Godbold Douglas L, Fritz Heinz-Werner, Jentschke Georg, Meesenburg Henning, Rademacher Peter
School of Agricultural and Forest Sciences, University of Wales, Bangor, Gwynedd LL57 2UW, U.K.
Tree Physiol. 2003 Sep;23(13):915-21. doi: 10.1093/treephys/23.13.915.
Fine root distribution and turnover were investigated in ca. 40-year-old pure Norway spruce (Picea abies Karst.) stands in Germany, growing on four sites that differed in soil acidity (Ebergötzen < Barbis < Fichtelgebirge = Harz). The density of fine root biomass and necromass in different soil horizons differed among the sites. At one of the most acidic sites (Harz), fine root density in the humus layer was more than twice that at the least acidic site (Ebergötzen). At the two most acidic sites, Fichtelgebirge and Harz, the ratio of biomass to necromass was significantly lower than at Ebergötzen and Barbis, particularly in the subsoil layer. In each stand, clear vertical gradients in fine root length density and root tip density were observed. Most of the roots and the root tips were in the humus layer and in the first mineral soil horizon (0-10 cm). There was a significantly different decrease in specific root length (cm gDM (-1)) and specific root tip density (root tips gDM (-1)) in the more acidified stands Fichtelgebirge and Harz compared with Ebergötzen and Barbis. Fine root production estimated by ingrowth cores and a net method was approximately twice as high in the more acidic stands Fichtelgebirge and Harz compared with Ebergötzen and Barbis. Rates of living fine root biomass turnover were higher at the Fichtelgebirge and Harz sites than at the Ebergötzen site. Rates of necromass turnover were similar at all sites. The results suggest that the accumulation of necromass was not due to a slower disappearance at the more acid sites, but to earlier root death. Roots contributed 46% to root + needle litter and 32% to root + total aboveground litter at the Harz site in 1997.
在德国约40年生的纯挪威云杉（Picea abies Karst.）林中，对细根分布和周转进行了研究，这些云杉林生长在四个土壤酸度不同的地点（埃贝格策恩＜巴尔比斯＜菲希特尔山 = 哈尔茨）。不同土壤层中细根生物量和死根量的密度在各地点间存在差异。在酸性最强的地点之一（哈尔茨），腐殖质层的细根密度是酸性最弱的地点（埃贝格策恩）的两倍多。在酸性最强的两个地点，菲希特尔山和哈尔茨，生物量与死根量的比值显著低于埃贝格策恩和巴尔比斯，尤其是在底土层。在每个林分中，均观察到细根长度密度和根尖密度存在明显的垂直梯度。大多数根系和根尖位于腐殖质层以及第一矿质土壤层（0 - 10厘米）。与埃贝格策恩和巴尔比斯相比，在酸化程度更高的菲希特尔山和哈尔茨林分中，比根长（厘米 克干物质⁻¹）和比根尖密度（根尖 克干物质⁻¹）的下降幅度显著不同。通过内生长芯和净方法估算的细根生产量，在酸性更强的菲希特尔山和哈尔茨林分中约为埃贝格策恩和巴尔比斯的两倍。菲希特尔山和哈尔茨地点活细根生物量的周转速率高于埃贝格策恩地点。所有地点死根量的周转速率相似。结果表明，死根量的积累并非由于酸性更强的地点死根消失速度较慢，而是由于根系更早死亡。1997年在哈尔茨地点，根系对根 + 针叶凋落物的贡献为46%，对根 + 地上总凋落物的贡献为32%。
