Volume 16, Issue 2 (8-2022)
مرتع 2022, 16(2): 312-330 |
Back to browse issues page
Download citation:
BibTeX | RIS | EndNote | Medlars | ProCite | Reference Manager | RefWorks
Send citation to:
BibTeX | RIS | EndNote | Medlars | ProCite | Reference Manager | RefWorks
Send citation to:
Rostampoor M, Sabzi R. Effect of slope gradient on vegetation, species composition and production of medicinal plants (Case study: Rom Rangelands, Qaen). مرتع 2022; 16 (2) :312-330
URL: http://rangelandsrm.ir/article-1-1050-en.html
URL: http://rangelandsrm.ir/article-1-1050-en.html
Department of Rangeland and Watershed Management and Research Group of Drought and Climate Change, Faculty of Natural Resources and Environment, University of Birjand, Birjand
Abstract: (1427 Views)
Background and objectives: In order to further protect of rangeland ecosystems, range suitability should be investigated before the utilization of medicinal and industrial plants. Plant composition, production and steep of the slope are among the criteria that determines the suitability of rangeland for the use of medicinal plants. In four habitats of the following species (Achillea santolinoides, Ziziphora tenuior, Sclerorhachis leptoclada and Hymenocrater calycinus) on three slope classes (less than 30%, 30-30% and more than 60%), importance Value Index (IVI) and accessible production were determined.
Methodology: After field visit and observation of medicinal plants as the dominant species in the rangelands of Room districts of Qaen county, plant habitats were identified and sketched. In herbaceous and woody habitats, plots sized 1 m2 and 2 m2 were respectively placed. Samples were taken randomly. After measuring the slope on all sampling plots, the slope was statistically analyzed at three levels of less than 30%, 30 to 60% and more than 60%. During the slope gradient, the structural characteristics of vegetation including density, frequency, abundance and dominance of species were measured and based on that, Importance Value Index (IVI) was determined. In order to compare the total production of medicinal plants for different slopes, analysis of variance (ANOVA) and Duncan multiple range tests were used. Cluster analysis was also used to group the habitats based on species composition. Species abundance distribution was investigated using geometric series, broken stick, log-normal, Zipf and Mandelbrot models and the data were fitted with each of the above models. The goodness of fit of these models was measured by the Akaike information criterion (AIC). All statistical analysis was done by R software.
Results: The floristic list of the study area showed that in total, 47 plant species belonging to 15 plant families were available, 31 herbaceous, 8 bush, 7 grasses and 1 shrub species. Among the observed species, 66% were medicinal and industrial, 23% forage plants and 11% invasive and thorny. Medicinal plants mostly belonged to Compositae, Apiaceae, Lamiaceae and Brassicaceae. The results showed that Ziziphora tenuior and Achillea santolinoides had the highest density and Artemisia aucheri and Sclerorhachis leptoclada had the highest ground cover. The low presence of medicinal and industrial were seen on low slopes and the highest on moderate and high slopes. The rank-abundance curve showed that the species abundance distribution (SAD) of the whole study area was fit by Mandelbrot model and log-normal, which indicates a stable community. The results showed that with increasing slope, the production of medicinal plants decreases. Achillea santolinoides and Ziziphora tenuior, located on slopes of less than 30%, have the highest production and relative importance, and in terms of these two factors, have the necessary competence for exploitation.
Conclusion: Although the relative composition of medicinal plants in the region increases with increasing slope, but in terms of plant composition and production, habitats with a slope of more than 60% are not suitable to be used as medicinal plants sites. Generally, in range suitability assessment studies, vegetation cover percentage alone is not enough, because there may be species that are pharmacologically and industrially valuable that have a low cover percentage. Although in this study, not all factors affecting rangeland suitability have been studied directly, but the important value index for rangeland suitability studied and the effect of slope on some vegetation characteristics have been investigated and the results showed that the moderate and high slope and production of medicinal plants decreased. Therefore, with increasing slope, rangeland's suitability for medicinal and industrial plants also decreases.
Methodology: After field visit and observation of medicinal plants as the dominant species in the rangelands of Room districts of Qaen county, plant habitats were identified and sketched. In herbaceous and woody habitats, plots sized 1 m2 and 2 m2 were respectively placed. Samples were taken randomly. After measuring the slope on all sampling plots, the slope was statistically analyzed at three levels of less than 30%, 30 to 60% and more than 60%. During the slope gradient, the structural characteristics of vegetation including density, frequency, abundance and dominance of species were measured and based on that, Importance Value Index (IVI) was determined. In order to compare the total production of medicinal plants for different slopes, analysis of variance (ANOVA) and Duncan multiple range tests were used. Cluster analysis was also used to group the habitats based on species composition. Species abundance distribution was investigated using geometric series, broken stick, log-normal, Zipf and Mandelbrot models and the data were fitted with each of the above models. The goodness of fit of these models was measured by the Akaike information criterion (AIC). All statistical analysis was done by R software.
Results: The floristic list of the study area showed that in total, 47 plant species belonging to 15 plant families were available, 31 herbaceous, 8 bush, 7 grasses and 1 shrub species. Among the observed species, 66% were medicinal and industrial, 23% forage plants and 11% invasive and thorny. Medicinal plants mostly belonged to Compositae, Apiaceae, Lamiaceae and Brassicaceae. The results showed that Ziziphora tenuior and Achillea santolinoides had the highest density and Artemisia aucheri and Sclerorhachis leptoclada had the highest ground cover. The low presence of medicinal and industrial were seen on low slopes and the highest on moderate and high slopes. The rank-abundance curve showed that the species abundance distribution (SAD) of the whole study area was fit by Mandelbrot model and log-normal, which indicates a stable community. The results showed that with increasing slope, the production of medicinal plants decreases. Achillea santolinoides and Ziziphora tenuior, located on slopes of less than 30%, have the highest production and relative importance, and in terms of these two factors, have the necessary competence for exploitation.
Conclusion: Although the relative composition of medicinal plants in the region increases with increasing slope, but in terms of plant composition and production, habitats with a slope of more than 60% are not suitable to be used as medicinal plants sites. Generally, in range suitability assessment studies, vegetation cover percentage alone is not enough, because there may be species that are pharmacologically and industrially valuable that have a low cover percentage. Although in this study, not all factors affecting rangeland suitability have been studied directly, but the important value index for rangeland suitability studied and the effect of slope on some vegetation characteristics have been investigated and the results showed that the moderate and high slope and production of medicinal plants decreased. Therefore, with increasing slope, rangeland's suitability for medicinal and industrial plants also decreases.
Type of Study: Research |
Subject:
Special
Received: 2021/09/10 | Accepted: 2021/12/3 | Published: 2022/08/1
Received: 2021/09/10 | Accepted: 2021/12/3 | Published: 2022/08/1
Send email to the article author
| Rights and permissions | |
 |
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. |
