Hooft van Huysduynen Alexander, Janssens Steven, Merckx Vincent, Vos Rutger, Valente Luis, Zizka Alexander, Larter Maximilian, Karabayir Betül, Maaskant Daphne, Witmer Youri, Fernández-Palacios José María, de Nascimento Lea, Jaén-Molina Ruth, Caujapé Castells Juli, Marrero-Rodríguez Águedo, Del Arco Marcelino, Lens Frederic
Naturalis Biodiversity Center Leiden The Netherlands.
Department of Biology University of Antwerp Antwerp Belgium.
Ecol Evol. 2021 Aug 17;11(17):12220-12231. doi: 10.1002/ece3.7986. eCollection 2021 Sep.
Insular woodiness (IW), referring to the evolutionary transition from herbaceousness toward woodiness on islands, has arisen more than 30 times on the Canary Islands (Atlantic Ocean). One of the IW hypotheses suggests that drought has been a major driver of wood formation, but we do not know in which palaeoclimatic conditions the insular woody lineages originated. Therefore, we provided an updated review on the presence of IW on the Canaries, reviewed the palaeoclimate, and estimated the timing of origin of woodiness of 24 insular woody lineages that represent a large majority of the insular woody species diversity on the Canaries. Our single, broad-scale dating analysis shows that woodiness in 60%-65% of the insular woody lineages studied originated within the last 3.2 Myr, during which Mediterranean seasonality (yearly summer droughts) became established on the Canaries. Consequently, our results are consistent with palaeoclimatic aridification as a potential driver of woodiness in a considerable proportion of the insular woody Canary Island lineages. However, the observed pattern between insular woodiness and palaeodrought during the last couple of million years could potentially have emerged as a result of the typically young age of the native insular flora, characterized by a high turnover.
岛屿木质化（IW）是指岛屿上植物从草本向木本的进化转变，在加那利群岛（大西洋）上这种现象已经出现了30多次。其中一个关于IW的假说认为干旱是木质形成的主要驱动力，但我们并不清楚岛屿木本谱系起源于何种古气候条件。因此，我们对加那利群岛上IW的存在情况进行了更新综述，回顾了古气候，并估计了24个岛屿木本谱系木质化的起源时间，这些谱系代表了加那利群岛上大部分的岛屿木本物种多样性。我们单一的、广泛尺度的年代测定分析表明，在所研究的60%-65%的岛屿木本谱系中，木质化起源于过去320万年之内，在此期间加那利群岛上形成了地中海季节性（每年夏季干旱）。因此，我们的结果与古气候干旱化是加那利群岛相当一部分岛屿木本谱系木质化的潜在驱动力这一观点一致。然而，在过去几百万年里观察到的岛屿木质化与古干旱之间的模式，可能是由于本地岛屿植物区系通常较为年轻、更替率高这一特点而出现的。
