Amelioration of planting stress by soil amendment with a hydrogel-mycorrhiza mixture for early establishment of beech (Fagus sylvatica L.) seedlings

Abstract

Introduction: The mortality of nursery-grown beech (Fagus sylvatica L.) seedlings after out planting into the field is usually high. Objectives: The goal of this study was to characterize the response of beech seedlings to planting stress and to test if soil amendment with a mixture of hydrogel and the ectomycorrhizal fungus Paxillus involutus could rescue the establishment of stressed plants. For this purpose, barerooted, dormant seedlings were exposed for 0, 2 and 6 h to air before planting. Results:Water loss in response to air exposure caused increasing concentrations of soluble carbohydrates in buds and fine roots suggesting only passive of osmoprotection. Short-term exposure for 2 h delayed bud burst in spring, whereas long-term stress for 6 h also increased mortality. Growth of the seedlings in amended soil improved plant performance compared with plant grown in untreated soil. In particular, mycorrhizal colonization, plant water status and biomass increased, whereas carbohydrate storage pools were decreased. Total plant nitrogen allocated to leaves but not the nitrogen or carbohydrate concentrations were correlated with the degree of ectomycorrhizal colonization. Conclusion: This suggests that soil amendment enhanced nitrogen uptake via ectomycorrhizals, which in turn stimulated growth, thereby, increasing carbon consumption and preventing starch accumulation. In conclusion, soil amendment with hydrogel and an ectomycorrhizal fungus significantly improved the performance of both stressed and unstressed young beech trees. © The Author(s) 2011. This article is published with open access at Springerlink.com.