The Preto River, located in the municipality of São Gonçalo do Rio Preto (Minas Gerais, Brazil), is one of the few perennial watercourses in the semi-arid region of northeastern Minas Gerais and is essential for the socio-environmental dynamics of the region. Its headwaters are located in the Southern Espinhaço Mountain Range, which is characterized by predominantly quartzite lithologies that form a relief with dissected altimetric variations interspersed with planation surfaces, where the climate is high-altitude tropical. The soils are poorly developed and small fragments of forest, together with phytophysiognomies of the Cerrado Biome such as wet grasslands (Campo limpo úmido), colonize the peatland ecosystems. The aim of this study is to contribute to the paleoenvironmental reconstruction of the headwaters of the River Preto, using sliliceous bioindicators associated with other indicators (multi-proxy analysis). It was possible to infer that there was no change in phytophysiognomies from around 23,330 cal years BP to the present. However, there were 4 periods with oscillations between a cooler, drier environment in the Late Pleistocene, which gradually became warmer and more humid in the Late Holocene. Period 1 (Late Pleistocene) corresponds to the interval from before 23,300 to 13,500 cal years BP, in which the low tree density index (D/P) indicates vegetation similar to the current. Period 2 (end of the Late Pleistocene) corresponds to the period between 13,500 and 11,700 cal years BP. The increase in the D/P index indicates a small expansion of tree vegetation, albeit with the continued predominance of open vegetation. The appearance of Arecaceae characteristic phytoliths, associated with the drop in the climate index (Ic%), indicates an increase in temperature in relation to the previous phase. Period 3 (Pleistocene to Holocene transition) corresponds to the period from 11,700 to 10,000 cal years BP. It is a little colder and drier than the previous period, as observed from the increase in the climate index (Ic%). This period includes the Younger Dryas event, which was colder and drier than currently and had a global influence. Period 4 (Holocene) corresponds to the last 10,000 cal years BP. During this period there was no change in vegetation cover, the D/P and Pa/P indexes remain low, and there is a tendency towards a gradual increase in temperature. The use of siliceous bioindicators associated with other proxies and the regional and global events that occurred during the Quaternary in the analyzed sediments enabled the observation that, at least in the last 23,300 cal years BP, there have been no changes in the local vegetation cover. However, there were small expansion episodes or decreases in the density of tree and Arecaceae cover, as well as a tendency towards increased temperature and humidity in the Upper Holocene. The results proved to be useful for paleoenvironmental research and highlighted how peatland ecosystems are fundamental for understanding the evolution of the landscape and for reconstructing the environmental history of the Cerrado biome.

普雷托河位于巴西圣米纳斯吉拉斯州圣贡萨洛·里奥普雷图市，是米纳斯吉拉斯州东北半干旱地区为数不多的多年生水道之一，对于该地区的社会环境动态至关重要。其上游源头位于南部的Espinhaço山脉，其特征是主要为石英岩岩性，形成了浮雕，上面夹杂着高海拔热带的高海拔气候。土壤发育不佳，森林小片，以及塞拉多生物群落的植物生理学，例如湿草原（Campo limpoúmido），在泥炭地生态系统中殖民。这项研究的目的是使用与其他指标相关的硅酸生物指示剂（多重代理分析），为普雷托河上游水源的古环境重建做出贡献。可以推断，从大约BP的23330 cal年到现在，植物生理学没有改变。然而，在晚更新世较凉爽，干燥的环境之间有4个周期的振荡，在晚更新世逐渐变暖和潮湿。时期1（晚更新世）对应于BP 23300至13500cal年之前的时间间隔，其中低树密度指数（D / P）表示与当前相似的植被。时期2（晚更新世末期）对应于BP 13500到11700 cal年之间​​的时期。D / P指数的增加表明树木植被的扩张很小，尽管开放植被继续占主导地位。槟榔科特征性植物石的出现与气候指数（Ic％）的下降有关，表明温度相对于前一阶段有所上升。时期3（更新世向全新世过渡）对应于BP 11700到10,000cal年的时期。从气候指数（Ic％）的增加中可以看出，与上一时期相比，它略冷和干燥。这个时期包括Younger Dryas事件，该事件比现在更冷和干燥，并且具有全球影响力。时期4（全新世）对应于最近10,000 cal BP。在此期间，植被盖度没有变化，D / P和Pa / P指数仍然很低，并且存在温度逐渐升高的趋势。使用硅质生物指示剂与其他代理以及第四纪期间发生在被分析沉积物中的区域和全球事件相关联，可以观察到至少在最近BP 23300 cal年内，当地植被没有变化。然而，树木和槟榔科的覆盖率出现较小的扩张或降低，并且在上全新世时温度和湿度都有升高的趋势。结果被证明对古环境研究有用，并强调了泥炭地生态系统对于理解景观演变和重建塞拉多生物群落的环境历史至关重要。使用硅质生物指示剂与其他代理以及第四纪期间发生在被分析沉积物中的区域和全球事件相关联，可以观察到至少在最近BP 23300 cal年内，当地植被没有变化。然而，树木和槟榔科的覆盖率出现较小的扩张或降低，并且在上全新世时温度和湿度都有升高的趋势。结果被证明对古环境研究有用，并强调了泥炭地生态系统对于理解景观演变和重建塞拉多生物群落环境历史的基础。使用硅质生物指示剂与其他代理以及第四纪期间发生在被分析沉积物中的区域和全球事件相关联，可以观察到至少在最近BP 23300 cal年内，当地植被没有变化。然而，树木和槟榔科的覆盖率出现较小的扩张或降低，并且在上全新世时温度和湿度都有升高的趋势。结果被证明对古环境研究有用，并强调了泥炭地生态系统对于理解景观演变和重建塞拉多生物群落的环境历史至关重要。