scholarly journals Stability in the plant communities of the Park Grass Experiment: the relationships between species richness, soil pH and biomass variability

1994 ◽  
Vol 346 (1316) ◽  
pp. 185-193 ◽  
Keyword(s):  
Species Richness ◽  
Plant Communities ◽  
Climatic Conditions ◽  
Species Number ◽  
Soil Reaction ◽  
Moisture Deficit ◽  
Rothamsted Experimental Station ◽  
Park Grass Experiment ◽  
The Relationship ◽  
Biomass Variability

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.

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

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.

scholarly journals Extrapolative Estimation of Benthic Diatoms (Bacillariophyta) Species Diversity in Different Marine Habitats of the Crimea (Black Sea)

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
A. N. Petrov ◽  
E. L. Nevrova
Keyword(s):  
Species Richness ◽  
Black Sea ◽  
Benthic Diatoms ◽  
Species Number ◽  
Depth Range ◽  
Marine Habitats ◽  
Total Species Richness ◽  
The Crimea ◽  
The Relationship ◽  
Total Species

Benthic diatoms species richness was analyzed based on 93 samples collected at 8 areas of Crimea (Black Sea) on sandy/muddy bottoms within depth range 6–48 m. Totally 433 species were found. Expected species richness Sexp was estimated by application of Jack-knife -1 and -2, Chao-2, and Karakassis-S∞ estimators. Magnitude of Sexp, resulted from S∞, displayed the most similar values to the observed species number (Sobs). Overestimation of Sobs (10–13%) occurred for small number of samples (<12), and slight underestimation (3–5%) occurred when sample numbers exceeded 40–43. The other estimators gave large overestimated results (Chao—from 21 to 70% higher than Sobs, Jack-knife—23–58%). The relationship between number of samples (X) and number of observed species (Y) was calculated considering all 93 samples: Y=79.01lnx+34.95. Accordingly, not less than 10 samples are required for disclosing about 50% of the total species richness (433); to detect 80% (347 species) not less than 46 samples should be considered. Different configurations of S∞ method were applied to optimize its performance. The most precise results can be achieved when the calculation of the Sexp is based on sequences of randomized samples with sampling lags of 10 to 15.

scholarly journals Methodological aspects in the study of species richness, diversity and homotony of grass cover

2008 ◽  
Vol 53 (No. 1) ◽  
pp. 33-41 ◽  
Author(s):  
F. Klimeš ◽  
L. Kolář ◽  
J. Květ ◽  
W. Opitz von Boberfeld ◽  
H. Laser
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Plant Species ◽  
Species Number ◽  
Regression Equations ◽  
Grass Cover ◽  
Methodological Aspects ◽  
The Relationship ◽  
Number Of Plant Species

This work proposes a new method for the assessment of species richness, diversity, and homotony in related vegetation relev&eacute;s of grass swards. Hypothetical vegetation relev&eacute;s with identical species number but differing constancy were generated to compare the techniques describing the species variety and diversity. By calculating these theoretical values in combination with data from real swards of Alopecuretum meadows, it has been shown that the determination of the constancy of particular species is essential for the evaluation of species diversity of grass swards. The relationship between the share of different combinations of vegetation relev&eacute;s in the whole sample and corresponding total number of plant species were expressed by generating regression equations and the mid values of these curves were worked out and evaluated for individual sets of relev&eacute;s; it was then possible to create homotony/heterotony indices for these sets. The indices of heterotony can be used, e.g., for expressing biotope diversity within a set of vegetation relev&eacute;s from different stands.

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

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.

scholarly journals Competition, facilitation and environmental severity shape the relationship between local and regional species richness in plant communities

Ecography ◽  
2014 ◽  
Vol 38 (4) ◽  
pp. 335-345 ◽  
Author(s):  
Richard Michalet ◽  
Jean-Paul Maalouf ◽  
Philippe Choler ◽  
Bernard Clément ◽  
David Rosebery ◽  
...  
Keyword(s):  
Species Richness ◽  
Plant Communities ◽  
The Relationship ◽  
Environmental Severity

ЗУБРЫ НА СЕВЕРЕ РОССИИ — НАСТОЯЩЕЕ И БУДУЩЕЕ

2019 ◽  
pp. 42-44
Author(s):  
I.V. GUSAROV ◽  
V.A. OSTAPENKO ◽  
T.V. NOVIKOVА
Keyword(s):  
Biological Diversity ◽  
Climatic Conditions ◽  
Economic Consequences ◽  
European Bison ◽  
Rare And Endangered Species ◽  
The North ◽  
Rare And Endangered ◽  
Relationship Of ◽  
First Time ◽  
The Relationship

Впервые в мире создана популяция зубров на территории 60 градусов северной широты. В новых климатических условиях разведения и сохранения зубров определены и проанализированы факторы существования вида на севере Европейской части РФ. Выявлены признаки, динамика численности, которые являются составной частью системы, предназначенной для управления биоразнообразием. Интродукция, являясь процессом введения в экосистему нехарактерных для нее видов, может усиливать изменения биоценозов как положительно, так и отрицательно. Насколько быстро и успешно проходит процесс адаптации заселенного вида, и усматривается его влияние на окружающую среду зависит дальнейшее существование зубров и в целом биоразнообразия. В статье обсуждаются вопросы взаимоотношения зубров с другими видами копытных и хозяйственной деятельностью человека, а также дальнейшим использованием зубров в сельскохозяйственном производстве. Пластичность зубров, выявление изменений и их анализ при вселении видов в новые условия обитания необходимы не только для определения развития или деградации биоценозов и в целом экосистемы, но и прогноза социально-экономических последствий интродукции как одного из методов сохранения редких и исчезающих видов фауны.For the first time in the world, a bison population has been created in an area of 60 degrees north latitude. In the new climatic conditions of breeding and preservation of bison, the factors of the species existence in the north of the European part of the Russian Federation are identified and analyzed. The signs, dynamics of abundance, which are an integral part of the system designed to manage biodiversity are identified, since the preservation of biological diversity on the planet is one of the main problems of our time. Introduction, being the process of introducing non-typical species into an ecosystem, can enhance changes in biocenoses, both positively and negatively. The question posing sounds especially when it comes to such a large hoofed animal as the European bison. How quickly and successfully the process of adaptation of the universe takes place and its environmental impact is seen depends on the continued existence of bison and biodiversity in general. The article discusses the relationship of bison with other types of ungulates and human activities, as well as the further use of bison in agricultural production. How these issues will be resolved positively depends on the future of these animals. Thus, the plasticity of bison, the identification of changes and their analysis, with the introduction of species into new habitat conditions is necessary not only to determine the development or degradation of biocenoses and the ecosystem as a whole, but also to predict the socio-economic consequences due to the introduction as one of the methods of preserving rare and endangered species of fauna.

Sign in / Sign up

Export Citation Format

Share Document