Pedrotta Tiziana, Gobet Erika, Schwörer Christoph, Beffa Giorgia, Butz Christoph, Henne Paul D, Morales-Molino César, Pasta Salvatore, van Leeuwen Jacqueline F N, Vogel Hendrik, Zwimpfer Elias, Anselmetti Flavio S, Grosjean Martin, Tinner Willy
Institute of Plant Sciences and Oeschger Centre for Climate Change Research, University of Bern, Altenbergrain 21, 3013 Bern, Switzerland.
Institute of Geography and Oeschger Centre for Climate Change Research, University of Bern, Hallerstraße 12, 3012 Bern, Switzerland.
Veg Hist Archaeobot. 2021;30(6):789-813. doi: 10.1007/s00334-021-00832-3. Epub 2021 Apr 21.
Knowledge about the vegetation history of Sardinia, the second largest island of the Mediterranean, is scanty. Here, we present a new sedimentary record covering the past ~ 8,000 years from Lago di Baratz, north-west Sardinia. Vegetation and fire history are reconstructed by pollen, spores, macrofossils and charcoal analyses and environmental dynamics by high-resolution element geochemistry together with pigment analyses. During the period 8,100-7,500 cal bp, when seasonality was high and fire and erosion were frequent, and woodlands dominated the coastal landscape. Subsequently, between 7,500 and 5,500 cal bp, seasonality gradually declined and thermo-mediterranean woodlands with and partially replaced communities under diminished incidence of fire. After 5,500 cal bp, evergreen oak forests expanded markedly, erosion declined and lake levels increased, likely in response to increasing (summer) moisture availability. Increased anthropogenic fire disturbance triggered shrubland expansions (e.g. and ) around 5,000-4,500 cal bp. Subsequently around 4,000-3,500 cal bp evergreen oak-olive forests expanded massively when fire activity declined and lake productivity and anoxia reached Holocene maxima. Land-use activities during the past 4,000 years (since the Bronze Age) gradually disrupted coastal forests, but relict stands persisted under rather stable environmental conditions until ca. 200 cal bp, when agricultural activities intensified and and were planted to stabilize the sand dunes. Pervasive prehistoric land-use activities since at least the Bronze Age Nuraghi period included the cultivation of , and after 3,500-3,300 cal bp, and after 2,500 cal bp. We conclude that restoring less flammable native and forest communities would markedly reduce fire risk and erodibility compared to recent forest plantations with flammable non-native trees (e.g. , ) and xerophytic shrubland (e.g. , ).
关于地中海第二大岛屿撒丁岛植被历史的了解十分匮乏。在此，我们展示了一份来自撒丁岛西北部巴拉茨湖的新沉积记录，涵盖了过去约8000年的历史。通过花粉、孢子、大化石和木炭分析重建植被和火灾历史，并通过高分辨率元素地球化学以及色素分析重建环境动态。在公元前8100 - 7500年期间，季节性强，火灾和侵蚀频繁，林地主导着沿海景观。随后，在公元前7500年至5500年之间，季节性逐渐下降，暖地中海林地部分取代了火灾发生率降低的群落。公元前5500年之后，常绿橡树林显著扩张，侵蚀减少，湖泊水位上升，这可能是对（夏季）水分供应增加的响应。约公元前5000 - 4500年，人为火灾干扰增加引发了灌木丛扩张（如金雀花和岩蔷薇）。随后，约公元前4000 - 3500年，当火灾活动减少，湖泊生产力和缺氧达到全新世最大值时，常绿橡木 - 橄榄林大规模扩张。过去4000年（自青铜时代以来）的土地利用活动逐渐破坏了沿海森林，但在相当稳定的环境条件下，残余林分一直持续到约公元200年，当时农业活动加剧，种植了松树和桉树以稳定沙丘。至少自青铜时代努拉吉时期以来普遍存在的史前土地利用活动包括公元前3500 - 3300年之后种植小麦、大麦和豆类，以及公元前2500年之后种植橄榄。我们得出结论，与近期种植易燃非本地树木（如松树、桉树）和旱生灌木丛（如金雀花、岩蔷薇）的森林种植园相比，恢复易燃性较低的本地橡木和橄榄林群落将显著降低火灾风险和可侵蚀性。
