Carbon sequestration in rangeland ecosystems has been identified as a suitable strategy to offset greenhouse gas emissions that information of carbon sequestration hotspots is a good tool to improve rangeland management. Objectives for this study were to assessment potential carbon sequestration in various rangeland types, to identify carbon sequestration hotspots and to study the effective factor on hotspots in semiarid rangeland of Kerman province. The content of above and underground biomass and litter carbon by Ash method and soil carbon by Walcky-Black method were determined in 300 plots 2m×2m that scattered randomly in rangeland types. Results showed that rangeland types had significant effect on carbon sequestration as Zygophyllum eurypterum-Artemisia sieberi, Artemisia sieberi-Pteropyrum aucheri, Astragalus microcephalus –Stipa barbata, Artemisa sieberi and Artemisia sieberi- Salsola brachiata respectively with 65.84, 53.92, 43.32, 33.17 and 24.77 (T/ha) contained from the highest to the lowest carbon sequestration. Carbon sequestration hotspots and coldspots were mapped by using hotspots analysis. Zygophyllum eurypterum-Artemisia sieberi and small parts of both types Artemisia sieberi-Pteropyrum aucheri and Astragalus microcephalus–Stipa barbata with 65.34 (T/ha) were carbon sequestration hotspots. Majority of Artemisia sieberi-Salsola brachiata and small parts of Artemisa sieberi with 23.78 (T/ha) included carbon sequestration coldspots. PCA analysis also showed that life form, clay and vegetation cover were the most important factors influencing on the hotspots. It was concluded although rangeland types demined with Phanerophyte species had a greater probability of being identified as carbon sequestration hotspots, soil characters also play effective role to stock carbon in semiarid rangeland ecosystems. پرونده مقاله

Scientists predict climate changes and warmer conditions for the world in future. Predicting the warming effect on plant performance is one of the most important challenges in ecological sciences. In this study, the effects of short-term warming on physiological traits of Pteropyrum aucheri as one of the domain shrubs was assessed in riverside of semi-arid rangelands of Kohpanj region, Bardsir, Kerman province, Iran in 2014. Five 5×5 m2 blocks were selected with the same elevation, slope and aspect. In each block, mature individuals of Pteropyrum aucheri were studied in 10 circular plots with 2m diameter during spring and summer. For simulating the warming phenomenon, Open-Top Chambers (OTCs) were placed on 5 plots and other plots were considered as control plots. OTC is applied in natural ecosystems and provides nearly the same growth condition for species with higher temperature. Results showed that the OTCs enhanced monthly average of air temperature (5cm above soil surface) as 1.5 ºC, surface soil temperature of 2 ºC and soil temperatures (5 cm below soil surface) as 1.7 ◦C in warming plots. Results showed that photosynthetic pigments (Chlorophyll a, b and total) were significantly reduced and carotenoid was significantly increased with short-term warming in warmingplots (p<0.05). Water content, leaf area and dry matter production were none significantly declined with warming. In general, short-term warming affected photosynthesis performance of Pteropyrum aucheri but biomass was not considerably affected by warming. پرونده مقاله

Forage is one of the main products of rangeland ecosystems, which is threatened by different anthropogenic disturbances. This study was conducted to assess the impact of urbanization, rural development, agriculture extension, road construction and industry on forage production in an arid and semiarid rangeland using InVEST habitat quality model in spring 2018. In 14 rangeland types, thirty 2×1m quadrats were randomly located to measure forage production using double sampling method. Habitat quality was mapped based on the relative impact of each threat, the relative sensitivity of each rangeland type to each threat and the distance between the habitats and threats. The results showed that there is a significant relationship between rangeland condition and habitat quality (p<0.01). Habitat quality varied between 0 and 0.77 across the study region. Habitats with low quality comprised half of the total area (51%) where anthropogenic factors were concentrated. Habitat quality was significantly correlated with forage production (p<0.01). The dominant species Artemisia sieberi was replaced by invasive species Salsola brachiata and forage production was decreased to the minimum 21 kg ha-1 in habitats with low quality. Rangelands with medium habitat quality produced two and a half times more forage than the ones with low habitat quality and half of the ones with high habitat quality. Astragalus gossypinus and Artemisia aucheri in high habitat quality areas supplied the highest forage production (216 kg ha-1). Since the large areas of agricultural lands are in the low quality habitats, agriculture can be considered as the main threat of forage production. Hence, the extension of agricultural lands with short-term benefits should be controlled in order to improve ecosystem services which have long-term benefits in sustainable development. پرونده مقاله