scholarly journals Arbuscular mycorrhizal association and dependency determined the pioneer plant community, diversity structure and plant cover in two river bank under same climate

2019 ◽  
Vol 6 (13) ◽  
pp. 453-465
Author(s):  
Somdatta Ghosh ◽  
D. Kuila ◽  
N. K. Verma

Early colonization of plants in an area is influenced mostly by climatic, edaphic and phytogeographic factors. As arbuscular mycorrhizae (AM) was associated with early invasion of land plants on earth, AM may have some role in defining the first seral community in any land. Two riverbanks were selected to study their pioneer plant community structure with species composition and diversity, soil characters and arbuscular mycorrhizal association; and correlations among these factors. Species composition, diversity and richness indices, active AM association of early colonizing plant species, soil texture, moisture, pH and E.C in two river banks differed. Similarity index for plant species between the two communities was poor. Diversity and richness indices were high in K site while evenness was high in R site. AM colonization and spore density correlated highly with plant cover and frequency in both riverbanks. Soil moisture showed a strong negative impact on mycorrhization, soil organic carbon showed little. Soil pH showed varied correlation in different sites. Early colonizing plants in R site with silt-loam soil with high moisture level are found poorly mycotrophic or nonmycotrophic; though plant cover correlated highly with mycotrophy in both sites. Plants in sandy soil of K site are highly mycotrophic and with high arbuscular and vesicular colonizations. The distribution of frequency in R site is highly deviated from Raunkiuer’s frequency class; in K site it is rather stable. The soil condition is only key factor to determine plant composition and plant-mycorrhizal relations influencing colonization of early seral community.

Botany ◽  
2008 ◽  
Vol 86 (12) ◽  
pp. 1416-1426 ◽  
Author(s):  
Amy C. Ganguli ◽  
David M. Engle ◽  
Paul M. Mayer ◽  
Eric C. Hellgren

Widespread encroachment of the fire-intolerant species Juniperus virginiana  L. into North American grasslands and savannahs where fire has largely been removed has prompted the need to identify mechanisms driving J. virginiana encroachment. We tested whether encroachment success of J. virginiana is related to plant species diversity and composition across three plant communities. We predicted J. virginiana encroachment success would (i) decrease with increasing diversity, and (ii) J. virginiana encroachment success would be unrelated to species composition. We simulated encroachment by planting J. virginiana seedlings in tallgrass prairie, old-field grassland, and upland oak forest. We used J. virginiana survival and growth as an index of encroachment success and evaluated success as a function of plant community traits (i.e., species richness, species diversity, and species composition). Our results indicated that J. virginiana encroachment success increased with increasing plant richness and diversity. Moreover, growth and survival of J. virginiana seedlings was associated with plant species composition only in the old-field grassland and upland oak forest. These results suggest that greater plant species richness and diversity provide little resistance to J. virginiana encroachment, and the results suggest resource availability and other biotic or abiotic factors are determinants of J. virginiana encroachment success.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Mesfin Belete Hailemariam ◽  
Tamru Demsis Temam

Vegetation-environment relationships are usually studied along elevational gradient. The patterns of plant community distribution in Gole forest, Ethiopia, were studied along elevational gradient and disturbances. Disturbances were recorded following the elevational gradient. For vegetation data collection, 62 sample plots of size 20 × 20 m were established along an elevational gradient (2728–3480 m.a.s.l). Data on species composition and environmental variables were measured and recorded in each plot. The elevation of each sample plot was measured using Garmin GPS. Anthropogenic disturbances in each plot were estimated using the following scales: 0 = no disturbance, 1 = slightly disturbed, 2 = moderately disturbed, and 3 = highly disturbed. R statistical package was used for cluster and ordination analysis. Boxplots and analysis of variance were used to assess the relationships between plant communities and environmental variables. Sorensen’s similarity coefficient was used to detect similarities and dissimilarities among communities. A total of 114 plant species belonging to 57 families and 94 genera were identified. Five plant community types were identified using agglomerative hierarchical cluster analysis. Every plant community had differences in composition and environmental variables. The variation in plant community distributions was significantly related to elevation and disturbance. Plant community distribution was negatively correlated with elevation ( P < 0.05 ) and also with disturbance ( P < 0.05 ). Sorensen’s similarity index showed that there was a difference in the distribution of plant species composition among the communities. The difference in plant community distribution of Gole forest was significantly related to elevation. Disturbances also have a considerable influence on the plant communities and mitigation of disturbance should be the main measure that needs to be taken into account in conservation planning in the study area.


2011 ◽  
Vol 59 (4) ◽  
pp. 369 ◽  
Author(s):  
Suzanne M. Prober ◽  
Rachel J. Standish ◽  
Georg Wiehl

Emerging ecological theory predicts that vegetation changes caused by introduction of livestock grazing may be irreversible after livestock are removed, especially in regions such as Australia that have a short evolutionary exposure to ungulate grazing. Despite this, fencing to exclude livestock grazing is the major tool used to restore vegetation in Australian agricultural landscapes. To characterise site-scale benefits and limitations of livestock exclusion for enhancing biodiversity in forb-rich York gum (Eucalyptus loxophleba Benth. subsp. loxophleba)–jam (Acacia acuminata Benth.) woodlands, we compared 29 fenced woodlands with 29 adjacent grazed woodlands and 11 little-grazed ‘benchmark’ woodlands in the Western Australian wheatbelt. We explored the following two hypotheses: (1) fencing to exclude livestock facilitates recovery of grazed woodlands towards benchmark conditions, and (2) without additional interventions after fencing, complete recovery of grazed woodlands to benchmark conditions is constrained by ecological or other limits. Our first hypothesis was supported for vegetation parameters, with fenced woodlands being more similar to benchmark woodlands in tree recruitment, exotic plant cover, native plant cover, native plant richness and plant species composition than were grazed woodlands. Further, exotic cover decreased and frequency of jam increased with time-since-fencing (2–22 years). However, we found no evidence that fencing led to decline in topsoil nutrient concentrations towards concentrations at benchmark sites. Our second hypothesis was also supported, with higher topsoil nutrient concentrations and exotic plant cover, and lower native plant richness in fenced than in benchmark woodlands, and different plant species composition between fenced and benchmark woodlands. Regression analyses suggested that recovery of native species richness is constrained by exotic species that persist after fencing, which in turn are more persistent at higher topsoil nutrient concentrations. We conclude that fencing to exclude livestock grazing can be valuable for biodiversity conservation. However, consistent with ecological theory, additional interventions are likely to be necessary to achieve some conservation goals or to promote recovery at nutrient-enriched sites.


2011 ◽  
Vol 40 (2) ◽  
pp. 175-196
Author(s):  
ERIK JONES ◽  
THERESA MILLER ◽  
JEREMY MONSMA ◽  
JILLIAN PUSZYKOWSKI ◽  
JOANNE WESTPHAL

ABSTRACT This paper describes plant species composition and coverage changes that occurred on an extensive (shallow) green roof system exposed to direct solar exposure and steep roof conditions over time. The green roof system, installed in August, 2005, involved a pre-seeded, manufactured mat product that initially was vegetated with twelve plant species. During the interim between installation and data collection for this paper, no maintenance, fertilizer, or irrigation was applied, despite the fact that observable differences in plant coverage were noted. In April, 2009, undergraduate student researchers revisited the green roof system and examined the green roof for species composition and absolute plant cover. These data were compared to a control area where solar incidence and slope were comparable to the conditions found on a flat roof system. This paper reports on the findings of this study, and offers insight to the types of modifications in extensive green roof technology that may be necessary if extensive green roof application is to be useful for steep roof conditions in cold climate environments.


2017 ◽  
Vol 4 (3) ◽  
pp. 51-58
Author(s):  
Aiswarya N.K ◽  
Muthuraj K ◽  
Siva Priya K.T ◽  
Krishnan E ◽  
Nagarajan N

The present investigation has brought out the AM fungal association in some plant species of Kodikuthimala, Malappuram district Kerala. Totally, 25 plant species belongs to 15 families were analyzed for arbuscular mycorrhizal association. The root samples of all collected plant species showed mycorrhizal infection. The percentage of colonization was varied with plant species and it ranges from 12 (Commelina benghalensis) to 79% (Sida rhombifolia). Maximum spore population was observed in Gloriosa superba (574/100g of soil) and minimum in Euphorbia hirta (143/10g of soil). Totally 26 AM fungal species belongs to 13 genera were found. Among this Glomus was most dominated. In most of the plants, spores of Rhizophagus fasciculatus are seen. Present study confirms the Arbuscular Mycorrhizal association in the collected plant species.


2008 ◽  
Vol 275 (1638) ◽  
pp. 1029-1035 ◽  
Author(s):  
Vincent Merckx ◽  
Martin I Bidartondo

The ancient arbuscular mycorrhizal association between the vast majority of plants and the fungal phylum Glomeromycota is a dominant nutritional mutualism worldwide. In the mycorrhizal mutualism, plants exchange photosynthesized carbohydrates for mineral nutrients acquired by fungi from the soil. This widespread cooperative arrangement is broken by ‘cheater’ plant species that lack the ability to photosynthesize and thus become dependent upon three-partite linkages (cheater–fungus–photosynthetic plant). Using the first fine-level coevolutionary analysis of mycorrhizas, we show that extreme fidelity towards fungi has led cheater plants to lengthy evolutionary codiversification. Remarkably, the plants' evolutionary history closely mirrors that of their considerably older mycorrhizal fungi. This demonstrates that one of the most diffuse mutualistic networks is vulnerable to the emergence, persistence and speciation of highly specific cheaters.


Land ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1191
Author(s):  
Alyson Gagnon ◽  
Nicole J. Fenton ◽  
Pascal Sirois ◽  
Jean-François Boucher

Mining activities generate residues during the ore concentration process. These wastes are placed into large tailing storage facilities, and upon mine closure, these tailings must be reclaimed. This study aimed to determine how different reclamation methods, involving combinations of planted boreal woody species and organic amendments application (paper mill sludge biosolids, chicken manure, and topsoil) affected plant community diversity at two tailing storage facilities in Québec, Canada. We recorded the composition of the plant communities using the percent cover of plant species within 1 m × 1 m quadrats. At the Niobec mine site, paper mill sludge mixed with topsoil enhanced total plant cover was compared with the use of topsoil only; the former amendment, however, reduced evenness (J′) and diversity (1−D) due to the increased growth of grasses and invasive forbs. At the Mont-Wright site, plots having received paper mill sludge mixed with a “Norco” treatment (a mixture of chicken manure, hay, and grass seeds) produced the highest total plant cover. The Norco treatment mixed with topsoil and the single application of topsoil and biosolids produced the highest evenness (J′) and diversity (1−D). Overall, organic amendment applications promoted vegetation cover on tailings and contributed to the colonization of diverse plant communities.


2020 ◽  
Vol 21 (2) ◽  
Author(s):  
Sutomo Sutomo ◽  
I Dewa Putu Darma ◽  
Rajif Iryadi

Abstract. Sutomo, Darma IDP, Iryadi R. 2020. Short communication: The dissimilarity in plant species composition of savanna ecosystem along the elevation gradient on Flores Island, East Nusa Tenggara, Indonesia. Biodiversitas 21: 492-496. Savannas in Indonesia are located from west to the east across the archipelago. The objective of this research was to investigate the dissimilarity of floristic composition among savannas at different elevations in Flores. Sixteen sampling plots, each measuring 20 x 20 m were spread over the lowland, midland, and upland savannas. We analyzed the differences in plant community composition among the savannas using NMDS ordination and SIMPER analyses available in PRIMER V.6. As many as 41 species of plants were found in all of the sampling plots. The lowland savanna plant community consisted of Themeda arguens, Zoesya sp., Chromolaena odorata, Crotalaria sp., Adenanthera pavonina, Ocimum sp., Lantana camara in the groundcover layer, and Ziziphus jujube, and Borassus flabellifer at the tree layer. The midland savanna had almost similar composition, except the occurrence of Imperata cylindrica and Leucaena leucocephala, and the upland savanna plant species were Cyperus sp., Polygala paniculata, I. cylindrica, Melastoma malabathricum, C. odorata, Centella asiatica, Vaccinium sp., and Cymbopogon sp. The savannas in Flores were invaded by invasive exotic species, namely L. camara and C. Odorata which may pose serious threat to the existence of savannas.


PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0244982
Author(s):  
Christina Alba ◽  
Richard Levy ◽  
Rebecca Hufft

In this age of rapid biodiversity loss, we must continue to refine our approaches to describing variation in life on Earth. Combining knowledge and research tools from multiple disciplines is one way to better describe complex natural systems. Understanding plant community diversity requires documenting both pattern and process. We must first know which species exist, and where (i.e., taxonomic and biogeographic patterns), before we can determine why they exist there (i.e., ecological and evolutionary processes). Floristic botanists often use collections-based approaches to elucidate biodiversity patterns, while plant ecologists use hypothesis-driven statistical approaches to describe underlying processes. Because of these different disciplinary histories and research goals, floristic botanists and plant ecologists often remain siloed in their work. Here, using a case study from an urban greenway in Colorado, USA, we illustrate that the collections-based, opportunistic sampling of floristic botanists is highly complementary to the transect- or plot-based sampling of plant ecologists. We found that floristic sampling captured a community species pool four times larger than that captured using ecological transects, with rarefaction and non-parametric species estimation indicating that it would be prohibitive to capture the “true” community species pool if constrained to sampling within transects. We further illustrate that the discrepancy in species pool size between approaches led to a different interpretation of the greenway’s ecological condition in some cases (e.g., transects missed uncommon cultivated species escaping from nearby gardens) but not others (e.g., plant species distributions among functional groups were similar between species pools). Finally, we show that while using transects to estimate plant relative abundances necessarily trades off with a fuller assessment of the species pool, it is an indispensable indicator of ecosystem health, as evidenced by three non-native grasses contributing to 50% of plant cover along the highly modified urban greenway. We suggest that actively fostering collaborations between floristic botanists and ecologists can create new insights into the maintenance of species diversity at the community scale.


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