The effect of the factors affecting production in the highlands of Hir and Neor using ground-based and remotely sensed methods

Dadjou, Farid (2017) The effect of the factors affecting production in the highlands of Hir and Neor using ground-based and remotely sensed methods. Masters thesis, University of Mohaghegh Ardabili.

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Text (بررسی اثر عوامل مؤثر بر میزان تولید در ارتفاعات هیر و نئور با استفاده از روش‌های زمینی و سنجش) FaridDadjou.pdf Download (1MB) | Preview

Abstract

The aim of this study was investigate the effects of environmental factors (topographic, climatic and soil) on aboveground net primary production (ANPP) of life forms (grasses, forbs and shrubs) and total ANPP in Hir and Neur rangelands using ground-based and remote sensing methods. Sampling in June 2016 was carried out in eleven locations of three elevation profiles using clipping and weighing method using one square meter plot (total of 330 plots). To analyze the significance and correlation between ANPP and environmental factors, one way ANOVA and multiple regression were used in SPSS16. To determine the most important factors, principle component analysis (PCA) was used in PC-ORD5. Also, the maps and vegetation indices required in the GIS were prepared. The results show a significant relationship (P<0.01) between the NPP with topographic factors. The NPP of grasses and forbs have direct relationship with elevation; however, the shrubs and total NPP have decreased in middle elevation classes (1850-2100 m) and increased again in the higher classes (2100-2600 m). The NPP of grasses and forbs have direct relationship with slope, however the shrubs NPP have decreased with the increases of slope and has no effect on total NPP. Grasses, forbs and total NPP were higher in the west aspect and shrubs higher in the northwest. According to the various classes of topographic index (CTI), the maximum amount of shrubs in the middle classes and the highest NPP of forbs on the lowest amount of CTI were observed. Also, the results showed that there is a significant relationship (P<0.01) between the ANPP with climatic factors. Results showed the ANPP of grasses and total ANPP have direct relationship with rain, however the maximum NPP of forbs recorded in the middle classes and maximum NPP of shrubs recorded in the higher classes of precipitation. Also, effects of temperature showed, grasses and total NPP had an inverse relationship with temperature and the maximum NPP of forbs and shrubs, recorded in the middle and lower classes of temperatures, respectively. The results of study between the ANPP with soil factors show a significant relationship (P<0.01). Among the measured soil factors, the parameters of Silt, EC, Ca, Ksoluble, OC, POC, pH, Mg, TNV, clay, P and volumetric moisture had the highest effect on ANPP changes. The results of PCA showed that factors of annual precipitation, annual temperature, elevation, seasonal temperature, seasonal precipitation and pH in the first component; factors of Silt, OC, OM, POC, sand, Kexchangeable and volumetric moisture in the second component; calcium and topography index in the third component; clay, slope and Ksoluble in the fourth component; P, Mg, EC and aspect in the fifth component; and, finally, sodium and TNV is in the sixth component. Correlation of indices showed that the VI3, GNDVI and GI indices with grasses; IO, VI2 and PD311 indices with forbs; RDVI, DVI and TNDVI indices with shrubs, and indices of DVI, RDVI and GNDVI had the highest correlation with total ANPP. The results of this study as a baseline data for future studies and in managing rangelands to balance the supply and demand of biomass and carbon balance can be used

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