Comparison of sampling pattern and plot dimensions, to estimate the percentage of crown cover and forage production in plant communities with different distribution patterns(Study area: Choghakhor Rangelands Chaharmahal and Bakhtiari province, Iran)

In the present study, we compared different sampling patterns and different plot dimensions to estimate the percentage of canopy cover and forage production in rangeland habitats around Choghakhor Wetland. The choice of sampling method was based on the opinion of the researcher. Sampling was performed in three different plant communities, in two patterns of six and three plots. Different dimensions of the plot (including 1×1, 1×2, 2×2, and 3×3 m2) were used as a nest to estimate the production and the percentage of canopy cover. Sampling was in each community within 30 sampling units along three transects. The canopy cover of the species was estimated by estimating and producing them by double sampling. Species density was calculated by counting bases in 2×2 plots. In each population, the type of distribution of dominant species was determined by statistical tests. The results showed that two different sampling patterns and four different plot dimensions have significant differences in estimating the percentage of cover and plant production (P≤0.01). According to the interaction of the community and the pattern, plot dimensions with pattern and plant community, patterns and plot dimensions with each other, there was no significant difference. The effect of plant community with plot dimensions on a cover percentage at (p≤0.05) and production at (p≤0.01) is significant. In Gundellia tournefortii-Couisinia Bakhtiari plant community with random distribution patterns, two different sampling patterns in 1×1 and 1×2 m2 plots were significantly different, and in other dimensions, no significant difference was observed. The two different sampling patterns in the Daphnea mucronata-Astragalus adsendence community with the uniform dispersion pattern were significantly different only in plot 1×1 (p≤0.05) and شdid not differ in other sizes. The mentioned patterns in the population of Melica persica-Agropyron trichophorum with the heap pattern distribution in statistical plots of 3×3 m2 did not show a statistical difference, but in other dimensions showed a significant difference (p≤0.05).