ABSTRACT

Treatments added to young conifer stands aiming to compensate for the loss of nutrients and alkalinity associated with whole-tree harvesting for bioenergy purposes have the potential to affect the growth of competitors to the conifers. Three different nutrient compensation treatments were applied to a young Picea abies (L.) Karst. stand in south-west Sweden, 2 or 3 years following final felling. The treatments were; fine fraction of harvest residues (15 Mg dw ha⁻¹); granulated wood ash (4.1 Mg dw ha⁻¹); nitrogen-free vitality fertiliser (twice 1.5 Mg ha⁻¹); untreated control. Root biomass and total biomass of graminoids (mainly Deschampsia flexuosa (L.) Trin) were significantly greater in the wood ash and vitality fertiliser treatments than in the residues and control treatments. The aboveground and coarse root biomass of naturally regenerated birch (Betula spp.) and the aboveground biomass of dwarf shrubs (mainly Calluna vulgaris (L.) Hull.) and bottom layer were not affected by the treatments. Calcium and magnesium concentrations in the aboveground biomass of graminoids and phosphorus concentration in the biomass of bottom layer were significantly the highest in the vitality fertiliser treatment. Thus, nutrient compensation with vitality fertiliser or granulated wood ash may increase competition from graminoids in the establishment phase.

摘要

添加到年轻针叶树林分的处理旨在补偿与用于生物能源目的的整棵树收获相关的营养和碱度的损失，有可能影响针叶树竞争对手的生长。三种不同的营养补偿处理被应用于年轻的Picea abies (L.) Karst。在最终砍伐后的 2 或 3 年，它们将位于瑞典西南部。治疗是; 收获残留物的细小部分（15 Mg dw ha ^-1）；颗粒状木灰（4.1 Mg dw ha ^-1）；无氮活力肥（两次 1.5 Mg ha ^-1）；未经处理的对照。禾本科（主要是Deschampsia flexuosa）的根生物量和总生物量(L.) Trin) 在木灰和活力肥料处理中显着高于残留和对照处理。自然再生桦树（Betula spp.）的地上和粗根生物量以及矮灌木（主要是C alluna vulgaris (L.) Hull.）和底层的地上生物量不受处理的影响。禾本科植物地上生物量的钙、镁浓度和底层生物量的磷浓度在活力肥处理中显着最高。因此，用活力肥料或颗粒状木灰进行营养补偿可能会在定植阶段增加来自禾本科植物的竞争。