Determination of relations between plant species diversity and productivity in Brutian pine stands

Abstract

This study examines the relationship between Brutian pine productivity and plant species diversity, focusing on its potential as a valuable resource. Data was collected from 101 natural Brutian pine stands in Muğla and Antalya through inventory studies. Age and height values were recorded for three selected Brutian pine trees in each plot, along with plant species diversity using the Braun-Blanquet scale. Site index values were used to assign productivity scores between 1 and 5 for each plot. Diversity values were adjusted to a scale of 1 to 9 according to Westhoff and Maarel (1973) to calculate alpha diversity indices (Shannon and Simpson) using BİÇEB software. Environmental variables such as elevation, slope, radiation index, annual mean temperature, and annual precipitation were also collected for further analysis. The Kolmogorov-Smirnov normality test was first applied to the data matrix. Since it was determined that the normality assumption was not met (p<0.05), the Kruskal-Wallis test, which is a non-parametric method, was used to determine whether there is a significant difference between the diversity values for the site index groups. Results indicated a statistically significant difference (p<0.05) in diversity values among these groups. Then, diversity values and environmental variables were correlated using principal component analysis method (PCA). At the same time, site index groups were also included in the PCA as class data. As a result, it was revealed that Shannon and Simpson diversity values have a negative relationship with elevation and slope and a positive relationship with total annual precipitation.