Document Type : Research Paper
Authors
Abstract
In this study, the distance methods of density measurementwere compared for four plant species in terms of accuracy, time, and efficiency of the random distribution patterns in Karsanak area, located in the eastern part of Shahrekord in Chaharmahal-va-Bakhtiary province. The study area with 32000m2(160*200) was divided into eight sections of 4000 m2. The total number of each species was counted in each section and considered as the basis for the simulation. Then, eight sections with 4000m2 area were simulated in Stochastic Geometry software, and in each section, a transect of 100m length was established in the center of small side along which 10 points were determined by random systematic method with nine-meter intervals. The distance methods compared included nearest neighbor, closest individual, third closest individual, random pairs, point center quarter, angle order, wandering quarter and variable area transect as well as control group (counting the number of each species in each section). The selected species included Astragalus effuses, Eryngium billardieri, Astragalus rhodosemius and Astragalusverus. The distribution pattern of plant communities was determined by Hopkines and Eberhardt indices. The density estimation error was calculated to evaluate the accuracy. Duncan's test was used to compare the accuracy of methods, and standard deviation and time method were used to compare the efficiency of methods. The results of this study showed that nearest neighbor and closest individual methods (in terms of time), random pairs method (in terms of accuracy) and variable area transect (in terms of precision) could be introduced as the most efficient methods.
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