Abstract Alpine regions of the Mediterranean realm are among the most climatically sensitive areas in the world. Thus, alpine wetlands from the southern Iberian Peninsula, in the westernmost part of the Mediterranean region, are highly sensitive sensors of environmental changes. Difficulties have surfaced in separating controls by temperature and/or precipitation in previous paleoenvironmental studies from alpine environments in this area. We present a Holocene biomarker record (n-alkanes and long-chain diols) from a high elevation lake, Laguna de Rio Seco (LdRS), in the south of the Iberian Peninsula, which contributes to the identification of these forcing mechanisms. The hydrological history of the area, primarily water availability and evapotranspiration, is reconstructed by means of the n-alkane record, including the indices of average chain length, portion aquatic, and carbon preference index, as well as hydrogen isotopes (δD) of aquatic (δDaq) and terrestrial (δDwax) n-alkanes. Temperatures are also estimated using the algae derived long-chain diols. We interpret δDaq and δDwax fluctuations as showing changes in the source and amount of precipitation throughout the LdRS record. An Atlantic precipitation source appears to have predominated during the early-middle Holocene, but an occasional Mediterranean influence with an isotopic enrichment in precipitation is detected in the middle-late Holocene that is likely related to the setting of the current atmospheric pattern in southeastern Iberia under the joint control of the North Atlantic Oscillation (NAO) and the Western Mediterranean dynamics, such as the Western Mediterranean Oscillation (WeMO). Our new record from LdRS is consistent with a generalized trend of a humid early-middle Holocene with low temperature variability, evolving towards an arid middle-late Holocene with abrupt temperature changes. In addition to these long-term trends during the last ∼10,500 years, two phases of climate instability, evidenced by abrupt depletions in δDaq, have been identified at the end of these periods, one between ∼6500 and 5500 cal yr BP and another in the last ∼500 years. These episodes would represent strengthened winter cold conditions that favoured the persistence of snowpack and frozen soil in the catchment, causing reduced terrestrial plant growth and low lake evaporation. According to the long-chain diol record, temperatures during these phases were relatively low, but experienced abrupt increases at the end of each period.

中文翻译：

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从西地中海高山湿地的脂质生物标志物对全新世水文和温度的新见解

摘要 地中海地区的高山地区是世界上气候最敏感的地区之一。因此，位于地中海地区最西端的伊比利亚半岛南部的高山湿地是环境变化的高度敏感传感器。在先前的古环境研究中，很难将温度和/或降水控制与该地区的高山环境分开。我们展示了来自伊比利亚半岛南部高海拔湖泊 Laguna de Rio Seco (LdRS) 的全新世生物标志物记录（正烷烃和长链二醇），这有助于确定这些强迫机制。该地区的水文历史，主要是可用水量和蒸散量，通过正烷烃记录重建，包括平均链长、水生部分和碳偏好指数，以及水生 (δDaq) 和陆地 (δDwax) 正构烷烃的氢同位素 (δD)。还使用藻类衍生的长链二醇估算温度。我们将 δDaq 和 δDwax 的波动解释为显示整个 LdRS 记录中降水来源和降水量的变化。大西洋降水源似乎在全新世中早期占主导地位，但在全新世中晚期检测到偶尔的地中海影响，降水同位素富集，这可能与伊比利亚东南部当前大气模式的背景有关北大西洋涛动（NAO）和西地中海动力学的共同控制，例如西地中海涛动（WeMO）。我们从 LdRS 获得的新记录与具有低温度变化的潮湿早中全新世的普遍趋势一致，演变为具有突然温度变化的干旱中晚期全新世。除了过去 10,500 年的这些长期趋势外，在这些时期结束时还确定了气候不稳定的两个阶段，即 δDaq 的突然消耗，一个在 6500 到 5500 cal BP 之间，另一个在近 500 年。这些事件将代表冬季寒冷条件加强，有利于集水区积雪和冻土的持续存在，导致陆地植物生长减少和湖泊蒸发量低。根据长链二醇的记录，这些阶段的温度相对较低，