Behind the scene of arctic-alpine greening – implementing a multi-parameter approach to disentangle the controls of spatio-temporal variation in dwarf-shrub growth

所观察到的主要是矮灌木引起的北极高山地区的绿化可能会在地方到全球范围内造成影响。面对这一重要性，不可避免地要了解目前初级生产和植物量模式的潜在驱动因素。因此，最近的研究集中在植物量增加和矮灌木扩张背后的机制。然而，这些方法往往是基于对整个生物群系或区域的遥感研究，其尺度非常粗略。显然，这样的研究既不能解释特别是高山地区的细尺度异质性，也不能解释由生理生态学触发的矮灌木的实际生长响应。因此，在研究矮灌木生长反应的同时，缺乏解释北极高山地区精细尺度异质性的方法。因此，所提出的研究项目的目的是在一个空间-时间的细尺度的生态学解释的木本植被的生长动态，这将进行沿着微地形和海拔梯度在挪威中部的高山地区。我们将遵循多参数的方法来解开灌木生长的驱动力，这是第一次，还包括一个系统的记录的特征矮灌木物种的生长动态在一个高的时间分辨率的树木生长计。这提供了弥合细胞分裂和细胞扩大的因果链内的差距的机会，这两者都是由短期事件引发的生理生态，以及在整个生长季节整合的年轮宽度。

The observed, mainly dwarf-shrub induced, greening of arctic-alpine regions is likely to cause impacts at local to global scales. Facing this importance, it is inevitable to get knowledge about the underlying drivers of the current patterns of both primary production and phytomass. Consequently, recent studies focus at the mechanisms behind the increase of phytomass and the expansion of dwarf shrubs. They are, however, often based on remote-sensing studies of entire biomes or regions at comparably coarse scales. Obviously, such studies can neither account for the fine-scaled heterogeneity of especially alpine regions, nor for the actual growth response of dwarf shrubs that is triggered by ecophysiology. As such, approaches that account for the fine-scaled heterogeneity of arctic-alpine regions while studying the growth response of dwarf shrubs are lacking. Thus, the presented research project aims at a spatio-temporally fine-scaled ecological interpretation of the growth dynamics of the woody vegetation, which will be conducted along micro-topographical and altitudinal gradients in the alpine region of central Norway. We will follow a multi-parameter approach to disentangle the driving forces of shrub growth that, for the first time, also includes a systematic recording of the growth dynamics of characteristic dwarf-shrub species at a high temporal resolution based on dendrometers. This offers the opportunity to bridge the gap within the causal chain of cell division and cell enlargement, both of which are ecophysiologically triggered by short-term events, and the annual ring width that integrates over the entire growing season.