Peatland complexes in the humid highlands of Hawai‘i are vital refuges of biodiversity and freshwater resources. Hawaiian peat deposits are also rare repositories of terrestrial ecosystem archives located in an otherwise vast expanse of ocean. We investigated the potential for researching the paleohydrological history of Hawaiian montane peatlands on Kohala, Hawai‘i Island through analyses of testate amoebae and Cladocera. Surface peat was collected from a variety of ecohydrological habitats (from water pools to hummocks) and analyzed for modern testate amoeba and cladoceran species relative abundance. We identified 54 morphotype taxa from 21 genera of testate amoebae, 4 taxa and genera of littoral Cladocera, and the common peat rotifer Habrotrocha angusticollis. Testate amoeba diversity and morphotype occurrence mirrored observations from many high-latitude peatland studies. Constrained and unconstrained ordinations support the hypothesis that surface moisture, measured as water-table depth, is an important control on the distribution of testate amoebae and Cladocera in Hawaiian peatlands. Transfer functions relying on weighted-averaging and modern analogs were developed to predict water-table depths from species relative abundance data, and these perform well under leave-one-site-out cross-validation: RMSEP = 9.75–10.3 cm, R² = 0.56–0.62. Including cladoceran abundance data in the calibration dataset produced modest model improvement: RMSEP = 1–8% and R² = 2–13%. A weighted-average partial-least-squares transfer function was applied to microfossil assemblages from a 0.5 m-long peat core with a ²¹⁰Pb decay chronology anchored by ten existing measurements of ²¹⁰Pb activity and a Bayesian statistical framework. Microfossils were well-preserved in the peat core. The water-table depth optima of an abundant down-core taxa, Hyalosphenia subflava, is not precisely constrained in the calibration data set, but estimates match those of other tropical studies. A reconstruction of water-table depth indicates dry early nineteenth-century conditions, wet conditions in the late 19th to early twentieth centuries, followed by progressive drying for much of the twentieth-century. Testate amoeba composition appears to have been sensitive to severe drought in recent decades. The results signal that assemblages of testate amoebae and Cladocera are useful proxies of Hawaiian peatland paleohydrology and should be considered alongside other archives of Hawaiian environmental history.

夏威夷湿润的高原地区的泥炭地综合体是生物多样性和淡水资源的重要避难所。夏威夷的泥炭矿床也是位于广阔的海洋中的陆地生态系统档案库的稀有仓库。我们通过对遗嘱性变形虫和克拉多菌的分析，研究了在夏威夷科哈拉的夏威夷山地泥炭地古水文历史的研究潜力。从各种生态水文生境（从水池到山岗）收集了表层泥炭，并分析了现代睾丸类阿米巴和枝角类物种的相对丰度。我们从21个睾丸变形虫科，4个分类单元和沿海克拉科属和普通的泥炭轮虫Habrotrocha angusticollis鉴定了54个形态型分类单元。睾丸变形虫的多样性和形态型的出现反映了许多高纬度泥炭地研究的观察结果。受约束和不受约束的法则支持这样的假说，即以水位深度测量的表面水分是控制夏威夷泥炭地的睾丸变形虫和克拉多菌的分布的重要控制。开发了依赖于加权平均和现代类似物的传递函数，可以根据物种相对丰度数据预测地下水位深度，并且在留一站式交叉验证中表现良好：RMSEP = 9.75–10.3 cm，R ²  = 0.56-0.62。在校准数据集中包含锁骨角的丰度数据可产生适度的模型改进：RMSEP = 1–8％和R ² = 2–13％。加权平均偏最小二乘传递函数应用于0.5 m长的泥炭岩心的微化石组合，其泥炭具有²¹⁰ Pb的衰变年代，并通过十个现有的²¹⁰ Pb活性和贝叶斯统计框架进行了锚定。微化石在泥炭芯中保存完好。丰富的下核心类群透明亚目的地下水位深度最优，并没有精确地限制在校准数据集中，但是估计值与其他热带研究的估计值相匹配。重建水位深度表示19世纪初处于干燥状态，19世纪后期至20世纪初处于潮湿状态，随后在20世纪的大部分时间逐渐干燥。近几十年来，睾丸变形虫的组成似乎对严重干旱敏感。结果表明，遗嘱性变形虫和克拉多菌的组合是夏威夷泥炭地古水文学的有用代表，应与夏威夷环境历史的其他文献一起考虑。