The Relationship between Species Richness and Evenness in Plant Communities along a Successional Gradient: A Study from Sub-Alpine Meadows of the Eastern Qinghai-Tibetan Plateau, China

The Park Grass Experiment (PGE), begun at Rothamsted Experimental Station in 1856 and still running, affords a unique opportunity to test for the influence of species number and soil reaction on biomass variability in a suite of comparable plant communities. Biomass variability was measured by calculating the coefficient of variation ( CV ) over time of annual hay yield in an eleven-year moving window. CV and species number were both strongly negatively correlated with biomass; both relations were affected by time and pH. Multiple regression of CV on species number and mean biomass for nonacidified plots in 42 years between 1862 and 1991 showed a relationship between biomass and CV which was negative in most years and significantly so in nearly three quarters of them (30/42). We are unable to tell how much of this effect is intrinsic to the statistical relation between the mean and CV of biomass. Species number was negatively correlated with CV in 29/42 years, but this was statistically significant on only three occasions. Because this relation was highly significant in the year (1991) for which we have the largest sample size (34 plots), we tentatively conclude that biomass variability may be lower in more species-rich communities, although the effect is possibly a weak one. We suggest that physiological stresses imposed by low pH may explain the greater variability of plots with acidified soil. An increase in the variability of biomass that occurred across plots with time may be due in part to acidification across the whole experiment. Three hypotheses are proposed to explain the relationship between species richness and biomass variability: (i) biomass variability on more species-rich plots is better buffered against climatic variation because species differ in their response to climatic conditions: (ii) there are fewer species on plots with greater biomass variability because species have been lost by competitive exclusion in years when biomass reaches high values; (iii) species richness and variability are both correlated with a third variable, for example soil moisture deficit within a plot. All three hypotheses are susceptible to testing within the PGE.

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Community assembly along a successional gradient in sub-alpine meadows of the Qinghai-Tibetan Plateau, China

Oikos ◽

10.1111/j.1600-0706.2012.20828.x ◽

2012 ◽

Vol 122 (6) ◽

pp. 952-960 ◽

Cited By ~ 19

Author(s):

Hui Zhang ◽

Benjamin Gilbert ◽

Xinxin Zhang ◽

Shurong Zhou

Keyword(s):

Tibetan Plateau ◽

Community Assembly ◽

Alpine Meadows ◽

Successional Gradient

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Relationships Between Soil Microbial Communities and Plant Communities on Different Slope Aspects in a Subalpine Coniferous Forest

10.21203/rs.3.rs-1177449/v1 ◽

2021 ◽

Author(s):

Luoshu He ◽

Suhui Ma ◽

Jiangling Zhu ◽

Xinyu Xiong ◽

Yangang Li ◽

...

Keyword(s):

Species Richness ◽

Plant Community ◽

Plant Communities ◽

Soil Microbial Communities ◽

Basal Area ◽

Coniferous Forests ◽

Slope Aspect ◽

Soil Microbial ◽

Plant Soil ◽

The Relationship

Abstract Purpose The local microclimate of different slope aspects in the same area can not only impact soil environment and plant community but also affect soil microbial community. However, the relationship between aboveground plant communities and belowground soil microbial communities on various slope aspects has not been well understood.Methods We investigated the above- and belowground relationship on different slope aspects and explored how soil properties influence this relationship. Plant community attributes were evaluated by plant species richness and plant total basal area. Soil microbial community was assessed based on both 16S rRNA and ITS rRNA, using High-throughput Illumina sequencing. Results There was no significant correlation between plant richness and soil bacterial community composition on the north slope, but there was a positive correlation on the south slope and a significantly negative correlation on the flat site. There was a significantly negative correlation between soil fungal community composition and plant total basal area, which did not change with the slope aspect. In addition, there was no significant correlation between plant community species richness and soil microbial species richness.Conclusions In subalpine coniferous forests, the relationship between plant-soil bacteria varies with slope aspect, but the plant-soil fungi relationship is relatively consistent across different slope aspects. These results can improve our understanding of the relationship between plant and soil microorganisms in forest ecosystems under microtopographic changes and have important implications for the conservation of biodiversity and forest management in subalpine coniferous forests.

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The Relationship of Dominance and Evenness with Productivity and Species Richness in Plant Communities with Different Organization Models

Russian Journal of Ecology ◽

10.1134/s1067413618040021 ◽

2018 ◽

Vol 49 (4) ◽

pp. 296-305 ◽

Cited By ~ 2

Author(s):

V. V. Akatov ◽

T. V. Akatova ◽

C. G. Chefranov

Keyword(s):

Species Richness ◽

Plant Communities ◽

Relationship Of ◽

The Relationship ◽

Organization Models

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Grazing Exclusion Changed the Complexity and Keystone Species of Alpine Meadows on the Qinghai-Tibetan Plateau

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.638157 ◽

2021 ◽

Vol 9 ◽

Author(s):

Yong Zhang ◽

Qingzhu Gao ◽

Hasbagan Ganjurjav ◽

Shikui Dong ◽

Qiuzhu Zheng ◽

...

Keyword(s):

Species Richness ◽

Tibetan Plateau ◽

Plant Community ◽

Field Survey ◽

Keystone Species ◽

Soil Bulk Density ◽

Clustering Coefficient ◽

Available Nitrogen ◽

Alpine Meadows ◽

Grazing Exclusion

Grazing exclusion is an effective approach to restore degraded grasslands. However, the effects of grazing exclusion on keystone species and the complexity of plant community were poorly investigated. Here, we conducted a field survey among different grazing exclusion durations, i.e., Grazing, grazing exclusion below 5 years, grazing exclusion with 5 years, grazing exclusion with 7 years, and grazing exclusion over 7 years, in alpine meadows on the central Qinghai-Tibetan Plateau (QTP). The complexity and keystone species of alpine meadows were analyzed by a network analysis. The results showed the following: (1) The species richness did not change, but aboveground biomass and the coverage of the plant community tended to increase with the extension of the grazing exclusion duration. (2) The soil nutrients, i.e., total nitrogen, total organic carbon, available nitrogen, and available potassium, remained stable, while the soil bulk density decreased under grazing exclusion conditions. (3) There was a hump-shaped change of the complexity (i.e., average connectivity and average clustering coefficient) of the plant community along with the extension of the grazing exclusion duration. Moreover, the keystone species were different among the grazing exclusion treatments. Based on the complexity of the plant community and the changes of keystone species, the optimum duration of grazing exclusion for alpine meadows should be between 5 and 7 years. Our results suggest that besides the productivity, the change of the complexity and keystone species of plant community should be considered when grazing exclusion is adopted to restore the degraded alpine meadows.

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Integrative models explain the relationships between species richness and productivity in plant communities

Scientific Reports ◽

10.1038/s41598-019-50016-3 ◽

2019 ◽

Vol 9 (1) ◽

Author(s):

Zhenhong Wang ◽

Alessandro Chiarucci ◽

Juan F. Arratia

Keyword(s):

Species Richness ◽

Plant Communities ◽

Resource Availability ◽

Plant Productivity ◽

Species Pool ◽

Combination Method ◽

Negative Effects ◽

Plant Richness ◽

The Relationship ◽

Underlying Processes

Abstract The relationship between plant productivity and species richness is one of the most debated and important issues in ecology. Ecologists have found numerous forms of this relationship and its underlying processes. However, theories and proposed drivers have been insufficient to completely explain the observed variation in the forms of this relationship. Here, we developed and validated integration models capable of combining twenty positive or negative processes affecting the relationship. The integration models generated the classic humped, asymptotic, positive, negative and irregular forms and other intermediate forms of the relationship between plant richness and productivity. These forms were linked to one another and varied according to which was considered the dependent variable. The total strengths of the different positive and negative processes are the determinants of the forms of the relationship. Positive processes, such as resource availability and species pool effects, can offset the negative effects of disturbance and competition and change the relationship. This combination method clarifies the reasons for the diverse forms of the relationship and deepens our understanding of the interactions among processes.

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