Baar J, Bastiaans T, van de Coevering M A, Roelofs J G M
Applied Plant Research, Wageningen University Research, P.O. Box 6042, 5960 AA Horst, The Netherlands.
Mycorrhiza. 2002 Jun;12(3):147-51. doi: 10.1007/s00572-002-0158-9. Epub 2002 Mar 27.
Effects of desiccation and eutrophication on ectomycorrhizal (ECM) root development in wet Alder carr forests in The Netherlands were studied. In northwestern Europe, wet Alder carr forests are found mostly in peatlands and along streams, forming an important component of wetland ecosystems. The dominant tree species in wet Alder carr forests is Alnus glutinosa (L.) Gaertn. (Black alder), which associates with ectomycorrhizal fungi. During recent decades, wet Alder carr forests in Europe have declined because of desiccation and eutrophication, particularly in The Netherlands. In the present study, the number of root tips of A. glutinosa trees was highest in an undisturbed wet Alder carr forest in a peatland area. Eutrophication in the peatland area significantly inhibited ectomycorrhizal (ECM) root development of A. glutinosa. In the eutrophied forest, ECM root tips were observed only close to A. glutinosa trees growing on hummocks. The concentrations of nitrate and potassium in soil water of the eutrophied forest were significantly higher than in the undisturbed forest, while magnesium and iron concentrations and the pH were significantly lower. The number of ECM root tips of A. glutinosa in a desiccated forest along a stream was generally lower than in an undisturbed wet Alder carr forest on waterlogged soil in the same area. The sulphate concentration in soil water in the desiccated forest was significantly higher than in the forest on waterlogged soil. ECM root development of A. glutinosa may have been negatively affected by the chemical composition of the soil water.
研究了干燥和富营养化对荷兰湿润桤木泥炭林中外生菌根（ECM）根系发育的影响。在欧洲西北部，湿润桤木泥炭林主要分布在泥炭地和溪流沿岸，是湿地生态系统的重要组成部分。湿润桤木泥炭林中的优势树种是欧洲桤木（Alnus glutinosa (L.) Gaertn.）（黑桤木），它与外生菌根真菌共生。近几十年来，欧洲的湿润桤木泥炭林因干燥和富营养化而减少，尤其是在荷兰。在本研究中，欧洲桤木树的根尖数量在泥炭地区一个未受干扰的湿润桤木泥炭林中最高。泥炭地区的富营养化显著抑制了欧洲桤木的外生菌根（ECM）根系发育。在富营养化的森林中，仅在生长于小土丘上的欧洲桤木树附近观察到ECM根尖。富营养化森林土壤水中的硝酸盐和钾浓度显著高于未受干扰的森林，而镁和铁浓度以及pH值则显著较低。溪流沿岸一片干燥森林中欧洲桤木的ECM根尖数量通常低于同一地区水涝土壤上未受干扰的湿润桤木泥炭林中的数量。干燥森林土壤水中的硫酸盐浓度显著高于水涝土壤上的森林。欧洲桤木的ECM根系发育可能受到了土壤水化学成分的负面影响。
