Recent climatic and anthropogenic impacts on endemic species in southwestern Morocco
Recent climatic and anthropogenic impacts on endemic species in southwestern Morocco
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DOI：
10.1016/j.quascirev.2019.105889
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发表时间：
2019-10
影响因子：
4
通讯作者：
Xue-qin Zhao;L. Dupont;R. Cheddadi;M. Kölling;H. Reddad;J. Groeneveld;F. Ain-Lhout;I. Bouimetarhan
中科院分区：
文献类型：
--
作者：
Xue-qin Zhao;L. Dupont;R. Cheddadi;M. Kölling;H. Reddad;J. Groeneveld;F. Ain-Lhout;I. Bouimetarhan
摩洛哥是一个经常遭受严重干旱、荒漠化和日益严重的土地退化的地区。它是生物多样性的地中海热点，因为它拥有许多受威胁的特有物种，如摩洛哥坚果树（Argania spinosa）。在这种情况下，需要过去的气候记录来分析气候变化对这些特有物种的发生和未来持续性的影响。为了评估过去气候变化对摩洛哥南部特有的摩洛哥坚果树的影响，我们使用广泛的花粉数据集重建了其现代范围。然后利用摩洛哥西南部的现代花粉分布来解释高分辨率的花粉记录与互补的微木炭和XRF元素记录从海洋沉积物芯GeoB 8601 -3关闭Cape Ghir在摩洛哥西南部覆盖了过去的三千年。这项多代理研究显示了明确的证据，表明更潮湿的条件导致更高的河流输入，这可能与北大西洋涛动（NAO）的负模式相关，与来自另一个附近核心的已发表的花粉和XRF元素记录相反，这些记录显示气候变化的影响有限。另一方面，在我们的化石记录中，观察到Argania spinosa的花粉出现率与火灾频率之间存在明显的相反趋势。增加ofArgania spinosaplanes发生，沿着与草本类群，和较低的火灾频率可能表明增加人类对景观的影响，导致稀疏的植被覆盖，随后增加侵蚀。重建花粉为基础的植被，微木炭为基础的火灾活动和地球化学变化在我们的海洋记录表明气候和人为影响的景观相互作用。
Morocco is an area subject to recurrent severe droughts, desertification and an increasing land degradation. It is within a Mediterranean hotspot of biodiversity as it harbors many threatened endemic species such as the argan tree (Argania spinosa). In this context, past climate records are needed to analyze the impact of climate variability on the occurrence and future persistence of these endemic species. In order to evaluate the impact of past climate changes on the endemic Argan tree in southern Morocco, we reconstructed its modern range using an extensive pollen dataset. The modern pollen distribution off southwestern Morocco was then utilized to interpret the high-resolution pollen record with complementary micro-charcoal and XRF element records from a marine sediment core GeoB8601-3 off Cape Ghir in southwestern Morocco covering the last three millennia. This multi-proxy study has shown clear evidence of wetter conditions resulting in higher fluvial input which could be correlated with a negative mode of the North Atlantic Oscillation (NAO), in contrast to the published pollen and XRF element records from another nearby core that showed limited effect of climate changes. On the other hand, clear opposite trend between the pollen occurrences ofArgania spinosaand the fire frequency was observed throughout our fossil record. The increase ofArgania spinosapollen occurrences, along with herbaceous taxa, and lower fire frequency might suggest an increase in human impact on the landscape leading to a sparse vegetation cover and subsequently increased erosion. The reconstructed pollen-based vegetation, micro-charcoal-based fire activities and geochemical changes in our marine record suggest interplay of climate and anthropogenic effects on the landscape.