Physiological integration of trees through root connections

拟议研究计划的主要目标是展示通过根嫁接或亲本根(发根物种)相互连接的树木的生理整合。我们最近证实，树木可以通过根连接影响邻居的生理，但树木之间的生理整合水平尚不清楚。例如，我们不知道树木之间在多大程度上(在空间和数量上)共享碳储量和资源，特别是不知道竞争与合作关系如何影响森林动态。 我们之前已经使用探索性的方法，在北方森林的大多数森林林中发现了根连接。我们发现许多树被嫁接到死树的活根上；这表明相连的树木为相连的根系提供能量，以维持它们的存活。我们将使用田间和实验室实验来演示从公共根系中支持大量地下生物量的成本，以及树木如何通过根嫁接以营养方式再生不同基因类型的树木。我们还将研究通过其根系相互连接的树木之间的竞争与合作关系。 这项研究有可能冲击传统的森林生态观念，这些观念认为树木是不同的个体，相互之间严格竞争资源。如果发现生理整合程度很高，森林管理做法可能也需要改变。

The main objective of the proposed research program is to demonstrate physiological integration of trees that are interconnected through root grafts or parental roots (root sprouting species). We recently demonstrated that trees could affect the physiology of their neighbours through root connections, but the level on physiological integration between trees is not known. For example, we do not know to what extent (spatially and quantitatively) C reserves and resources are shared between trees, and in particular, how relationships of competition vs cooperation affect forest dynamics. We have previously shown that root connections are found in most forest stands of the boreal forest, using exploratory approaches. We found many trees grafted to live roots of dead trees; this indicates that connected trees provide energy to linked root systems to keep them alive. We will use field and lab experiments to demonstrate the «cost» of supporting large underground biomass from communal root systems, and how trees can vegetatively regenerate trees from different genotypes with root grafting. We will also examine competitive vs cooperative relationships between trees interconnected through their root system. This research has the potential to impact classical notions of forest ecology that consider trees as distinct individuals, strictly competing for resources with each other. If the level of physiological integration is found to be high, forest management practices may also need to be changed.