Life at the extreme: aquatic invertebrates across environmental gradients in high altitude saline lakes of Central Andes (Argentina).

Purpose The principal objective of this study is to investigate the authorship pattern and the relationship between them based on some statistical indices for the role of libraries in promoting education at the global level. Design/methodology/approach Data were searched for the peer reviewed and full text available journal articles that contained specific words of either libraries and education or libraries and e-learning in ERIC database. The data was analyzed based on certain statistical calculations to find out the degree of collaboration, collaborative coefficient, Shannon Index, Simpson's Indices, Spearman's coefficient and co-authorship pattern. Findings The criteria were met by 262 publications by 517 authors. The highest number of articles related with the role of libraries in education was published in the year 2013 and the highest numbers of articles were authored by single author rather than multiple authors. The degree of collaboration was found to be highest in the year 2015 and 2016 with a value of 0.66, whereas the collaborative coefficient was highest in the year 2016 with a value 0.42. The Shannon's diversity index was found to be 2.73705 with an evenness of 1.24568. The Simpson's index, Simpson's index of diversity and Simpson's reciprocal index were found to be 0.299, 0.701 and 3.3444 respectively. The Spearman's coefficient was found to be highest with a positive correlation of value 0.95 in the year 2013. Furthermore, 6 co-occurrences were found made by 8 authors. Research limitations/implications Only ERIC database was chosen for the study with the articles published from the year 2012 to 2016. Originality/value This study would be useful to the researchers to get an insight into the collaborative research pattern by the authors in role of libraries in education with different statistical approaches.

The aim of this study was to present the relationship between soil properties and biodiversity indexes in upland fir (Abies alba) forest associations (Abietetum albae). Our study was conducted in six areas representing the growth conditions of upland fir forests and the research plots were located in the Roztoczański and Świętokrzyski National Parks as well as Przedbórz, Radomsko, Piotrków and Janów lubelski Forest District. on every plot, the topography was described, soil cores were examined and samples for laboratory analysis were taken. the following characteristics were determined for the soil samples: ph, c, n, ca, Mg, na and K content, particle size, exchangeable acidity, aluminum content and hydrolytic acidity. additionally, enzyme activity in the soil samples (urease and dehydrogenase) was measured. in each test area, the stand characteristics were measured (diameter at breast height and height), floristic characteristics were described and the biodiversity indexes (Shannon, Simpson and Margalef indexes) were calculated. Different soil types (gleysols, Brunic arenosols, gleyic Podzols and hyperdistric cambisols) were recorded for the investigated forest stands and the soils were categorized according to soil texture, c content, enzyme activity and different humus types (moder-mor, moder, moder-mull). the upland mixed coniferous forest sites were characterized by lower biodiversity indexes (2.6 shannon index; 0.72 simpson index; 4.9 Margalef index) while the upland mixed broadleaf forest sites showed higher indexes (3.3 Shannon index; 0.87 Simpson index; 9.4 Margalef index). The site index obtained for the fir stands confirmed these results.

Dominance and diversity are important characteristics for the description of communities. The most commonly used indices are Simpson's dominance indexand Shannon's and Simpson's indices of diversity. This paper uses the basic concepts of statistics as applied to community analysis to develop new dominance and diversity indices that will enable scientists to establish correlations among various indices. The present study proves that the variance of the number of individuals of different species in a sample can be used to calculateSimpson's dominance and diversity indices. New indices have been developed from the ratios ofthe variance to number of species, and the mean number of individuals per species in a quadrat. A wide range of data, varying from high dominance to high evenness, was simulated for 25 quadrats, with each quadrat having ten species and 100 individuals in different combinations. Variance and standard deviation-based indices were computed using the simulated data and were found to be highly correlated with Simpson's and Shannon's indices. The proposed indices will give both the dominance and diversity of a community on the same scale based on the same statistic. Another important contribution of the present study relates to the variance of a sample consisting of a single value. It has been proved that the variance of a sample having only one value is equal to the square of that value. The paper establishes a new link between diversity studies and statistics.

PDF HTML阅读 XML下载 导出引用 引用提醒 吕梁山森林群落草本层植物物种多样性的空间格局及其对模拟增温的响应 DOI: 10.5846/stxb201803300700 作者: 作者单位: 太原师范学院地理科学学院,太原师范学院地理科学学院,太原师范学院地理科学学院,太原师范学院地理科学学院 作者简介: 通讯作者: 中图分类号: 基金项目: 山西省应用基础研究计划项目（2016021136）；山西省高等学校重点学科建设项目（晋教研函〔2016〕4号）；山西省高等学校科技创新项目（晋教科函〔2016〕4号） Spatial pattern of herbaceous plant species diversity and its changes due to simulated warming in the forest community of the Luliang Mountains Author: Affiliation: Taiyuan Normal University,Taiyuan Normal University,Taiyuan Normal University,Taiyuan Normal University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为研究气候变暖背景下森林群落草本层植物物种多样性对温度升高的响应及其随海拔、纬度的空间分布格局，按照纬度梯度选择吕梁山系北段的管涔山和南段的五鹿山为研究区，并在每个山地的不同海拔梯度（高、中、低）分别设置对照（CK）、低度增温（OTC1）和高度增温（OTC2）3种试验样地。于2017年植被生长季对植物多度、频度、盖度、高度进行调查，计算物种多样性指数（Simpson指数、Shannon指数、Pielou指数、Patrick指数）。结果表明：（1）吕梁山森林群落草本层植物物种多样性随海拔呈"v型"变化格局，即在中间海拔梯度处最低，且海拔梯度对各多样性指数的影响均达到极显著水平（P < 0.01）。（2）物种多样性随纬度升高呈递增趋势（P > 0.05），即较高纬度山地具有较高的物种多样性。（3）物种多样性随温度升高整体呈递减趋势（P > 0.05），即温度升高可抑制林下草本层植物物种多样性。（4）在增温处理下，五鹿山草本植物的Simpson指数、Shannon指数和Patrick指数呈递减趋势，Pielou指数先降低后升高；管涔山草本植物的Simpson指数、Shannon指数和Pielou指数先增加后减小，Patrick指数呈递增趋势。整体来说，在吕梁山较低海拔，持续增温会使物种多样性降低；在中等海拔，物种多样性随温度升高呈现先下降后上升的变化趋势；在较高海拔，适度增温可提高物种多样性，持续增温则抑制多样性。因此，增温对吕梁山森林群落草本植物物种多样性的影响随海拔升高整体呈下降趋势。 Abstract:The objective of this study was to investigate the species diversity of herbaceous plant communities in forests regarding changes due to temperature increases, and the spatial distribution pattern at varying elevations and latitudes in a warming climate. Adhering to a latitudinal gradient, Guancen Mountain in the northern section of the Luliang Mountains and Wulu Mountain in the southern section of the Luliang Mountains were selected as study areas. Three plot categories [control, low temperature increase (OTC1), and high temperature increase (OTC2)]were set at different altitudes (high, medium, and low) in each of the study areas. During the vegetation growth season in 2017, plant diversity, frequency, coverage, and height were investigated to calculate species diversity indices (Simpson index, Shannon index, Pielou index, and Patrick index). An S-THB-M008 air temperature probe with an RS3-B radiation shield was set up at a height of 20 cm above ground level to measure ambient temperature. Our data revealed that the herbaceous species diversity in the forest community of the Luliang Mountains exhibited a "v-shaped" pattern depending on elevation (i.e., the lowest species diversity was found in the middle elevation). Altitude effects were most strongly correlated with the Simpson index (R2=0.1711), and the effects of the altitude gradient on diversity indices were highly significant (P < 0.01). Additionally, species diversity increased with latitude, and latitude effects were most correlated with the Simpson index (R2=0.1221, P > 0.05). This is followed by the Shannon index (R2=0.0807), the Pielou index (R2=0.0785), and the Patrick index (R2=0.0382). In response to increasing temperatures, each diversity index initially decreased, but then increased, with an overall downward trend (P > 0.05). Thus, increasing temperatures may decrease the plant species diversity of herbaceous layers under the forest canopy. Among species diversity indices, the Simpson index produced the strongest correlation of temperature effects (R2=0.3374, P > 0.05). Moreover, under simulated warming conditions, the Simpson index, Shannon index, and Patrick index of herbaceous species in Wulu Mountain exhibited a decreasing trend. In contrast, the Pielou index increases first and then decreases. In comparison, the Simpson index, Shannon index, and Pielou index of herbaceous plants in Guancen Mountain increased at first and then decreased, whereas the Patrick index increased. Overall, continued warming will decrease species diversity at lower altitudes of the Luliang Mountains. At moderate altitudes, species diversity will first decrease and then increase with rising temperatures. At relatively high altitudes, moderate warming will increase species diversity, but continued warming will negatively affect species diversity. Moreover, the effect of the altitude gradient on plant species diversity in the understory herbaceous layer was highly significant (P < 0.01). In Guancen Mountain, different treatments showed a significant effect on the Pielou Index (P<0.05). However, in other plots, different treatments did not significantly affect plant species diversity. The diversity of plant species was least affected by the combination of high gradients and different treatments. Therefore, the effects of warming on the diversity of herbaceous species in the forest community of the Luliang Mountains exhibit a decreasing trend with elevation. 参考文献 相似文献 引证文献

Vegetation characteristics and soil properties of artificially remediated grasslands: The case study of the Shimenhe mining area in Qilian Mountains, northwest China

Patterns of vegetation diversity and soil carbon storage along a transect from Al-Madinah Al-Munawwarah to Al-Rayis in the Hijaz Mountains, Saudi Arabia

This study examined the variety and abundance of land snails in a specific rice field located in Lower Katingawan, Midsayap, Cotabato. Land snails are mollusks that dwell on land and possess spiral shells on their backs. Notably, no published research is available on land snails in the municipality of Midsayap, North Cotabato. The study identified three noteworthy species of land snails in the selected rice field, namely Paropeas achatinaceum, Achatina fulica, and Pomacea canaliculata, totaling 1048. The study utilized the quantitative-descriptive method and computed the diversity indices. Simpson's index was calculated, indicating a low probability of two randomly chosen individuals belonging to the same taxon. Shannon's index yielded a value indicating relatively low species richness and uneven distribution of individuals among taxa. These findings offer valuable insights into the community's structure and ecological significance, emphasizing the need for further research to comprehensively understand its diversity and dynamics. Keywords: Biology; diversity indices; shells; snails; taxonomy; terrestrial ecosystem

Method: The methodology adopted for the research included an exhaustive bibliographic search in high impact databases such as Scopus and Web of Science, complemented with semi-structured interviews with relevant members of the RECB, field trips within the reserve, development of plots in one hectare of land, determination of diversity indices and expert judgment. Results and Discussion: The results revealed the current state of the Cofan Bermejo Ecological Reserve, which should be improved in different social aspects. In addition, the diversity indexes for the 609 individuals sampled within the study area were evaluated, of which 9 families, 9 genera and 9 species were recognized. Of which there is one cosmopolitan species of the Polypodiaceae family. On the other hand, Simpson's dominance indexes are low, with a value of (0.281) and Simpson's diversity is determined on average with (0.719). Meanwhile, Shannon's index shows a medium diversity (1.609) and Shannon's evenness index indicates a low diversity (0.732). Research Implications: The results of this study have implications for the planning and management of the Cofan Bermejo Ecological Reserve in the lowland evergreen forest. The research highlights the need for a multidisciplinary approach to the conceptualization and management of the reserve, as well as the importance of considering the landscape as a central element in the development of sustainable tourism products and experiences. Originality/Value: This study contributes to the literature by providing a comprehensive and up-to-date review of the relationship between the natural landscape and reserve management, bringing together knowledge from a variety of disciplines.

Shannon's and Simpson's indices have been the most widely accepted measures of ecological diversity for the past fifty years, even though neither statistic accounts for species abundances across geographic locales (“patches”). An abundant species that is endemic to a single patch can be as much of a conservation concern as a rare cosmopolitan species. I extend Shannon's and Simpson's indices to simultaneously account for species richness and relative abundances – i.e. extend them to multispecies metacommunities – by making the inputs to each index a matrix, rather than a vector. The Shannon's index analogue of diversity is mutual entropy of species and patches divided by marginal entropy of the individual geographic patches. The Simpson's index analogue of diversity is a modification of mutual entropy, with the logarithm moved to the outside of the summation, divided by Simpson's index of the patches. Both indices are normalized for number of patches, with the result being inversely proportional to biodiversity. These methods can be extended to account for time‐series of such matrices and average age‐classes of each species within each patch, as well as provide a measure of spatial coherence of communities.

A Review of Concentration, Diversity or Entropy Metrics in Economics, Finance, Ecology and Communication Science

Wetlands are under threat from the inflow of urban pollutants on a daily basis. The phytoplankton community is the most affected by increasing eutrophication. Biodiversity based on species richness and evenness can reflect the phytoplankton community composition, as well as describing the water pollution impacts on biotic communities. Eutrophication is a major problem in tropical wetland systems because they receive various waste discharges. Therefore, an attempt was made in this study to analyse the eutrophication status of a tropical wetland (part of the Vembanad Wetland in Cherthala‐Aroor‐Edakochi coastal belt, Kerala) that is being affected by seafood effluent discharges. Alpha indices (Shannon–Weiner Diversity Index; Simpson Index) and beta diversity (Jaccard Index and Sorensen Index) were used to identify appropriate diversity index in a eutrophic environment. Analysis of the plankton populations indicated significant variations among the wetland sampling sites, with the highest percentage of pollution indicators observed in the interconnected channels than in the main portion of the wetland. The results of this study also reveal that a dangerous level of reduction in Chlorophyceae occurred which, in turn, affects the wetland primary productivity. If this situation continues, the wetland will become dominated by fewer, more pollution‐tolerant species over time, indicating serious attention must be given to stopping the loss of diversity in the wetland. This study revealed that β diversity indices are more suitable for studying diversity in a eutrophic wetland system than α diversity indices, mainly because β diversity indices indirectly consider the pollution indicator species, whereas the Shannon Index fails to do so. This study also notes the importance of using the Simpson Index over the Shannon Index for eutrophic waterbodies.

SummaryEcological phenomena exist at multiple scales, but measurements of diversity frequently consider only the smallest scale, that of the original sample plots. Additive partitioning of diversity allows multiple, hierarchical spatial scales of analysis to reveal the scale at which diversity is maximized.We examined the spatial partitioning of diversity across 378 permanent plots established in 10 7–369‐ha research natural areas (RNA) in the 294 455‐ha Shawnee National Forest, Illinois, USA. Diversity (richness and Shannon's and Simpson's indices) was partitioned across four spatial scales, i.e. within and between plots, and between RNA and natural divisions (corresponding to α and three levels of β diversity), for two strata of vegetation (trees and woody understorey).For both strata, the highest contribution to diversity measured as species richness was between plots and between RNA. Diversity was lower than expected within plots, although Simpson's and Shannon's indices achieved their maximum values at this scale. However, Shannon's index values were higher than Simpson's index values at the between‐RNA scale and for all strata, indicating that the most common species were found at this scale.There was a simple asymptotic relationship between plot occupancy and local abundance, suggesting high colonization rates and rapid colonization of open habitat indicative of a wide niche breadth of the most abundant species.Synthesis and applications.The implications of these findings are that maximum diversity across a forested landscape is not necessarily at the scale of sampling (i.e. within plots) but may be at higher scales corresponding to larger landscape units. Moreover, the largest contribution of richness to total diversity occurred at a larger scale than diversity expressed using measures based upon information theory, which incorporate species abundance and evenness. Conservation efforts seeking to preserve diversity must identify and target the correct scales to allow effective management. In this study, management at and within the RNA represents the most appropriate scale for conserving maximum diversity.

Understanding the variation of diversity patterns requires analysis at multiple spatial scales. In this study we estimated the diversity components (alpha, beta and gamma) of the spider community at El Vo´nculo Natural Regional Park, using the additive partitioning of diversity (species richness, Shannon's diversity index and Simpson's index) for the first time on this taxon in Colombia. We collected the specimens following a nested sampling design that consisted of two spatial scales. At the local scale, we quantified additive diversity components in 238 sampling units, and at the regional scale in five vegetation types. Total observed regional diversity (c) was partitioned into its additive components: within sampling units (a1), among sampling units (bl) and among vegetation types (b2). We used the same approach to compare common and infrequent spider species and to compare sampling methods. A total of 1565 adult spiders and 72 identifiable juveniles, including 193 morphospecies from 36 families, was sampled during the study. In all cases (entire community, infrequent species, common species and four different sampling methods) we found that a significant percentage, relative to that of randomization tests, of the diversity measurements used was attributed to beta diversity among vegetation types. The relative contributions of alpha and beta diversity to total observed regional diversity depended on the diversity measurement used. The contribution of beta diversity with respect to alpha diversity was low using Simpson's index (less than 20%), whereas with species richness and Shannon's index the contribution was high (up to 90% and up to 66%, respectively). Our results suggest that beta diversity is the main component of diversity in the natural park. We concluded that the maintenance of a large variety of vegetation types can be an important tool for the conservation of spider richness at the natural park.

The aim of this study was to assess and compare the water quality of the Gwebi and Mukuvisi Rivers, on the basis of selected physicochemical variables and macroinvertebrate community structure. Five sites where selected on both rivers and these were sampled on three separate occasions between January and July of 1998. The water variables measured were the concentrations of iron, chromium, zinc, lead, copper, manganese, chlorides, fluorides, sulphates, total phosphates, nitrates, ammonia, total dissolved salts, dissolved oxygen, biological oxygen demand, as well as pH, conductivity, temperature, water surface velocity and discharge. The concentration of most of the chemical variables was relatively similar along the course of the Gwebi River, but there were drastic increases in the levels of iron, chromium, copper, zinc, chlorides, fluorides, sulphates, and ammonia along the Mukuvisi River. The two rivers were different with respect to the physicochemical variables, with the exception of the first site on the Mukuvisi, which was similar to sites on the Gwebi River. This was because of the differences in the levels of human activities on the two rivers. Industrial, sewage and domestic pollution has had an adverse effect on the water quality of the Mukuvisi River. There was a sharp decline in the number of macroinvertebrate taxa along the Mukuvisi River. The lower reaches of the river where dominated by oligochaetes and Chironimidae larvae. Sample score classification of water quality based on the South African Scoring System Version 4 (SASS4) showed that most of the Mukuvisi river had poor quality water quality, whilst much of the Gwebi River had fair quality water. The HABS1 habitat assessment index was used to assess habitat quality at each site. Although much of the Mukuvisi recorded fair to good habitat scores and had generally higher habitat scores than sites on the Gwebi, the SASS scores were generally lower compared to those along the Gwebi. The sample scores and average score per taxon (ASPT) of the SASS4 showed that the Mukuvisi River was of much lower quality than the Gwebi. Both the sample score and ASPT were negatively and significantly (p<0.05) correlated to most of the physicochemical variables. The water quality variables accounted for 61.1% and 59.0% of the differences in the sample score and ASPT respectively. There was a marginal decrease in the Margalef and Shannon indices along the Gwebi River, but the Simpson's index remained relatively constant. Along the Mukuvisi River, there was a clear and distinct decrease in the magnitude of all three diversity indices, indicating decreasing macroinvertebrate community structure. The change in water physicochemical variables accounted for 61.3%, 69.2% and 87.2% of the changes in the Margalef, Shannon and Simpson's index respectively. The study provides evidence that the changes in macroinvertebrate community structure along the Mukuvisi River is due to decline in the water quality. On the Gwebi, water quality is not the main factor determining macroinvertebrate community structure.

Aims Our major objective was to reveal the distribution pattern of plant species diversity in the mountainous region of Ili River Valley, Xinjiang, China and explore how environmental gradients influenced the pattern. Methods Based on a survey of 94 sample plots in the study area, DCCA was performed to analyze the relation- ships between diversity indices and environmental gradients and GAM was employed to model the response curve of diversity indices to elevation. Important findings We recorded 259 plant species, including 235 herbaceous species; the species of woody plants were very limited. Communities with complex vertical structure had higher values of diversity. The distri- bution pattern of species diversity on the northern slope was affected by elevation, slope aspect, slope gradient, total nitrogen, total potassium, soil water content, organic matter, etc., and that on the southern slope was mainly affected by slope gradient, elevation, available phosphorus, soil water content, etc. On the northern slope, Patrick index and Shannon-Wiener index had a bimodal pattern with elevation and Simpson index and Pielou index showed a partially unimodal pattern. On the southern slope all the distribution pattern of species diversity indices showed two peaks, though that of the Patrick index was not obvious. These patterns were formed by the synthetic action of a variety of environmental factors in which elevation played an important role.