Zahra Heidari Ghahfarrokhi; Pejman Tahmasebi; Ali Asghar Naghipour
Abstract
Assessing rangeland health is of great importance due to its impact on ecosystem sustainability. This study investigated the relationship between evaluation criteria of rangeland health and functional diversity indices in part of the Sabzkouh Protected Area (Chaharmahal Va Bakhtiari Province, Iran). ...
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Assessing rangeland health is of great importance due to its impact on ecosystem sustainability. This study investigated the relationship between evaluation criteria of rangeland health and functional diversity indices in part of the Sabzkouh Protected Area (Chaharmahal Va Bakhtiari Province, Iran). For this purpose, four rangeland sites with different grazing intensities (reference, light, moderate, and heavy grazing) were selected. In each site, two representative areas were sampled using three 30×30 meter macroplots. Plant functional traits, including plant height, various leaf traits, mean crown diameter, and growth form, were measured. Functional diversity indices, including Functional Richness, Functional Evenness, Functional Dispersion, Rao’s Quadratic entropy and growth forms, were calculated using the FD package in R 4.4.2. Additionally, three evaluation criteria of rangeland health, including soil/site stability, hydrologic functions, and biotic integrity, were evaluated. The data were analyzed using ANOVA, correlation, and univariate regression tests, employing the aov and duncan.test functions and the R packages ggcorrplot, dplyr, reshape2, ggpubr, and ggpmisc for 21 data pairs. Results revealed that soil/site stability, hydrologic function, and biotic integrity had significant positive relationships with certain functional traits such as leaf dry weight (R² = 0.6), leaf area (R² = 0.5), leaf length (R² = 0.5), perennial forb (R² = 0.3), and perennial grass (R² = 0.5). Conversely, negative correlations were observed with other indices including functional divergence (R² = 0.5), functional dispersion (P < 0.05), mean crown diameter (P < 0.05), annual grass (P < 0.05), and shrub (R² = 0.5). These findings emphasize the importance of incorporating quantitative biodiversity indices alongside qualitative assessments to improve rangeland management and develop a quantitative evaluation protocol.
Ali Norouzi; iman haghiyan; Esmaeil Sheidai Karkaj
Abstract
Rangelands as a source of meat, forage, water and soil play a significant role in the country's economy, but the increase in the number of livestock and livestock in the rangelands has eliminated the balance between production and harvest. In this research, the effect of rangeland projects on various ...
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Rangelands as a source of meat, forage, water and soil play a significant role in the country's economy, but the increase in the number of livestock and livestock in the rangelands has eliminated the balance between production and harvest. In this research, the effect of rangeland projects on various indices such as plant diversity, condition, rangeland trend, production and canopy cover percentage in five rangeland (Tajrud, Sangolabad, Ali Abad, Garmab and Dochahi) located in Torbat Heydarieh county has been investigated. For this purpose, after measuring the mentioned indices in the rangelands (treatment) and their adjacent sites as a control, statistical analysis were performed using t-test. The results of the comparison of the mean vegetation percentage indicate that the canopy cover percentage of the planted area with the rate of 51/64% is higher than the ungraded area with a rate of 47.5% with a significant canopy at 5%. Also, despite the high number of production in the area with a plot (73.08 kg / ha), compared to the area without design (67/99), this difference is not significant. The average score of the score for the area inside the project (27.4) and outside the plan (23.4) are not statistically significant with each other. The implementation of rangelands in three regions from all five regions has been proven to negatively affect rangeland tendency. Also, the implementation of the rangeland scheme has significantly increased the Shannon-Wiener heterogeneity indices and Simpson's uniformity in the design, rangeland has not changed significantly in the Margalaf richness index.
zahra Abdolalizadeh; Ardavan Ghorbani; Raoof Mostafazadeh; Mehdi Moameri
Abstract
The purpose of this research is to facilitate the quantitative evaluation of various ecological factors in determining the rangeland condition by four-factors method and six-factors method using mainly structural variables of vegetation. In this study, the condition of 28 sites located in the northern ...
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The purpose of this research is to facilitate the quantitative evaluation of various ecological factors in determining the rangeland condition by four-factors method and six-factors method using mainly structural variables of vegetation. In this study, the condition of 28 sites located in the northern part of Ardebil province was determined by 4 and 6 factors methods, separately for grassland and shrubland habitats, and some parameters of vegetation were quantitatively measured. The results of condition determination were compared in the two mentioned methods. Finally, using Pearson correlation test, the relationship between variables of vegetation and the scores of rangeland condition were compared and regression relations were extracted. The results indicated that the average score of the rangeland condition in the modified four-factors in both grasslands and shrublands (69 and 60 scores, respectively) was higher than the six-factors method (64 and 54 respectively), and paired t-test comparison showed a significant difference (P≤ 0.05) between the two methods. Also, the results showed that variables such as canopy cover of decreasing specious canopy cover, forbs canopy cover, annual forbs canopy cover and production had the most significant positive relationship (P≤ 0.05), and the variables of invaders and pebble-gravel cover had the highest negative correlation (P≤ 0.05) with rangeland condition. The results of extraction of multivariate linear regression models by step-by-step method showed strong relationship (R2=68.46-88.41) between evaluated variables with condition score. Also, validation analysis of the models indicated the ability of both methods to predict the rangeland condition score.
