Species turnover drives grassland community to phylogenetic clustering over long-term grazing disturbance

2019 ◽  
Vol 13 (2) ◽  
pp. 157-164
Author(s):  
Juntao Zhu ◽  
Yangjian Zhang ◽  
Wenfeng Wang ◽  
Xian Yang ◽  
Ning Chen ◽  
...  
Keyword(s):  
Community Structure ◽  
Species Composition ◽  
Phylogenetic Diversity ◽  
Species Turnover ◽  
Extreme Environments ◽  
Grazing Intensity ◽  
The Tibetan Plateau ◽  
Phylogenetic Community Structure ◽  
Grazing Disturbance

Abstract Aims Grazing exerts profound effects on grassland ecosystem service and functions by regulating species composition and diversity, and structuring community assembly worldwide. However, adaptions of phylogenetic diversity and phylogenetic community structure to long-term grazing disturbance remain poorly studied, especially for ecosystems distributed in extreme environments. Methods Here, we conducted an experiment with multigrazing intensities to explore the impacts of grazing disturbance on plant phylogenetic diversity and community structure in an alpine grassland of the Tibetan Plateau. Important Findings Grazing disturbance enriched plant species richness (SR), and stimulated species turnover from regional species pool, consequently changing community species composition. Under low intensities, grazing exerted no obvious effects on phylogenetic diversity and community structure, whereas communities changed from overdispersion to clustering under high grazing intensity. High grazing intensity resulted in stronger environmental filtering, which consequently selected those species with high resilience to grazing disturbance. The observed clustering structure was associated with the colonizing species which were closely related to resident species, and locally extinct species, and distantly related to residents. At the plant functional trait level, high grazing intensity increased species colonization largely by altering the effect of root depth on species colonization compared to light grazing. Our results highlight that solely utilization of SR and diversity cannot fully represent grassland communities responses to grazing. The effects of species turnover on community phylogenetic diversity and structure are entailed to be explored in the future grazing studies.

scholarly journals Kalahari vegetation: veld condition trends and ecological status of species

Koedoe ◽  
1991 ◽  
Vol 34 (1) ◽  
Author(s):  
N. Van Rooyen ◽  
G.J. Bredenkamp ◽  
G.K. Theron
Keyword(s):  
Species Composition ◽  
Plant Species ◽  
National Park ◽  
Ecological Status ◽  
Grazing Intensity ◽  
Sampling Period ◽  
River Terrace ◽  
River Bed

Grazing intensity gradients were determined in the duneveld, river terrace and river bed habitats of the Kalahari Gemsbok National Park. Under increased grazing, a species composition characterised mostly by annual forbs and grasses results. In all three habitats the relatively heavily grazed areas were closest to the watering points, although this was less evident in the river terrace and river bed habitats. Monitoring degradation at a watering point over the long term, produced results similar to those observed from a single sampling period. The identification of grazing gradients within homogeneous habitats, is a prerequisite for the classification of plant species into different categories. The allocation of a species to a category is based on the changes in frequency along this grazing gradient and this approach is more acceptable than the classification of species commonly used. The use of terminology such as Decreasers and Increasers is discussed.

scholarly journals Changes in plant composition and diversity in an Alpine heath and meadow after 18 years of experimental warming

2020 ◽  
Author(s):  
Juha Alatalo ◽  
Mohammad Bagher Erfanian ◽  
Ulf Molau ◽  
Shengbin Chen ◽  
Yang Bai ◽  
...  
Keyword(s):  
Species Composition ◽  
Plant Communities ◽  
Phylogenetic Diversity ◽  
Dominant Species ◽  
Experimental Warming ◽  
Alpine Plant ◽  
Arctic Ecosystems ◽  
Alpine Plant Communities ◽  
The Impact

Background and aim Global warming is expected to have large impacts on high alpine and Arctic ecosystems in future. Here we report the effects of 18 years of experimental warming on two contrasting high alpine plant communities in subarctic Sweden.Methods Using open-top chambers (OTCs), we analysed the effects of long-term passive experimental warming on two high alpine plant communities, a species- and nutrient-poor heath and a more nutrient- and species-rich mesic meadow. We determined the impact on species composition, species diversity (at the level of rare, frequent and dominant species in each community), and phylogenetic and functional diversity.Key results Long-term warming drove differentiation in the species composition in both heath and meadow vegetation, with the warmed plots having distinctly different species composition in 2013 compared with 1995. In addition, variability in species composition increased in the meadow, while it decreased in the heath. The long-term warming had a significant negative effect on the three orders of phylogenetic Hill diversity in the meadow. There was a similar tendency in the heath, but only the phylogenetic diversity of dominant species was significantly affected. Long-term warming caused a reduction in graminoids in the heath, while deciduous shrubs increased. In the meadow, cushion-forming plants showed an increase in abundance from 2001 to 2013 in the warmed plots. Conclusions Responses in species and phylogenetic diversity to experimental warming varied over both time (medium vs long-term responses) and space (i.e. between the two neighbouring plant communities heath and meadow). The meadow community was more negatively affected in terms of species and phylogenetic diversity than the heath community. A potential driver for the changes in the meadow may be decreased soil moisture caused by the long-term warming.

scholarly journals An enhanced calibration of a recently released megatree for the analysis of phylogenetic diversity

2016 ◽  
Vol 76 (3) ◽  
pp. 619-628 ◽  
Author(s):  
M. Gastauer ◽  
J. A. A. Meira-Neto
Keyword(s):  
Community Structure ◽  
Vascular Plants ◽  
Phylogenetic Trees ◽  
Phylogenetic Diversity ◽  
Vascular Plant ◽  
Divergence Times ◽  
Evolutionary Divergence ◽  
Phylogenetic Community Structure ◽  
Branch Lengths ◽  
Age Estimates

Abstract Dated or calibrated phylogenetic trees, in which branch lengths correspond to evolutionary divergence times between nodes, are important requirements for computing measures of phylogenetic diversity or phylogenetic community structure. The increasing knowledge about the diversification and evolutionary divergence times of vascular plants requires a revision of the age estimates used for the calibration of phylogenetic trees by the bladj algorithm of the Phylocom 4.2 package. Comparing the recently released megatree R20120829.new with two calibrated vascular plant phylogenies provided in the literature, we found 242 corresponding nodes. We modified the megatree (R20120829mod.new), inserting names for all corresponding nodes. Furthermore, we provide files containing age estimates from both sources for the updated calibration of R20120829mod.new. Applying these files consistently in analyses of phylogenetic community structure or diversity serves to avoid erroneous measures and ecological misinterpretation.

Influence of Deforestation on the Community Structure of Sand Flies (Diptera: Psychodidae) in Eastern Amazonia

2019 ◽  
Vol 56 (4) ◽  
pp. 1004-1012
Author(s):  
José Manuel Macário Rebêlo ◽  
Jorge Luiz Pinto Moraes ◽  
Gustavo Barbosa Vieira Cruz ◽  
Joudellys Andrade-Silva ◽  
Maria Da Conceição Abreu Bandeira ◽  
...  
Keyword(s):  
Community Structure ◽  
Species Composition ◽  
Significant Influence ◽  
Sand Fly ◽  
Forest Fragments ◽  
Sand Flies ◽  
Human Occupation ◽  
Short Term

Abstract Variation in the structure of phlebotomine (sand fly) communities in forest fragments with different degrees of preservation and human occupation (peridomicile) in eastern Amazonia was studied. We identified 43 species of sand flies in our study, of which 38 occurred in both preserved forest areas and in the peridomiciles of short-term settlements, while another 28 species occurred in altered forest fragments and long-term settlements. The composition of the community at each site changed with the type of environment (forest or peridomicile), with the species Lutzomyia evandroi, L. whitmani, L. choti, L. serrana, L. triacantha, L. migonei, L. hirsuta, L. shannoni, and L. brachyphylla accounting for more than 54% of the differences among environments. The quality of the environment exerted a significant influence on the structure of phlebotomine communities, and affected their species composition, richness, and abundance.

scholarly journals Actinobacterial Community Structure in Soils Receiving Long-Term Organic and Inorganic Amendments

2007 ◽  
Vol 74 (2) ◽  
pp. 526-530 ◽  
Author(s):  
Zhe Piao ◽  
Linzhang Yang ◽  
Liping Zhao ◽  
Shixue Yin
Keyword(s):  
Community Structure ◽  
Phylogenetic Diversity ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Inorganic Amendments ◽  
Significant Difference ◽  
Gradient Gel Electrophoresis ◽  
Statistical Approaches ◽  
The Impact ◽  
V3 Region

ABSTRACT The impact of long-term organic and inorganic amendments on the actinobacterial community in soils was studied. Denaturing gradient gel electrophoresis patterns based on the V3 region of 16S rRNA suggested that there was no significant difference between the communities occurring in the different amendments. However, analysis of the clone libraries of the actinobacterial communities by the use of multiple statistical approaches showed that these communities were significantly different from each other. Results showed that long-term organic and inorganic soil amendments did not significantly alter the overall phylogenetic diversity of the actinobacterial communities but did significantly change the community structure.

scholarly journals Phylogenetic turnover during subtropical forest succession across environmental and phylogenetic scales

2017 ◽  
Author(s):  
Oliver Purschke ◽  
Stefan G. Michalski ◽  
Helge Bruelheide ◽  
Walter Durka
Keyword(s):  
Community Structure ◽  
Community Assembly ◽  
Deterministic Model ◽  
Species Turnover ◽  
Subtropical Forest ◽  
List Type ◽  
Spatial And Temporal Patterns ◽  
Species Sorting ◽  
Phylogenetic Community Structure ◽  
Successional Stages

SummaryAlthough spatial and temporal patterns of phylogenetic community structure during succession are inherently interlinked and assembly processes vary with environmental and phylogenetic scale, successional studies of community assembly have yet to integrate spatial and temporal components of community structure, while accounting for scaling issues. To gain insight into the processes that generate biodiversity after disturbance, we combine analyses of spatial and temporal phylogenetic turnover across phylogenetic scales, accounting for covariation with environmental differences.We compared phylogenetic turnover, at the species-and individual-level, within and between five successional stages, representing woody plant communities in a subtropical forest chronosequence. We decomposed turnover at different phylogenetic depths and assessed its covariation with between-plot abiotic differences.Phylogenetic turnover between stages was low relative to species turnover and was not explained by abiotic differences. However, within the late successional stages, there was high presence/absence-based turnover (clustering) that occurred deep in the phylogeny and covaried with environmental differentiation.Our results support a deterministic model of community assembly where (i) phylogenetic composition is constrained through successional time, but (ii) towards late succession, species sorting into preferred habitats according to niche traits that are conserved deep in phylogeny, becomes increasingly important.

scholarly journals Acoustic community structure and seasonal turnover in tropical South Asian birds

2019 ◽  
Author(s):  
Anand Krishnan
Keyword(s):  
Community Structure ◽  
Phylogenetic Diversity ◽  
Species Turnover ◽  
Bird Community ◽  
Urban Ecosystems ◽  
Valuable Insight ◽  
Tropical Regions ◽  
Acoustic Community ◽  
Acoustic Space ◽  
Coexisting Species

AbstractBirds produce diverse acoustic signals, with coexisting species occupying distinct ‘acoustic niches’ to minimize masking, resulting in overdispersion within acoustic space. In tropical regions of the world, an influx of migrants from temperate regions occurs during winter. The effects of these migrants on acoustic community structure and dynamics remain unstudied. Here, I show that in a tropical urban bird community, the influx of winter migrants is accompanied by a turnover of the acoustic community. However, in spite of this turnover, the acoustic community remains overdispersed in acoustic niche space. The winter acoustic community additionally exhibits lower frequency-band diversity, consistent with species singing less continuously, as well as lower phylogenetic diversity. My data thus suggests that acoustic niches and community structure are stable across seasons in spite of species turnover. Migrants occupy similar regions of acoustic space as residents, and are relatively closely related to some of these species. Their arrival therefore leads to greater phylogenetic clustering in the winter, and thus lower phylogenetic diversity, although the acoustic community remains overdispersed. Studying seasonal dynamics of acoustic communities thus provides valuable insight into assembly processes, as well as a potential framework for long-term monitoring of urban ecosystems.

scholarly journals Long-Term Changes in Thecomposition, Abundance and Diversity of Phytoplankton Community of Oshika Rivers State

2021 ◽  
pp. 92-116
Author(s):  
Nkechinyere Gladys Nwambara ◽  
John Onwuteaka ◽  
Onyinye Prince Choko
Keyword(s):  
Community Structure ◽  
Oil Spill ◽  
Phytoplankton Community ◽  
Species Turnover ◽  
Diversity Indices ◽  
Dry Season ◽  
Wet Season ◽  
Long Term Changes ◽  
Abundance And Diversity

This study was aimed at determining the long-term changes in composition, abundance, and diversity of the phytoplankton community of the Oshika freshwater biota. Phytoplankton samples at Oshika lake were collected from the same stations and similar months as in the year 1983 study of the 5000 barrels of oil spill. The samples were handled with optimum care and treated according to standard practices in order to preserve the plankton for further analysis and identification. The results of the analysis showed that the phytoplankton yielded a total of 40 species belonging to three groups in 1983 and 36 species belonging to four groups in 2019. Xanthophyceae was the group absent in 1983 but present in 2019, while Chlorophyceae, Cyanophyceae and Bacilariophyceae were common to both 1983 and 2019. Generally, the abundance of phytoplankton in each group in 1983 was significantly different from those of 2019. The Chlorophyceae was the most abundant in both 1983(12.31-186.5) and 2019 (1.27-6.58). The diversity indices result showed that the phytoplankton in 1983 (2.123- 2.563) had lower diversity compared to 2019 (2.381- 2.815). The cluster analysis revealed two groups in 1983 viz the generalist and the dry season specialist, while three groups viz the dry season specialist, wet season specialist and the generalist were observed in 2019. More so, greater data variations were observed in 1983 than 2019. Hence, we infer that there were changes in the phytoplankton community structure between 1983 and 2019. There were changes in the biological community structure between 1983 and 2019. These changes cannot be linked to the oil spill but seems more likely a result of natural variation since results of studies on the hydrocarbon values in water were very insignificant. Since the lake-riverine system is subject to flooding it can be concluded that new plankton from unaffected areas are transported into this area during the flood. The mixing of the water over the years leads to the high variable change. The high variable change brings about high species turnover given the unrestricted hydrodynamics of the River Niger flooding system and its influence on the floodplain Oshika lake.

scholarly journals Seasonal Variations In Species Composition And Community Structure In The Eastern Coast of South Korea

2021 ◽  
Author(s):  
Jeonghoon Han ◽  
Do-Hyung Kang ◽  
Heung-Sik Park ◽  
Young-ung choi
Keyword(s):  
Community Structure ◽  
Species Composition ◽  
Water Temperature ◽  
Seasonal Variations ◽  
Eastern Coast ◽  
Monthly Variation ◽  
Fish Community Structure ◽  
Average Water Temperature ◽  
Number Of Individuals

Abstract The seasonal variations in species composition of set net fisheries were investigated in the eastern coast of Korea, from 2007 to 2008. In total, 51 species were found that were classified into 15 orders and 33 families. The water temperature of the study area was 0.1–2.1 °C during the study period, which was higher than the average water temperature in the last decade. Monthly variation in the number of species peaked twice, in May (spring) and November (autumn) when the water temperature increased and decreased, respectively, and monthly variation in the number of individuals showed a remarkably high trend in winter and autumn and was mainly caused by large migratory species. Based on the cluster analysis of the 18 most dominant species with more than 0.4% of the total number of individuals, we divided the species composition and community structure into three groups: fishes with temporary appearance (Group A), fishes with long-term appearance (Group B), and dominant pelagic fishes appearing with long-term appearance (Group C). We could conclude that seasonal variation in the fish community structure was mainly caused by pelagic migration of species under high water temperature conditions during the study period.

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