scholarly journals Ephemeroptera (Mayflies) Assemblages and Environmental Variation along Three Streams Located in the Dry-Hot Valleys of Baima Snow Mountain, Yunnan, Southwest China

Insects ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 775
Author(s):  
Muhammad Farooq ◽  
Xianfu Li ◽  
Lu Tan ◽  
Davide Fornacca ◽  
Yanpeng Li ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Community Composition ◽  
Environmental Variation ◽  
Diversity Indices ◽  
Freshwater Ecosystems ◽  
Environmental Data ◽  
Elevation Gradients ◽  
Depth Analysis ◽  
The Impact

Mountain freshwater ecosystems are threatened all over the world by a range of human-induced stresses, ensuing in a rapid loss of habitats and species diversity. Many macroinvertebrates are reactive to habitat disturbance, and mayflies (Ephemeroptera) are amongst the most sensitive groups. Despite they are susceptible to environmental deviation, knowledge concerning their species richness and diversity is still unknown in remote areas. The objectives of this study were to (1) investigate the mayfly species assemblage and community composition along different mountain streams and assess potential differences, and (2) identify the environmental variation and its influence on the structure of mayfly communities within such freshwater systems. We collected biological and environmental data from 35 sites situated along elevation gradients in the Baima Snow Mountain, northwest Yunnan, China. Multivariate analyses were performed on the environmental variables and the mayfly species composition, as well as on richness and diversity indices. We found that the community composition of mayflies was different across all three watercourses. Among the 18 Ephemeroptera taxa identified, Baetis sp. and Baetiella marginata were highly dominant, accounting for over 50% of the dissimilarity of each stream. In terms of species assemblages, almost all sites in the Yeri stream hosted good-quality habitats for several mayfly species, as reflected by the highest species richness. The Benzilan stream followed, whereas the Sharong stream showed relatively low mayfly assemblage. This variation was explained by the high environmental heterogeneity between the three watercourses. In particular, the RDA model revealed that among the different environmental factors analyzed, altitude, conductivity, total dissolved solids, water temperature, dissolved silicon, and pH explained most of the variation in species composition. Moreover, the altitude alone explained 17.74% of the variation, and in-depth analysis confirmed its significant effect on diversity indices. Further research should focus on evaluating the scale of threats to this important group of insects in the mountain freshwater ecosystem, particularly the impact of human-induced disturbances such as land use/landcover alterations.

Aquatic and semi aquatic Hemiptera community of Sonebeel, the largest wetland of Assam, northeastern India

2018 ◽  
Vol 10 (13) ◽  
pp. 12792-12799
Author(s):  
Anupama Saha ◽  
Susmita Gupta
Keyword(s):  
Species Richness ◽  
Pest Control ◽  
Relative Abundance ◽  
Species Distribution ◽  
Diversity Indices ◽  
Environmental Data ◽  
Northeastern India ◽  
Ecological Roles

Aquatic and semiaquatic Hemiptera bugs play significant ecological roles, and they are important indicators and pest control agents.  Little information is currently available concerning its populations in southern Assam.  This study assessed hemipterans in four sites of Sonebeel, the largest wetland in Assam (3458.12 ha at full storage level), situated in Karimganj District.  The major inflow and outflow of the wetland are the rivers Singla and Kachua, respectively (the Kachua drains into the Kushiyara River).  Samples were trapped with pond nets and were seasonally recorded.  This study recorded a total of 28 species of aquatic and semiaquatic hemipterans belonging to 20 genera under nine families.  Population, geographical and environmental data (e.g., rainfall) were used to assess the relative abundance of species, species richness and different diversity indices, and species distribution. 

scholarly journals Native forests but not agroforestry systems preserve arbuscular mycorrhizal fungal species richness in southern Ethiopia

Mycorrhiza ◽  
2020 ◽  
Vol 30 (6) ◽  
pp. 749-759
Author(s):  
Zerihun Belay ◽  
Mesele Negash ◽  
Janne Kaseva ◽  
Mauritz Vestberg ◽  
Helena Kahiluoto
Keyword(s):  
Land Use ◽  
Species Richness ◽  
Species Composition ◽  
Arbuscular Mycorrhizal ◽  
Soil Samples ◽  
Southern Ethiopia ◽  
Native Forest ◽  
Native Forests ◽  
Land Use Types ◽  
The Impact

Abstract The rapid conversion of native forests to farmland in Ethiopia, the cradle of biodiversity, threatens the diversity of the arbuscular mycorrhizal fungi (AMF) pivotal to plant nutrition and carbon sequestration. This study aimed to investigate the impact of this land-use change on the AMF species composition and diversity in southern Ethiopia. Soil samples were collected from nine plots in each of three land-use types: native forest, agroforestry, and khat monocropping. The plots of the three land-use types were located adjacent to each other for each of the nine replicates. Three 10 × 10m subplots per plot were sampled. AMF spores were extracted from the soil samples, spore densities were determined, and species composition and diversity were evaluated through morphological analysis. Both spore density and species richness were statistically significantly higher in the native forest than in the agroforestry plots with no clear difference to khat, whereas the true diversity (exponential of Shannon–Wiener diversity index) did not differ among the three land-use types due to high evenness among the species in agroforestry. In total, 37 AMF morphotypes belonging to 12 genera in Glomeromycota were found, dominated by members of the genera Acaulospora and Glomus. The highest isolation frequency index (78%) was recorded for Acaulospora koskei from native forest. Consequently, the agroforestry system did not appear to aid in preserving the AMF species richness of native forests relative to perennial monocropping, such as khat cultivation. In contrast, the native forest areas can serve as in situ genetic reserves of mycorrhizal symbionts adapted to the local vegetative, edaphic, and microbial conditions.

scholarly journals Microclimate determines community composition but not richness of epiphytic understory bryophytes of rainforest and cacao agroforests in Indonesia

2009 ◽  
Vol 36 (2) ◽  
pp. 171 ◽  
Author(s):  
S. Goda Sporn ◽  
Merijn M. Bos ◽  
Monika Hoffstätter-Müncheberg ◽  
Michael Kessler ◽  
S. Robbert Gradstein
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Community Composition ◽  
Natural Forest ◽  
Native Forest ◽  
Shade Trees ◽  
Natural Forests ◽  
High Turnover ◽  
Forest Flora ◽  
Understory Trees

Management intensification in cultivated, tropical forests drives changes in the microclimate that can threaten native forest flora and fauna. In this study, we use epiphytic bryophytes, known to be sensitive to microclimatic changes due to their lack of a protective cuticle and the exposed habitat, to investigate the predictive power of microclimate for changes in species richness and composition. Bryophytes were sampled from understory trees in natural forest and cacao (Theobroma cacao L.) trees in two types of cacao agroforests (natural shade trees and planted shade trees) in Central Sulawesi, Indonesia. The microclimate in the agroforests was characterised by low air humidity and high air temperature during the afternoon. Bryophyte species richness did not differ between habitat types but species composition changed markedly from the natural forest to the cacao agroforests. Although no correlation between species richness and microclimate values could be found, a series of matrix-based analyses revealed a significantly positive relationship between similarities in species composition and in maximum values for temperature and minimum values for humidity, which suggests that microclimatic changes are a good predictor for high turnover of bryophyte community composition from natural forests to cacao agroforests.

scholarly journals Multiple comparisons of diversity indices invaded by Lantana camara

2020 ◽  
Author(s):  
H. Qureshi ◽  
T. Anwar ◽  
N. Habib ◽  
Q. Ali ◽  
M. Z. Haider ◽  
...  
Keyword(s):  
Species Richness ◽  
Diversity Index ◽  
Diversity Indices ◽  
Lantana Camara ◽  
Native Plant ◽  
Heterogeneous Nature ◽  
Significant Magnitude ◽  
Native Plant Diversity ◽  
And Control ◽  
The Impact

Abstract Current study assessed the impact of Lantana camara invasion on native plant diversity in Pothohar region of Pakistan. The approach used for study was random samplings and comparisons of diversity indices [number of species (S), abundance (N), species richness (R), evenness (Jꞌ), Shannon diversity index (Hꞌ) and Simpson index of dominance (λ)] with two categorical factors i.e., invaded and non-invaded (control). Control plots harboured by an average of 1.74 more species/10m2. The control category was diverse (Hꞌ=2.56) than invaded category (Hꞌ=1.56). The higher value of species richness in control plots shows heterogeneous nature of communities and vice versa in invaded plots. At multivariate scale, ordination (nMDS) and ANOSIM showed significant magnitude of differences between invaded and control plots at all sites. The decrease in studied diversity indices in invaded over control sites indicated that plant communities become less productive due to Lantana invasion.

scholarly journals Changes in community composition determine recovery trajectories from multiple agricultural stressors in freshwater ecosystems

2020 ◽  
Author(s):  
Francesco Polazzo ◽  
Talles Bruno Oliveira dos Anjos ◽  
Alba Arenas-Sánchez ◽  
Susana Romo ◽  
Marco Vighi ◽  
...  
Keyword(s):  
Species Richness ◽  
Community Composition ◽  
Community Dynamics ◽  
Pesticide Exposure ◽  
Population Level ◽  
Experimental Period ◽  
Freshwater Ecosystems ◽  
Nutrient Loads ◽  
Protection Measures ◽  
Pesticide Mixtures

AbstractPesticides have been identified worldwide as a threat for aquatic biodiversity due to their widespread use in agriculture and their capacity to reach freshwater ecosystems. Very little is known about the consequences of pesticide mixtures targeting different organism groups on community dynamics. Especially, how horizontal changes within one trophic level are propagated vertically across the food web has been rarely investigated. To get insight on the effects of pesticide mixtures on community dynamics, we performed a mesocosm experiment manipulating three common agricultural stressors: chlorpyrifos (an insecticide), diuron (an herbicide) and nutrients. The results of this study show that all stressors had significant effects on community composition, species richness and abundance. However, recovery trajectories and ecosystem functioning effects largely depended on the type of stressor as well as on post-disturbance trophic and non-trophic interactions. Effects of pesticides were generally recovered by the end of the experimental period when considering abundance, whereas community composition further departed from control systems. High nutrient loads led to a shift in community composition characterized by high taxa dominance and lower species richness, which in turn contributed to increased total organism abundance and reduced recovery times to pesticide exposure. We found interactions between the tested stressors to be significant only few times at the community level, while interactions were more common at the population level. Our findings indicate that management of freshwater ecosystems should consider pre-disturbance community composition and long-term changes in interactions across different organism groups to set effective protection measures.

scholarly journals Fisheries management under climate and environmental uncertainty: control rules and performance simulation

2013 ◽  
Vol 71 (8) ◽  
pp. 2208-2220 ◽  
Author(s):  
André E. Punt ◽  
Teresa A'mar ◽  
Nicholas A. Bond ◽  
Douglas S. Butterworth ◽  
Carryn L. de Moor ◽  
...  
Keyword(s):  
Fishery Management ◽  
Climate Models ◽  
Global Climate ◽  
Management Strategies ◽  
Environmental Variation ◽  
Global Climate Models ◽  
Reference Points ◽  
Environmental Data ◽  
And Performance ◽  
The Impact

Abstract The ability of management strategies to achieve the fishery management goals are impacted by environmental variation and, therefore, also by global climate change. Management strategies can be modified to use environmental data using the “dynamic B0” concept, and changing the set of years used to define biomass reference points. Two approaches have been developed to apply management strategy evaluation to evaluate the impact of environmental variation on the performance of management strategies. The “mechanistic approach” estimates the relationship between the environment and elements of the population dynamics of the fished species and makes predictions for population trends using the outputs from global climate models. In contrast, the “empirical approach” examines possible broad scenarios without explicitly identifying mechanisms. Many reviewed studies have found that modifying management strategies to include environmental factors does not improve the ability to achieve management goals much, if at all, and only if the manner in which these factors drive the system is well known. As such, until the skill of stock projection models improves, it seems more appropriate to consider the implications of plausible broad forecasts related to how biological parameters may change in the future as a way to assess the robustness of management strategies, rather than attempting specific predictions per se.

Potential impacts of fire and grazing in an endangered ecological community: plant composition and shrub and eucalypt regeneration in Cumberland Plain Woodland

2004 ◽  
Vol 52 (1) ◽  
pp. 23 ◽  
Author(s):  
Sarah J. Hill ◽  
Kristine French
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Species Interactions ◽  
Ecological Community ◽  
Plant Composition ◽  
Shrub Species ◽  
Pre Treatment ◽  
Species Richness And Abundance ◽  
The Impact ◽  
Canopy Species

Exclosure plots were used to determine the effect of fire and grazing on the structure of a grassy-woodland community. Eighteen months after fire and fence treatments were applied, the species richness, cover and composition of shrubs, trees, herbs and grasses were assessed and compared to pre-treatment censuses. Unburned plots had fewer shrub species and a lower abundance of shrubs, indicating the importance of fire in promoting regeneration of shrub species. Eucalypt species were more abundant and richer following the wildfire burn in summer, suggesting timing of fires is an important aspect in the establishment of the canopy species. Interactions between fire and grazing were found for the abundance of eucalypts (although weak) and resprouting eucalypts, suggesting a subtle interaction between fire and grazing shortly after fire. There was no effect of grazing and no interaction effect between fire and grazing on shrub species richness and abundance or tree species richness and seedling abundance.All plots showed a change in species composition despite treatment, and 46 species (32% of total richness) were recorded only in the final survey. The high rainfall during the 18-month study is likely to be an important factor in facilitating the establishment of species following all disturbances. This may have ameliorated the impact of grazing as abundant food was available throughout the woodland. The interaction between fire and grazing may be more important in structuring these grassy communities during periods of lower rainfall.

The impact of logging on the abundance, species richness and community composition of butterfly guilds in Borneo

2005 ◽  
Vol 129 (1) ◽  
pp. 52-59 ◽  
Author(s):  
D. F. R. Cleary ◽  
T. J. B. Boyle ◽  
T. Setyawati ◽  
S. B. J. Menken
Keyword(s):  
Species Richness ◽  
Community Composition ◽  
The Impact

scholarly journals From genotype to phenotype: maintenance of a chemical polymorphism in the context of high geneflow

2020 ◽  
Author(s):  
Bodil K. Ehlers ◽  
Perrine Gauthier ◽  
Palle Villesen ◽  
Sylvain Santoni ◽  
John D. Thompson ◽  
...  
Keyword(s):  
Gene Flow ◽  
Phenotypic Selection ◽  
Environmental Variation ◽  
Environmental Data ◽  
Terpene Synthase ◽  
Major Question ◽  
Genetic Determination ◽  
Chemical Polymorphism ◽  
Evolutionary Response ◽  
The Impact

AbstractA major question in evolution is how to maintain many adaptive phenotypes within a species. In Mediterranean wild thyme, a staggering number of discrete chemical phenotypes (chemotypes) coexist in close geographic proximity. Plant chemotypes are defined by the dominant monoterpene produced in their essential oil. We study the genetics of six distinct chemotypes nested within two well established ecotypes. Ecotypes, and chemotypes within ecotypes, are spatially segregated, and their distribution tracks local differences in the abiotic environment. The ecotypes have undergone a rapid shift in distribution associated with current climate change. Here, combining genomic, phenotypic, and environmental data, we show how the genetics of ecotype determination can allow for such rapid evolutionary response despite high gene flow among ecotypes. Variation in three terpene-synthase loci explains almost all variation in ecotype identity, with one single locus accounting for as much as 78% of it. Phenotypic selection on ecotypes combined with low segregating genotypic redundancy and tight genetic determination leaves a clear footprint at the genomic level: alleles associated with ecotype identity track environmental variation despite extensive gene flow. Different chemotypes, nested within each ecotype, also track environmental variation. However, in contrast to ecotypes, chemotype identity is determined by more loci and show a wider range of genotypic redundancy, which dilutes the impact of phenotypic selection on alleles associated with different chemotypes. Identifying the genetics behind this polymorphism in thyme is a crucial step towards understanding the maintenance of this widespread chemical polymorphism found in many aromatic Lamiaceae.

scholarly journals Roads affect the spatial structure of butterfly communities in grassland patches

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5413 ◽  
Author(s):  
Piotr Skórka ◽  
Magdalena Lenda ◽  
Dawid Moroń
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Plant Species ◽  
Butterfly Species ◽  
Road Mortality ◽  
Road Verge ◽  
Total Species Richness ◽  
Butterfly Communities ◽  
Road Verges ◽  
The Impact

Roads may have an important negative effect on animal dispersal rate and mortality and thus the functioning of local populations. However, road verges may be surrogate habitats for invertebrates. This creates a conservation dilemma around the impact of roads on invertebrates. Further, the effect of roads on invertebrates is much less understood than that on vertebrates. We studied the effect of roads on butterflies by surveying abundance, species richness and composition, and mortality in ten grassland patches along high-traffic roads (∼50–100 vehicles per hour) and ten reference grassland patches next to unpaved roads with very little traffic (<1 vehicle per day) in southern Poland. Five 200-m transects parallel to the road were established in every grassland patch: at a road verge, 25 m from the verge, in the patch interior, and 25 m from the boundary between the grassland and field and at the grassland-arable field boundary. Moreover, one 200-m transect located on a road was established to collect roadkilled butterflies. The butterfly species richness but not abundance was slightly higher in grassland patches adjacent to roads than in reference grassland patches. Butterfly species composition in grasslands adjacent to roads differed from that in the reference patches. Proximity of a road increased variability in butterfly abundances within grassland patches. Grassland patches bordering roads had higher butterfly abundance and variation in species composition in some parts of the grassland patch than in other parts. These effects were not found in reference grassland patches, where butterfly species and abundance were more homogenously distributed in a patch. Plant species composition did not explain butterfly species. However, variance partitioning revealed that the presence of a road explained the highest proportion of variation in butterfly species composition, followed by plant species richness and abundance in grassland patches. Road mortality was low, and the number of roadkilled butterflies was less than 5% of that of all live butterflies. Nevertheless, the number and species composition of roadkilled butterflies were well explained by the butterfly communities living in road verges but not by total butterfly community structure in grassland patches. This study is the first to show that butterfly assemblages are altered by roads. These results indicate that: (1) grassland patches located near roads are at least as good habitats for butterflies as reference grassland patches are, (2) roads create a gradient of local environmental conditions that increases variation in the abundance of certain species and perhaps increases total species richness in grassland patches located along roads, and (3) the impact of roads on butterflies is at least partially independent of the effect of plants on butterflies. Furthermore, (4) the direct impact of road mortality is probably spatially limited to butterflies living in close proximity to roads.

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