Effect of soil compaction on early growth of Quercus robur seedlings since germination

Negative consequences of compaction can be particularly relevant for seedlings development. Plantlets may delay both germination and penetration of the soil surface by the radicle and the alterations in compacted soil may also affect plants rooting through variations in structural arrangement in attempt to avoid the mechanical obstacle. This study aimed at assessing the soil compaction on growth of Quercus robur seedlings during the first month since germination. The experiment was carried out in a nursery, where compaction was obtained by direct compression of the soil surface on the top of containers using a compression machine in laboratory. In particular, we investigated the effect of soil compaction on morphological attributes of seedlings grown in plastic containers on above and below ground traits during the first month after germination. Three compaction levels were considered (low:<0.5 MPa, medium: 1 MPa, and high: 2 MPa). Results showed significant differences in seedlings traits among treatments and a constraint effect of increasing levels of compaction on early seedlings growth. The effect was particularly detrimental on root system development in depth, thus, it represents an additional critical factor for regeneration establishment, particularly in Mediterranean environments where the early growth stages are crucial to overcome the dry season.