Summary Here, we developed and applied models to quantitatively reconstruct forest cover and biomass changes at three lakes in northwestern Amazonia over the past > 1500 yr. We used remotely sensed data and a modern dataset of 50 Amazonian lakes to develop generalized linear models that predict aboveground biomass, using phytolith morphotypes and forest cover as predictor variables. Also, we applied a published beta regression model to predict forest cover within 200 m of each lake, using Poaceae phytoliths. Charcoal and maize phytoliths were analysed to identify past land use. Results showed forest cover and biomass changes at our study sites ranged between 48–84% and 142–438 Mg ha−1, respectively. Human occupation was discontinuous, with major changes in forest cover and biomass coinciding with periods of land use. Forest cover and biomass decreased notably after fire (at all sites) or cultivation events (Lakes Zancudococha, Kumpaka). The timing and ecological impact of past land use were spatially and temporally variable. Our results suggest past human impact was small‐scaled and heterogenous in northwestern Amazonia, with a significant impact of fire on forest cover and biomass changes.

中文翻译：

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量化厄瓜多尔亚马逊地区过去的森林覆盖率和生物量变化


总结 在这里，我们开发并应用模型来定量重建过去 > 1500 年亚马逊西北部三个湖泊的森林覆盖率和生物量变化。我们使用遥感数据和 50 个亚马逊湖泊的现代数据集，使用植硅体形态型和森林覆盖率作为预测变量，开发预测地上生物量的广义线性模型。此外，我们还应用了已发布的 beta 回归模型，使用禾本科植硅体预测每个湖泊 200 m 范围内的森林覆盖率。对木炭和玉米植硅体进行了分析，以确定过去的土地用途。结果显示，我们研究地点的森林覆盖率和生物量变化分别在 48-84% 和 142-438 毫克公顷-1 之间。人类居住是不连续的，森林覆盖和生物量的重大变化与土地使用时期相吻合。火灾（所有地点）或耕作事件（Zancudococha 湖、Kumpaka）后，森林覆盖率和生物量显著下降。过去土地利用的时间和生态影响在空间和时间上都是可变的。我们的结果表明，过去人类对亚马逊西北部的影响规模较小且异质性，火灾对森林覆盖和生物量变化有重大影响。