مجله جنگل ایران (Dec 2015)
Effects of soil compaction in skid trails on seedling architecture and dry biomass allocation in oak Quercus castaneifolia C.A.M. seedlings in greenhouse conditions
Abstract
Heavy soil compaction may impose a serious threat to soil ecosystem functioning.The penetration resistance reduces the elongation and penetration of roots and thus lowers the uptake of water and nutrients. This study used a soil strength (penetration resistance) experiment in a greenhouse to test the hypotheses that increasing soil strength would adversely alter seedling architecture by changing above- and below-ground biomass allocation patterns. The effects of soil compaction were explored in a loam to clay-loam textured soil with optimal conditions of water on a continuous scale (0.1–1.0 MPa penetration resistance) on biomass allocation responses and architecture of the deciduous Quercus castaneifolia (C.A.M.). Results showed that below-ground metrics of fresh and dry biomass (main and lateral root biomass) were negatively affected by soil compaction. Increasing soil strength did not change above- and below-ground biomass allocation patterns (i.e., root mass ratio, root: shoot ratio, specific root length), resulting in unchanged seedling architecture. It is concluded that in loam to clay-loam textured soil with optimal conditions of water and soil strengths of up to 1.0 MPa, increasing soil compaction did not cause significant growth allocation patterns to above- and below-ground portions leading to architectural changes in the seedlings, concluding that plant architecture was found to be less sensitive to increased soil compaction than size/growth and hence not a very reliable predictor of size/growth responses.
