Impacts of changing climate and land use on vegetation dynamics in a Mediterranean ecosystem: insights from paleoecology and dynamic modeling
Impacts of changing climate and land use on vegetation dynamics in a Mediterranean ecosystem: insights from paleoecology and dynamic modeling
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气候和土地利用变化对地中海生态系统植被动态的影响：古生态学和动态建模的见解
DOI：
10.1007/s10980-012-9782-8
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发表时间：
2012
影响因子：
5.2
通讯作者：
W. Tinner
中科院分区：
文献类型：
--
作者：
Paul D. Henne;C. Elkin;D. Colombaroli;S. Samartin;H. Bugmann;O. Heiri;W. Tinner
地中海沿岸附近的森林是经过数千年的人类干扰而形成的。因此，依赖现代观测或历史记录的生态研究可能难以评估当前和未来气候下的自然植被动态。我们将意大利托斯卡纳马萨丘科利湖的沉积花粉记录与 LandClim 动态植被模型的模拟相结合，以确定在强烈的人类干扰之前有哪些植被，过去植被的变化与火灾和啃食有何关系，以及在当前气候下灭绝植被类型的可能性。我们使用当地摇蚊推断的温度重建，结合三种火情（小不频繁、大不频繁、小频繁）和三种浏览强度（无浏览、轻度浏览和中度浏览）的组合，模拟了过去 7000 年 Lago di Massaciucoli 附近的植被动态，并将模型输出与花粉数据进行了比较。低扰动模拟支持了花粉推断的证据，表明存在以栎属冬青（地中海物种）和白冷杉（山地物种）为主的混交林。虽然花粉数据记录了银花在 6000 cal yr bp 后崩溃，但模拟种群在全新世晚期随着夏季气温下降而扩张。火烧和啃食增加的模拟与白银花倒塌后落叶物种扩张的证据是一致的。根据我们综合的古环境和模拟证据，在当前的气候和有限的干扰下，冬青树和阿尔巴树的混合森林仍然是可能的，并为地中海沿岸附近和预计未来将经历地中海型气候的地区的生态系统提供了可行的管理目标。
Forests near the Mediterranean coast have been shaped by millennia of human disturbance. Consequently, ecological studies relying on modern observations or historical records may have difficulty assessing natural vegetation dynamics under current and future climate. We combined a sedimentary pollen record from Lago di Massacciucoli, Tuscany, Italy with simulations from the LandClim dynamic vegetation model to determine what vegetation preceded intense human disturbance, how past changes in vegetation relate to fire and browsing, and the potential of an extinct vegetation type under present climate. We simulated vegetation dynamics near Lago di Massaciucoli for the last 7,000 years using a local chironomid-inferred temperature reconstruction with combinations of three fire regimes (small infrequent, large infrequent, small frequent) and three browsing intensities (no browsing, light browsing, and moderate browsing), and compared model output to pollen data. Simulations with low disturbance support pollen-inferred evidence for a mixed forest dominated by Quercus ilex (a Mediterranean species) and Abies alba (a montane species). Whereas pollen data record the collapse of A. alba after 6000 cal yr bp, simulated populations expanded with declining summer temperatures during the late Holocene. Simulations with increased fire and browsing are consistent with evidence for expansion by deciduous species after A. alba collapsed. According to our combined paleo-environmental and modeling evidence, mixed Q. ilex and A. alba forests remain possible with current climate and limited disturbance, and provide a viable management objective for ecosystems near the Mediterranean coast and in regions that are expected to experience a mediterranean-type climate in the future.