Long Term Ecological Research (LTER) to study the management of coniferous forests in Israel: The effects of overstory thinning treatments in mature Pinus halepensis forests on forest structure, function, and dynamics.
Research team: Yagil Osem and Train Paz-Kagan
Abstract: This proposal is a continuation of long-term ecological research ongoing since 2008. The proposal refers to 2024-2026. In this research plan, we established a long-term research site to investigate the management of Israel's coniferous forests. This to develop silvicultural guided Israel designing the next forest generation as diverse, vital, and resilient forests providing varied ecosystem services to humans and the environment. The research focuses on mature Pinus halepensis forests. It was planned to assist in achieving the following management objectives: 1) expanding the longevity of the current forest generation while maintaining its vitality, scenic value, and durability, 2) establishing the next forest generation based on natural processes, 3) increasing forest biodiversity, 4) promoting ecosystem functions with an emphasis on primary productivity, and water use efficiency. The study examines the effects of silvicultural thinning treatments on the vitality and survival of residual trees, the structure and dynamics of the forest's vegetation, biodiversity, water budget, and primary productivity. The experimental structure includes four thinning treatments: 1) clear-cut, 2) intense thinning – 10 trees/dunam, 3) moderate thinning – 30 trees/dunam, 4) non-thinned control – ca. 50 trees/dunam. In addition, a reference, non-planted area was assigned beside the forested area. Since 2009, continuous monitoring has been tracking the following: 1) climate and microclimate, 2) mature pine trees' condition, 3) understory structure, 4) forest leaf area index. Several new monitoring tools were developed and integrated into the monitoring system in the last years, including satellite remote sensing, LiDAR scans, TDR sensors for soil moisture, and dendrometers on tree stems. The new tools enable continuous tracking of several parameters: 5) forest leaf area organization, 6) carbon and water fluxes, 7) soil water content, and 8) daily and seasonal fluctuation in tree stem thickness. The research thrives on improving our understanding of long-term ecological processes in the forest, as affected by silvicutural thinning treatments and environmental changes. It aims to contribute to optimal forest management for designing the next forest generation.
