scholarly journals The Influence of Plant Dominants on the Associated Species Abundance in Wet Tall-Herb Meadow Plant Communities

Author(s):  
Vera Lebedeva ◽  
Marina Tikhodeyeva ◽  
Elena Koptseva

Abstract Plant interactions in wet tall-herb meadow plant communities were described through dominant and edificator species identification. Five dominant species were identified: Alopecurus pratensis, Filipendula ulmaria, Deschampsia cespitosa, Anthriscus sylvestris, and Angelica sylvestris. The effects of species were studied using ANOVA and correlation analyses. Not all dominants were recognised as edificators. Edificators (Alopecurus pratensis, Filipendula ulmaria, Deschampsia cespitosa, Angelica sylvestris) had a negative effect on the various abundance indicators of associated species: percent cover, number, phytomass, and height. The edificator effects differed significantly in their level and duration and depended on the biomorphs of dominants. The perennial species Alopecurus pratensis, Filipendula ulmaria, and Deschampsia cespitosa were strong constant edificators. Angelica sylvestris, a short-lived monocarpic from the Apiaceae, is a weak seasonal edificator, while Anthriscus sylvestris is not an edificator. Analysis of the life strategies of species showed that competitors are not always edificators (Anthriscus sylvestris), whereas stress-tolerant may show edificator properties (Deschampsia cespitosa). The associated plant species often show positive interactions. Most of the associated species are stress-tolerant and have not an edificator effect.

Web Ecology ◽  
2012 ◽  
Vol 12 (1) ◽  
pp. 49-55 ◽  
Author(s):  
C. Ariza ◽  
K. Tielbörger

Abstract. Despite efforts to discern the role of plant size in resource competition, the circumstances under which size-dependent plant-plant interactions occur are still unclear. The traditional assumption is that competition intensifies with increasing neighbour size. However, recent studies suggest that the size (biomass) dependence of competitive interactions is strongest at very low biomass levels and becomes negligible after a certain threshold neighbour biomass has been reached. We searched for the generality of such patterns for three common annual plant species in Israel. We monitored target and neighbour biomass along their entire lifecycle using an even-aged, intraspecific and intrapopulation competition screenhouse experiment under water-limited conditions. For all focal species, neighbour presence had a net negative effect on vegetative biomass at harvest. However, this was not explained by increasing neighbour biomass over time, as a consistent pattern of size-dependent facilitative, rather than competitive, interactions was observed at all life stages. We explain these observations in terms of co-occurring aboveground facilitation and dominant belowground competition for water. Since our findings are the first of their kind and contradict theoretical predictions of biomass dependence of net negative interactions, we advocate further experiments addressing size dependence in interactions among plants. In particular, theoretical models addressing size dependence of positive interactions must be developed.


Author(s):  
M. I. Dzhalalova ◽  
A. B. Biarslanov ◽  
D. B. Asgerova

The state of plant communities in areas located in the Tersko-Sulak lowland was studied by assessing phytocenotic indicators: the structure of vegetation cover, projective cover, species diversity, species abundance and elevated production, as well as automated decoding methods. There are almost no virgin soils and natural phytocenoses here; all of them have been transformed into agrocenoses (irrigated arable lands and hayfields, rice-trees and pastures). The long-term impact on pasture ecosystems of natural and anthropogenic factors leads to significant changes in the indigenous communities of this region. Phytocenoses are formed mainly by dry-steppe types of cereals with the participation of feather grass, forbs and ephemera, a semi-desert haloxerophytic shrub - Taurida wormwood. At the base of the grass stand is common coastal wormwood and Taurida wormwood - species resistant to anthropogenic influences. Anthropogenic impacts have led to a decrease in the number of species of feed-rich grain crops and a decrease in the overall productivity of pastures. Plant communities in all areas are littered with ruderal species. The seasonal dynamics of the land cover of the sites was estimated by the methods of automatic decoding of satellite images of the Landsat8 OLI series satellite for 2015, dated by the periods: spring - May 20, summer - July 23, autumn - October 20. Satellite imagery data obtained by Landsat satellite with a resolution in the multispectral image of 30 m per pixel, and in the panchromatic image - 10 m per pixel, which correspond to the requirements for satellite imagery to assess the dynamics of soil and vegetation cover. Lower resolution data, for example, NDVI MODIS, does not provide a reliable reflection of the state of soil and vegetation cover under arid conditions. In this regard, remote sensing data obtained from the Internet resource https://earthexplorer.usgs.gov/ was used.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Alexia Stokes ◽  
Guillermo Angeles ◽  
Fabien Anthelme ◽  
Eduardo Aranda-Delgado ◽  
Isabelle Barois ◽  
...  

Abstract Objectives Altitude integrates changes in environmental conditions that determine shifts in vegetation, including temperature, precipitation, solar radiation and edaphogenetic processes. In turn, vegetation alters soil biophysical properties through litter input, root growth, microbial and macrofaunal interactions. The belowground traits of plant communities modify soil processes in different ways, but it is not known how root traits influence soil biota at the community level. We collected data to investigate how elevation affects belowground community traits and soil microbial and faunal communities. This dataset comprises data from a temperate climate in France and a twin study was performed in a tropical zone in Mexico. Data description The paper describes soil physical and chemical properties, climatic variables, plant community composition and species abundance, plant community traits, soil microbial functional diversity and macrofaunal abundance and diversity. Data are provided for six elevations (1400–2400 m) ranging from montane forest to alpine prairie. We focused on soil biophysical properties beneath three dominant plant species that structure local vegetation. These data are useful for understanding how shifts in vegetation communities affect belowground processes, such as water infiltration, soil aggregation and carbon storage. Data will also help researchers understand how plant communities adjust to a changing climate/environment.


2001 ◽  
Vol 79 (4) ◽  
pp. 510-519 ◽  
Author(s):  
Philippe Lebreton ◽  
Bernard Jeangros ◽  
Christiane Gallet ◽  
Jan Scehovic

Organic and mineral components have been analysed on 18 dicotyledonous species of permanent grassland communities. Multivariate analysis revealed an opposition between a macromolecular pool (cellulose and lignin) and a nutrient pool (potassium and phosphorus, nitrogen). The first pole is characterized by Tragopogon pratensis L. (Compositae) and Galium mollugo L. (Rubiaceae), the second by Anthriscus sylvestris (L.) Hoffm. (Umbelliferae) and Geranium sylvaticum L. (Geraniaceae). The most thermo-helio-xerophilous species (Knautia arvensis (L.) Coult and Tragopogon pratensis) belong to the first group, whereas the second group includes the cool-environment species (like Alchemilla xanthochlora Roth.), which reveals an ecophysiological determinism. Moreover, correlations between the biochemical and ecological structure, and other interrelated parameters, including sclerophylly, have been shown. Compared to lignous and sempervirent plant communities, the grassland species have lower phenolic and lignin contents but higher glucide and nutrient (potassium and phosphorus) contents, which is in accordance with their food value. For this herbaceous community, the C/N ratio indicates the same general equilibrium between cell-wall macromolecules and nitrogen than for two other plant communities (mainly ligneous) previously studied, with some differences revealing distinct trends from the same general metabolic sheme.Key words: dicotyledonous plant communities, biochemical organization, C/N ratio, ecophysiology.


1984 ◽  
Vol 62 (9) ◽  
pp. 1968-1970 ◽  
Author(s):  
William G. Roland ◽  
L. Michael Coon

Recovery of intertidal Porphyra beds following hand harvest was studied near the northwest tip of the Queen Charlotte Islands, B.C. Twenty-six percent of the standing crop of Porphyra perforata J. Ag. was removed in a large plot in June 1981; no negative effect on standing crop was apparent in May 1982 as compared with the adjacent control area. There was no negative impact on percent cover of Porphyra (mostly P. perforata) within 1 year after hand harvest of seven, approximately 1-m2 plots, as compared with respective controls. Annual fluctuation in cover, biomass, and relative mix of Porphyra species was large. Porphyra cover in a small plot harvested in early June 1981 increased to 86% of the June value by mid-July 1981, indicating substantial growth of the remaining thallus fragments and small, whole plants within one season. It was concluded that sustained yield of Porphyra beds can be assured if harvest is restricted to gathering by hand.


Author(s):  
Y. Erfanifard ◽  
E. Khosravi

Evaluating the interactions of woody plants has been a major research topic of ecological investigations in arid ecosystems. Plant-plant interactions can shift from positive (facilitation) to negative (competition) depending on levels of environmental stress and determine the spatial pattern of plants. The spatial distribution analysis of plants via different summary statistics can reveal the interactions of plants and how they influence one another. An aggregated distribution indicates facilitative interactions among plants, while dispersion of species reflects their competition for scarce resources. This study was aimed to explore the intraspecific interactions of eshnan (<i>Seidlitzia rosmarinus</i>) shrubs in arid lands, central Iran, using different summary statistics (i.e., pair correlation function g(<i>r</i>), O-ring function O(<i>r</i>), nearest neighbour distribution function D(<i>r</i>), spherical contact distribution function Hs(<i>r</i>)). The observed pattern of shrubs showed significant spatial heterogeneity as compared to inhomogeneous Poisson process (α=0.05). The results of g(<i>r</i>) and O(<i>r</i>) revealed the significant aggregation of eshnan shrubs up to scale of 3 m (α=0.05). The results of D(<i>r</i>) and Hs(<i>r</i>) also showed that maximum distance to nearest shrub was 6 m and the distribution of the sizes of gaps was significantly different from random distribution up to this spatial scale. In general, it was concluded that there were positive interactions between eshnan shrubs at small scales and they were aggregated due to their intraspecific facilitation effects in the study area.


2021 ◽  
Author(s):  
Laura del Rio-Hortega ◽  
Irene Martín-Forés ◽  
Isabel Castro ◽  
José M. de Miguel ◽  
Belén Acosta-Gallo

Associated with the introduction of exotic species in a new area, interactions with other native species within the recipient community occur, reshaping the original community and resulting in a unique assemblage. Yet, the differences in community assemblage between native and invaded ranges remain unclear. Mediterranean grasslands provide an excellent scenario to study community assembly following transcontinental naturalisation of plant species. Here we compared the community resemblance of plant communities in Mediterranean grasslands from both the native (Spain) and invaded (Chile) ranges. We used a novel approach based on network analysis applied to co-occurrence analysis in plant communities, allowing us to study the coexistence of native and alien species in central Chile. This useful methodology is presented as a step forward in invasion ecology studies and conservation strategies. We found that community structure differed between the native and the invaded range, with naturalised species displaying more significant interactions and playing a key role within the invaded community. In addition, alien species displayed positive interactions among them within the communities in the invaded range. Alien species acting like keystones within the Chilean grassland communities might exacerbate the threat posed by biological invasions for the native biodiversity assets. We suggest controlling the spread of the alien species identified as keystones and developing early detection strategies in surrounding areas as management guidelines.


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