Collaborative Research: Evolution and Systematics of the Neotropical Plant Clade of Schefflera (Araliaceae)

植物学家的一个主要目标是描述和命名我们星球上发现的植物物种的巨大多样性，并了解植物是如何，何时以及在何处进化的。 这对于拥有大量物种的群体来说尤其具有挑战性，特别是当它们难以观察时，因为它们生长在难以到达的地方。 热带树木属与许多物种是研究最不足的植物群之一，在我们的知识创造了一个显着的差距。 为了克服这一差距，需要一个高效和有效的战略来发现、描述、理解和保护世界生物多样性的这一巨大而重要的部分。 本研究计画将以热带美洲的鹅掌柴属（五加科常春藤科的一员）为模式群，发展出一套精简的策略。 超过400种鹅掌柴分布在这片广阔的地区，特别是在北方安第斯山脉的山区。 其中许多物种只被科学家发现过一次或几次，几乎一半还没有学名。 此外，很少有工具可以识别和识别这些具有重要生态意义的植物，我们几乎不知道它们是如何进化成如此多的不同形式的，或者它们是如何适应广泛的栖息地的。 这项研究的战略包括在四个安第斯国家（玻利维亚、哥伦比亚、厄瓜多尔和秘鲁）进行实地工作，目的是增进我们对这些演变过程的了解。 它还将侧重于确定和命名出现在数量有限的地方和最有灭绝威胁（主要是由于热带森林砍伐）的物种，以便它们可以成为保护工作的目标。 该项目产生的信息将在网上提供给科学界内外的广大用户。 为了帮助培养下一代植物系统学家，12名本科生将有机会通过在密苏里州和纽约植物园的两个为期6周的暑期实习项目了解植物学的这一重要但未得到充分重视的分支，12名植物学或生物学高级学生将参加热带植物学项目，加入项目科学家，在南美洲实地工作期间获得实践经验。研究将涉及利用最新技术进步，特别是高通量DNA测序方法，利用基于DNA的证据构建安第斯鹅掌柴属物种的遗传学。 该系统将提供对这400多个物种的主要谱系的更好理解，这反过来将为它们的分类和命名以及理解它们的进化和地理关系提供一个框架。 一个简化的“绿名单”方法来评估最有可能受到威胁的物种的保护状况，将为命名和保护新的和罕见的鹅掌柴安第斯成员的优先事项提供信息。 密集的标本室研究将提供地理、形态和分子数据来源，并将指导安第斯山脉中部和北方国家的实地工作，以尚未取样的物种最集中的地点为目标，并侧重于厄瓜多尔南部和北方秘鲁的地区，在这些地区，该群体似乎经历了异常的多样化。 将使用有时间日期的植物发生学来探索植物地理学情景，并检验形态学、生态学、地理学和进化历史之间的相互关系，从而深入了解安第斯山脉植物多样性的进化。 这些研究将与来自南美四个国家的当地植物学家和学生合作进行，并将进行实地工作。这将促进一个长期的国际研究人员网络，能够维持充分记录和了解在热带安第斯山脉的鹅掌柴的巨大多样性的长期目标。

A major goal of botanists is to describe and name the vast diversity of plant species found on our planet and to understand how, when, and where plants evolved. This is particularly challenging for groups with very large numbers of species, especially when they are difficult to observe because they grow in hard to reach places. Tropical tree genera with many species are among the most under-studied plant groups, creating a significant gap in our knowledge. To overcome this gap, an efficient and effective strategy is needed to discover, describe, understand and conserve this large and important part of the world's biodiversity. This research project will develop a streamlined strategy, using the genus Schefflera (a member of the ivy family, Araliaceae) in tropical America as a model group. More than 400 species of Schefflera occur in this vast region, especially in the very mountainous areas of the northern Andes. Many of these species have only been seen by scientists once or a few times, and almost half do not yet have scientific names. Moreover, very few tools are available to recognize and identify these ecologically important plants, and we know almost nothing about how they evolved into so many different forms, or how they were able to adapt to the wide range of habitats. The strategy of this study, which includes field work in four Andean countries (Bolivia, Colombia, Ecuador and Peru), aims to improve our understanding of these evolutionary processes. It will also focus on identifying and naming the species that occur in a limited number of places and are most threatened with extinction (mostly by tropical deforestation) so that they can be targeted by conservation efforts. The information generated by the project will be made available on-line to a wide range of users, both within and beyond the scientific community. To help develop the next generation of plant systematists, 12 undergraduate students will be given an opportunity to learn about this important yet under-appreciated branch of botany through two 6-week summer internship programs at the Missouri and New York Botanical Gardens, and 12 more advanced students in botany or biology will participate in a tropical field botany program, joining the project scientists to gain hands-on experience during field work in South America.The research will involve constructing phylogenies for the species of Andean Schefflera using DNA-based evidence, taking advantage of recent advances in technology, especially high-throughput approaches to DNA sequencing. The phylogenies will provide a greater understanding of the major lineages of these 400+ species, which in turn will provide a framework for classifying and naming them, and for understanding their evolutionary and geographic relationships. A streamlined 'green-listing' approach to assessing conservation status of the species that are most likely to be threatened will inform priorities for naming and conserving new and rare Andean members of Schefflera. Intensive herbarium studies will provide sources of geographic, morphological, and molecular data, and will guide field work in the countries of the central and northern Andes, targeting sites with the highest concentration of species that remain unsampled, and focusing on areas in southern Ecuador and northern Peru where the group appears to have undergone exceptional diversification. Time-dated phylogenies will be used to explore biogeographic scenarios and to test for correlations among morphology, ecology, geography and evolutionary history, providing insights into the evolution of plant diversity in the Andes. These studies will be conducted with the collaboration of local botanists and students from each of the four South American countries where field work will be done. This will promote a long-term network of international researchers capable of sustaining the long-term goals of fully documenting and understanding the tremendous diversity of Schefflera in the tropical Andes.