Epsilon Archive for Student Projects

Abstract

Deadwood is a key structural and ecological component in boreal forest ecosystems. One particularly distinctive type in northern Fennoscandia is dead standing Scots pines (Pinus sylvestris L.), known as kelo trees. Kelo trees play a crucial ecological role by offering habitat for specialized species and are primarily found in areas with minimal human disturbance. While previous studies have focused on Finnish boreal forests, little is known about kelo tree dynamics in other boreal ecosystem systems. Using dendrochronological field data, I assessed the age, year of death, and spatial distribution of 110 kelo trees in an old-growth forest within Tjeggelvas nature reserve (TNR) in northern Sweden. I found that they typically were clustered, died at an advanced age, and have remained standing for decades after death, however, some individuals died younger and showed no signs of reduced growth preceding death. Kelo tree recruitment in the study area did not follow previously assumed patterns in terms of recruitment rate and disturbance history, particularly due to the absence of fire. My findings suggest that kelo tree recruitment is influenced by a combination of long-term ecological processes and episodic stress events, and that the drivers and processes behind kelo tree recruitment vary between parts of Finland and this area in Sweden. However, these processes remain not yet fully understood, highlighting the need for further research. With climate change expected to increase small-scale disturbances, future kelo trees may emerge at younger ages and smaller sizes. Their ecological importance, slow recruitment rate, and low numbers in managed forests compared to the past show their high conservation value within natural Fennoscandian forests. Understanding the drivers of kelo tree formation under different disturbance regimes will be essential for informing conservation strategies in boreal forests facing climate-driven change.