Finnish Forest Research Institute, Oulu Unit, BOX 413, FI 90014 University of Oulu Finland.
J Environ Manage. 2012 Oct 15;108:120-9. doi: 10.1016/j.jenvman.2012.05.003. Epub 2012 Jun 15.
Partial removal of the forest humus layer was performed in nitrogen-enriched urban Scots pine forest stands in the northern Finland in order to improve soil conditions for ectomycorrhizal (ECM) fungi, important symbionts of trees. Aboveground part of understory vegetation and the uppermost half of the humus layer were removed (REMOVAL treatment) from sample plots in six urban and eight rural reference forest sites at the beginning of the 2001 growing season. During the seasons 2001-2005, we inventoried sporocarp production of ECM and saprophytic fungi, and in 2003 the recovery of understory vegetation. The REMOVAL treatment resulted in a higher number of fruiting ECM species and sporocarps than controls at the rural, but not at urban sites. The sporocarp number of saprophytic fungi declined in the REMOVAL subplots at the urban sites. The recovery of bryophytes and lichens in the REMOVAL treatment was slow at both the urban and rural sites, whereas Vaccinium dwarf shrub cover, and herb and grass cover returned rapidly at the urban sites. We conclude that the partial vegetation and humus layer removal as a tool to promote the reproduction of ECM fungal species is limited in the boreal urban forests.
为改善土壤条件以促进外生菌根真菌（树木的重要共生体）的生长，在芬兰北部的富氮城市欧洲赤松林中进行了森林腐殖质层的局部去除。在 2001 年生长季开始时，从六个城市和八个农村参考林分的样地中去除了林下植被的地上部分和腐殖质层的上半部分（去除处理）。在 2001 年至 2005 年期间，我们对 ECM 和腐生真菌的子实体产量进行了清查，并于 2003 年对林下植被的恢复情况进行了清查。与对照相比，去除处理在农村地区导致了更多的 ECM 物种和子实体的结实，但在城市地区则没有。在城市样地的去除处理中，腐生真菌的子实体数量减少。在城市和农村样地中，去除处理中苔藓和地衣的恢复都很慢，而在城市样地中，越橘矮灌木的覆盖度以及草本和草类的覆盖度迅速恢复。我们的结论是，作为促进外生菌根真菌物种繁殖的工具，局部植被和腐殖质层的去除在北方城市森林中的应用是有限的。
