Elnaz Hassanzadeh Kuhsareh; ardavan ghorbani; Mehdi Moameri; kazem hashemi majd; Ardeshir pounemati
Abstract
The purpose of this study was to determine the effects of altitude, slope, aspect and topographic index on life forms and total net primary production (NPP) in mountains meadows in Fandoghlou in Namin county in Ardabil province. NPP in three altitude, slope, topographic index classes and four aspect ...
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The purpose of this study was to determine the effects of altitude, slope, aspect and topographic index on life forms and total net primary production (NPP) in mountains meadows in Fandoghlou in Namin county in Ardabil province. NPP in three altitude, slope, topographic index classes and four aspect classes was estimated using one m2 plots (totally 180 plots) by harvesting and weighting method. Correlation between life forms and total NPP with topographic factors were analyzed using stepwise multivariate regression method and using derived regression equations, the maps of NPP were derived. Results show that different topographic factors has significant effects on forbs (p<0.01) and grasses (p<0.01), however on total NPP have no significant effects. The highest NPP of forbs (1584/1 Kg/ha) and total NPP (2339/3 Kg/ha) were observed in the second altitude (1525-1564 m) but has no significant effect on grasses. The NPP of grasses show direct relationship with slope, however the NPP of forbs were decreased with the increase of slope and has no significant effect on total NPP. The highest amount of grasses (894/3 kg/ha) and forbs (1875/5 Kg/ha) were observed in the south and northwest aspect, respectively. According to the various classes of topographic index, the maximum amount of grasses (853/4 Kg/ha) were observed in the first classes and the highest NPP of forbs (1568/6 Kg/ha) on the third classes. The results of this study can be used to balance the amount of biomass, carbon, the supply and demand of and to plan for proper rangeland management.
Maryam Asadi
Abstract
In this research, was investigated the effect of grazing intensities on carbon and nitrogen allocation in aerial and belowground biomass of Artemisia austriaca in summer rangelands of Darvishchae (including Alvares, Aldeshin and Asbmarz villages) at southern slope of Sabalan. The study areas based on ...
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In this research, was investigated the effect of grazing intensities on carbon and nitrogen allocation in aerial and belowground biomass of Artemisia austriaca in summer rangelands of Darvishchae (including Alvares, Aldeshin and Asbmarz villages) at southern slope of Sabalan. The study areas based on grazing rate, rangeland condition, previous researches and department of Natural Resources and field survey in three grazing intensity low, medium and heavy was selected. Sampled in each grazing intensity, from vegetation and soil with randomized-systematic method on 3 transects parallel with the length of 200 meters and plot 1×1 m2 was carried out at intervals of 50 meters. Biomass was determined using cut and weighting method. After digging profiles at the base of the plant, roots were harvested. Then, allocation in aerial and underground plant was determined. The comparisonof allocation in plant was conducted using analysis of variance (ANOVA) and Tukey's test was performed to examine the differences between means. Results showed the effect of different grazing intensities (mostly sheep of Moghani breed) on biomass of A. austriaca was significant. Results of compare mean showed that the greatest amount of nitrogen allocation in the aerial biomass of A. austriaca (2.2 mg/kg) was observed in the moderate grazing intensity. Moreover, the greatest amount of carbon allocation in the roots of A. austriaca (22 mg/kg) was occurred in the moderate grazing intensity. In general, attention to effects of grazing different intensities on vegetation factors such as carbon and nitrogen allocation, is essential for rangelands correct management and protection.
sahar sabaghzade; Mohammad Zare; Mohamad Hosein Mokhtari
Abstract
Vegetation is an important component of each global ecosystem. Determining of the biomass of plant is important to assess its impact upon climate, soil erosion, and as well for management of natural resources. The aim of this study was to estimate biomass using vegetation indices based on remote sensing. ...
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Vegetation is an important component of each global ecosystem. Determining of the biomass of plant is important to assess its impact upon climate, soil erosion, and as well for management of natural resources. The aim of this study was to estimate biomass using vegetation indices based on remote sensing. The Landsat 8 data of May 2013 and field studies coinciding with field imaging in Marac (South Khorasan province) were used. Tamarix plant biomass measured in 30 random plots of 11 vegetation indices including DVI, IPVI, NDVI, PVI, RVI, SAVI, TSAVI, WDVI, and Tasselcap were used to estimate biomass of Tamarix.Then, using cluster analysis, vegetation indices were divided into three groups among which SAVI, RVI , and IPVI were chosen. The results showed that indexes which consider soil factors are more accurate than other measures. In this study, biomass map was prepared using the SAVI index.