Soil Compaction Effects on the Abundance, Dynamics and Characteristics of Fine Roots and Mycorrhizal Associations in Forest Soils

Stockholm

2024

772

Bandaufführung

40005282

Logging-induced soil compaction poses a significant threat to soil habitat functions, particularly to root systems and their symbiotic relationships with mycorrhizae. Understanding the consequences of soil compaction is essential for sustainable forest management, as intact forest ecosystems play a critical role in climate change resilience and mitigation efforts. Remaining knowledge gaps highlight the need for comparative studies of different harvesting methods, finescale analysis to understand the spatial heterogeneity of compaction effects, and the interactions between soil compaction, root growth and mycorrhizal associations. To gain a detailed insight into these complex relationships, we conducted an empirical Before-After Control-Impact study in a beech-dominated forest in Lower Austria. Different harvesting methods (harvester-forwarder with/without tracks and cable-yarding with motor-manual-felling), were applied in the winter 2022/23, taking into account previous harvests (18 years earlier). Our study used a transect approach to determine spatially explicit effects on standing root biomass and growth rates by using soil cores and in-growth cores, respectively. Transects were placed transversely across the tracks, covering areas directly (tracks, cable-yarding corridor) or indirectly (between the wheel tracks, marginal areas) affected by the logging activities. Comprehensive assessments of root biomass (distribution), nutrient content, anatomy and morphology were undertaken. In addition, logging effects on mycorrhizal morphotypes, mycorrhization rates of root tips, and hyphae growth (in-growth bags) were analysed. Preliminary data show a significant influence of both recent and historical timber harvesting on the standing root biomass, indicating altered patterns of root growth and distribution, with significant differences between and within transects. Our results indicate that different harvesting methods cause widely varying degrees and patterns of soil compaction – with contrasting effects on fine root dynamics. The long-lasting consequences of soil compaction, hindering root system establishment and mycorrhizal symbionts, underlines the importance of maintaining soil as an intact habitat. The implications of this research are relevant for sustainable forestry practices, emphasising the need for appropriate soil management strategies to mitigate the negative effects of logging related soil compaction to ensure the long-term functionality of the soil as a habitat for roots and mycorrhizae.