| چکیده انگلیسی مقاله |
Background and purpose
Choosing range management methods (RMM) is a useful and effective step for managing rangeland habitats. According to RMM, it is possible to improve the range condition (RC) without any manipulation of vegetation and soil and expensive range modification operations (RMO). Therefore, the question arises as to which places of rangeland habitats with what kind of ecological and environmental characteristics are suitable for enrichment. The answer to the above question requires the classification of rangeland in terms of RMM. In the current research, based on the approach of rangeland science experts (in this approach, grazing management is emphasized more and operations that lead to a major change in vegetation are not emphasized) and according to the category of RC, customary law of Lar habitats (which belongs to ETKA organization), was classified in terms of RMM and suitable places were determined for the enrichment of vegetation.
Materials and methods
For this purpose, first, a map of plant types (PTs) was prepared by field visit and based on physionomy. Then, by measuring the vegetation indicators, the RC class of each PTs was determined based on their distance from the climax, using the four-factor method. Based on scoring the characteristics of soil and vegetation, range condition trend (RCT) of each PT was also determined in different situations. In the next step, according to the RC and RCT of PTs and according to the proposed guidelines (guidelines for classification of rangeland in terms of range management method (GCRMM) which is in accordance with the principles of range management, the RMM and the type of grazing system (GS) or if necessary RMO, were proposed for each of the PTs, based on which, the planning map and the management of rangeland in the region was prepared.
Results
According to the surveys, the RC of any PTs was not recognized as poor or very poor. Therefore, according to the proposed guidelines (GCRMM), it is scientifically not recommended to perform vegetation enrichment operations (RMO) for the habitats associated with customary law of Lar PTs. The highest score obtained is related to the PT Perennial grasses and Perennial grasses-Perennial forbs, with 45 and 49 points,and the lowest value is related to the PT Ferula ovina-Onobrychis cornuta with a score of 31.4 is. Other PT include Onobrychis cornuta- Bromus tomentellus- Thymus kotschyanus, Onobrychis cornuta- Agropyron trichophorum, Ferula ovina- Onobrychis cornuta- Thymus kotschyanus and Astragalus aureus- Thymus kotschyanus- Agropyron trichophorum, with average condition in terms of vegetation and soil. Balanced range management method (BRMM) or natural range management method (NRMM) was recommended for all PTs according to the environmental conditions and RC class. In 27% of rangeland in the region, we can recommend the BRMM method and in 73%, the NRMM. Considering the environmental conditions and the RC, range improvement operations (vegetation enrichment operations) or artificial range mangement method (ARMM) are not suggested for the rangeland of the region. Based on the surveys, for 27% of rangeland in the region, rotation grazing system was proposed and for 29%, deferred grazing system was proposed. The proposed area for other GS includes; deferred- rotation grazing system and rest-rotation grazing with a year off, equal 24 % and 20 %.
Conclusion
In the conditions where the rangeland is in excellent, good and average condition, it is possible to upgrade and increase the capacity of the vegetation, with RMM, and to increase the performance of grazing animals, while improving the RC or maintaining the existing condition; it is recommended to design and implement GS and there is no need for any kind of manipulation and costly RMO. In general, currently, the most important executive policy of the institution responsible for rangeland is the preparation and implementation of range plans; maintaining, revitalizing, developing and exploiting rangeland in such conditions also depends on knowing the existing RC and choosing one of the RMM (BRMM, NRMM and ARMM) based on the RC and implementing it in the form of a range plan. Accordingly, when preparing new or updating previous grazing plans, the selection of RMM should be on the agenda. In the current research, taking into account the approach of rangeland experts and choosing RMM; it is not recommended to carry out RMO with the aim of enriching the vegetation for customary law of Lar habitats. However, according to different approaches regarding range improvement (the approach of rangeland science experts, the approach of plant ecologists, and the approach of ecological restoration experts); in some rangeland, vegetation manipulation is still the only practical way to increase forage production for livestock and improve wildlife habitat, and in addition, some pastoralists may still consider this method the best way to increase the economic yield of rangeland. |