Search Results (2)

In urban areas, typhoons frequently cause the tilting and uprooting of trees, resulting in damage to city infrastructure. During periods of intense rainfall, at shallow soil depths, soil water content is typically high, reducing the anchoring resistance of tree roots in the soil. Tree root systems play an important role in providing anchoring resistance against severe winds during typhoons. In this study, we examined the influence of high soil saturation on the turning resistance of trees by conducting winching tests on three tree species found in urban areas. In highly saturated soils, the maximum resisting moment of camphor trees (Cinnamomum camphora (L.) J. Presl.) is 35–50% lower than in soils with low saturation levels. A tree’s maximum resisting moment (TM_max) exhibits a linearly positive relationship with its diameter at breast height (DBH) in near-saturated soil conditions. The ratio of TM_max values to DBH in near-saturated soils is noticeably lower than in low-moisture soils. Our research establishes a relationship between the DBH of trees and the strength of the wind that they can resist during typhoons, as measured on the Beaufort scale. Full article

This research concerns the impact of air and soil pollution on the health status of selected tree species in parks and urban forests. The analysis was carried out over a decade, which allowed for creating the best models illustrating the impact of selective factors related to air and soil pollution on the health status of small-leaved limes, maples, oaks, and chestnut trees in the city. (1) Background and Objectives: The research aimed to identify the environmental factors that have the greatest impact on the health condition of trees in urban conditions and show which species are the most resistant to pollution in urban areas. The research object was 2441 individuals of four tree species inhabiting 11 parks and urban forests in Poznań. We assessed the trees in terms of dendrometric parameters and health status. Tree-stand soils were tested for P, K, Ca, Mg, and Na content using various analytical methods. Air data were obtained from a generally accessible WIOS website. The above data were statistically analyzed using one-way ANOVA and canonical correlation analysis (CCA). Our research has shown that unfavorable environmental parameters impact the health status of trees growing in urban areas. The most significant negative impact of O₃ on the health of three out of four examined tree species was demonstrated. Other pollutants that affect the trees health include Mn (in the soil) and NO, NO₂, CO, and C₆H₆ (in the air). Oak turned out to be the most resistant species to urban pollution. The area where chestnut trees grew turned out to be the most Fe, Mn, Na, and Pb soil-polluted and air-polluted with most of the substances recorded. The permissible concentration levels were exceeded in the case of tropospheric NO_x, PM₁₀, PM₂.₅, and Pb. Full article