Descriptions of regional climate expression require data from multiple lakes, yet little is known of how variation in records within morphometrically complex lakes may affect interpretations. In northeast Ontario (Canada), this issue was addressed using records of pollen, pigments, and diatoms in three sediment cores from two small boreal lakes spanning the last ~6000 years. Pollen analysis suggested warm conditions between ~6000 and ~4000 cal yr BP, coherent with previous assessments from boreal eastern Ontario and western Quebec. Analysis of phototrophic communities from fossil pigments and diatom valves suggested relatively eutrophic conditions with lower lake-levels during this interval. Generalized additive model trends identified significant regional changes in pollen assemblages and declines in pigment concentrations after ~4000 cal yr BP consistent with cooler and wetter climate conditions that resulted in regional lake oligotrophication and increased lake levels during the late-Holocene. Despite contemporaneous changes in pollen and pigment biomarkers across lakes, cores collected from adjacent basins of the same lake (Green Lake) did not show similar trends in fossil pigments likely reflecting preferential deposition of clay-rich allochthonous material in the deeper central basin and suggesting that regional signals in climate may be complicated by lake- or basin-specific catchment processes.

区域气候表达的描述需要来自多个湖泊的数据，但对于形态复杂的湖泊内记录的变化如何影响解释知之甚少。在安大略省东北部（加拿大），过去约 6000 年的两个小北方湖泊的三个沉积岩芯中的花粉、色素和硅藻记录解决了这个问题。花粉分析表明温暖的气候条件在大约 6000 到大约 4000 cal yr BP 之间，与之前对安大略东部和魁北克西部的评估一致。对来自化石色素和硅藻阀的光养群落的分析表明，在此期间湖泊水位较低，相对富营养化。广义加性模型趋势确定了大约 4000 卡年 BP 后花粉组合的显着区域变化和色素浓度的下降，这与较冷和较湿的气候条件一致，导致区域性湖泊贫营养化和全新世晚期湖泊水位增加。尽管整个湖泊的花粉和色素生物标志物同时发生了变化，但从同一湖泊（绿湖）的相邻盆地收集的岩心并未显示出类似的化石色素趋势，这可能反映了富含粘土的外来物质在更深的中央盆地中的优先沉积，并表明气候中的区域信号可能因湖泊或盆地特定的集水过程而变得复杂。