant water availability on plant-pollinator interactions are well-documented; however, empirical evidence of their impact on flowering phenology in high-elevation meadows remains scarce. In this study, we assessed three levels of flowering phenology, i.e. population-, individual- and flower-level (floral longevity), in two nearby but contrasting (wet versus dry) sub-alpine meadows on Yulong Snow Mountain, southwestern China. We also measured a series of floral traits (pollen number, ovule number, and the ratio of pollen to ovule number per flower, i.e. pollen:ovule ratio [P/O]) and floral rewards (nectar availability and pollen presentation) as plausible additional sources of variation for each phenological level. Floral longevity in the wet meadow was significantly longer than that for the dry meadow, whereas population- and individual-flowering duration were significantly shorter. Our results showed a significant positive relationship between flowering phenology with pollen number and P/O per flower; there was no relationship with ovule number per flower. Further, we found a significant effect of flowering phenology on nectar availability and pollen presentation. Our findings suggest that shorter floral longevity in dry habitats compared to wet might be due to water-dependent maintenance costs of flowers, where the population- and individual-level flowering phenology may be less affected by habitats. Our study shows how different levels of flowering phenology underscore the plausible effects of contrasting habitats on reproductive success.

Elevational patterns of warming effects on plant community and topsoil properties: focus on subalpine meadows ecosystem

Elevational patterns of warming effects on plant community and topsoil properties: focus on subalpine meadows ecosystem

Diversity of Arbuscular Mycorrhizal Fungi in Distinct Ecosystems of the North Caucasus, a Temperate Biodiversity Hotspot.

Investigations that are focused on arbuscular mycorrhizal fungus (AMF) biodiversity is still limited. The analysis of the AMF taxa in the North Caucasus, a temperate biodiversity hotspot, used to be limited to the genus level. This study aimed to define the AMF biodiversity at the species level in the North Caucasus biotopes. The molecular genetic identification of fungi was carried out with ITS1 and ITS2 regions as barcodes via sequencing using Illumina MiSeq, the analysis of phylogenetic trees for individual genera, and searches for operational taxonomic units (OTUs) with identification at the species level. Sequences from MaarjAM and NCBI GenBank were used as references. We analyzed >10 million reads in soil samples for three biotopes to estimate fungal biodiversity. Briefly, 50 AMF species belonging to 20 genera were registered. The total number of the AM fungus OTUs for the "Subalpine Meadow" biotope was 171/131, that for "Forest" was 117/60, and that for "River Valley" was 296/221 based on ITS1/ITS2 data. The total number of the AM fungus species (except for virtual taxa) for the "Subalpine Meadow" biotope was 24/19, that for "Forest" was 22/13, and that for "River Valley" was 28/24 based on ITS1/ITS2 data. Greater AMF diversity, as well as number of OTUs and species, in comparison with that of forest biotopes, characterized valley biotopes (disturbed ecosystems; grasslands). The correlation coefficient between "Percentage of annual plants" and "Glomeromycota total reads" r = 0.76 and 0.81 for ITS1 and ITS2, respectively, and the correlation coefficient between "Percentage of annual plants" and "OTUs number (for total species)" was r = 0.67 and 0.77 for ITS1 and ITS2, respectively. High AMF biodiversity for the river valley can be associated with a higher percentage of annual plants in these biotopes and the active development of restorative successional processes.

Межэкотопические различия в видовом составе растительных сообществ с низким и высоким участием доминирующих видов

Межэкотопические различия в видовом составе растительных сообществ с низким и высоким участием доминирующих видов

The Impact and Determinants of Mountainous Topographical Factors on Soil Microbial Community Characteristics.

Soil bacterial and fungal community communities play significant ecological functions in mountain ecosystems. However, it is not clear how topographic factors and soil physicochemical properties influence changes in microbial community structure and diversity. This study aims to investigate how altitude and slope orientation affect soil physicochemical properties, soil microbial communities, and their contributing factors. The assessment was conducted using Illumina MiSeq sequencing in various altitude gradients and on slopes with different aspects (shady slopes and sunny slopes) in the subalpine meadow of Dongling Mountain, Beijing. Topographical factors had a significant effect on soil physicochemical properties: the primary factors determining the structure of microbial communities are total potassium (TK), ammonium nitrogen (NH4+-N), and soil organic carbon (SOC). There was no significant change in the diversity of the bacterial community, whereas the diversity of the fungal community displayed a single-peaked trend. The effect of slope orientation on microbial communities was not as significant as the effect of elevation on them. The number of bacterial communities with significant differences showed a unimodal trend, while the number of fungal communities showed a decreasing trend. The co-occurrence network of fungal communities exhibits greater intricacy than that of bacterial communities, and bacterial communities are more complex in soils with sunny slopes compared to soils with shady slopes, and the opposite is true for fungal communities. The identification of the main factors that control soil microbial diversity and composition in this study, provided the groundwork for investigating the soil microbial response and adaptation to environmental changes in subalpine meadows.