Sherbo et al. 2023 Data Package. Data associated with study assessing effects of dissolved organic matter on phytoplankton productivity in boreal lakes. The majority of data was collected in 2018 at the IISD Experimental Lakes Area in Northwestern Ontario

Allochthonous dissolved organic matter (DOM) structures many physical, chemical, and biological properties of lakes, including key variables that control productivity at the base of freshwater food webs. We examined phytoplankton biomass and productivity and their drivers, across eight pristine boreal lakes with DOM ranging from 3.5 to 9.5 mg DOC L-1. Increases in DOM were associated with significant increases in epilimnetic nitrogen, phosphorus and chlorophyll a (Chl a) concentrations suggesting that nutrients associated with DOM stimulate phytoplankton biomass and productivity. Such results were misleading; there was no significant relationship between Chl a and phytoplankton biomass measured via microscopy, and results did not incorporate the effects of DOM on thermocline and euphotic depth. Chl a:biomass and Chl a: carbon ratios indicated that increases in Chl a with DOM were driven by photo-acclimation to declining light availability. Increases. Further, increases in DOM led to large declines in thermocline (~50 %) and euphotic (~75 %) depths, and depth-integrated phytoplankton biomass and primary production (~70 %).外源溶解性有机物（Allochthonous dissolved organic matter, DOM）可塑造湖泊的诸多物理、化学与生物学属性，其中包含调控淡水食物网底层生产力的关键变量。本研究针对8座原始北方湖泊开展分析，探究了浮游植物（phytoplankton）生物量、生产力及其调控因子，这些湖泊的DOM浓度以溶解性有机碳（dissolved organic carbon, DOC）计，介于3.5至9.5 mg·L⁻¹之间。外源溶解性有机物浓度升高与湖上层（epilimnetic）水体的氮、磷及叶绿素a（chlorophyll a, Chl a）浓度显著升高呈相关关系，这表明与DOM结合的营养盐可促进浮游植物的生物量与生产力。但此类结论存在误导性：通过显微镜观测得到的Chl a浓度与浮游植物生物量之间并无显著相关性，且原有研究未考虑DOM对温跃层（thermocline）与真光层（euphotic）深度的影响。Chl a与生物量的比值、Chl a与碳的比值均表明，随DOM浓度升高而出现的Chl a浓度升高，实则是浮游植物对光照可用性降低产生的光适应（photo-acclimation）过程所驱动。此外，外源溶解性有机物浓度升高会导致温跃层深度下降约50%、真光层深度下降约75%，同时深度积分浮游植物生物量与初级生产力下降约70%。