Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 46
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Sci Total Environ ; 912: 169137, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38070553

RESUMO

Invasive alien species are currently considered as one of the dominant drivers of global environmental change. Till now, the majority of studies have focused on single or a few traits of alien species that facilitate their invasion. Also inclusion of all the traits which determine the transition of aliens along the different stages of invasion continuum (casual, naturalised and invasive) has remained largely overlooked. In this study, we collected a comprehensive trait dataset on 144 alien plant species of Kashmir Himalaya - a global biodiversity hotspot region. To test which traits of alien species, individually or in combination along with anthropogenic factors, determine their transition along the invasion continuum, we employed chi-square tests, boosted regression trees and phylogenetic methods. We found the perennial life span, longer residence time, greater number of introduced regions, and better seed dispersal mechanism were critical in determining the transition from casual to naturalised. The herbaceous growth form, therophyte Raunkiaer life-form, annual life span, achene fruit, longer residence time and broader introduced range were the species' traits determining transition from naturalised to invasive. Aliens introduced as ornamentals have more propensity to become naturalised; whereas aliens introduced unintentionally show overrepresentation at the invasive stage. Phylogeny alone showed mixed results indicating both clustering and dispersion; however, in combination with other traits, it plays a significant role in determining the stage of invasion. Overall, our study disentangles the individual and interactive roles of multiple traits that determine the transition of alien species' along the invasion continuum. Further, we foresee the potential applicability of our findings in designing robust invasion risk analysis protocols and stage-specific invasion management strategies in this Himalayan region, with learnings for elsewhere in the world.


Assuntos
Biodiversidade , Espécies Introduzidas , Filogenia , Plantas , Sementes , Ecossistema
2.
Int. microbiol ; 26(4): 1053-1071, Nov. 2023. mapas
Artigo em Inglês | IBECS | ID: ibc-227492

RESUMO

Investigating the microbial communities associated with invasive plant species can provide insights into how these species establish and thrive in new environments. Here, we explored the fungal species associated with the roots of the invasive species Anthemis cotula L. at 12 sites with varying elevations in the Kashmir Himalaya. Illumina MiSeq platform was used to identify the species composition, diversity, and guild structure of these root-associated fungi. The study found a total of 706 fungal operational taxonomic units (OTUs) belonging to 8 phyla, 20 classes, 53 orders, 109 families, and 160 genera associated with roots of A. cotula, with the most common genus being Funneliformis. Arbuscular mycorrhizal fungi (AMF) constituted the largest guild at higher elevations. The study also revealed that out of the 12 OTUs comprising the core mycobiome, 4 OTUs constituted the stable component while the remaining 8 OTUs comprised the dynamic component. While α-diversity did not vary across sites, significant variation was noted in β-diversity. The study confirmed the facilitative role of the microbiome through a greenhouse trial in which a significant effect of soil microbiome on height, shoot biomass, root biomass, number of flower heads, and internal CO2 concentration of the host plant was observed. The study indicates that diverse fungal mutualists get associated with this invasive alien species even in nutrient-rich ruderal habitats and may be contributing to its spread into higher elevations. This study highlights the importance of understanding the role of root-associated fungi in invasion dynamics and the potential use of mycobiome management strategies to control invasive species.(AU)


Assuntos
Humanos , Micobioma , Anthemis , Microbiota , Raízes de Plantas/microbiologia , Micorrizas/genética , Microbiologia , Técnicas Microbiológicas , Microbiologia do Solo
3.
Environ Monit Assess ; 195(10): 1139, 2023 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-37665531

RESUMO

Protected areas are the cornerstone of biodiversity and serve as a haven for biodiversity conservation. However, due to immense anthropic pressures and ongoing changes in climate, the protected reserves are under immense threat. Human interference through land system changes is a major precusor of fragmentation of landscapes resulting in the decline of Himalayan biodiversity. In this context, this research assessed land use land cover changes (LULCCs) and fragmentation within and outside the Dachigam National Park (DNP) using remote sensing data, GIS-based models and ground truth over the past 55 years (1965-2020). Landscape Fragmentation Tool (LFT) helped to compute edge effect, patchiness, perforation and core areas. The Land Change Modeller (LCM) of IDRISI TerrSet was used for simulating the future LULC for the years 2030, 2050, 2700 and 2100. The analysis of LULCCs showed that built-up and aquatic vegetation expanded by 326% and 174%, respectively in the vicinity of the DNP. The area under agriculture, scrub and pasture decreased primarily due to intensified land use activities. Within the DNP, the area under forest cover declined by 7%. A substantial decrease was observed in the core zone both within (39%) and outside (30%) the DNP indicative of fragmentation of natural habitats. LCM analysis projected 10% increase in the built-up extents besides forests, shrublands and pastures. This knowledge generated in this study shall form an important baseline for understanding and characterising the human-wildlife relationship, initiating long-term ecological research (LTER) on naturally vegetated and aquatic ecosystems (primarily Dal Lake) of the region.


Assuntos
Ecossistema , Parques Recreativos , Humanos , Monitoramento Ambiental , Índia , Agricultura
4.
Environ Monit Assess ; 195(7): 812, 2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-37285042

RESUMO

The foremost role of forest vegetation in storing biomass and carbon (C) stock constitutes one of the main nature-based solutions to mitigate climate change. In this study, we aimed to quantify biomass and C stock partitioning in multiple vegetation strata (tree, shrub, herb, and ground floor layers) of major forest types in Jammu and Kashmir, Western Himalaya, India. We used a stratified random cluster sampling strategy to collect field data in 96 forest stands of 12 forest types (altitudinal range: 350 to 3450 m) in the study region. We evaluated the degree to which the carbon stock of the entire ecosystem was dependent on the multiple vegetation strata using the Pearson method. Across all the forest types, the average total ecosystem-level biomass was estimated to be 181.95 Mgha-1 (range: 60.64-528.98). Forest strata-wise, the maximum biomass of 172.92 Mgha-1 (range: 50.64-514.97) was found in the tree vegetation, followed by 5.58 Mgha-1 (range: 2.59-8.93) in understory vegetation (shrubs and herbaceous), and 3.44 Mgha-1 (range: 0.97 and 9.14) in the forest floor. The total ecosystem-level biomass showed a peak at mid-elevation coniferous forest types, whereas the lowest was observed in low-elevation broad leaved forest types. At the ecosystem-level, on average, the understory contributed 3% and the forest floor 2% to the total C stock across the forest types. The shrub layer contributed up to 80% of total understory C, with the herbaceous layer accounting for the remaining 20%. The ordination analysis clearly shows that anthropogenic and environmental variables significantly (p ≤ 0.002) influence the forest types' C stock in the region. Our findings have significant implications for conserving natural forest ecosystems and restoring degraded forest  landscapes in this Himalayan region, which in turn can lead to better carbon sequestration and climate mitigation outcomes.


Assuntos
Ecossistema , Árvores , Biomassa , Carbono/análise , Monitoramento Ambiental , Florestas , Sequestro de Carbono , Solo
5.
Environ Sci Pollut Res Int ; 30(35): 84283-84299, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37358769

RESUMO

Soil microbial communities, being situated at the interface of aboveground plant and belowground soil systems, can play a pivotal role in determining ecosystem response to the drivers of global environmental change, including invasive species. In mountains, invasive plants occurring along elevational gradients offer a unique natural experimental system to investigate the impact of invasions in determining patterns and relationships of soil microbial diversity and nutrient pools at much shorter spatial distances. Here, we studied the impact of a global plant invader, Leucanthemum vulgare, on the diversity of soil microbiome and physico-chemical attributes along an elevational gradient (1760-2880 m) in Kashmir Himalaya. We used Illumina MiSeq platform to characterize the soil microbiome in pair-wise invaded and uninvaded plots at four different sites along the gradient. We found a total of 1959 bacterial operational taxonomic units (OTUs) belonging to 152 species, and a relatively higher number of 2475 fungal OTUs belonging to 589 species. The α-diversity of soil microbiome showed a gradual increase from low to high elevation and differed significantly (p < 0.05) between the invaded and uninvaded plots. The ß-diversity revealed distinct microbiome clustering among the sampling sites. Plant invasion also altered soil physico-chemical attributes along the elevational gradient. Overall, our findings suggest that the L. vulgare-induced shifts in soil microbiome and nutrient pools may be a belowground self-reinforced mechanism to facilitate its successful invasion along the elevational gradient. Our study provides new insights into invasive plant-microbe relationships with wide implications for climate warming-driven elevational range shifts in mountains.


Assuntos
Ecossistema , Microbiota , Solo/química , Biodiversidade , Espécies Introduzidas , Bactérias , Plantas
6.
Sci Total Environ ; 884: 163856, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37142012

RESUMO

Biotic homogenization by invasive alien species is one of the dominant drivers of global environmental change. However, little is known about the patterns of biotic homogenization in global biodiversity hotspots. Here, we fill this knowledge gap by studying the patterns of biotic homogenization and associated geographic and climatic correlates in Indian Himalayan Region (IHR). For this, we use a novel biodiversity database comprising 10,685 native and 771 alien plant species across 12 provinces of the IHR. The database was assembled by screening 295 and 141 studies published from 1934 to 2022 for natives and aliens, respectively. Our results revealed that each native species on average was distributed among 2.8 provinces, whereas the alien species in 3.6 provinces, thereby indicating wider distribution range of alien species in the IHR. The Jaccard's similarity index between the provinces was higher for alien species (mean = 0.29) as compared to natives (mean = 0.16). Addition of alien species pool has homogenized most of the provincial pairwise floras (89.4 %) across the IHR, with greater dissimilarity in their native floras. Our results revealed that the alien species have strong homogenization effect on the provincial floras, regardless of their differences in geographic and climatic distances. The biogeographic patterns of alien and native species richness in the IHR were better explained by a different set of climatic variables, the former by precipitation of driest month and the latter by annual mean temperature. Our study contributes to better understanding of the patterns of biotic homogenization in the IHR and its geographic and climatic correlates. Looking ahead, in an era of Anthropocene, we discuss the wide implications of our findings in guiding biodiversity conservation and ecosystem restoration in global hotspot regions.


Assuntos
Ecossistema , Espécies Introduzidas , Biodiversidade , Temperatura , Índia
7.
Environ Pollut ; 327: 121541, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37019257

RESUMO

Particulate matter from both natural and anthropogenic sources is known to affect air quality and human health. However, the abundance and varied composition of the suspended particulate matter make it difficult to locate the precise precursors for some of these atmospheric pollutants. Plants deposit appreciable quantities of microscopic biogenic silica in and/or between their cells, known as phytoliths, which get released into the soil surface after the death and decomposition of plants. Dust storms from exposed terrains, forest fires, and stubble burning disperse these phytoliths into the atmosphere. Their durability, chemical composition, and diverse morphology prompt us to view phytoliths as a possible particulate matter that could impact air quality, climate, and human health. Estimating the phytolith particulate matter, its toxicity, and environmental impacts will help take effective and targeted policies for improving air quality and decreasing health risks.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Humanos , Material Particulado/análise , Clima , Plantas , Atmosfera , Poluentes Atmosféricos/toxicidade , Poluentes Atmosféricos/análise , Monitoramento Ambiental
8.
Environ Res ; 229: 115967, 2023 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-37086883

RESUMO

Wetland degradation through a diverse spectrum of anthropogenic stressors worldwide has taken a heavy toll on the health of wetlands. This study examined the health of a semi-urban wetland Bodsar, located in the Kashmir Himalaya using multicriteria analysis approach assimilating data on land use land cover (LULC), landscape fragmentation, soil loss, and demography. Wetland and catchment-scale land system changes from 1980 to 2022 were assessed using high-resolution imagery. Fragmentation of the natural landscape was assessed using the Landscape Fragmentation Tool (LFT) and soil loss was assessed using the Revised Universal Soil Loss Equation (RUSLE). In addition, the water quality was examined at 12 sites distributed across the wetland using standard methods. Satellite data revealed 12 categories of land use with areas under exposed rock, orchards, built-up and sparse forest having increased by 1005%, 623%, 274%, and 37% respectively. LFT indicated that the core (>500 acres) and core (<250 acres) zones decreased by approximately 16% and 64%, respectively, whereas the areas under the perforated, edge and patch classes increased significantly. RUSLE estimates show a ∼77% increase in soil erosion from 116.26 Mg a-1 in 1980 to 205.68 Mg a-1 in 2022, mostly due to changes in LULC. Total phosphorus (0.195-2.04 mg L -1), nitrate nitrogen (0.306-2.79 mg L -1), and total dissolved solids (543-774 mg L-1) indicated nutrient enrichment of the wetland influenced by anthropogenically-driven land system changes. The wetland degradation index revealed that 21% of the wetland experienced high-to-severe degradation, 62% experienced moderate degradation, and 17% did not face any significant degradation pressure. The novel GIS-based approach adopted in this study can act as a prototype for ascertaining the catchment-scale degradation of wetlands worldwide.


Assuntos
Sistemas de Informação Geográfica , Áreas Alagadas , Monitoramento Ambiental/métodos , Solo , Florestas , Conservação dos Recursos Naturais
9.
Int Microbiol ; 26(4): 1053-1071, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37093323

RESUMO

Investigating the microbial communities associated with invasive plant species can provide insights into how these species establish and thrive in new environments. Here, we explored the fungal species associated with the roots of the invasive species Anthemis cotula L. at 12 sites with varying elevations in the Kashmir Himalaya. Illumina MiSeq platform was used to identify the species composition, diversity, and guild structure of these root-associated fungi. The study found a total of 706 fungal operational taxonomic units (OTUs) belonging to 8 phyla, 20 classes, 53 orders, 109 families, and 160 genera associated with roots of A. cotula, with the most common genus being Funneliformis. Arbuscular mycorrhizal fungi (AMF) constituted the largest guild at higher elevations. The study also revealed that out of the 12 OTUs comprising the core mycobiome, 4 OTUs constituted the stable component while the remaining 8 OTUs comprised the dynamic component. While α-diversity did not vary across sites, significant variation was noted in ß-diversity. The study confirmed the facilitative role of the microbiome through a greenhouse trial in which a significant effect of soil microbiome on height, shoot biomass, root biomass, number of flower heads, and internal CO2 concentration of the host plant was observed. The study indicates that diverse fungal mutualists get associated with this invasive alien species even in nutrient-rich ruderal habitats and may be contributing to its spread into higher elevations. This study highlights the importance of understanding the role of root-associated fungi in invasion dynamics and the potential use of mycobiome management strategies to control invasive species.


Assuntos
Anthemis , Microbiota , Micobioma , Micorrizas , Humanos , Raízes de Plantas/microbiologia , Micorrizas/genética , Microbiologia do Solo , Fungos/genética
10.
Microbiol Res ; 269: 127318, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36753851

RESUMO

In recent years, the microbiome has attracted much attention because of the multiple roles and functions that microbes play in plants, animals, and human beings. Seed-associated microbes are of particular interest in being the initial microbial inoculum that affects the critical early life stages of a plant. The seed-microbe interactions are also known to improve nutrient acquisition, resilience against pathogens, and resistance against abiotic stresses. Despite these diverse roles, the seed microbiome has received little attention in plant ecology. Thus, we review the current knowledge on seed microbial diversity, community structure, and functions obtained through culture-dependent and culture-independent approaches. Furthermore, we present a comprehensive synthesis of the ecological literature on seed-microbe interactions to better understand the impact of these interactions on plant health and productivity. We suggest that future research should focus on the role of the seed microbiome in the establishment, colonization and spread of plant species in their native and non-native ranges as it may provide new insights into conservation biology and invasion ecology.


Assuntos
Microbiota , Plantas , Humanos , Sementes , Ecologia , Interações Microbianas
11.
Sci Rep ; 13(1): 1882, 2023 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-36732529

RESUMO

Periphytic algal assemblages in the River Sindh of Kashmir Himalaya were studied in relation to environmental factors and anthropogenic alterations like flow regulation for Run-of-River hydropower plants to understand their ecology in a regulated river ecosystem. Sites were sampled from unregulated, regulated, and downstream reaches along the river on a seasonal basis from the year 2017 to 2019. A total of 48 species were identified, spread over 31 genera. Non-metric multidimensional analysis showed clear distinction in periphytic algal assemblage samples based on sites and potentially some more minor distinction based on seasons rendering the sites into two distinct groups (G1 and G2). The ADONIS test showed that the groups (G1 and G2 sites) do not significantly differ in terms of how communities differ from one another, but there is a difference in species compositions based on seasons. However, the betadisper test indicated that groups (G1 and G2 sites) and seasons present homogeneity among group dispersions (compositions vary similarly) while having significantly different compositions. Geo-physical factors (discharge and altitude) accounted for most variations, while the scraper community played a minor role. This study provides scientific insights related to the ecology of a regulated Himalayan river and may provide information relevant to managing the River Sindh sustainably.


Assuntos
Altitude , Ecossistema , Ecologia , Rios , Estações do Ano , Monitoramento Ambiental/métodos
12.
Plant Physiol Biochem ; 196: 339-349, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36739841

RESUMO

Agricultural productivity relies on plant resistance to insect pests, with silicon (Si) being increasingly recognized as an important anti-herbivore defense. However, the processes by which Si works to counteract the effects of insect injury are not completely understood. The role of Si in mitigating the adverse effects of herbivory has been mostly studied at the species level in various crops, ignoring the sensitivity and variability at the genotypic level. Understanding such variation across genotypes is important because Si-derived benefits are associated with the amount of Si accumulated in the plant. Therefore, the present investigation was pursued to study the effect of different Si concentrations (0, 125, and 250 mg L⁻1) on Si accumulation and plant growth using two wheat genotypes (WW-101 and SW-2) under grasshopper herbivory for 48 h. The higher Si absorption increased the concentration of leaf chlorophyll, carotenoids, soluble sugars, and proteins. Silicon application at higher concentrations increased the dry weight, antioxidant enzyme activity, total phenolics, flavonoids and shoot Si concentration, whereas it decreased the electrolyte leakage, hydrogen peroxide (H2O2) and malonaldehyde (MDA) levels, thereby preventing leaf damage. We infer that the higher Si concentration alleviates the adverse effects of herbivory in wheat by improving the accumulation of secondary metabolites and enhancing the antioxidant defense system. The effects were pronounced in the genotype 'WW-101' compared to 'SW-2' for most of the studied traits, indicating overall stress response to be genotype-dependent. Thus, Si acquisition efficiency of genotypes should be considered while developing efficient crop management strategies.


Assuntos
Antioxidantes , Silício , Antioxidantes/metabolismo , Silício/farmacologia , Silício/metabolismo , Triticum/genética , Triticum/metabolismo , Herbivoria , Peróxido de Hidrogênio/metabolismo , Plantas/metabolismo , Genótipo
13.
Nat Ecol Evol ; 7(3): 405-413, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36702858

RESUMO

High-elevation ecosystems are among the few ecosystems worldwide that are not yet heavily invaded by non-native plants. This is expected to change as species expand their range limits upwards to fill their climatic niches and respond to ongoing anthropogenic disturbances. Yet, whether and how quickly these changes are happening has only been assessed in a few isolated cases. Starting in 2007, we conducted repeated surveys of non-native plant distributions along mountain roads in 11 regions from 5 continents. We show that over a 5- to 10-year period, the number of non-native species increased on average by approximately 16% per decade across regions. The direction and magnitude of upper range limit shifts depended on elevation across all regions. Supported by a null-model approach accounting for range changes expected by chance alone, we found greater than expected upward shifts at lower/mid elevations in at least seven regions. After accounting for elevation dependence, significant average upward shifts were detected in a further three regions (revealing evidence for upward shifts in 10 of 11 regions). Together, our results show that mountain environments are becoming increasingly exposed to biological invasions, emphasizing the need to monitor and prevent potential biosecurity issues emerging in high-elevation ecosystems.


Assuntos
Altitude , Ecossistema , Espécies Introduzidas , Plantas , Dispersão Vegetal
14.
Risk Anal ; 43(3): 467-479, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-35318710

RESUMO

Huge economic costs and ecological impacts of invasive alien species (IAS) in the protected areas (PAs) worldwide make their timely prediction and potential risk assessment of central importance for effective management. While the preborder weed risk assessment framework has been extensively evaluated and implemented, the postborder species risk assessment framework has not been subjected to the same degree of scrutiny. Here we used a rather more realistic modified version of the Australian Weed Risk framework (AWRM) for Dachigam National Park (DNP) in Kashmir Himalaya against 84 plant species, including 55 alien species and 29 fast spreading native species, for risk analysis. We found two very high-risk species, three high-risk species, 10 medium-risk species, 29 low-risk species, and 40 negligible-risk species in the DNP. The containment scores accordingly ranged from 14.4 to 293.5 comprising of 27 species that can be contained with very high feasibility, 23 species with high feasibility, 14 species with medium feasibility, and 12 species which cannot be contained easily thereby having low feasibility of containment (FOC) score. However, eight species which have a negligible FOC score are difficult to contain within their infestation sites. Our results demonstrate the merit of the AWRM with a caution that the necessary region-specific modifications may help in its better implementation. Overall, these results provide quite a promising tool in the hands of protected area managers to timely and effectively deal with the problem of plant invasions.


Assuntos
Ecossistema , Parques Recreativos , Austrália , Espécies Introduzidas , Plantas , Medição de Risco
15.
Environ Sci Pollut Res Int ; 30(11): 29942-29960, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36418815

RESUMO

Glaciers across the Kashmir Himalayan region are melting at an accelerated pace compared to other regions across the Himalayan arc. This study analyzed the recession patterns of nine glaciers in the Kashmir Himalaya region over 28 years between 1992 and 2020 using satellite images and field measurements. The recession patterns were correlated with debris cover, topographic factors, and ambient black carbon (BC) concentration at glacier sites. HYSPLIT model was used to track the air mass sources at a 7-day time-step from September 1, 2014, to September 28, 2014, over the selected region. All nine glaciers revealed high recession as indicated by changes in the area (average recession: 20.8%) and snout position (~ 14 m a-1). The relative percentage of debris on each glacier varied between ~ 0% (clean glacier) and 43%. Although the investigated glaciers lie in the same climatological regime, their topographical behavior is dissimilar with mean altitude ranging between 4000 and ~ 4700 m asl and the average slope varying from 17 to 24°. All the investigated glaciers are north-facing except G3 (southerly aspect). Our results indicate anomalously high ambient BC concentrations, ranging from 500 to 1364 ng m-3, at the glacier sites, higher than previously studied for glaciers in the Himalayas and neighboring Tibetan Plateau. The backward air-mass trajectory modeling indicated both local and global sources of particulate matter in the study area. A comparative analysis of BC measurements and glacier recession with the studies conducted across high Asia indicated the influence of BC in accelerating the melting of glaciers in the Kashmir region.


Assuntos
Efeitos Antropogênicos , Camada de Gelo , Monitoramento Ambiental/métodos , Índia , Ásia , Fuligem
16.
Micromachines (Basel) ; 13(9)2022 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-36144124

RESUMO

The optimization of heating or cooling during an industrial system may result in power savings, reduced processing time, enhanced thermal efficiency, and increased equipment operating lifespan. The advancement of high-efficiency thermal systems for heat and mass transport improvement has become increasingly popular in recent years. The analysis of aligned magnetohydrodynamics (MHD) on engine oil-based Casson nanofluid with carbon nanotubes (single and multi-wall) passing a shrinking sheet following the thermal radiation and wall mass transport phenomena is carried out in this aspect. The dynamic model is utilized to reduce difficult ordinary differential equations into nondimensional forms, which are then analytically assessed. To study the repercussions of a physical parameter on the velocity field, skin friction at the wall, the stream pattern, the temperature distribution, isotherm, and the local Nusselt, numeric data and visualizations are generated. When the value of ϕ increases, the velocity field decelerates, and the velocity pattern of multi-walled CNTs drops considerably when compared to single-walled CNTs. The local Nusselt number is a decreasing function of N and ϕ and the opposite trend is shown for Pr. The local Nusselt number is a decreasing function of N and ϕ and the opposite trend is shown for Pr. The single-walled CNTs have a higher degradation rate as compared to multi-walled CNTs. It is found that higher temperature distribution occurs in the case of multi-walled CNT-based fluid as compared to single-walled CNT-based fluid.

17.
Sci Rep ; 12(1): 13321, 2022 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-35922649

RESUMO

Over the past few decades, many countries have attempted to carry out forest landscape restoration over millions of hectares of degraded land. Such efforts, however, have met with limited success because of several factors, including a lack of adequate emphasis on ectomycorrhization of the nursery seedlings. A similar scenario is seen in the Kashmir Himalaya, where the natural regeneration of degraded forests is poor despite ample restoration efforts by forest managers. To overcome this challenge, we identified two promising ectomycorrhizal species, namely Clitocybe nuda and Cortinarius distans, for their use in ectomycorrhization of seedlings of three common conifers, namely Abies pindrow, Cedrus deodara, and Picea smithiana. Laboratory studies were carried out to investigate the requirements for optimum mycelial growth of these ectomycorrhizal fungi. Best ECM mycelial growth was obtained in the basic MMN medium containing glucose as the source of carbon and nitrogen in ammonium form. C. distans showed higher growth than C. nuda across all the treatments and also proved significantly more effective in enhancing the survival and growth of the conifer host plant seedlings. The present study resulted in standardizing the requirements for mass inoculum production of the two mycobionts which could help in successful forest restoration programmes.


Assuntos
Recuperação e Remediação Ambiental , Florestas , Traqueófitas , Recuperação e Remediação Ambiental/métodos , Micorrizas/crescimento & desenvolvimento , Plântula
18.
Environ Monit Assess ; 194(9): 626, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35913530

RESUMO

As the run-of-river (RoR) hydropower projects remain understudied, we conducted this study to understand how these projects affect the hydro-chemical dynamics and water quality index (WQI) of the Sindh River in the Kashmir Himalayas. We used multivariate statistical techniques and WQI to identify the spatiotemporal dynamics of 18 physico-chemical parameters from 11 sampling stations distributed along the length of river Sindh from December 2017 to December 2019. The dataset was classified into three groups using hierarchical cluster analysis based on similarities between hydro-chemical characteristics, and the results were confirmed by discriminant analysis. Wilk's quotient distribution further showed that ions, nutrients, free carbon dioxide, water temperature, and pH contributed to the formation of clusters. Principle component analysis revealed that the chloride (Cl-), total phosphorus (TP), ortho-phosphorus (PO4-P), nitrate-nitrogen (NO3-N), nitrite-nitrogen (NO2-N), and sulfate ion (SO42-) are significant factors that influence the water quality. Furthermore, our results suggest that diverting water for RoR operation did not significantly raise the WQI value to the point where water in the bypassed reaches could be declared unfit for drinking. Our analysis concluded that inclusive assessments are vital for framing policies on expanding RoR hydropower in the region.


Assuntos
Rios , Poluentes Químicos da Água , Monitoramento Ambiental/métodos , Nitrogênio/análise , Fósforo/análise , Poluentes Químicos da Água/análise , Qualidade da Água
19.
Data Brief ; 42: 108176, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35510261

RESUMO

Glaciers in the Himalayan arc are receding rapidly in the eastern and western parts as compared to other regions. Contrararily, the glaciers in the Trans-Himalayan region of Ladakh are comparatively stable. The differential retreat could be due to various climatic, topographic, and geologic influences. The use of multi-source remotely sensed imagery from open-source platforms and the GlabTop model has been discussed in this paper. This paper draws insights from a recently published paper which details the recession of 87 glaciers in the Trans Himalayan region of Ladakh using remote sensing data [1]. The use of remote sensing data from USGS and Planet Labs for assessing glacier area changes, frontal retreat, debris cover, topographic characteristics, and comparison with existing inventories has been discussed in this study. The geodetic mass changes have been assessed using SRTM and TanDEM-X of 2000 and 2012 respectively. The use of remotely sensed data discussed in this article will help glaciologists to better characterize and understand the glacier recession in the region. The GlabTop model has been used to simulate proglacial lake expansion to understand glacier-bed overdeepenings of four glaciers in the region. The GlabTop simulations will help disaster managers to better quantify the vulnerability and risk of downstream population and infrastructure to Glacial Lake Outburst Floods (GLOFs).

20.
Environ Monit Assess ; 194(3): 175, 2022 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-35150329

RESUMO

In view of huge ecological impacts and exorbitantly high economic costs of biological invasions, the risk assessment for timely prediction of potential invaders and their effective management assumes central importance, yet having been little addressed. Hence, we did the risk analysis of 39 plant species, including both alien and fast-spreading native species, in Hokera wetland, an important Ramsar site in Kashmir Himalaya, using the post-border Australian Weed Risk Management (AWRM) framework. Based on the AWRM scores, we listed these species into different categories, such as alert, destroy infestation, contain spread, manage weed, manage sites and monitor, with management implications. Out of the eight decisions created for Hokera wetland, alien Alternanthera philoxeroides was identified as 'alert species', while Typha angustifolia, Typha latifolia, Phragmites australis, Sparganium ramosum and Myriophyllum aquaticum were placed under the 'manage weed' category of the management priorities. To check the predictability and reliability of the AWRM scheme, we developed the receiver operating characteristic (ROC) curve that yielded a positive diagonal value of above 0.5, with 88.6% and 83.1% area under the curve for comparative weed risk (CWR) score and the feasibility of coordinated control (FOC) score, respectively. The outcomes of the ROC analysis were compared with the results of the WRM evaluation of other regions across the globe. Our results indicate that the risk assessment using the AWRM model is quite efficient at discriminating and flagging the most troublesome plant species and offsetting their impacts on native biodiversity and ecosystem functioning in wetland ecosystems. Given the growing threat of biological invasions in the protected areas, we recommend an integrated and strategic approach, well informed by the data on the species biology and ecology, in the form of the AWRM management system to effectively deal with the alarmingly spreading species.


Assuntos
Ecossistema , Espécies Introduzidas , Austrália , Monitoramento Ambiental , Reprodutibilidade dos Testes , Medição de Risco
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...