Javad Motamedi; Esmaeil Sheidai Karkaj; Azizeh Babazadeh; Morteza Mofidi Chelan
Volume 29, Issue 2 , July 2022, , Pages 166-175
Abstract
One of the objectives in rangeland management is the accurate and rapid determination of forage production to determine grazing capacity. The relationship between forage production and morphological characteristics was investigated in this study. For this purpose, two grazed and non-grazed units were ...
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One of the objectives in rangeland management is the accurate and rapid determination of forage production to determine grazing capacity. The relationship between forage production and morphological characteristics was investigated in this study. For this purpose, two grazed and non-grazed units were selected in the mountainous rangelands of Nazlouchay, Urmia. In each of them, the morphological characteristics of A. aucheri, as the only dominant plant species that accounts for more than 50% of the plant composition, were measured within 60 one-square-meter plots located along with 100-meter transects in July 2017. After cutting off bases growth, the dry weight of the samples was determined, and its regression relationship with morphological characteristics was examined using hierarchical regression. The results showed that it was possible to estimate A.aucheri production in the unit where the plant bases were not grazed using multiple linear regression models based on diameter, average crown size (D1), collar diameter (D2), and height (H). In the grazed units, where plant bases were grazed in the fall of last year, only the average diameter of the crown (D1) and height (H) was validated with multiple linear regression models, as the best model with RMSE equal to 3.53 and coefficient of 0.52. Due to the relatively good performance of the model and the preference for combining several morphological features in production estimation, separating models into inside and outside the exclosure can play a role in rangeland monitoring and production estimation to calculate grazing capacity and assess the intensity of rangeland utilization.
Amir Ghorbankhani; Hossein Arzani; Ali Tavili; Javad Motamedi
Volume 29, Issue 1 , February 2022, , Pages 1-10
Abstract
Salsola laricina is one of the main elements of vegetation communities in the steppe rangelands of the dryland region, which protects it from disturbances and provides conditions that can preserve its ability to rehabilitate after chest, is one of the basic requirements of rangeland management in such ...
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Salsola laricina is one of the main elements of vegetation communities in the steppe rangelands of the dryland region, which protects it from disturbances and provides conditions that can preserve its ability to rehabilitate after chest, is one of the basic requirements of rangeland management in such fields. Therefore, in the present study, the variability of structural and functional traits and morphological characteristics and seed germination were tested under supportive grazing. For this purpose, by establishing a sampling system inside and outside of the 10 year old Khoshkerood detention, the vegetation cover and structural and functional traits of Salsola laricina species, such as crown cover, density and forage production in the field were measured. Seed of healthy and healthy rootstocks, morphological characteristics and seed germination, such as; 1000 seed weight, germination percentage, germination rate, root length, stem, seedling, and finally vigor index (straw) Seed) was measured in laboratory conditions. The results showed that the values of structural and functional traits, inside the enclosure, are more than outside the enclosure. In this regard, the percentage of crown cover, density, and amount of production of Salsola laricina species were respectively in the enclosure relative to the outcrop, 5.46 and 3.6%, 21600 and 17000 bases per hectare and 161.4 and 12.71 kg respectively hectare. The average of morphological and germination characteristics of the seeds collected from the intruder was also greater than the outside grazing. So that the highest index of seed vigor as a sum of outcomes of morphological and germinating properties in inoculated and outcroped seeds is 389.88 and 1037.37, respectively. The increase of these values in the enclosure relative to the outcrop; indicates the effect of supportive grazing on the improvement of structural and functional characteristics and the morphological and seed germination characteristics of rangeland species in vulnerable ecosystems in arid areas.