Diversity and management effects on forest evolution - TREEvolution

森林覆盖了欧洲近40%的面积，是我们文化景观中最多样化、物种最丰富的栖息地之一。森林还通过其对气候强迫的生物地球物理反馈对区域气候产生重大影响，并提供各种生态系统服务。然而，极端天气事件，如2018年至2020年德国春夏季的干旱，威胁到中欧森林的健康，从而威胁到生态系统的功能。欧洲中部最重要的森林树种森林Fagus sylvatica在这些干旱之后遭受了严重的破坏。然而，它很快变得明显，即使在林分内，树木对干旱的反应也因干旱受损的树木邻近健康的树木而有很大差异，从而表明了基因型背景。大多数森林树木的一个共同的生活史特征是，一生中大量产生种子，并结合着众所周知的大的遗传变异，为选择提供了坚实的基础。假设极端年份的频率增加，这种选择将确保未来的山毛榉林更好地适应初夏干旱事件。随着染色体水平的山毛榉基因组的可用性和生物多样性探索实验室独特的实验设置，我们计划利用生物多样性探索实验室所有含山毛榉的实验森林地块，在一个具有代表性的大样本中，研究山毛榉种群在生命阶段（幼苗、树苗和成年树）的基因组多样性动态。采用FOX多站点实验，采用减少代表性和低覆盖度测序方法，研究了森林管理和建立年份的影响。考虑到大量的非生物和生物环境变量可能会影响对山毛榉幼苗和树苗的选择，生物多样性探索区为TREEvolution提供了一个完美的环境，因为这些地点以前和正在进行的研究提供了大量的数据。反过来，我们将提供一个关键物种的全基因组多样性信息，在实验区，它是存在的。TREEvolution将提供对幼树年龄的进化动态的见解，这将塑造我们未来森林的抵抗力和恢复力。这将有助于我们了解山毛榉林是否以及以多快的速度进化跟踪当前的气候变化，并能够适应当前标准的造林管理。

Forests cover nearly 40% of Europe and are among the most diverse and species-rich habitats in our cultural landscape. Forests also exert a significant influence on regional climates through their biogeophysical feedbacks to climate forcing and provide various ecosystem services. However, extreme weather events, like the drought during spring and summer in the years 2018 to 2020 in Germany, threaten the health and thus the ecosystem functioning of forests in central Europe. Fagus sylvatica, still the most important forest tree species in Central Europe, showed significant damages following these droughts. However, it became quickly evident, that even within stands tree reactions to the drought varied substantially with drought-damaged trees neighboring healthy trees and thus suggesting a genotypic background. One life-history trait common to most forest trees is the massive life-time production of seeds combined with a well-known large standing genetic variation, offering a substantial basis for selection to act upon. Assuming that extreme years increase in frequency, such selection would ensure that beech forests in the future are better adapted to early summer drought events. With the availability of a chromosome-level beech genome and the unique experimental setup of the Biodiversity-Exploratories, we plan to investigate the genomic diversity dynamics in beech populations among life stages (seedlings, saplings and adult trees) across a large representative sample using all beech-containing Experimental Forest Plots of the Biodiversity-Exploratories. We aim at identifying the demographic processes and genes under selection, investigate the effects of forest management and the year of establishment using the FOX multi-site experiment, applying reduced-representation and low-coverage sequencing methods. Given the multitude of abiotic and biotic environmental variables that potentially can influence the selection acting on beech seedlings and saplings, the Biodiversity-Exploratories provide a perfect environment for TREEvolution, due to the large amount of data available from previous and ongoing research on these same sites. In turn, we will provide genome-wide diversity information for one of the key-species in the Experimental plots in which it is present. TREEvolution will provide insights into the evolutionary dynamics at young tree age, which shape the resistance and resilience of our forests of tomorrow. This will help us to understand if and how fast beech forests can evolutionarily track the current climatic changes, and to be able to adapt the current standard silvicultural management.