Martín-Hernanz Sara, G Fernández de Castro Alejandro, Moreno-Saiz Juan Carlos, Valcárcel Virginia
Department of Biology (Botany), Universidad Autónoma de Madrid, Madrid, Spain.
Department of Biodiversity and Conservation, Real Jardín Botánico, CSIC, Madrid, Spain.
PLoS One. 2016 Jul 27;11(7):e0159484. doi: 10.1371/journal.pone.0159484. eCollection 2016.
Integration of unexpected discoveries about charismatic species can disrupt their well-established recovery plans, particularly when this requires coordinate actions among the different governments responsible. The Critically Endangered Coronopus navasii (Brassicaceae) was considered a restricted endemism to a few Mediterranean temporary ponds in a high mountain range of Southeast Spain, until a new group of populations were discovered 500 km North in 2006. Ten years after this finding, its management has not been accommodated due to limited information of the new populations and administrative inertia. In this study, DNA sequences and species distribution models are used to analyse the origin of the C. navasii disjunction as a preliminary step to reassess its recovery plan. Molecular results placed the disjunction during Miocene-Pleistocene (6.30-0.49 Mya, plastid DNA; 1.45-0.03 Mya, ribosomal DNA), which discards a putative human-mediated origin. In fact, the haplotype network and the low gene flow estimated between disjunct areas suggest long-term isolation. Dispersal is the most likely explanation for the disjunction as interpreted from the highly fragmented distribution projected to the past. Particularly, a northward dispersal from Southeast is proposed since C. navasii haplotype network is connected to the sister-group through the southern haplotype. Although the reassessment of C. navasii conservation status is more optimistic under the new extent of occurrence, its long-term survival may be compromised due to the: (1) natural fragmentation and rarity of the species habitat, (2) genetic isolation between the two disjunct areas, and (3) northward shift of suitable areas under future climate change scenarios. Several ex-situ and in-situ conservation measures are proposed for integrating Central East Spanish populations into the on-going recovery plan, which still only contemplates Southeast populations and therefore does not preserve the genetic structure and diversity of the species.
有关魅力物种的意外发现若要整合起来，可能会打乱其既定的恢复计划，尤其是当这需要不同责任政府之间采取协调行动时。极度濒危的纳瓦斯岩荠（十字花科）曾被认为是西班牙东南部一座高山上少数地中海临时池塘的特有种，直到2006年在其以北500公里处发现了一群新种群。这一发现十年后，由于新种群信息有限和行政惰性，其管理仍未得到调整。在本研究中，利用DNA序列和物种分布模型分析了纳瓦斯岩荠间断分布的起源，作为重新评估其恢复计划的初步步骤。分子结果表明间断分布发生在中新世 - 更新世时期（质体DNA为630 - 49万年前；核糖体DNA为145 - 3万年前），这排除了人为介导起源的可能性。事实上，单倍型网络以及间断区域间估计的低基因流表明存在长期隔离。从过去预测的高度碎片化分布来看，扩散是间断分布最有可能的解释。特别是，由于纳瓦斯岩荠的单倍型网络通过南部单倍型与姐妹群相连，因此提出了从东南部向北扩散的观点。尽管根据新的分布范围重新评估纳瓦斯岩荠的保护状况更为乐观，但其长期生存可能会因以下因素而受到威胁：（1）该物种栖息地的自然碎片化和稀有性，（2）两个间断区域之间的遗传隔离，以及（3）未来气候变化情景下适宜区域向北转移。为了将西班牙中东部的种群纳入正在进行的恢复计划，提出了若干迁地和就地保护措施，该计划目前仍只考虑东南部的种群，因此无法保护该物种的遗传结构和多样性。
