Tree recovery following disturbance in the boreal forest

北方森林干扰后的树木恢复

基本信息

批准号：
37582-2013
负责人：
Lieffers, Victor
金额：
$ 2.4万
依托单位：
University of Alberta
依托单位国家：
加拿大
项目类别：
Discovery Grants Program - Individual
财政年份：
2018
资助国家：
加拿大
起止时间：
2018-01-01 至 2019-12-31
项目状态：
已结题

来源：
https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=657611
关键词：
Tree recovery following disturbance boreal

项目摘要

We will study the substrate, seeding and regeneration environments affecting the recruitment of trembling aspen and white spruce of boreal forests of western Canada. First we will refine our understanding of how successional stage, including stand composition and density before disturbance and type of disturbance affects the regeneration environment for trees. We will use a combination of remote sensing prior to disturbance and remote and ground sampling after disturbance to determine successional trajectories in each system. Further. we will use similar techniques to assess the recovery of intensively managed boreal forests that have been converted to pure conifer forests and then redisturbed by fire. As many of the legacy elements of these forests have been removed by herbicide applications, their natural pattern of successional development will be impeded by lack of sprouting propagules and by the presence of aggressive grasses. A third area of study will examine regeneration of aspen from seed - allowing movement of aspen into higher elevations and latitudes with climate change. The silky hairs of aspen seed allows it to move great distances by wind and even after it lands it will continue to move over the ground surface until it is lodged on its final microsite. Using both field and lab experiments, we will examine the resorting of aspen seed onto microsites of different moisture and texture, after the seed lands, in order to more accurately assess probability of seeds stopping on good microsites. Fourth, feather mosses dominate the understory in conifer-dominated boreal forests. These mosses have neither roots for water uptake nor stomata to control water loss, therefore they undergo rapid dry-down after rainfall, but they influence nitrogen cycling, tree recruitment and ecosystem processes. Using both field observations and experiments, we will assess these wet-dry cycles in relation to feather moss vigor, substrate porosity, hydraulic conductivity and N availability. Work applies to seedling establishment and modelling risk of fire for this important substrate. Four students will be trained.******

我们将研究影响加拿大西部北方森林的颤抖asspen和白云杉的底物，播种和再生环境。首先，我们将完善我们对演替阶段的理解，包括干扰之前的林分组成和密度和干扰类型会影响树木的再生环境。我们将在干扰之前使用遥感，在干扰后进行遥感和接地采样，以确定每个系统中的继任轨迹。更远。我们将使用类似的技术来评估已转化为纯针叶树森林的强化管理的北方森林的恢复，然后被大火重新扰动。除草剂的应用所消除了这些森林的许多遗产元素，因此它们的自然继承发展模式将因缺乏发芽的繁殖以及存在侵略性草而阻碍。第三个研究领域将检查asspen从种子中的再生 - 使白杨运动随着气候变化而流入更高的海拔和纬度。 Aspen种子的丝般毛发使其可以通过风移动距离，即使在降落后，它也会继续在地面上移动，直到将其放在其最终微型材料上。使用田间和实验室实验，我们将检查asspen种子在种子地陆后的微斑线上的求解，以更准确地评估种子在良好的微座上停止的概率。第四，羽毛苔藓在针叶树主导的北方森林中占主导地下。这些苔藓既没有摄入水的根，也没有气孔来控制水分流失，因此它们在降雨后会快速干燥，但它们会影响氮循环，树木募集和生态系统过程。使用现场观测和实验，我们将评估这些湿干的周期，相对于羽毛苔藓的活力，底物孔隙率，液压电导率和N可用性。工作适用于该重要底物的幼苗建立和建模火风险。将接受四个学生的培训。******