Pielou Index Research Articles

Response of Plant Species Diversity to Flood Irrigation in the Tarim River Basin, Northwest China

This study quantitatively analyzes the effects of flooding on the growth and species diversity of riparian forests along the Yarkant River and the Tarim River, Xinjiang, in northwest China, and provides important information for the efficient utilization of water and water resource management in arid regions. Monitoring of species diversity of riparian forests was conducted every year from 2016 to 2019 in the Xiamale forest district in the lower reaches of the Yarkant River, and in the Shaya forest district and the lunnan forest district in the upper and middle reaches of the Tarim River. The Pielou index, Shannon–Wiener index, Simpson index, and importance value were used to analyze the influence of flooding. The results showed the following: (1) After three years of flooding, indices for the lower reaches of the Yarkant River and Tarim River were significantly increased and 11 new plant species appeared. (2) With increasing distance from the river channel, plant density and species diversity decreased. Flooding trends are the main factors affecting the distribution of plant species and water is the main restricting factor that influences plant growth in arid areas; thus, desert riparian forests improved significantly after flooding. (3) Flooding increases the regeneration capacity and species diversity of plant communities in desert riparian forests. In order to maintain the current trend of ecological improvement, flooding irrigation must continue.

An Approach to Assess the Water Resources Reliability and Its Management

One of the factors limiting the possibility of the development of urban agglomerations is access to drinking water. Due to progressive climate change, the available water resources are limited. The paper proposes new indicators of limiting the development of agglomerations related to the availability of water resources and the production capacity of water treatment plants, a method for assessing the diversification of water resources (using the Pielou index), and a water loss balance was prepared based on International Water Association (IWA) standards. On the basis of the obtained results, the potential increase in the number of inhabitants indicators (∆PR, ∆PP) and the time for the development of agglomeration indicators (TR, TP), the directions of development of the studied agglomerations in terms of the possibility of water supply were indicated. The main problems were reducing the amount of water losses, appropriate management of the migration policy of the population, and the necessity to look for alternative sources of water.

Changes of bacterial communities in restored Phragmites australis wetlands indicate the improvement of soil in the Yellow River Delta

AbstractWith increasing global awareness of the ecological services that wetlands can provide, an increased emphasis has been placed on the need for wetland restoration projects. Among the types of wetland restoration projects that have been initiated are those that aim to return farmlands back to their previous wetland state to restore wetland vegetation and regain the ecological services that had been lost. However, studies on the changes of belowground bacterial diversities following the conversion of farmlands back to wetlands are rare, especially in coastal areas. In the present study, we examined the soil characteristics and the microbial diversity of the soil and roots across Phragmites australis–dominated coastal marshes within the Yellow River Delta. We sampled two marshes that had been restored 11 and 3 years prior to sampling (11‐year site and 3‐year site, respectively). We also sampled two additional, undisturbed wetlands—one within the new Yellow River course (NC site), and the other within the abandoned Yellow River course (OC site)—to serve as controls to assess the effectiveness of the wetland restoration project. Specifically, we measured the concentrations of nutrients and organic matter in the soil, the activities of the enzymes urease, sucrase, and alkaline phosphatase in the soil, and the diversity of the microbial communities in the soil and roots. The results showed that the concentrations of soil nutrients and the activities of the soil enzymes were significantly greater in the 11‐year site compared to the 3‐year site but were similar between the 11‐year site and the NC site. Shannon, Simpson, and Pielou indices of diversity among the soil bacteria were positively correlated with the concentrations of soil nutrients and the activities of the soil enzymes, which were generally lowest in the 3‐year site compared to the other study sites. The diversity indices among the root bacteria, however, did not exhibit a similar trend. The bacterial community composition of the soil and roots differed between sites. The relative abundance of Firmicutes in the soil and roots was highest in the 3‐year site compared to the 11‐year, NC, and OC sites. The relative abundance of soil Bacteroidetes was higher in the soils of the NC and OC sites compared to in those of the restoration sites. Overall, the diversity richness of the subsurface bacterial communities increased with the time since the restoration of these wetlands, and after 11 years post‐restoration, appeared to resemble those of the natural wetlands of the area. Our results therefore imply that future assessments of coastal wetland restoration projects could be made based in part on soil nutrient concentrations, enzyme activities, and the microbial diversity of the soil and plant roots within these systems.

广西大石围天坑群草本植物多样性及其生态位变化规律

PDF HTML阅读 XML下载 导出引用 引用提醒 广西大石围天坑群草本植物多样性及其生态位变化规律 DOI: 10.5846/stxb202204251137 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金（31960047）；珍稀濒危动植物生态与环境保护教育部重点实验室研究基金（ERESEP2019Z04）；广西重点研发计划项目（桂科AB21220057）；广西漓江流域景观资源保育与可持续利用重点实验室研究基金（LRCSU21Z0101） Diversity and niche characteristics of herbaceous plants in Dashiwei Tiankeng Group, Guangxi Author: Affiliation: 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:研究不同发育时期天坑草本植物的多样性，能更好的理解草本层对天坑环境变化的响应机制。以广西大石围天坑群中不同发育时期天坑（初期、中期和后期）为研究对象，采用空间代替时间的方法，分析不同发育时期天坑草本植物多样性和生态位变化规律。结果表明：（1）广西大石围天坑群调查样地共记录到草本植物34科71属98种，以鳞毛蕨科、荨麻科、凤尾蕨科、菊科和禾本科为主。（2）后期天坑草本植物的Pielou's指数和Shannon-Wiener指数均显著高于初期天坑（P<0.05），表明随着天坑发育到后期，草本层物种数逐渐增多，物种分布更为均匀。（3）随着天坑的发育，草本层喜阴植物重要值下降，喜阳、半阴植物重要值上升，喜阳植物逐渐取代喜阴植物在群落中占据优势地位，草本层将经历喜阴植物-喜阴、半阴植物-喜阳植物的三个生态型转变过程。（4）各发育时期优势草本生态位相似性比例和生态位重叠平均值均<0.5，表明天坑不同发育时期对草本植物的生态位影响较小，各时期草本层总体呈现生态分化明显、种间竞争较弱的特点。（5）各发育时期优势草本生态位重叠值大、相对高度差小的种对数中，不同生态习性的种对数占比不同，中期天坑种对数远高于初期和后期天坑，表明不同发育时期中不同生态习性的草本对光能的竞争程度存在差异，中期天坑草本植物对光能竞争最为激烈。综上所述，广西大石围天坑群各发育时期草本层生态分化明显、群落结构稳定，后期天坑草本多样性最为丰富。 Abstract:Studying the diversity and niche characteristics of herbaceous plants in different developmental stages of Tiankeng can better understand the response mechanism of the herbaceous layer to the environmental changes and provide an important scientific basis for the protection of ecological environment and biodiversity resources in Tiankeng. In this study, the herbaceous in different developmental stages of Tiankeng (the earlier stage, middle stage, and later stage) were selected as the objects. We used the method of space instead of time to establish 168 herbaceous quadrates in Dashiwei Tiankeng Group, Guangxi and carried out investigations. Shannon-Wiener index, Simpson index, Pielou's index and Patrick index were used to evaluate the herb diversity at different developmental stages of the Tiankeng. The ecological niche characteristics (niche width and niche overlap) of main species in the herb layer of the different developmental stages of Tiankeng were calculated. The results showed that:(1) a total of 98 species of herbaceous plants belonging to 71 genera and 34 families were recorded in Dashiwei Tiankeng Group, Guangxi. The principal families were Dryopteridaceae, Urticaceae, Pteridaceae, Asteraceae and Poaceae. (2) Pielou's index and Shannon-Wienner index of herbs in the later development stage of Tiankeng were significantly higher than those in the earlier development stage of Tiankeng (P<0.05), indicating that with the Tiankeng developed to the later stage, the number of species in the herb layer increased and the species distribution pattern was steady. (3) With the development of Tiankeng, the importance value of sciophiles in herb layer decreased, while the importance value of heliophiles and semishade increased and the dominance was prevalent in heliophiles than sciophiles. The herb layer would go through three ecotype transition processes of sciophiles-sciophiles and semishade-heliophiles. (4) The average value of niche similarity and niche overlap of dominant herbs at each developmental stage of Tiankeng were lower than 0.5, indicating that different developmental stages of Tiankeng had a slight impact on the niche of herbs. The herbaceous layer had obviously ecological differentiation and weakly inter-specific competition. (5) In the species pairs of dominant herbs large niche overlap and small relative height at each development stage, the species pairs of different ecological habits accounted for different proportions. The species pairs of the middle development stage of Tiankeng was much higher than that of earlier and later development stages of Tiankeng. The results showed that herbaceous plants with different ecological habits at different development stages had different competition degrees for light energy. The herbs in the middle development stage of Tiankeng had the fierce competition for light. In a word, the herb layer of Dashiwei Tiankeng Group in Guangxi was obviously differentiated, the community structure was relatively stable, and the species diversity of the later development stage of Tiankeng in herb layer was rich. 参考文献 相似文献 引证文献

Evolutionary trend of plant community and adaptive strategies of dominant plants in the water-level-fluctuation zone of the Three Gorges Reservoir

三峡水库周期性蓄水显著改变了消落区植物群落组成及多样性,植物群落的演变过程能反映和影响整个消落区生态系统的变化,但目前还缺乏长期连续的观测数据记录,因而本研究基于2009-2021年6月的固定样方长时间序列监测数据和优势植物叶片功能性状数据,分析了消落区3个高程(145~155、155~165和165~175 m)区域植物群落多样性和优势植物重要值的变化趋势,通过冗余分析和蒙特卡罗检验揭示了水库运行特征参数和气象因子对消落区植物特征的影响。研究发现:1)消落区3个高程区域,优势植物差异明显,145~155和155~165 m区域以狗牙根、香附子和苍耳等为主,165~175 m区域以狗牙根、野胡萝卜和鬼针草等为主。145~155 m区域植物群落Shannon-Wiener多样性指数(1.47±0.47)和Pielou 均匀度指数(0.67±0.07)显著低于165~175 m区域。2)2009-2021年期间,高程145~155和155~165 m区域Shannon-Wiener多样性指数和Pielou 均匀度指数呈波动下降趋势,优势植物狗牙根和香附子的重要值呈增加趋势。3)RDA分析表明,与水库运行特征密切相关的淹没时间、周期性淹没次数和高程均能显著影响消落区优势植物重要值的大小。狗牙根、喜旱莲子草和苍耳等物种重要值与周期性淹没次数呈正相关,狗尾草和水蓼的重要值与淹没次数呈负相关。野胡萝卜、鬼针草和黄花蒿等物种重要值与高程呈正相关,狗牙根、香附子和水蓼的重要值与高程呈负相关。4)不同植物的适应策略各有不同,消落区植物狗牙根的比叶面积最大,为(32.8±7.2)mm²/mg,鬼针草和苍耳次之,分别为(30.6±3.9)和(30.0±3.0)mm²/mg,均小于未淹没对照区植物的比叶面积。5)狗牙根耐水淹能力强,以S策略投资为主(53.4%),苍耳的比叶面积大,以C投资策略主(61.3%)。小白酒草(64.6%)和鬼针草(50.9%)以R策略为主,种子小数量多,喜旱莲子草也以R策略为主(71.3%),具有发达的根茎。本研究结果可加深对大型水库消落区植物群落演变趋势及优势植物的生态适应策略的科学认知。;The periodic impoundment of the Three Gorges Reservoir has significantly changed the composition and diversity of plant communities in the water-level-fluctuation zone (WLFZ), and its succession process can reflect and influence the changes of the whole reservoir bank ecosystem. At present, there is still a lack of long-term continuous observational records. Based on the monitoring data of fixed sample sites from June 2009 to June 2021 and leaf functional traits of dominant plants, this study analyzed the change trend of plant community diversity and the important value of dominant plants at the altitudes of 145-155 m, 155-165 m and 165-175 m in the WLFZ, and revealed the influence of reservoir operation characteristic parameters and meteorological factors on plant characteristics in the WLFZ through redundancy analysis. The results showed that: 1) dominant plants varied obviously in different elevation areas. The dominant species exhibiting higher important value (IV) at the altitude of 145-155 m and 155-165 m were Cynodon dactylon, Cyperus rotundus and Xanthium sibiricum with the higher water-tolerant capacity, while C. dactylon, Daucus carota and Bidens pilosa were dominant at the altitude of 165-175 m. The Shannon-Wiener diversity index of plant communities (1.47±0.47) and the Pielou index (0.67±0.07) at the altitude of 145-155 m were significantly lower than those at the altitude of 165-175 m. 2) From 2009 to 2021, the Shannon-Wiener diversity index and Pielou index at the elevation of 145-155 m and 155-165 m decreased, while the importance value of C. dactylon and C. rotundus increased. 3) RDA analysis showed that the flooding time, number of periodic flooding and elevation can significantly affect the IV of dominant plants. The IV of species such as C. dactylon, A. philoxeroides and X. sibiricum were positively correlated with number of periodic flooding. The IV of Setaria viridis and Polygonum hydropiper were negatively correlated with number of periodic flooding. With increasing elevation, the IV of D. carota, B. pilosa and Artemisia annua increased, however, the IV of C. dactylon, C. rotundus and P. hydropiper declined. 4) The adaptation strategies of different plants varied. Specific leaf area (SLA) of C. dactylon (32.8±7.2) mm²/mg was the largest, followed by B. pilosa (30.6±3.9) mm²/mg and X. sibiricum (30.0±3.0) mm²/mg. The SLA of these plans in the WLFZ were lower than those of plants in the unflooded area. 5) The investment proportion of S strategy of C. dactylon was 53.4% with high flooding-resistant ability. The investment proportion of C strategy of X. sibiricum was 61.3% with the largest leaf area. The proportions of R strategy of Comnyza canadensis and B. pilosa were 64.6% and 50.9% that have a lot of small seeds. The proportions of R strategy of A. philoxeroides was 71.3% with developed roots. The results of this study may deepen the scientific understanding of the change trend of plant communities and the ecological adaptation strategies of dominant plants in the WLFZ of large reservoirs.

松嫩平原湿地植物群落多样性的环境梯度分布格局及控制因子

PDF HTML阅读 XML下载 导出引用 引用提醒 松嫩平原湿地植物群落多样性的环境梯度分布格局及控制因子 DOI: 10.5846/stxb202201150145 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 中央高校自主科研项目计划（2572019DF07） Environmental gradient distribution patterns of wetland plant community diversity and controlling factors in Songnen Plain Author: Affiliation: Fund Project: Supported by: The Independent Research Project of the Central Universities of China (2572019DF07) 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:物种丰富度格局及其决定因素是生态学核心问题，但对其形成机制仍缺乏共识。为探究松嫩平原西部半干旱区沿湖岸至高地环境梯度（局地尺度）植物群落多样性分布格局及其决定因素，以沿该梯度依次分布的7种群落（狭叶香蒲沼泽、小香蒲沼泽、芦苇沼泽、草丛沼泽、拂子茅草甸、羊草草甸和榆树疏林）为对象，采用样带网格调查法及聚类分析法划分群落类型，测定物种丰富度、α多样性和β多样性及其环境因子（水位、土壤含水率、有机质等），揭示群落多样性空间分布规律及其形成机制。结果表明，沿湖岸至高地环境梯度：（1）物种丰富度（2.00-18.00）和α多样性（Simpson指数0.12-0.90；Shannon-Wiener指数0.23-2.57和Pielou指数0.34-0.88）总体上均呈类似N字型分布（在下部深水生境狭叶香蒲沼泽最低、中下部季节性积水生境草丛沼泽最高、中上部湿润生境拂子茅草甸较低、上部沙丘干旱生境榆树疏林又较高）；（2）广义的β多样性（Jaccard指数0.56-0.96）可以分解成物种周转（丰富度没有变化的地点间的物种替代）和嵌套（物种贫乏地点是物种丰富地点子集时的物种差异）两个过程，其在该梯度上半段干旱生境和下半段浅水生境相对较高，且主要由周转过程控制。在常年积水生境上最低且仅由嵌套过程控制，而在环境梯度中间地段则由周转和嵌套过程共同控制；（3）物种丰富度和α多样性的主控因子沿该梯度发生了明显转换，在高水位区由水位、有机质和全磷共同控制；中水位区仅由速效磷控制；低水位区由pH和含水率控制。因此，松嫩平原半干旱区沿湖岸至高地环境梯度物种丰富度和α多样性存在明显的空间分布格局及具有较高的β多样性，且其主要形成机制为微地形创造局地空间环境异质性与物种库相互作用共同塑造了植物群落多样性，故在生物多样性管理实践中应对其空间分布格局完整性加以重点保护。 Abstract:Patterns and determinants of species richness are the central issues in ecology, but there is still a lack of consensus on their formation mechanisms. In order to explore the distribution patterns and determinants of community diversity along lakeshore-highland environmental gradient (local scale) in western Songnen Plain semi-arid region, species richness, α diversity, β diversity and environmental factors including water level (WL), soil water content (WC), organic matter (OM), etc. were measured by setting up sample belts and cluster analysis in seven communities (Typha angustifolia wetland, Typha minima wetland, Phragmites australis wetland, hassock wetland, Calamagrostis epigeios meadow, Leymus chinensis meadow and elm sparse forest) along this gradient, to reveal the spatial variation and formation mechanisms of community diversity. The results show that, along lakeshore-highland environmental gradient:(1) both species richness (2.00-18.00) and α diversity (Simpson index 0.12-0.90; Shannon-Wiener index 0.23-2.57 and Pielou index 0.34-0.88) showed a similar N-shaped distribution pattern (Typha angustifolia wetland was the lowest at the lower deep-water habitats, hassock wetland was the highest at the lower-middle seasonal inundated habitat, the lower at the middle-upper wet habitats of Calamagrostis epigeios meadow and the higher at the upper arid habitats of dune elm sparse forest). (2) We partitioned the generalized β diversity (Jaccard index 0.56-0.96) into two components:species turnover (species replacement among sites without changes in richness) and nestedness (species differences among sites when species-poor sites constitute subsets of those with a greater number of taxa). β diversity was relatively high at arid habitats located in upper half and shallow-water habitat located in lower half of the gradient, and it was mainly controlled by turnover processes. At the permanently inundated habitats, it was the lowest one, which is controlled only by nestedness processes. But in the middle of the environmental gradient, the turnover and nestedness processes control it togther. (3) The main controlling factors of species richness and α diversity were significantly converted along the gradient. The high water level area was jointly controlled by water level, organic matter and total phosphorus (TP), the medium water level area was controlled only by available phosphorus (AP) and the low water level area was jointly controlled by pH and water content. Therefore, there were obviously spatial distribution patterns of species richness and α diversity, and higher β diversity along lakeshore-highland environmental gradient in the Songnen Plain semi-arid region. Our results suggested that the main mechanism was the interaction between the local spatial environmental heterogeneity created by microtopography and the region species pool, which jointly shaped the plant community diversity. Thus, its spatial distribution patterns integrity should be protected in the practice of biodiversity management. 参考文献 相似文献 引证文献

Colchicine effects on the gut microbiome in adults with metabolic syndrome.

Obesity-induced inflammation plays a substantial role in the development of insulin resistance and type 2 diabetes. The altered gut flora in obesity can also contribute to metabolic dysregulation and systemic inflammation. However, it remains unclear how dysregulation of systemic inflammation in obesity affects the gut microbiome. We hypothesized that colchicine's systemic anti-inflammatory effects in obesity would be associated with improvements in gut microbial diversity. We conducted a secondary analysis of a double-blind randomized placebo-controlled trial, in which 40 adults with obesity, high C-reactive protein (CRP) (≥2.0 mg/L), insulin resistance (homeostatic model of insulin resistance: HOMA-IR ≥2.6 mg/L), and metabolic syndrome (MetS) were randomized to three months of colchicine 0.6 mg or placebo tablets twice daily. Serum and stool samples were collected at baseline and final visit. Gut microbiota composition was characterized from stool DNA by dual-index amplification and sequencing of 16S ribosomal RNA. Pre- and post-intervention stool samples were available for 15 colchicine- and 12 placebo-treated subjects. Circulating high sensitivity CRP (hsCRP), interleukin-6, resistin, white blood count, and neutrophils were significantly decreased in the colchicine arm as compared to placebo. However, changes in stool microbiome alpha diversity, as assessed by the Chao1, Shannon, and Pielou indices, were not significant between groups. Amplicon sequence variant counts were unchanged among all examined phyla or families. Oscillibacter was the only genus to demonstrate even a nominally significant change. Among adults with obesity and MetS, colchicine significantly improved systemic inflammation. However, this anti-inflammatory effect was not associated with significant changes in the gut microbiome. Further studies are warranted to investigate this relationship.

Tree Species Diversity and Regenerating Potential along Disturbance Gradient in Chandragiri Hill, Kathmandu, Central Nepal

Tress species regeneration is greatly influenced by climatic, topographic, and anthropogenic activities. Present study was designed to examine the tree species diversity and their regeneration patterns along the anthropogenic disturbance gradient in the temperate forest of Chandragiri Hill, Central Nepal. Data were obtained from 90 sample plots ranging between 1560 to 2290 m asl after randomly sampling along three disturbance classes classified based on canopy coverage and degrees of disturbance activities in 2021. Circumference at breast height (1.37 m height above the ground) of each tree individual was measured and classified into tree, sapling, and seedling. A total of 47 tree species belonging to 42 genera and 26 families were obtained by this study. The highest species richness for seedlings and saplings was obtained in severely disturbed areas and tree species richness in the moderately disturbed area. The tree stands density varied between 350 to 1017 individuals ha-1 with the total basal area between 12.7 to 72.78 m2 ha-1 with the least value in a highly disturbed area and highest in the least disturbed area. The seedling and sapling densities were found increased from lower to more disturbed forests indicating that the forest fragmentation negatively affected the regeneration. The highest values of the Shannon Weiner index, Pielou Index, and the lowest value of the Simpson index were observed at moderate disturbance areas. About 36 to 60% of species were found regenerating in the less disturbed and moderately disturbed forests and no regeneration in severely disturbed areas. Elevation, canopy cover, landslide, and slopes were found to be the most influential variables in forest regeneration as significantly represented by CCA1. The present study has found a moderate level of disturbance to become beneficial for better regeneration of tree species. So, the reduction of excessive disturbance from local people would be a better option for the adequate regeneration of tree species.

Spatio-temporal differences in pollinator species richness, abundance and conservation status in a Mediterranean island

Although the Mediterranean basin is a hotspot of pollinator diversity, little is still known about how such diversity is distributed in the region and about its conservation status. This study contributes to filling this information gap by studying pollinator diversity parameters in one of the main Mediterranean islands, Mallorca, and further evaluating their conservation category according to the IUCN criteria. We focus on three communities, two coastal and one mountain shrubland, which we have studied for several years. For each community, we obtained the following variables: (1) Shannon diversity (H'), (2) Pielou's index (J'), (3) Number of pollinators per plant (Lp), (4) Flower visitation rate (FVR), (5) Specialisation index (d') and (6) Normalised degree of pollinators, i.e. the number of plants visited per pollinator species relative to the total number of plant species in the community (ND). All pollinators were categorised into functional groups to test for differences in such variables among them. Differences across communities, years and functional groups were tested through GLMMs. The three communities showed differences in pollinator species composition, species richness and diversity. Pollinator diversity also varied with time, especially in the coastal community, which suffered a major disturbance during one of the study years. Regardless of the functional group, the pollinator specialisation degree seems context-dependent. Native and endemic species might disappear in the short term if appropriate management measures are not taken to narrow down the threats to pollinator populations. Further research is urgently needed to assess most insect pollinators' conservation status in the Mediterranean before such rich diversity is lost forever.

Characteristics and pollution risks of potentially toxic elements and nematode community structure on farm soil near coal mines.

As one of the most important coal-producing provinces of China, Shanxi Province has been concerned about soil potentially toxic elements (PTEs) contamination in recent years. The study aimed to determine the status and sources of PTEs contamination and evaluate the quality of the soil ecology. This study investigated the degree of 13 PTEs contamination. The sources and contributions of PTEs were traced by the absolute principal component score followed by a multiple linear regression model (APCS-MLR). And the status of the soil ecosystem was verified by evaluating the soil nematode community around the coal mining areas in Jinzhong. The results showed that the mean PTEs concentration of 5 trace elements were higher than the background values of Shanxi, and safe to considerable was indicated by the pollution and ecological risk values. Soil Hg was the most contaminated element, followed by Cd. The distribution of PTEs was determined by coal mining activities (44.72%) followed by agricultural practice (32.37%) and coal transportation (21.37%). The nematode genera Acrobeloides (4.01%), Aphelenchus (20.30%), Meloidogyne (11.95%) and Aporcelaimus (2.74%) could be regarded as bioindicators of soil PTEs contamination by their tolerance. Concentrations of soil Cr, Mn, Ti and Cd showed remarkable influences on the total nematode abundance, maturity index, enrichment index, structural index, Shannon-Wiener diversity index and Pielou index of soil nematode. It is an appropriate method to evaluate the status of soil PTEs contamination combining the response of a single nematode genus and the nematode community evaluation index.

Effects of habitat loss on migratory shorebird community structure at stopover sites: A case study in the Yellow River Delta, China

Coastal wetlands in China provide important stopover sites for migratory shorebird species. The loss of natural wetlands caused by land reclamation over the past few decades poses a major threat to shorebird populations. Although habitat loss at key stopover sites has been shown to lead to reductions in shorebird populations, the effects of habitat loss at specific stopover sites on shorebird populations remain unclear. Here, we used shorebird diversity indices and landscape metrics to elucidate the long-term (19952020) effects of habitat change on shorebird community structure in the Yellow River Delta, which is an important stopover site for shorebirds along the Yellow Sea coast. The results showed that the habitat area, largest patch index, mean patch area, and the aggregation index decreased over 25 years. By contrast, the number of patches and patch density increased over the same period. The richness, Shannon-Wiener index, Pielou index, and Simpson index of the shorebird community increased from 1995 to 2020, while abundance of shorebird declined by 90.14%. Declines in the abundance of species were more pronounced in larger-bodied ones than in smaller-bodied species (T=1.156, df=42, p=0.02). On the other hand, there were no significant differences in the decline in the abundance of threatened species and non-threatened species (T=-0.483, df=42, p=0.632) and coastal specialist species and generalist/inland specialist species (T=-1.197, df=42, p=0.239). The decrease in mean patch area significantly contributed to the reduction in abundance of shorebirds (N=6, p=0.01), and its effects were more pronounced on larger-bodied ones than on smaller-bodied species (T=-2.113, df=42, p=0.04). These results suggest that habitat loss in the Yellow River Delta has contributed to declines in shorebird populations and that larger-bodied ones are more sensitive to habitat change than smaller-bodied species. Existing wetlands are in urgent need of conservation, and further land reclamation in this region should be avoided. In addition, the development of conservation plans for coastal wetlands requires consideration of variation in the responses of different functional groups to habitat change.

Warming changed the relationship between species diversity and primary productivity of alpine meadow on the Tibetan Plateau

Climate warming are supposed to have irreversible effects on the biodiversity and ecosystem functions of grassland. Alpine meadow is the predominant ecosystem in Qinghai-Tibet Plateau, which has attracted much attention because of its sensitivity to global changes. However, there is still no unified understanding of the impact of warming on the relationship between diversity and productivity of alpine meadows. In this study, we conducted multi-gradient warming, used fiberglass open-top chambers (OTCs) to raise the temperature, based on the investigation of community structure and productivity, we evaluated the effect of field simulated warming on the relationship of species diversity-primary productivity. Our result showed that gradient warming reduced species richness, diversity and dominance, inhibited the accumulation of above-ground biomass (AGB) and below-ground biomass (BGB), which was more significant under higher warming (P < 0.05). AGB had a significant linear positive correlation with Margalef index (R) and Shannon-Wiener index (H) (P < 0.05), but was weakly dependent on Simpson index (H′) and Pielou index(E), while BGB was not affected by species diversity during the experiment. Our results revealed that simulated warming weakened the dependence of AGB on species diversity, and aggravated the negative correlation between BGB and species diversity (P < 0.05), which was mainly caused by the decrease of R, H, H' after warming. Functional group level, we found the AGB of Forbs increased significantly with the increase of species richness (P < 0.05), but warming had little effect on the relationship between them, while the relationship between species richness and AGB of Poaceae was significantly strengthened under warming. It concludes that the interaction between Poaceae and Forbs leads to a gradual decrease in above-ground biomass at the community level with the increase of species richness under warming. Our work provides an experimental data source for BEF research and verification under climate change scenarios, and an important reference for predicting and dealing with the impact of global climate change on adaptive management and grassland protection.

Predicting spatial variability of species diversity with the minimum data set of soil properties in an arid desert riparian forest

Species diversity has spatial heterogeneity in ecological systems. Although a large number of studies have demonstrated the influence of soil properties on species diversity, most of them have not considered their spatial variabilities. To remedy the knowledge gap, a 1ha (100m × 100m) plots of arid desert riparian forest was set up in the Ebinur Wetland Nature Reserve (ELWNR) in the NW China. Then, the minimum data set of soil properties (soil MDS) was established using the Principal Component Analysis (PCA) and the Norm Value Determination to represent the total soil property data set (soil TDS). The Geo-statistics and two models (i.e., Random Forest/RF and Multiple Linear Regression/MLR) were used to measure the spatial variability of species diversity, and predict its spatial distribution by the soil MDS, respectively. The results showed that the soil MDS was composed of soil salt content (SSC), soil total phosphorus (STP), soil available phosphorus (SAP), soil organic carbon (SOC) and soil nitrate nitrogen (SNN); which represented the soil TDS perfectly (R2 = 0.62). Three species diversity indices (i.e., Shannon-Wiener, Simpson and Pielou indices) had a high spatial dependence (C0/(C0+C)< 25%; 0.72m ≤ range≤ 0.77m). Ordinary kriging distribution maps showed that the spatial distribution pattern of species diversity predicted by RF model was closer to its actual distribution compared with MLR model. RF model results suggested that the soil MDS had significant effect on spatial distribution of Shannon-Wiener, Simpson and Pielou indices (Varex = 56%, 49% and 36%, respectively). Among all constituents, SSC had the largest contribution on the spatial variability of species diversity (nearly 10%), while STP had least effect (< 5.3%). We concluded that the soil MDS affected spatial variability of species diversity in arid desert riparian forests. Using RF model can predict spatial variability of species diversity through soil properties. Our work provided a new case and insight for studying the spatial relationship between soil properties and plant species diversity.

Species Diversity Has a Positive Interrelationship with Aboveground Biomass and a Mismatch with Productivity in a Subtropical Broadleaf Forest on the Wuyi Mountains, China

The Wuyi Mountains in China are one of the largest and most complete subtropical forest ecosystems at the same latitude in the world. However, our limited understanding of the function of this distinctive ecosystem means that the interrelationship between species diversity and ecosystem functioning needs to be investigated if evergreen broadleaf forests (EBLFs) are to be protected. Here, we calculated species richness, the Shannon–Wiener index, and the Pielou index in large-, medium-, and small-scale (20 m × 20 m, 10 m × 10 m, and 5 m × 5 m) forest dynamics plots (FDPs). We also investigated the interrelationships between species diversity and aboveground biomass (AGB)/productivity in FDPs at the different scales using the generalized linear regression model. The results showed that species diversity and AGB positively interrelated with each other, whereas there was no species diversity-productivity interrelationship in the subtropical BLF on the Wuyi Mountains. The structural equation model (SEM) showed that elevation was a key factor directly affecting AGB. These findings lead to the conclusion that productivity is not solely correlated with species diversity and that abiotic factors probably mediate the positive interrelationship between species diversity and ecosystem functioning. This study provides theoretical basis that can be used to protect EBLFs in subtropical areas and the results can be used to improve the construction of artificial forest communities and vegetation restoration at the same latitude.

Regulation of Abiotic Factors on Aboveground Biomass and Biodiversity of Ditch Slope in Coastal Farmland

Ditch plant biomass and diversity play an important role in maintaining ditch ecosystem structure and function stability, which are subject to environmental changes. However, the regulation of abiotic factors on the aboveground biomass and diversity of plants on the slopes of coastal agricultural ditches remains unclear. In this study, the spatial distribution of soil physicochemical properties, aboveground biomass, and diversity of vegetation on different slope positions (upper slope, middle slope, and lower slope) and slope aspects (north-south direction) of farmland drainage ditches and their correlations were investigated through field surveys of vegetation on the slopes of coastal farmland drainage ditches at different sampling sites. First, water content and bulk density) decreased with the increase of slope position, while the salinity showed the opposite spatial distribution characteristics and the distribution of soil nutrients in space was mainly concentrated in the 0–20 cm soil layer. Second, the aboveground biomass of vegetation was significantly higher on the south slope than on the north slope, with the highest biomass at the lower slope on the south slope and higher aboveground biomass on the north slope at the upper and middle slopes. The Shannon-Wiener index, Pielou index, and Margalef index of ditch slope vegetation in Dongying and Binzhou farmland ditch slopes showed the same pattern of change at different slope positions and directions, which were significantly higher at the upper and middle slopes than at the lower slopes. In contrast, the Simpson index showed the opposite pattern, decreasing with the increase in slope position. Further, WC, BD, organic matter content, and total nitrogen content had positive effects on vegetation aboveground biomass, while soil pH, salinity, and available potassium content hindered vegetation growth. Finally, the Shannon-Wiener index and Pielou index were positively correlated with soil BD and available phosphorus content, and negatively correlated with organic matter and total nitrogen content, while the Simpson index was positively correlated with soil BD and WC, and had a significant negative correlation with soil salinity.

Play fighting versus real fighting in piglets (Sus scrofa): Similar patterns, different structure

When animals engage in ‘non-serious’ fighting (play-fighting) they ‘borrow’ motor patterns especially from the aggressive context. It may be difficult to distinguish play- and real-fighting. This is particularly true for piglets (Sus scrofa), which can use play-fighting as a substitute for aggression. To check for the structural differences between play- and real-fighting in piglets, we: i) video recorded 496 interactions from three litters (at Parva-Domus extensive ethical farm; Turin, Italy); ii) extracted (by video analyses) duration, patterns, and data on involved individuals; iii) calculated session structural/ecological indices; and iv) compared the indices (play- vs real-fighting). Compared to real-fighting – play-fighting was longer (informing its rewarding nature), more symmetrical (lower asymmetry index) and variable (higher Shannon index). Moreover, play-fighting showed less pattern repetition (lower Repetition Index) and was not more polyadic and evenly distributed (comparable polyadic and Pielou indices). By being longer, and more variable and symmetrical than real-fighting, play-fighting could serve some of its functions such as motor training, social assessment and training for the unexpected. However, play-fighting in piglets did not comply with all the expected play features, possibly because play is a fluid behavioural system that under certain circumstances may escalate into or replace aggression.

Differences in planktonic and benthic diatoms reflect water quality during a rainstorm event in the Songhua River Basin of northeast China

Diatoms are useful indicators of lotic ecosystem environmental conditions, but little is known of differences between benthic and planktonic diatom assemblages as it relates to water quality changes in large lotic systems. Heavy rainfall event in Songhua River Basin is infrequent. The water quality of Songhua River Basin is closely implication for regional ecological health and food safety. The aim of this study was to compare the effectiveness of benthic and planktonic diatom assemblages for indicating water quality during a rainstorm event, which has been little studied. Spatial variation of benthic and planktonic diatom assemblages were investigated in Songhua River Basin during a rainstorm event. Firstly, we found that richness and abundances of benthic and planktonic diatom communities were low. Secondly, results of two-way cluster analysis (TWCA) and principal component analysis (PCA) revealed that diatom assemblage still had the potential to indicate water quality despite the strong flow caused by rainstorm event. Thirdly, alpha diversity indices (Shannon-weaver, Margalef, and Pielou indices) had a weak ability in indicating water quality during rainstorm event. Conversely, trophic diatom index (TDI) was observed closely associate with water quality change. Fourthly, Redundancy analysis (RDA) indicating that planktonic diatoms assemblages were more sensitive to changes in turbidity. RDA also revealed that benthic diatom assemblages was closely related to chemical oxygen demand (CODcr), total phosphorus (TP), and dissolved oxygen (DO) concentrations. These results demonstrate the effectiveness of water quality assessment between planktonic and benthic diatoms had a significant different. The results of the study provide a key information about diatom-based biomonitoring in the extreme condition at lotic ecosystem. Our study highlights that rational choices of appropriate diatom metrics for biological monitoring of water quality in large lotic ecosystems are critical for assessments during a rainstorm event. More studies during rainstorm period at different precipitation are required to fully understand how natural disturbance shape diatom assemblage in lotic ecosystem with aims to improve biomonitoring efforts.

Quantifying Plant Species α-Diversity Using Normalized Difference Vegetation Index and Climate Data in Alpine Grasslands

Quantitative plant species α-diversity of grasslands at multiple spatial and temporal scales is important for investigating the responses of biodiversity to global change and protecting biodiversity under global change. Potential plant species α-diversity (i.e., SRp, Shannonp, Simpsonp and Pieloup: potential species richness, Shannon index, Simpson index and Pielou index, respectively) were quantified by climate data (i.e., annual temperature, precipitation and radiation) and actual plant species α-diversity (i.e., SRa, Shannona, Simpsona and Pieloua: actual species richness, Shannon index, Simpson index and Pielou index, respectively) were quantified by normalized difference vegetation index and climate data. Six methods (i.e., random forest, generalized boosted regression, artificial neural network, multiple linear regression, support vector machine and recursive regression trees) were used in this study. Overall, the constructed random forest models performed the best among the six algorithms. The simulated plant species α-diversity based on the constructed random forest models can explain no less than 96% variation of the observed plant species α-diversity. The RMSE and relative biases between simulated α-diversity based on the constructed random forest models and observed α-diversity were ≤1.58 and within ±4.49%, respectively. Accordingly, plant species α-diversity can be quantified from the normalized difference vegetation index and climate data using random forest models. The random forest models of plant α-diversity build by this study had enough predicting accuracies, at least for alpine grassland ecosystems, Tibet. The proposed random forest models of plant α-diversity by this current study can help researchers to save time by abandoning plant community field surveys, and facilitate researchers to conduct studies on plant α-diversity over a long-term temporal scale and larger spatial scale under global change.

DIVERSIDADE GENÉTICA ENTRE GENÓTIPOS DE MELÃO-DE-SÃO-CAETANO ACESSADA POR VARIÁVEIS MORFOAGRONÔMICAS

ABSTRACT Bitter melon (Momordica charantia L.) is a plant species recommended by the Brazilian Health Regulatory Agency (Anvisa) as hypoglycemiant. The characterization of plants is an essential step in any breeding program. The objective of the present work was to organize and characterize a bitter melon germplasm collection, based on morpho-agronomic characters, to assess its genetic diversity and identify genotypes of agronomic interest. Eighty-eight genotypes were characterized for 38 descriptors. Redundant descriptors were identified through Principal Component Analysis (PCA); after their exclusions, a new PCA was carried out to verify the dispersion among the genotypes. Groups in the PCA were defined using the kmeans clustering method. The groups were studied for phenotype pattern using radar chart. Populational diversity was estimated through Shannon and Pielou indexes. Intra group diversity was estimated through analysis of similarity (anosim). The relative importance of variables for diversity was also estimated. Seventeen variables were redundant. The genotypes were grouped into 5 groups. Groups G1 and G5 were antagonist regarding fruit and seed productions and fruit, leaf, and seed sizes. A trend of decrease in fruit, leaf, and seed sizes was found in groups from G1 to G5. The diversity was high. Intra group diversity was high among small fruit genotypes, and low for medium-sized fruit genotypes. The variable number of male flowers (NMFL) was identified as that presented the greatest contribution to estimation of diversity. The genotypes UFRRJ MSC072, 042, 028, and 087 stood out with the highest number of fruits produced.

Mixed conifer-broadleaf trees on arbuscular mycorrhizal and ectomycorrhizal communities in rhizosphere soil of different plantation stands in the temperate zone, Northeast China.

In comparison with ectomycorrhizal (EM) tree species, arbuscular mycorrhizal (AM) trees have different litter quality and nitrogen cycle modes, which may affect mycorrhizal colonization and the community composition and diversity. However, available studies addressing the mycorrhizal fungal colonization rate, diversity and community composition in mixed forest stands composed of AM and EM trees are rare. In the present study, we assessed litter quality, soil physicochemical properties and correlated them with mycorrhizal community characteristics in rhizosphere soils of monoculture and mixture plantation stands of AM tree species (Fraxinus mandschurica Rupr.) and EM tree species (Larix gmelinii Rupr., Picea koraiensis Nakai) in Northeast China. We hypothesized that (1) the effect of mixture pattern on mycorrhizal colonization rate and diversity would change with tree species, (2) the effect of mixture pattern on mycorrhizal community composition would be less pronounced in comparison with that of tree species. We found that mixture did not change AMF colonization rate regardless of mixture identity, whereas mixture and tree species exerted significant effects on EMF colonization rate. For AMF community, both M-AS (Fraxinus mandschurica Rupr. and Picea koraiensis Nakai) and M-AL (Fraxinus mandschurica Rupr. and Larix gmelinii Rupr.) mixtures significantly increased Pielou index and Simpson index, whereas only M-AS significantly increased Sobs. For EMF community, mixture significantly affected examined diversity indices except for Chao1. Mixture significantly shifted AMF and EMF community, and the magnitude was tree species dependent. The dominant genera in AMF and EMF communities in plantation stands were Glomus and Tomentella, respectively. The EnvFit analysis showed that the determinant factors of EMF community are soil moisture, pH, nitrate nitrogen content, dissolved organic nitrogen content, soil organic matter content, soil organic carbon/total nitrogen and litter carbon/total nitrogen. In conclusion, mixed conifer-broadleaf trees significantly changed soil physicochemical properties, litter quality as well as mycorrhizal fungi community diversity and composition.