Pianka's Niche Overlap Research Articles

Water Niche Characteristics of Subalpine Shrub in Eastern Qilian Mountains, China

ABSTRACTThe investigation and research of plant niche provide new ideas for understanding the extent of resource utilization by plants and the coexistence relationship among species. Taking the subalpine shrub plants in the eastern Qilian Mountains as the research object, the contribution rate of each potential water source to the shrub plants was estimated using the Bayesian mixed modelling (MixSIAR), and the spatial and temporal characteristics of their water niche were analysed quantitatively using Levins' niche breadth index and Pianka's niche overlap index. The results showed that shrub plants on the semi‐shady slope exhibited larger water niche breadth and overlap compared to those on the semi‐sunny slope, which indicated that shrub plants on the semi‐shady slope had strong adaptability to the water environment, but the competition for water among them was more intense. Furthermore, the water niche breadth and overlap of shrub plants decreased with the promotion of the growth stage, which was related to changes in precipitation and plant physiological characteristics during their growth cycle. Among the studied species, Potentilla fruticosa Linn., Salix oritrepha Schneid., Salix cupularis Rehd. and Rhododendron thymifolium Maxim. had broader water niche breadth in different habitats, indicating superior adaptability to the subalpine environment. Despite that the water niche overlap among shrub plants was high and their competition for water resources was intense, there was no absolute positive correlation between niche breadth and overlap. The research can provide a theoretical reference for the rational allocation of species during vegetation restoration in Qilian Mountain National Park.

Drivers of plant diversification along an altitudinal gradient in the alpine desert grassland, Northern Tibetan Plateau

Revealing alpine plant diversity patterns can contribute to conserving mountain plant diversity. However, the spatial variation in the ecological niche and diversity patterns of the plant community and the mechanism by which it maintains itself in alpine desert grasslands remain poorly understood. Here, we conducted a field investigation across altitudinal gradients (3093, 3296, 3549, and 3790 m) in the northern Tibetan Plateau and compared species composition, diversity indices, Levins' niche breadth, and Pianka's niche overlap. The results showed that perennial herbs replaced semi-shrubs and xermesophytes and mesophytes replaced xerophytes with increasing altitude. The plant community heights decreased with altitude. The cover of the herb layer increased with altitude, whereas that of the shrub layer was hump-shaped. Species diversity indices (Patrick, Pielou, Shannon-Wiener, and Simpson) increased with increasing altitude. Sympegma regelii (1.05), Leymus chinensis (1.03), and Reaumuria kaschgarica (0.94) had larger niche breadths and were widespread. Species with a high niche overlap occupied a considerable proportion at higher altitudes, indicating strong interactions among species. The redundancy analysis revealed that altitude, soil water content, soil organic matter content, and pH were the main factors driving changes in plant diversity (P = 0.036, F = 3.7). Our study illustrated that environmental filtering and biotic interactions jointly shape plant composition and diversity in alpine desert grasslands along altitudinal gradients.

Correlation of plasticities to drought and shade: implications for environmental niche overlap in drylands

Phenotypic plasticity can increase the extent of the environmental gradient occupied by a species (niche breadth) and modify the portion of niche space shared among co‐occurring species (niche overlap). Thus, phenotypic plasticity may play a role in community assembly processes. Given that plants deal with a multivariate environment, and that functional traits are often correlated, plastic responses to different environmental factors are likely correlated. However, the implications of correlations of plasticities for niche overlap remain unexplored. Here, we present and evaluate a conceptual framework that links correlations of plasticities and niche overlap patterns among co‐occurring plant species. We specifically tested in an arid shrubland whether positive, negative, or null correlations between plasticity to light and water availability would be associated with patterns of high, low, or random niche overlap, respectively. Field data identified light and water availability as key factors shaping herbaceous plant community structure. We estimated species' niche breadth and niche overlap using two‐dimensional kernel–density estimations (NOK) and standardised effect sizes of Pianka's niche overlap index (OSES). We measured phenotypic plasticity to light and water availability in the six most abundant species in a greenhouse experiment. We used the plasticity index (PI) to test 1) the relationship between plasticity to light and water availability, and 2) the association between overall plasticity (average PI across traits) and niche breadth. We found a positive relationship between plasticity to light and water availability. Increased overall plasticity was associated with a broader niche breadth. Both NOK and OSES estimations indicated a significant niche overlap pattern. Results supported one of the predictions of our conceptual framework: that a positive correlation of plasticities would lead to increased niche overlap. The verified conceptual framework broadens our understanding of the role of phenotypic plasticity in plant community coexistence.

Morphological characteristics influence the spatial mixing patterns of shorebirds at Shengjin Lake.

The coexistence of species with similar ecological niches is one of the core interests of community ecology research. However, how functional feeding traits, including bill size and leg length, determine the niche of mixed flocks of shorebird species has seldomly been studied, as well as, microhabitat variables affect the spatial patterns of availability and the quality of patches for wintering. From October 2016 to March 2017 at Shengjin Lake, Anhui Province, China, we recorded 226 scan samples from the different microhabitats and 93 focal animal videos of four common shorebird species: common greenshank, spotted redshank, Kentish plover, and little ringed plover. We found that the species participating in the mixed groups were different in each microhabitat. The results of the overlap index for microhabitats and foraging techniques between the species were consistent with the morphological characteristics of these species. Kentish and little ringed plovers had the highest Pianka's niche overlap index values of 0.95 and 0.98 for microhabitats and foraging techniques, respectively, whereas common greenshank and spotted redshank had values of 0.78 and 0.89, respectively. Common greenshank and spotted redshank used four foraging techniques: a single probe (PR), multiple probes (MPR), a single peck (PE), and multiple pecks (MPE). Kentish and little ringed plovers only used PE and MPE. The mean bill size, mean leg length, and mean foraging frequency were significantly associated with water depth. The mean bill size and mean leg length were both significantly correlated with the mean foraging frequency of shorebirds. The vegetated area was the most important variable for grouping among shorebirds. We concluded that the four species showed differences in their preferred microhabitats and foraging patterns. Interspecific morphological differences, including bill and leg lengths, resulted in niche differentiation. Thus, effective resource allocation by regional species was realized, and a dynamic balance was achieved by the mixed foraging species. The information on foraging behavior and habitat requirements could be useful in the management of water levels in natural areas and conservation of a diversity of wintering shorebirds.

Habitat degradation, vegetation damage, and wildlife‐livestock interactions in Amboseli ecosystem wildlife sanctuaries, Kenya

AbstractIt is important to assess whether anthropogenic activity affects wildlife distribution and resource use to appraise the efficacy of multi‐use protected areas. Habitat degradation and vegetation damage as indicators of competitive and facilitative livestock‐wildlife interactions were the focus of this study. Foot transects were conducted in the dry season of 2011, wet season of 2012, and dry season of 2012 in five wildlife sanctuaries in the Amboseli ecosystem, Kenya, to determine whether habitat degradation and vegetation damage affected wildlife distribution and wildlife‐livestock interactions. Simpson's and Jaccard's biodiversity indices and Pianka's niche overlap index were used to assess wildlife‐livestock interactions across a gradient of habitat degradation. In the dry season, Jaccard's, Pianka's, and Simpson's indices (0.50, 0.84, and 0.99, respectively) peaked at the highest level of degradation. In the wet season, Jaccard's index (0.42) peaked at a fairly high level of habitat degradation, Pianka's index (0.82) at a fairly low level, and Simpson's (0.80) at the lowest level. Two‐way ANOVA revealed that there was no effect of degradation or vegetation damage on wildlife distribution irrespective of the feeding guild. Therefore, it appears that continued shared use of the Amboseli landscape by wildlife and livestock is feasible.

入侵植物藿香蓟与常见伴生杂草的生态位特征

PDF HTML阅读 XML下载 导出引用 引用提醒 入侵植物藿香蓟与常见伴生杂草的生态位特征 DOI: 10.5846/stxb202104060881 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 浙江省自然科学基金项目(LY20C030002);浙江省教育厅一般项目(Y202045218) Niche characteristics of the invasive plant Ageratum conyzoides and its commonly associated weeds 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:基于传统生态位理论的生物入侵机制假说认为外来种和土著种生态位的差异是决定入侵成功与否和危害程度的关键。藿香蓟(Ageratum conyzoides L.)是一种在我国南方快速蔓延的恶性入侵种。为了了解藿香蓟与其他杂草在群落中的生态关系,探究造成藿香蓟成功入侵的可能机制及危害,在浙西南的丽水市开展了杂草群落调查,计算了藿香蓟和16种常见本地杂草的生态位宽度、生态位重叠和种间相关系数,并对主要物种进行典范对应分析(CCA)排序。结果表明(1)藿香蓟与常见本地杂草间的生态位重叠度显著高于本地杂草间的生态位重叠度,这与藿香蓟具有最大的生态位宽度有关;(2)藿香蓟与常见本地杂草的Pianka生态位重叠指数介于0.04-0.296之间,重叠度处于中下水平;(3)常见本地杂草对于藿香蓟的n-维超体积生态位重叠值显著高于藿香蓟对于常见本地杂草的n-维超体积生态位重叠值;(4)藿香蓟在CCA排序图上处于较中心的位置,说明其具有较高的中生性;不仅如此,外来杂草和本地杂草在排序图上充分混杂,说明外来种相对于本地种并无明显特化;(5)群落中大多数常见杂草间未出现显著种间负相关,仅7个种对显著正相关,大多数种对不相关。总的来说,丽水农村的杂草群落稳定较差,资源相对充足,种间生态位重叠较低,本地植物对于藿香蓟的竞争阻抗较小,加上藿香蓟本身较大的生态位宽度,导致了藿香蓟在本地区广泛而严重的入侵。 Abstract:According to the hypothesized mechanism of biological invasion, which is based on traditional niche theory, niche differentiation between alien species and native species is the key to the success of invasion and the damage it causes. Ageratum conyzoides L. is a malignant invasive species that is spreading rapidly in southern China. In order to understand the ecological relationships between A. conyzoides and native weeds in the community and to explore the possible mechanism of A. conyzoides invasion and its harmfulness, an investigation of the weed community was carried out in southwestern Zhejiang Province (28°06'-28°44'N, 119°32'-120°08'E) from 2014 to 2016. A total of 109 plots (1 m×1 m) and 286 plant species were investigated in the following habitats: roadside, abandoned farmland, streamside, and open forest. For each plot, all aboveground plant material was harvested, classified, and weighed according to species. In addition, slope, aspect, and altitude of the plot as well as the rate of sunshine arriving at the plot were measured. Moreover, pH value and the contents of total nitrogen, alkaline nitrogen, effective phosphorus, available potassium, and organic material in superficial soil (0-10 cm depth) of each plot were tested. Levin's niche breadth, Pianka's niche overlap, probability of n-dimensional niche overlap, and interspecific correlation coefficients of A. conyzoides and 16 common native weeds were calculated, and a canonical correspondence analysis (CCA) was conducted. The results showed that (1) the degree of niche overlap between A. conyzoides and common native weeds was significantly higher than that between any two native weeds, due to the largest niche breadth of A. conyzoides. (2) The Pianka niche overlap index between A. conyzoides and common native weeds was in the middle or lower level of 0.04-0.296. (3) The probabilities of n-dimensional niche overlap of common native weeds with A. conyzoides were significantly higher than those of A. conyzoides with common native weeds. (4) A. conyzoides was distributed in the central region of a CCA ordination chart, which indicated that A. conyzoides was a mesophilic species; moreover, exotic weeds (including A. conyzoides) and native weeds were fully mixed in the ordination chart, which indicated that there was no obvious specialization of exotic species relative to native species; and (5) there were no significantly interspecific negative correlations among the 17 common weed species; only 7 species pairs showed significantly positive correlation, and most species did not correlate with each other. In general, the weed community in the rural areas of southwestern Zhejiang Province is unstable, with relatively sufficient resources and low niche overlap among species. Low competition resistance from native plants and large niche width of A. conyzoides lead to extensive and serious invasion of A. conyzoides in the rural area of southwestern Zhejiang Province. 参考文献 相似文献 引证文献

洮河自然保护区大峪沟林区紫果云杉群落木本植物种群生态位特征

PDF HTML阅读 XML下载 导出引用 引用提醒 洮河自然保护区大峪沟林区紫果云杉群落木本植物种群生态位特征 DOI: 10.5846/stxb202102070395 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 甘肃省林业科技创新项目（KJCX201909，KJCX202001）；甘肃省林业科技项目（2015KJ051）；林业科技推广项目（2020ZYTG16） Niche of woody plant populations of Picea purpurea community in Dayugou forest area, Taohe Nature Reserve, Gansu Province 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:基于群落调查数据，以样地代表多种资源的综合状态，物种重要值作为生态位的计测指标，利用Levins和Shannon生态位宽度，Schoener生态位相似和Pianka生态位重叠对洮河自然保护区大峪沟林区的紫果云杉群落木本植物种群生态位进行定量研究。结果表明：紫果云杉群落乔木层共有树种8种，隶属于4科6属，紫果云杉占绝对优势，岷江冷杉为次优势种；灌木层共有植物50种，隶属于16科25属，忍冬科的蓝靛果、葱皮忍冬和唐古特忍冬等以及蔷薇科的峨眉蔷薇和银露梅等构成了灌木层的主体，紫果云杉幼苗优势不明显，但生态位宽度最大。本研究表明，生态位宽度受物种生态特性及其分布和生境共同影响，重要值大的物种生态位宽度一般较大，生态位宽度大的物种之间生态位相似性和重叠性一般较大，并与其它物种重叠的概率高、重叠程度大，生态位宽度小的物种集中出现时也会出现较大的生态位重叠，同科或同属的物种间常有较大生态位相似和重叠。生态位宽度反映着种群的扩散潜力，生态位相似反映着群落的稳定性，生态位重叠反映着物种间存在或潜在的竞争程度。紫果云杉在乔、灌木层均有最大的生态位宽度，生态适应性最强，群落结构稳定，具有进一步扩散的可能。 Abstract:Based on the plant community investigation data, and with plots representing the comprehensive status of multiple resources, and species importance values as measurement indicators of niche, the niche characteristics of woody plant species in the Picea Purpurea Community in Dayugou forest area of the Taohe Nature Reserve were quantified with the indices of Levins niche breadth, Shannon niche breadth, Schoener niche similarities and Pianka niche overlap. The results showed that there were 8 tree species in the tree layer of the picea purpurea community, belonging to 4 families and 6 genera, among which the picea purpurea was the absolute dominant species, and the Abies faxoniana was the subdominant species; the shrub layer had a total of 50 species of plants belonging to 16 families and 25 genera, among which Lonicera caerulea, Lonicera ferdinandii and Lonicera tangutica of the Caprifoliaceae and Rosa omeiensis and Potentilla glabra of the Rosaceae are the dominant species of the shrub layer, and the picea purpurea seedlings did not have obvious advantages but they had the widest niche breadth. This study indicated that the niche breadth was affected by the ecological characteristics of species as well as their distribution and habitat. The species with large important values generally had larger niche breadth, and the species with large niche breadth generally had the larger niche similarity and overlap, and had higher probability and degree of overlap with other species; there were also large niche overlaps when species with small niche breadth were concentrated, and the species of the same family or genus often had larger niche similarities and overlaps. Niche breadth reflected the population dispersal potential, the niche similarity reflected the stability of a community, and the niche overlap reflected the degree of the existing or potential competition among species. Picea Purpurea had the widest niche breadth in both the tree layers and shrub layers, the strongest ecological adaptability, the stable community structure, and thus the possibility of further dispersal. 参考文献 相似文献 引证文献

Competition versus opportunism: Diet and trophic niche relationship of two sympatric apex carnivores in a tropical forest

There is a little understanding of how apex carnivores partition their diet to coexist. We studied food habit and trophic niche overlap of two apex carnivores, tiger and leopard in the tropical forest of Similipal tiger reserve, eastern India. We used line transect and scat analysis method, to estimate the prey availability and determine the diet and prey selection of two apex carnivores. Tigers consumed mostly large and medium-sized prey, whereas leopards mostly consumed medium and small-sized prey. Both carnivores were not random in their consumption of prey, sambar and wild pigs were selectively consumed by tigers, whereas leopards selectively consumed wild pigs, barking deer and mouse deer. Dietary overlap between two carnivore species was moderate (Pianka's niche overlap index: 0.55), and trophic niche breadth (Levin's standardized niche breadth) of the leopard (0.52) was greater than that of the tiger (0.37). Overall, tigers exhibited specialized feeding habits, whereas leopards showed generalist feeding habits. Our study highlights the opportunistic nature of leopards and probably a reason for the species successfully coexist with tigers.

Density dependence influences competition and hybridization at an invasion front

AbstractAimLandscape and climatic change are promoting range shifts, potentially leading to competition and hybridization between formerly isolated species. However, density‐dependent interactions can impede the timely identification of associated conservation problems. The barred owl's expansion into the spotted owl's range provides a natural experiment to test for density dependence in niche overlap and hybridization in the early versus late stages of a biological invasion, thus illuminating an important biogeographical process.LocationPacific Northwest, USA to the northern Sierra Nevada, California, USA.MethodsIn the northern Sierra Nevada, where barred owl density was low, we quantified niche overlap between barred owls and spotted owls along three axes (landscape‐scale habitat selection based on passive acoustic survey data, foraging habitat selection measured with GPS tag data, and diet measured with stable isotopes) and assessed hybridization with phenotypic data. We then compared our findings to studies on these species from the Pacific Northwest, where barred owl density is high.ResultsIn the Sierra Nevada, overlap in landscape‐scale habitat selection was low (spotted owl sites also occupied by barred owls: 21%), overlap in foraging habitat selection and diet was high (Pianka's niche overlap: 0.802; stable isotope ellipse overlap: 0.52), and hybridization was common (hybrid:barred owl ratio: 0.364). In the Pacific Northwest, niche overlap was high (barred owl occupancy of spotted owl territories: 40%–95%, Pianka's niche overlap of foraging habitat selection and diet: 0.809 and 0.429) and hybridization was rare (hybrid:barred ratio: 0.061).Main conclusionsForaging habitat selection and diet were density‐independent and therefore predictive of the competitive exclusion of spotted owls in the Pacific Northwest that has resulted from the barred owl invasion. Landscape‐scale monitoring programmes capable of yielding systematic data on multiple species can offer an early warning of biological invasions; however, individual‐level traits such as foraging habitat selection may influence the population processes that can determine the outcome of those invasions.

Abiotic controls, but not species richness, shape niche overlap and breadth of ant assemblages along an elevational gradient in central Spain

Niche overlap and breadth are fundamental characteristics of ecological niches that have been hypothesized to relate both to environmental conditions and to biotic interactions within a community. Abiotic factors and interspecific competition may have opposing effects on those niche characteristics by respectively filtering out species from the niche space and limiting among-species similarity. Here we set out to assess niche overlap and breadth of ant assemblages in Mediterranean grasslands along a 1668-m elevational gradient in the Guadarrama range (Central Spain). We carried out an outdoor cafeteria experiment considering two niche dimensions on resource acquisition: food type and period of aboveground activity. We compared metrics describing niche overlap and breadth to null models and related the metrics to elevation, temperature at ground level and a proxy of interspecific competition (species richness) with general linear models. Pianka's niche overlap indexes were higher than those calculated with random assemblages, but differences among observed and random assemblages were only significant at mid-elevations and were unrelated to the explanatory variables. Overlap along elevation seemed more due to overlap in period of activity. Niche breadth at the assemblage level was significatively smaller than null expectations and was related to elevation (negatively) and to species richness (positively). These were significantly larger than estimates for the species level. These results show that ant assemblages exploit a subset of available conditions, in a pattern only partially coincident with a scenario of abiotic control. Moreover, their constituent species share time of activity and, to a lesser extent, food resources, in spite of the interspecific competition structuring communities that is often assumed. Overall, the patterns we recorded suggest that other mechanisms should be acting to promote species coexistence, such as trade-offs among ecological functions.

EDNA metabarcoding reveals dietary niche overlap among herbivores in an Indian wildlife sanctuary

AbstractAs many ecosystems are under increasing pressure from invasive species, habitat degradation, overgrazing and overharvesting, pollution, and climate change, dietary niche monitoring is gaining importance. The Malai Mahadeshwara Wildlife Sanctuary (MMH) in southern India is home to several long‐standing ethnic and tribal groups and supports a considerable number of domestic herbivores (cattle, goats and water buffalo) as well as a range of wildlife (including several species of deer, bonnet macaque, and Asian elephant). We reconstructed dietary niche partitioning of the herbivores occurring in MMH using eDNA metabarcoding to quantify diet richness, composition, and overlap. In total, we distinguish 134 diet items (molecular operational taxonomic units), covering 31 plant families. Overall, our results indicate 35% overlap in domestic and wild herbivore diet items. The greatest overlap is found for the dietary niches of cattle and sambar deer (Pianka's niche overlap index: 0.68), and the dietary niche of cattle also overlaps considerably with those of Indian hare (0.65) and Asian elephant (0.46). This suggests that these herbivores may compete for these food plants in the case of limited availability, which could lead to exclusion of some herbivore species. Particular concern should go to bonnet macaque and Asian elephant as their below average dietary richness could make them vulnerable to changes in their environment. With increasing pressures on local wildlife from a range of different factors, DNA metabarcoding of fecal samples is a non‐invasive method for monitoring changes in animal diets, providing valuable information for the management of biodiversity in mosaic natural and anthropogenic landscapes.

The effects of land degradation on plant community assembly: Implications for the restoration of the Tibetan Plateau

AbstractUnderstanding how biotic and abiotic filters drive plant distributions is critical for informing restoration efforts of degraded lands. However, it remains unclear whether or not it is possible to develop efficient restoration strategies that are based on field investigations? Here, we conducted a field‐based investigation along a land degradation gradient on the Tibetan Plateau. Along this gradient, we compared species composition, Pianka's niche overlap, and total aboveground biomass among grasses, sedges, legumes, and forbs. We also used Faith's (1992) phylogenetic diversity index (PD) and the net relatedness index (NRI) to measure community phylogenetic patterns. To understand the effects of abiotic filtering, we measured soil pH, moisture, electrical conductivity, total soil organic carbon, microbial biomass carbon, and microbial biomass nitrogen. Our results show that grasses replaced sedges and mesoxerophytes replaced mesohydrophytes with increasing land degradation. We also found that niche overlap declined with increasing degradation intensity. Furthermore, grass biomass increased, while sedges and legumes decreased, and forb biomass showed a hump‐shaped relationship with degradation intensity. In addition, the communities transitioned from a clustered to a more random phylogenetic pattern. Soil conditions changed from acidic to alkaline and from fertile to harsh (p < .05). High niche overlap indicates a high biotic filtering at lightly degraded land where abiotic filtering is less stressful. However, when degradation is intense, abiotic filtering is apparent, as indicated by low levels of niche overlap. Overall, we suggest that distantly related, arid tolerant and hardy plants, and soil reclamation should be considered in degraded alpine lands restoration.

Guild Composition and Niche Overlap of Insectivorous Birds in Evergreen Rainforest

A guild is a group of species that have similar requirements of resource and foraging behavior. The knowledge of insectivorous guild could explain foraging patterns, niche exploitation, and competition in a tropical forest. This information could help to monitor the forest by understanding the guild composition and their response to the habitat condition. In order to describe the guild composition and niche overlap of insectivorous birds, we observed all of the individual birds found foraging in the evergreen forest, Baluran National Park. Bray-Curtis similarity index and Pianka niche overlap index were used to analyze the data and grouping the birds into a guild. The cluster analysis consists of 27 bird species revealed 4 guilds: ground gleaner, foliage gleaner, aerial sallier, and bark prober. Based on species richness, foliage gleaner dominates the other groups while bark prober had the least species richness in the evergreen forest. The scarcities of feeding substrate affect guild existence and proved that the diversity of habitat substrate could affect the diversity of guild in an area. Ten congeneric species were found in this habitat and most of them are grouped into foliage gleaner. The junglefowl has the highest niche overlap than any other congeneric species. It seemed that the more specific the foraging substrate niche, the higher the competition among sympatric species. The level of congeneric/sympatric species competition could become the indicator to monitor a specific habitat or forest by understanding their niche partitioning, especially if the species is protected by the law.

桂林岩溶石山青冈群落灌木层主要物种生态位与种间联结

PDF HTML阅读 XML下载 导出引用 引用提醒 桂林岩溶石山青冈群落灌木层主要物种生态位与种间联结 DOI: 10.5846/stxb201904090689 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31860124）；广西自然科学基金项目（2016GXNSFBA380030） Niche and interspecific association of main species in shrub layer of Cyclobalanopsis glauca community in karst hills of Guilin, southwest China Author: Affiliation: Fund Project: The National Natural Science Foundation of China(31860124); Guangxi Natural Science Foundation Project (2016GXNSFBA380030) 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:基于样方调查，采用生态位测定、方差比率法、χ2检验、Pearson相关检验和Spearman秩相关检验等方法对桂林岩溶石山青冈群落灌木层主要物种的生态位与种间联结进行研究。结果表明：（1）青冈的生态位宽度最大，占绝对竞争优势；重要值较大（小）的物种，其生态位宽度一般较大（小），但两者顺序并非完全一致。（2）主要物种间的生态位相似性较小，各物种对资源利用的相似程度不高；一般生态位宽度较大的物种，其生态位相似性也越大。（3）生态位宽度较大的物种间产生生态位重叠的概率较大，但生态位重叠程度并不一定大；生态位宽度与生态位重叠有一定的联系，但并不存在绝对的正相关关系；生态位相似性和生态位重叠程度的变化趋势基本吻合。（4）灌木层主要物种的总体联结性表现为显著正联结，表明该群落处于相对稳定的演替阶段。（5）χ2检验、Pearson相关检验和Spearman秩相关检验结果的显著率均较低，种间联结性不强。（6）物种间的Pearson相关系数、Spearman秩相关系数与相应的生态位相似性和生态位重叠程度之间均呈显著正相关，表现为种间正（负）联结越强，生态位相似性和生态位重叠程度越大（小）。 Abstract:Niche and interspecific associations, which are significant quantitative and structural characteristics, reflect relationships among species in a plant community as well as community stability, and thus providing an important theoretical basis for forest vegetation restoration and reconstruction, forest management and biodiversity conservation. In order to understand mechanisms underlying the formation of niche and interspecific associations of main species in the shrub layer of Cyclobalanopsis glauca communities, a total of 100 shrub plots were established and investigated in the Cyclobalanopsis glauca communities in karst hills of Guilin. We selected 20 shrub layer species on the basis of their importance values. The niche characteristics of main species in shrub layers were quantified with the indices of Levins niche breadth, Shannon niche breadth, Schoener niche similarity and Pianka niche overlap. The interspecific association was researched by using a set of methods, namely, variance ratio(VR), χ2 test, Pearson's correlation test and Spearman's rank correlation test. The results showed that:(1)the Levins and Shannon niche breadth index indicated that the niche breadth of Cyclobalanopsis glauca was the largest among the twenty species that we have studied. It indicated that Cyclobalanopsis glauca had a stronger ability to compete and utilize resources in the shrub layer, with the absolute competitive advantage and stronger ecological adaptability. The species with larger importance values generally had larger niche breadth, but the rank orders of them were not exactly the same. (2)the mean value of niche similarity of main species in the shrub layer was 0.156. There was a lower degree of niche similarity among species within the community, indicating that they had a lower similarity in resource utilization. (3)the result of niche similarity proportion and niche overlap was similar but not the same. The differences between them suggest that using similar resources are not sufficient to cause competition among these species. (4)the W test showed that the overall interspecific associations were significantly positive associations among the main species in the shrub layer. This reflected that the Cyclobalanopsis glauca community in karst hills of Guilin was in a relatively stable succession status. (5)the results of the χ2 test, Pearson's correlation test, and Spearman's rank correlation test showed that the significance ratios of the species pairs were all lower. The species pairs with insignificant interspecies correlations accounted for the majority of the species pairs in the shrub layer, reflecting a weak association among the various species pairs in the shrub layer. Most of the species showed an independent distribution pattern. (6)both Pearson's correlation coefficient and Spearman's rank correlation coefficient showed significantly positive correlations with niche similarity and niche overlap value. In other words, the species pairs with stronger positive association generally had larger niche similarity and niche overlap. On the contrary, the species pairs with stronger negative association generally had smaller niche similarity and niche overlap. 参考文献 相似文献 引证文献

Feeding strategy and morphology as indicators of habitat use and coexistence of two loricariid fishes from a Brazilian coastal stream

Abstract: We aimed to evaluate the relationship between form and function of two Loricariidae species (Hypostomus punctatus and Parotocinclus maculicauda) from a Neotropical coastal stream. We performed morphological-dietary analysis and discussed their coexistence strategies, as well. We hypothesized that both species use similar food resources according to their morphology but differences in habitat use facilitate their coexistence. In order to test this hypothesis, morphology, diet and habitat use were analyzed for both species. Trophic variance and the Pianka Niche Overlap index were calculated to explore the differences in trophic niche. Correlations between species abundance and water flow were applied to test habitat use. Principal Component Analysis and one Permutational Multivariate Analysis of Variance were applied to test differences between morphology and diet of both species. Morphological-dietary relationships were tested with Mantel test correlations. Total abundance of H. punctatus was higher in the stream channel with higher water flow. The dominant food items were sediment and organic matter for both species, and high trophic niche overlap was revealed. Additionally, morphology did not explain feeding habits for both species. Morphological characteristics were significantly different, especially for intestine length, relative area of the dorsal fin, ventral flattening and mouth attributes. The study site was rich in sand sediment, mud, and clay that are not considered good substrates to the establishment and growing of periphyton, which is an important trophic resource to Loricariidae species. Here, low consumption of periphyton can provide a possible explanation for the feeding similarity and the weak morphological-dietary relationships for both species. Thus, the environmental conditions can be more important for diet composition when compared to the similar and specialized morphology of loricariids.

Niche of main woody plant populations of Pterocarya stenoptera community in riparian zone of Lijiang River, China.

To understand the niche characteristics of main woody species in Pterocarya stenoptera community, we investigated P. stenoptera communities in riparian zone of Lijiang River, China. The niche characteristics of main species in tree layers and shrub layers were quantified with the indices of Levins niche breadth, Shannon niche breadth, Schoener niche similarities and Pianka niche overlap. The results showed that P. stenoptera in the tree layer, and Ficus abelii and Morus alba in the shrub layer had higher niche breadth than other species. The species with larger importance values generally had larger niche breadth, but the rank orders of which were not exactly the same. The niche similarity of main populations in the tree layer was generally smaller than that in the shrub layer. The mean value of niche similarity of main populations in the tree layer and shrub layer was 0.151 and 0.236, respectively. There was a low degree of niche similarity among species within the community, indicating that they had a low similarity in resource use. The niche overlap of main populations in the tree layer was generally smaller than that in the shrub layer, with the mean value of niche overlap of main populations in the tree layer and shrub layer being 0.217 and 0.273, respectively. The niche overlap between the main species in the community was relatively lower. There was no significant correlation between niche breadth and niche similarity. The species with larger niche breadth often had more opportunities to overlap with other species. However, their overlap value was not necessarily larger. Larger niche similarity was often associated with higher degrees of niche overlap. The P. stenoptera community in riparian zone of Lijiang River was the climax community, the relationship among species was relatively stable, the population regeneration was very slow, and the development trend of this community was declining in the future.

Comparing habitat preferences of a set of waterbird species wintering in coastal wetlands of North Africa: implication for management

AbstractEvery year, the Coastal wetlands of North Africa support an important wintering waterbird population of many Palearctic and sub-Saharan species of various contrasting habitat requirements. In this study, we describe the habitat use by24 water-obligate species wintering in a coastal wetland of the Northeastern Algeria (the wetland of Lake Tonga), highlighting thereby the ecological mechanisms that support their coexistence and their resources partitioning. The analysis of resource exploitation (Relative frequency, Feinsinger niche breadth, Pianka niche overlap and Ivlev’s electivity indexes) showed that waterbird species inhabiting the lake wetland have several similarities in using the different habitat categories, which lead us to cluster them into 5 guilds (G1: one rails, two grebes and eight ducks; G2: five wading species and one gull; G3: three herons; G4: cormorants, mallards, and on gull; finally, G5: only one species Cattle egret (Bubulcus ibis).Almost all the species were specialists in resource utilization patterns (narrow niche breadths, both under 0.3) and therefore, vulnerable to fluctuations in resources, particularly the feeding habitats. Mean niche overlaps for all the pairs of species ranged from 0.05 to 0.68. The overall pattern in the community was higher niche overlaps between the species of a particular guild than those between other species. According to Ivlev’s electivity index, we found that only three microhabitats from seven were the most important for the discussed species, open water body was the most attractive, followed by meadows, muddy areas and floating- leafed vegetation. Similarities on habitat requirements derived from our region can provide important and optimal wetland management at multi-species assemblage level for this wetland and similar area around the African coast.

Winter food habits of sympatric carnivores, Amur tigers and Far Eastern leopards, in the Russian Far East

Amur tigers and Far Eastern leopards are sympatric in the Russian Far East. Different ecological characteristics, such as different resource use, may enable coexistence of these two large predators, as indicated in other tiger–leopard habitats in Asia. We examined the winter food habits of tigers and leopards in the sympatric range in Southwest Primorskii Krai, Russian Far East using feces collected during four winters (2000–01, 2001–02, 2002–03, and 2004–05). Fecal samples were identified as either tiger or leopard by genetic analysis, and we examined 63 and 139 samples of tiger and leopard feces, respectively. We found that leopards preyed on 13 species and tigers on 8 species. Wild boar and sika deer were the most frequently consumed prey for tigers and leopards, respectively. Three ungulates (sika deer, roe deer, and wild boar) appeared to be the essential prey because they provided a large proportion of the relative biomass consumed by tigers (92%) and leopards (87%). Tigers showed a strong preference for wild boar (Jacobs index: +0.55), whereas leopards did not show such a strong preference for any particular ungulate species. Moreover, both species consumed mid-sized carnivores and small mammals, with leopards consuming a more diverse range of prey, including squirrels, rodents, birds, and clams, none of which were identified in the tiger feces. There was a significant difference in the composition of their prey, suggesting resource partitioning between the two predators; however, Pianka's niche overlap index was high (0.77) because both species heavily relied on the three ungulates. Our study suggests that the availability of three different ungulate species, the tigers’ preference for wild boar, and the diverse prey base of leopards contribute to the coexistence of tigers and leopards in this region.

Spatial and Dietary Overlap Creates Potential for Competition between Red Snapper (Lutjanus campechanus) and Vermilion snapper (Rhomboplites aurorubens)

Understanding the complex nature of direct and indirect species interactions is a critical precursor to successful resource management. In the northern Gulf of Mexico fisheries ecosystem, red snapper (Lutjanus campechanus) and vermilion snapper (Rhomboplites aurorubens) are two commercially harvested species within a larger reef fish complex. These two species share similar habitats and diets; however, little is known about how these species partition habitat and dietary resources. In this study we examined the extent of spatial and dietary overlap between red snapper and vermilion snapper, and experimentally compared their feeding behavior. Field data from multiple gear types demonstrates that red snapper and vermilion snapper frequently cohabited reefs in the northern Gulf of Mexico, and Pianka’s niche overlap indices suggest significantly overlapping diets. Experimental manipulations show that red snapper are the dominant forager of the two species, as red snapper foraging alone ate more shrimp per fish than vermilion snapper in both the single species (p = 0.003) and mixed species (p = 0.02) treatments. In addition, red snapper ate significantly more shrimp per fish in the mixed species treatment than in the single species treatment (p = 0.04). Vermilion snapper shrimp consumption per fish did not differ significantly between mixed and single species treatments. Cumulatively, our results suggest that spatial and dietary overlap could lead to competition between red and vermilion snapper in the study area; however, conclusively determining the existence of such competition would require further research.

Monopolization of resources by ground-nesting ants foraging on trees in Mediterranean forests

Ant communities are generally structured by territoriality, dominance and resource monopolization, but in Mediterranean hot grassland thermal tolerance plays a more important role. The main purposes of the present research were to investigate the hypothesis that in cooler Mediterranean forests resource monopolization structures the generalist ground-nesting ant community while foraging on trees, and to learn if tree heterogeneity plays any role in this structure. In Mediterranean forests in Israel, I visually recorded and trapped ants on the forest floor and those climbing on trees of five species. Ants of 27 species were detected, while the Chao2 index indicated an asymptotic richness estimation of 31 ± 8.1 species (mean ± S.D.). The numerically dominant species were Crematogaster lorteti and Tapinoma simrothi followed by Tapinoma israele and Crematogaster scutellaris. In more than 80% of the cases, specimens of only one ant species climbed at the same time on any individual tree, and no tree was occupied by more than three species. The C-score of climbing ants was statistically higher than simulated indexes when resources were individual trees, indicating that the ants strongly monopolized each tree. No difference was detected between observed and simulated C-scores when resources were tree species. The observed index of Pianka's niche overlap indicated no species specific interaction between trees and ants. In conclusion, this study confirms that ant mosaic structure may be formed by ground-nesting ants while foraging on trees. Tree species heterogeneity did not have a selective impact on the ants nor a central role in the ant community structure.