Genetic diversity, stand structure and sex ratio of Populus euphratica floodplain forests at the Tarim River, Xinjiang, NW China

新疆塔里木河漫滩胡杨林遗传多样性、林分结构及性别比

• 批准号: 31068660
• 负责人: Professor Dr. Martin Schnittler
• 金额: --
• 依托单位: Institut für Botanik und Landschaftsökologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2009-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/31068660?language=en
• 关键词: Genetic; diversity; stand; structure; sex

Watered by rivers draining glaciers of the surrounding mountain ranges, the so-called Tugai forests in the extremely arid Tarim basin of Chinas Xinjiang province are made up mainly by a single tree species, the dioecious Populus euphratica. Although germinating exclusively at riverbanks after high floods, adult trees can survive up 10 m ground water depth and produce root suckers up to 30 m apart from the mother tree. The proposed project aims to investigate the spatial and genetic structure of these forests, addressing the following questions:1. Meandering rivers have stands ranging from seedlings to dying old trees. What is the time scale of stand development; how can a contiguous forest develop from germination rows?2. Does spatial mapping of trees and their sexes allow an estimation of clone size (to be calibrated by molecular analyses)? Can we identify pockets of high genetic diversity in the forests by using this method at a landscape scale?3. How depends the large-scale genetic structure of Tugai forests from past river movements, and can we predict the genetic diversity of the forests from landscape features?4. Forests under drought stress seem to have a male-biased sex ratio. What are the reasons, and does an even sex ratio indicate more suitable growth conditions?

在中国新疆极度干旱的塔里木盆地，以周围山脉冰川的河流为灌溉水源的所谓土盖林，主要由单一树种组成，雌雄异株的胡杨。虽然洪水过后只在河岸发芽，但成年树可以在地下10米深的地方存活下来，并在距离母树30米的地方产生根吸管。拟议的项目旨在调查这些森林的空间结构和遗传结构，解决以下问题：1.蜿蜒的河流有从幼苗到垂死的老树的林。林分发展的时间尺度是什么？如何从萌发行发展成毗连的森林？2.树木及其性别的空间测绘是否可以估计克隆大小(通过分子分析进行校准)？我们能否利用这种方法在景观尺度上识别出森林中的高遗传多样性片段？3.土盖林的大规模遗传结构如何取决于过去的河流运动，以及我们能否从景观特征中预测森林的遗传多样性？4.干旱胁迫下的森林似乎具有男性偏见的性别比。原因是什么？均匀的性别比例是否意味着更适合的生长条件？