Epsilon Archive for Student Projects

Abstract

This study investigates the relationship between tree size, measured by diameter at breast height (dbh), and tree-related microhabitats (TreMs) in pedunculate oak (Quercus robur) in a forested area, Krubbemölla, outside Vitaby in Skåne, Sweden. TreMs offer a valuable method for assessing forest biodiversity without the need to track individual species. Oaks, being a keystone species, provide numerous ecological services, making them highly important in the ecological matrix. This research aims to broaden the understanding of the relationship between dbh and TreMs, hypothesizing that both the amount and variation of TreMs increase with dbh in oak trees.
The study area, Krubbemölla, encompasses 11.9 hectares of mixed-age forest stands, with species such as oak, alder, lime, bird cherry, beech, ash, and goat willow. The fieldwork involved measuring dbh and visually inspecting each tree for TreMs. Data was collected for all oaks in the study area with a dbh greater than 10 cm.
A total of 95 oaks were surveyed, and 403 TreMs were identified. Statistical analysis showed a significant positive correlation between dbh and the number of TreMs, indicating that larger trees host more TreMs. The variation in TreM types also increased with dbh, supporting the hypothesis. Specific TreMs, such as those suitable for beetles and slowly developing TreMs, also showed a positive relationship with dbh. The study confirms that older, larger trees are more likely to develop diverse TreMs, which aligns with existing literature on the subject.
The findings emphasize the importance of preserving old trees and large-diameter oaks, as they significantly contribute to forest biodiversity through the provision of various microhabitats. While dbh is a critical factor in TreM development, other elements like competition, site conditions, and natural disturbances also play roles in TreM formation. The results suggest that forest management practices should consider the preservation of large and old oaks to enhance biodiversity.