Long-term hydrochemical monitoring in an Oyasan Experimental Forest Watershed comprised of two small forested watersheds of Japanese cedar and Japanese cypress
Long-term hydrochemical monitoring in an Oyasan Experimental Forest Watershed comprised of two small forested watersheds of Japanese cedar and Japanese cypress
复制标题
对由日本雪松和日本柏树的两个小型森林流域组成的 Oyasan 实验森林流域进行长期水化学监测
作者：
R. Urakawa;H. Toda;K. Haibara;Y. Aiba
森林生态系统是自肥系统，林分的发育取决于生态系统内生物地球化学循环的养分供应。因此，阐明介导生长和发育的营养循环非常重要。此外，需要长期水化学监测来了解环境变化对森林生态系统生物地球化学循环的影响。 Oyasan 实验森林流域 (OEFW) 位于日本群马县东京农业科技大学大学森林 Oyasan 田野博物馆内。 OEFW 包括两个相邻的小型森林流域 - A 流域和 B 流域 - 面积分别为 1.3 和 1.8 公顷。 A流域是1976年重建的森林，种植了杉树和扁柏，并通过施肥进行了集约化管理。相比之下，B流域是1907年种植杉树和扁柏的已建成森林。除了1983年对受抑制的树木进行间伐外，没有进行任何森林实践。然而，最低坡度的杉树种植园（占流域面积的18%）在2000年被砍伐，并于次年重新种植杉树。在本数据论文中，我们提供了自1978年11月以来的日降水量、流量、pH值以及雨水和溪水中主要营养盐（Ca2+、Mg2+、K+、Na+、NH4+、Cl−、NO3−和SO42−）浓度的数据。从监测开始至今，A、B流域降水、溪流水的算术平均pH值为4.77±0.67，分别为 6.85 ± 0.41 和 6.88 ± 0.36（平均值 ± SD）。 mmolc L−1 沉淀中的算术平均浓度 Ca2+ 为 0.030 ± 0.030，Mg2+ 为 0.010 ± 0.011，K+ 为 0.009 ± 0.013，Na+ 为 0.020 ± 0.024，NH4+ 为 0.035 ± 0.041， Cl− 为 0.026 ± 0.029，NO3− 为 0.033 ± 0.038，SO42− 为 0.046 ± 0.043。 A 流域溪水中的 Ca2+ 平均浓度为 0.180 ± 0.032，Mg2+ 为 0.073 ± 0.013，K+ 为 0.018 ± 0.009，Na+ 为 0.182 ± 0.024，NH4+ 为 0.010 ± 0.010， Cl− 为 0.060 ± 0.008，NO3− 为 0.111 ± 0.038，SO42− 为 0.074 ± 0.012；而对于 B 分水岭，Ca2+ 的平均浓度为 0.169 ± 0.025，Mg2+ 为 0.079 ± 0.016，K+ 为 0.018 ± 0.005，Na+ 为 0.192 ± 0.026，NH4+ 为 0.010 ± 0.010， Cl− 为 0.065 ± 0.010，NO3− 为 0.093 ± 0.025，SO42− 为 0.087 ± 0.011。
Forest ecosystems are self-fertilizing systems, and development of forest stands depends on nutrient supply via biogeochemical cycling within the ecosystem. Therefore, it is important to clarify the nutrient cycle mediating growth and development. In addition, long-term hydrochemical monitoring is needed to understand the influence of environmental changes on biogeochemical cycling in forest ecosystems. The Oyasan Experimental Forest Watershed (OEFW) is located in the Field Museum Oyasan, the university forest of Tokyo University of Agriculture and Technology, in Gunma prefecture, Japan. OEFW comprises two small adjacent forested watersheds—A-watershed and B-watershed—with respective areas of 1.3 and 1.8 ha. A-watershed is a reestablished forest planted with sugi (Japanese cedar; Cryptomeria japonica) and hinoki (Japanese cypress; Chamaecyparis obtusa) in 1976, and has been managed intensively with fertilizer application. By contrast, B-watershed is an established forest planted with sugi and hinoki in 1907. No forest practices have been carried out except for thinning of suppressed trees in 1983. However, the sugi plantation on the lowest slope (18% of the watershed area) was cut in 2000, and sugi was replanted the following year. In this data paper, we present data on the daily precipitation, discharge, pH, and concentrations of major nutrients (Ca2+, Mg2+, K+, Na+, NH4+, Cl−, NO3−, and SO42−) in rainwater and stream water since November 1978. The arithmetical mean pH of precipitation, stream water in A- and B-watershed from the beginning of the monitoring to the present were 4.77 ± 0.67, 6.85 ± 0.41 and 6.88 ± 0.36 (average ± SD), respectively. The arithmetical mean concentrations in precipitation in mmolc L−1 were 0.030 ± 0.030 for Ca2+, 0.010 ± 0.011 for Mg2+, 0.009 ± 0.013 for K+, 0.020 ± 0.024 for Na+, 0.035 ± 0.041 for NH4+, 0.026 ± 0.029 for Cl−, 0.033 ± 0.038 for NO3−, and 0.046 ± 0.043 for SO42−. The mean concentrations in stream water in A-watershed were 0.180 ± 0.032 for Ca2+, 0.073 ± 0.013 for Mg2+, 0.018 ± 0.009 for K+, 0.182 ± 0.024 for Na+, 0.010 ± 0.010 for NH4+, 0.060 ± 0.008 for Cl−, 0.111 ± 0.038 for NO3−, and 0.074 ± 0.012 for SO42−; whereas for B-watershed the mean concentrations were 0.169 ± 0.025 for Ca2+, 0.079 ± 0.016 for Mg2+, 0.018 ± 0.005 for K+, 0.192 ± 0.026 for Na+, 0.010 ± 0.010 for NH4+, 0.065 ± 0.010 for Cl−, 0.093 ± 0.025 for NO3−, and 0.087 ± 0.011 for SO42−.