Effects Of Local Environmental Factors Research Articles

Microtopography and vegetation generate uneven predation pressure on forest insects

Predation plays an important role in the coexistence of multiple species within forest ecosystems. It is spatially heterogeneous and influenced by the surrounding environment at different spatial scales. Studies focusing on multiple environmental factors in systems with high spatial complexity are lacking, but elucidating the effects of local environmental factors within a forest could assist in understanding the effects of local differences in predation pressures on multispecies coexistence. Here, we examined the effects of microtopography and vegetation on predation pressure using the model caterpillar method. We hypothesized that differences in microtopography and vegetation types would result in different predation pressures on invertebrates within a forest. Insect attacks were dominant throughout the study period. The attack rates on the model caterpillars were also lower on hill tops and evergreen deciduous trees. Predation pressure within the forest was heterogeneous and independently influenced by topography and vegetation type. Our results suggest that environmental heterogeneity within forests may lead to highly variable predation pressures and affect multispecies coexistence. This study suggests that microtopography and vegetation types within forests should be considered for biological control.

Characteristics of Small and Medium-Sized Towns of the Irkutsk Region in Terms of Ambient Air Pollution and Incidence Rates in the Child Population

Introduction: Air pollution affects human health and causes considerable damage to the economy by hindering urban development, including that of small towns inhabited by more than half of the Russian population. Objective: To characterize small and medium-sized towns of the Irkutsk Region in terms of ambient air pollution and incidence rates in the child population. Materials and methods: Ambient air pollution was assessed based on annual reports issued by the Federal Service for Hydrometeorology and Environmental Monitoring (Roshydromet). Incidence rates in children living in five small and medium-sized towns of the Irkutsk Region were analyzed by 16 disease categories based on report forms and collections of the Ministry of Health for 2015–2022. We applied methods of comparative analysis, calculated health indicators, and established the significance of differences using Student’s t-test. Results: The 2021 Priority List of the Most Polluted Russian Cities included seven towns of the Irkutsk Region. In small and medium-sized regional towns from this list, high ambient concentrations of benzo(a)pyrene, formaldehyde, hydrogen chloride, nitrogen dioxide, total suspended particles, and PM10 were registered, all exceeding maximum permissible levels. In 2015–2022, long-term incidence rates in children were 1.1–1.4 times higher than the national averages in the towns of Shelekhov, Usolye-Sibirskoye, and Svirsk. In all the towns under study, the number of disease categories with a high incidence among children (4–7 years of age), the list of categories, and the multiplicity of excess of the Russian rates (1.1 to 3.8 times) differ, which is determined by specifics of effects of local environmental factors. Conclusions: The levels of ambient air pollution in five small and medium-sized towns of the Irkutsk Region are assessed as very high with air pollution indices in 2022 ranging from 22 to 45. In the descending order of disease incidence in children, the regional towns were ranked as follows: Shelekhov, Usolye-Sibirskoye, Svirsk, Zima, Cheremkhovo.

Population trends and effects of local environmental factors on waterbirds at Tanguar Haor freshwater wetland complex in northeast Bangladesh

Population trends and effects of local environmental factors on waterbirds at Tanguar Haor freshwater wetland complex in northeast Bangladesh

The Effect of Local Environmental Factors on the Stable Carbon Isotopic Composition of Soils in the Olkhon Region

The Effect of Local Environmental Factors on the Stable Carbon Isotopic Composition of Soils in the Olkhon Region

Microbial community dynamics from a fast-receding glacier of Western Himalayas highlight the importance of microbes in primary succession, nutrient recycling, and xenobiotics degradation

Climate change has caused an unimaginable upsurge in glacier retreats. The melted ice exposes bare areas offering sites for new ecosystem development where primary microbial succession initiates the build-up of organic mass for plant colonisation. Chhota Shigri glacier is one such glacier that has retreated immensely and provides an ideal site for microbial succession studies. Here, we studied the shift in microbial communities and their functional traits along the glacier forefield from bare glacier snout to mature vegetated foreland through amplicon and whole metagenome sequencing approaches. The forefield sites closer to the glacier snout were abundant in the microbial phyla, such as Patescibacteria, Gemmatimonadota, Proteobacteria, Bacteroidota, Chloroflexi, Cyanobacteria, Verrucomicrobiota and Myxococcota that have potential in carbon (C), nitrogen (N), and sulphur (S) cycling. The sites away from glacier snout were abundant in the phyla Actinobacteria and Acidobacteriota, which are heterotrophic and help in organic carbon recycling. The microbes at the sites closer to the glacier terminus were richer and more diverse than those away from the terminus. The abundance and diversity of the microbes were primarily affected by the local soil's temperature, followed by pH and elements concentration (Calcium (Ca), Phosphorous (P), Potassium (K), Iron (Fe), Copper (Cu), Zinc (Zn), Lead (Pb)). Moreover, the whole-genome metagenome study revealed the prevalence of genes associated with N, C and S cycling. Additionally, the microbes and genes involved in xenobiotics compounds (Aminobenzoate, Benzoate, Caprolactam) degradation are also observed in the forefield soils. This study pointed out microbial successional gradients, the effect of local environmental factors in driving microbial succession and the role of glacier microbes in nutrients cycling and xenobiotics degradation along glacier forefield, helping our understanding of microbial succession and functional roles played by the microbes at nutrient-poor glacial soil.

Parallel evolution of morphological traits and body shape in littoral and pelagic brook charr, Salvelinus fontinalis, along a gradient of interspecific competition.

The parallel evolution of similar ecotypes in response to comparable environmental conditions is believed to reveal the importance of divergent selection in phenotypic diversifying processes. Systems characterized by the presence of multiple replicate populations expressing resource polymorphism thus provide an ideal opportunity to address the occurrence and factors affecting the parallel evolution of ecotypes. Previous studies have shown that brook charr (Salvelinus fontinalis) exhibit resource polymorphism in some Canadian Shield lakes, where a littoral ecotype feeds mainly on zoobenthos and a pelagic ecotype feeds mostly on zooplankton. Using morphological traits and geometric morphometric analyses on 18 native brook charr populations, we explicitly tested (i) whether brook charr ecotypes show parallel evolution across populations (i.e. the same morphological traits discriminate ecotypes among lakes) and (ii) whether interspecific competition decreases the amplitude of morphological differentiation between ecotypes, if any, because brook charr experience some level of competitive exclusion from the littoral habitat in the presence of creek chub or white sucker. We observed a low level of parallel evolution, where the littoral ecotype was overall stouter with longer fins and smaller eyes than the pelagic ecotype. Interspecific competition had no clear impacts on the amplitude of morphological differentiation. We also observed that inter-lake morphological differences are greater than between ecotypes within lakes, suggesting an important effect of local environmental factors on population morphology. Early-stage of diversification as well as phenotypic plasticity and morphological integration could explain why resource polymorphism is still subtle in brook charr populations.

Taxonomic and phylogenetic beta diversity in headwater stream fish communities of the Paraná and Paraguai River basins

ABSTRACT Patterns of species replacement and richness differences along environmental gradients or ecoregions shed light on different ecological and evolutionary mechanisms acting on community structure. Communities of aquatic ecosystems of different watersheds are supposed to host distinct species and lineages. Quantifying and understanding the degree to which these differences are affected by environmental and biogeographical factors remains an open question for these environments, particularly in the Neotropical region. We investigated patterns of taxonomic and phylogenetic composition of headwater streams of the Paraná and Paraguai River basins to understand how local and biogeographical factors affect the assembly of fish communities. We also quantified taxonomic and phylogenetic beta diversity by decomposing them into nestedness and turnover components. We found that local environmental factors are the main factors influencing the composition of stream fish communities. Whereas pH affected both taxonomic and phylogenetic turnover, water velocity was responsible for phylogenetic turnover and pH was the main driver of phylogenetic nestedness. Our results indicate an effect of local environmental factors in determining the structure of headwater stream fish communities through a combination of a species sorting mechanism (water velocity and pH) and phylogenetic habitat filtering (pH).

Investigating the Hubble Constant Tension: Two Numbers in the Standard Cosmological Model

Abstract The current Hubble constant tension is usually presented by comparing constraints on H 0 only. However, the postrecombination background cosmic evolution is determined by two parameters in the standard ΛCDM model, the Hubble constant (H 0) and today’s matter energy fraction (Ωm). If we therefore compare all constraints individually in the H 0–Ωm plane, (1) various constraints can be treated as independently as possible, (2) single-sided constraints are easier to consider, (3) compatibility among different constraints can be viewed in a more robust way, (4) the model dependence of each constraint is clear, and (5) whether or not a nonstandard model is able to reconcile all constraints in tension can be seen more effectively. We perform a systematic comparison of different constraints in the H 0–Ωm space based on a flat ΛCDM model, treating them as separately as possible. Constraints along different degeneracy directions consistently overlap in one region of the space, with the local measurement from Cepheid variable–calibrated supernovae being the most outlying, followed by the time-delay strong-lensing result. Considering the possibility that some nonstandard physics may reconcile the constraints, we provide a general discussion of nonstandard models with modifications at high, mid, or low redshifts and the effect of local environmental factors. Due to the different responses of individual constraints to a modified model, it is not easy for nonstandard models to reconcile all constraints if none of them have unaccounted-for systematic effects.

Effects of local environmental factors on the spiciness of habanero chili peppers (Capsicum chinense Jacq.) by coulometric electronic tongue

This work investigates the effects of local environmental factors on the spiciness of Habanero chili peppers (Capsicum chinense Jacq.) by a coulometric electronic tongue. Chili fruits grown in red soil showed significantly higher spiciness (8.4 ± 1.9 mg g−1, expressed as mg of capsaicin per g of fresh fruit), than the one observed for fruits grown in brown (6.9 ± 2.5 mg g−1) and black (6.3 ± 1.7 mg g−1) soils. Moreover, the spiciness of the chili fruits increased when fruits ripened from green (6.4 ± 1.9 mg g−1) to orange (8.0 ± 2.2 mg g−1). In addition, subsequent harvesting cycles performed on the same plants stimulate the production of new fruits with higher spiciness level, especially on green fruits. Furthermore, this work will extend, from one side, the knowledge of coulometric electronic tongues as fast, comprehensive, and easy-to-handle alternative to estimate the taste of spicy foods in large-scale industrial experiments. On the other side, this work will also extend the knowledge on the effect of local environmental factors on the expression of capsaicinoids in Habanero chili.

Temporal discrepancy of airborne total bacteria and pathogenic bacteria between day and night

As the most abundant microbes in the atmosphere, airborne bacteria are closely involved in affecting human health, regional climate and ecological balance. The mobility of airborne microorganisms makes it necessary to study the community dynamic in short cycle. Nevertheless, it remains obscure how the airborne bacteria especially the pathogenic bacteria vary on the small time scale of day and night. To investigate the nycterohemeral discrepancy of airborne total bacteria and pathogenic bacteria, PM2.5 samples were collected in Hangzhou between day and night. Microbial taxonomic information was obtained through 16S rRNA gene sequencing and “human pathogens database” screening. Further analyses based on Multiple Regression Matrices (MRM) approach and Concentration Weighted Trajectory (CWT) model were conducted to elucidate the effect of local environmental factors and long-range transport. The community composition of total bacteria tended to be similar in the daytime while pathogenic bacteria turned out to be homogeneous in the nighttime. To be vigilant, the diversity of airborne pathogenic bacteria echoed the frequency of anthropogenic activities with the pathogen inhalation rate roughly at 428 copies/h and 235 copies/h respectively in daytime and nighttime. The nycterohemeral discrepancy of total bacteria was principally driven by the filtering of environmental factors, i.e., CO and NO2, indicating that anthropogenic activities brought about the homogeneity. Airborne pathogenic bacteria coupled with the strong resistances of environmental filtering stood out from their non-pathogenic counterpart, which enabled the long-range transport. Indeed, the nycterohemeral discrepancy of pathogenic bacteria was shaped by the transport of air masses. This research filled the gaps in temporal variance of airborne microorganisms on the small time scale of day and night, providing crucial foundation for precisely predicting ecological and health effects of bioaerosols.

Two Mediterranean annuals feature high within-population trait variability and respond differently to a precipitation gradient

Intraspecific trait variability plays an important role in species adaptation to climate change. However, it still remains unclear how plants in semi-arid environments respond to increasing aridity. We investigated the intraspecific trait variability of two common Mediterranean annuals (Geropogon hybridus and Crupina crupinastrum) with similar habitat preferences. They were studied along a steep precipitation gradient in Israel similar to the maximum predicted precipitation changes in the eastern Mediterranean basin (i.e. −30% until 2100). We expected a shift from competitive ability to stress tolerance with decreasing precipitation and tested this expectation by measuring key functional traits (canopy and seed release height, specific leaf area, N- and P-leaf content, seed mass). Further, we evaluated generative bet-hedging strategies by different seed traits. Both species showed different responses along the precipitation gradient. C. crupinastrum exhibited only decreased plant height towards aridity, while G. hybridus showed strong trends of generative adaptation to aridity. Different seed trait indices suggest increased bet-hedging of G. hybridus in arid environments. However, no clear trends along the precipitation gradient were observed in leaf traits (specific leaf area and leaf N-/P-content) in both species. Moreover, variance decomposition revealed that most of the observed trait variation (≫50%) is found within populations. The findings of our study suggest that responses to increased aridity are highly species-specific and local environmental factors may have a stronger effect on intraspecific trait variation than shifts in annual precipitation. We therefore argue that trait-based analyses should focus on precipitation gradients that are comparable to predicted precipitation changes and compare precipitation effects to effects of local environmental factors.

Local environment and social factors in primary school children's afterschool commute in China.

The rapid decline in young children's active commutes to and from school has prompted investigations into ways to raise activity levels. The period after school is recognized as very important in the daily activity regime of primary school children. In this study, we examine the relative effects of local environmental factors and socio-economic status on children's after-school commute mode choice. Environmental factors are pedestrian priority streets, street intersection density, motorways, shops, and play spaces. Property values are used as a proxy for income. Twenty-four school districts are selected using intersection density and motorway length as criteria. All children's exit behaviors were film-recorded on October weekdays and extracted as four choices–alone, in a group of children, on foot with a parent or guardian, on e-bike driven by an adult. A multinomial logistic regression reveals that gated communities, higher priced housing, motorways and bus stops are associated with children accompanied by adults. The presence of pedestrian streets is associated with children travelling alone and in groups. Greater travel distance is also associated with parents accompanying children on foot or on e-bike. The amount of play space is associated with children leaving school in groups. Overall, social and environmental factors are influential in the independent travel of primary school children after the school day ends in south China.

Effect of environmental factors (wave exposure and depth) and anthropogenic pressure in the C sink capacity of Posidonia oceanica meadows

AbstractSeagrass are among the most important natural carbon sinks on Earth with Posidonia oceanica (Mediterranean Sea) considered as the most relevant species. Yet, the number of direct measurements of organic carbon burial rates in P. oceanica is still scarce and the effect of local environmental factors remains largely unexplored. In addition, P. oceanica meadows are declining due to the increase in anthropogenic pressure in coastal areas during the last century. The aim of this study is to assess the recent carbon sink capacity of P. oceanica and particularly the effect of human pressure and two environmental factors, water depth and exposure to wave energy (based on a fetch index), on the carbon burial rate since 1900. We conducted an extensive survey of sediment cores in meadows distributed across a gradient of depth, fetch, and human pressure around The Balearic Islands. Sediment and carbon accumulation rates were obtained from 210Pb concentrations profiles. Top‐30 centimeters carbon stocks (6.1 ± 1.4 kg C m−2) and burial rates (26 ± 6 g C m−2 yr1) varied up to fivefold across meadows. No significant effect of water depth in carbon burial rates was observed. Although fetch was significantly correlated with sediment mean grain size, confirming the effect of wave exposure in the patterns of sedimentation, fetch alone could not explain the differences in carbon burial rates among the meadows examined. Human pressure affected carbon burial rates, leading to increased rates since the onset of the rise in anthropogenic pressure, particularly so in sheltered meadows supporting high human pressure.

Is metapopulation size important for the conservation of understory plants and epiphytic lichens?

For a given species, reducing the extent, connectivity and health status of source populations will diminish the probability of colonizing suitable habitats. In this study, we evaluated if metapopulation size helped predict species presence in suitable habitats, by using boreal understory plants and epiphytic lichens as case studies. We sampled a network of 792 vegetation plots located across a 240,000-km2 section of pristine boreal forests. Landscape-level species abundance (LLSA), a proxy for metapopulation size, was quantified in a 50km radius surrounding each plot. The effects of local environmental factors and LLSA on species presence were modelled with general linear models (GLMs). Forty-eight vascular plant species and 8 pendulous epiphytic lichens were abundant enough to be considered in the statistical analyses. Habitat variables explained the presence of 30 vascular plants and 4 lichen species to a relatively strong degree (Tjur's R2>0.15). Among these species, 16 vascular plants and 4 lichens were significantly influenced by LLSA, independently of local habitat characteristics. Vascular plant species whose presence was significantly affected by LLSA did not exhibit particular morphological traits or habitat preferences compared with those that were not affected. By contrast, the 4 epiphytic lichen species that were affected by LLSA were all associated with older forests. No species exhibited obvious metapopulation size thresholds below which the probability of species presence in suitable habitats dropped drastically. In terms of conservation, these results suggest that coarse-filter approaches are probably more robust and easy to implement than species-specific threshold approaches in this kind of ecosystem.

When Males Are Larger than Females in Ecthotherms: Reproductive Investment in the Eastern Spadefoot Toad Pelobates syriacus

The way animals allocate resources to growth and reproduction is of major importance in understanding life-history trade-offs. Because the investment in reproduction of the two sexes differs, comparing the costs and the reproductive strategies adopted offers an insight into the evolutionary forces that shaped them. In the Eastern Spadefoot Toad, Pelobates syriacus the males are larger than females in body length, but not in body mass. We studied the reproductive effort and output in a population of P. syriacus from the Danube Delta Biosphere Reserve (Romania), during two consecutive years (2010 and 2011). Body mass loss during mating and egg deposition in females averaged 27%, while in males it was 3.9%. Body mass loss in females was proportional with size, with larger females losing more weight than smaller ones. Initial body mass and body mass loss during reproduction were significantly correlated with clutch size, but egg size was not correlated to female size or body mass loss. Year had a significant effect on body size in both sexes, suggesting high plasticity and the effect of local environmental factors on growth and reproduction. Age of adults ranged between 2–12 years and did not differ significantly between sexes. A nonrandom, but not completely assortative, mating was observed, with the age and body size of paired animals slightly positively correlated, indicating an explosive breeder reproductive strategy.

Effects of grazing and rainfall variability on root and shoot decomposition in a semi-arid grassland

Overgrazing increasingly affects large areas of Inner Mongolian semi-arid grasslands. Consequences for ecosystem functions and, in particular, for the decomposition as a key process of ecosystem carbon (C) and nitrogen (N) cycling are still unclear. We studied the effects of grazing on shoot and root decomposition with the litter bag method in a long-term grazing exclosure (UG79), a moderate winter grazed (WG) and a long-term heavily grazed site (HG). We separated the effects of local environmental factors and litter quality as altered by grazing. Growing seasons of average and very low precipitation allowed us to study the effect of inter annual rainfall variability on decomposition. Grazing-induced differences in environmental factors of the three studied grassland sites had no effect on decay rates of shoot and root dry mass. Also differences in litter quality among the grazing sites were not reflected by root decomposition dynamics. The accelerated shoot decay at site HG could not clearly be linked to litter quality parameters. Shoot decay rates were more or less constant, even under very dry conditions. This indicates the possibility of photodegradation (solar UV-B radiation) to control aboveground decomposition in this semi-arid ecosystem. By selecting the best predictors of root decomposition from regression analysis, we found that soil water content was the best parameter explaining the dynamics. Net N immobilization was generally not detected during the decay process of shoot and root. It is likely, when root decomposition is strongly reduced in dry periods, shoot decomposition becomes relatively more important for nutrient cycling. A separate analysis of shoot and root decay dynamics is required in order to describe C and N cycling in this semi-arid grassland. The grazing impact on C and N fluxes through decomposition of plant material likely exhibits a strong interaction with seasonal rainfall pattern.

Comparison of the rapidly evolving KIR locus in Parsis and natives of India

The extreme variability at the Killer cell Immunoglobulin-like Receptor (KIR) locus along with that of the genes encoding their ligands, HLA class I, appears to modulate risk for viral, autoimmune, and malignant diseases, and reproductive failure. Differences in KIR gene and haplotype frequencies across world populations may reflect some combination of ancestral genotypes, locale-specific selection pressures, and genetic drift. We genotyped unrelated healthy Parsis and Maharashtrian Hindus, neighboring peoples from Western India. These two populations showed remarkable similarity in KIR gene frequencies despite their distinct ethnic background and the fairly recent migration of Parsis to Western India from Persia around 900 A.D: . One clear exception is KIR3DS1, which is found at a significantly higher frequency in the Parsis than in the Maharashtrians, previously characterized North Indians, and most other world populations. The high KIR3DS1 frequency of Parsis corresponds with a low frequency of its putative HLA-B ligand group, an inverse correlation that has been observed previously across other world populations. Thus, KIR3DS1 frequency in Parsis may be a remnant of their distinct ancestral Persian origin. KIR gene frequencies and profiles of the Parsis and Maharashtrians were more similar to one another than they were to North Indians, suggesting a potential effect of local environmental factors on KIR evolution and/or some degree of admixture between Parsis and populations from Western India. Overall, these data support other studies indicating the rapid evolution of the KIR locus and the apparent dependency of this evolution on the loci encoding HLA class I ligands.

Characterizing Location and Classification Error Patterns in Time-Series Thematic Maps

Studies the spatial patterns of location error and of classification error in spatio-temporal datasets, assess the role of environmental factors in determining error rate and pattern, and test for possible correlation within and between these error types in space and time. A multiple regression was used to determine the effects of local environmental factors (topography, vegetation cover) on each error type. Topographic structure and vegetation cover had significant effects on location error, where larger error was associated with north-facing aspects, steeper slopes and woody vegetation cover. Classification error was also affected by topography, and vegetation cover. Slope was the major factor that affected classification quality. Strong correlation was found between error in different time steps, for both error types. Correlation between these two error types in the same time step was much smaller and in most cases insignificant.

Unsaturation and regional influences on species richness in ecological communities: A review of the evidence

According to the traditional Volterra-Gause viewpoint, the number of species in ecological communities (local richness) was thought to be controlled mainly by species interactions operating within the community itself. In order for this viewpoint to be correct, communities had to be close to equilibrium, species interactions had to be intense, and local richness had to be limited by the number of resources and physical factors. Here I argue that resource limitation and other local factors often fail to set upper limits on local richness. Revised theoretical models that add realism in the form of environmental complexity and non-equilibrium population densities of the constituent species do not predict such limits. In addition, critical evidence for such limits in real communities is often lacking. Local richness frequently correlates with the number of species in the surrounding region, and does not become independent of the latter in the richest regions as would be expected if the community became saturated. Similarly, communities in comparable environments but in regions supporting different numbers of species are not always convergent. In some cases, the effects of local environmental factors, which are known to have strong effects on local richness under some circumstances, can be severely constrained by history under other circumstances. Finally, evidence for classical interaction-imposed limits on local richness, such as density compensation and invasion resistance, does not consistently appear in many assemblages. Taken together, the evidence suggests that a more complete understanding of species richness in communities requires information on regional/historical as well as local processes. Hence, we need to broaden our perspective beyond the familiar Volterra-Gause equilibrium viewpoint and embrace community history as a relevant determinant of community structure and species composition.

Patterns of variation in Ontario wild rice ( Zizania aquatica L.) 4. Influence of regional and local environmental factors on variation within and among field populations

Analyses of covariance were used to examine morphological and productivity data from 17 indigenous wild rice populations in six empirically defined climatic regions. Statistical compensation for effects of local environmental factors (principal components of sediment nutrient concentrations, water depth and other emergent macrophytes) permitted direct comparisons of populations in different regions. there was a general trend of increasing stem and root weight, leaf width, and pistillate floret number with decreasing climatic severity. Tiller production was greatest in populations from intermediate climatic regimes. These results were consistent with those obtained in greenhouse experiments. Seed length and weight did not appear to be systematically related to climatic regime, and plant height was primarily a function of local environmental factors, especially water depth.