Abstract Native to Eurasia, Eastern Europe, and Western Asia, Oriental beech (Fagus orientalis Lipsky) stands extend from the north-western part of Turkey, the eastern part of the Caucasus Mountains in Georgia and Russia to the Alborz Mountains in Iran. The effect of different development stages of beech stands on the forest floor and soil characteristics are so far almost unknown. For this purpose, the Langa forest that is located in northern Iran was investigated to detect the effect of forest development on major traits of soil biology and related soil characteristics. For this aim, 45 forest floors and soil samples (15 samples per each development stage i.e. initial, optimal, and decay stage) were analysed. In addition, the water content, temperature, and biological dynamics were monitored over the different development stages in summer and fall. Among the considered independent factors, the development stage of beech had the largest explanatory power for the variations of the soil water content (34.7%), total earthworm density and biomass (29.6% and 32.3%, respectively), Acarina (30.3%), nematode (64.3%), protozoa (57.7%), bacteria, (62.8%), fungi (59.5%), basal respiration (53.0%), substrate-induced respiration (53.8%), microbial biomass carbon (30.4%), microbial biomass nitrogen (36.0%), microbial biomass phosphorous (59.1%) and net nitrification rate (19.1%). Soil temperature (42.5%), collembola density (18.2%), net ammonification rate (29.9%), and net N mineralization rate (2.1%) were predominantly determined by the seasons. With the ageing of the forest stands, soil fertility, biota abundance, and soil function were enhanced. To figure out the most vital soil features affecting C and N sequestrations, a stepwise regression model was applied. Carbon sequestration correlated positively to N, the C/N ratio, and negatively to porosity, and the nematode abundance. In addition, nitrogen sequestration correlated positively to C, the sand content, and fine root biomass and negatively to the C/N ratio, soil porosity, and aggregate stability. Although all forest stages of the Oriental beech have an important ecological role and their place in the evolutionary process, the old-growth (i.e. decay) stage is especially important for the soil functions exhibiting the highest fertility and biological relevance. The understanding of ecological changes within different development stages can be helpful in forest management and the evaluation of silvicultural methods.

中文翻译：

---

东方山毛榉林不同发育阶段的林地和土壤性质

摘要原产于欧亚大陆、东欧和西亚，东方山毛榉 (Fagus orientalis Lipsky) 林分从土耳其西北部、格鲁吉亚和俄罗斯的高加索山脉东部延伸到伊朗的阿尔伯兹山脉。山毛榉不同发展阶段对林地和土壤特征的影响到目前为止几乎是未知的。为此，对位于伊朗北部的兰加森林进行了调查，以检测森林发展对土壤生物学主要特征和相关土壤特征的影响。为此，分析了 45 个森林地面和土壤样本（每个发展阶段 15 个样本，即初始、最佳和衰退阶段）。此外，含水量、温度、并在夏季和秋季的不同发育阶段监测生物动态。在考虑的独立因素中，山毛榉发育阶段对土壤含水量（34.7%）、蚯蚓总密度和生物量（分别为29.6%和32.3%）、蜱螨（30.3%）、线虫 (64.3%)、原生动物 (57.7%)、细菌 (62.8%)、真菌 (59.5%)、基础呼吸 (53.0%)、基质诱导呼吸 (53.8%)、微生物生物质碳 (30.4%)、微生物生物量氮（36.0%）、微生物生物量磷（59.1%）和净硝化率（19.1%）。土壤温度（42.5%）、弹尾虫密度（18.2%）、净氨化率（29.9%）和净氮矿化率（2.1%）主要由季节决定。随着林分的老化，土壤肥力，生物群丰富，土壤功能增强。为了找出影响 C 和 N 固存的最重要的土壤特征，应用了逐步回归模型。固碳与 N、C/N 比呈正相关，与孔隙度和线虫丰度呈负相关。此外，固氮与 C、沙子含量和细根生物量呈正相关，与 C/N 比、土壤孔隙度和团聚体稳定性呈负相关。尽管东方山毛榉的所有森林阶段都具有重要的生态作用及其在进化过程中的地位，但老生长（即腐烂）阶段对于表现出最高肥力和生物相关性的土壤功能尤为重要。