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Three dimensional tree and gap architecture affected by forest managemen t- A comparison of different forest types in the Pacific North West, USA based on terrestrial laser scanning

受森林管理影响的三维树木和间隙结构 - 基于地面激光扫描的美国西北太平洋地区不同森林类型的比较

基本信息

批准号：
247288248
负责人：
Professor Dr. Dominik Seidel
金额：
--
依托单位：
Department of Forest Ecosystems and Society
依托单位国家：
德国
项目类别：
Research Fellowships
财政年份：
2013
资助国家：
德国
起止时间：
2012-12-31 至 2015-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/247288248?language=en
关键词：
Three dimensional tree gap architecture

项目摘要

Until the Northwest Forest Plan came into effect in 1993 the US area covered by old-growth forests has been decreasing in an alarming rate. Douglas-fir (Pseudotzuga menziesii (Mirbel) Franco) as one of the economically most important tree species of the Pacific North West was planted after clear-cutting and monospecific even-aged stands replaced the ancient forests. Today, silviculture in the US is undergoing a change in the management paradigm. Alternative silvicultural regimes have been proposed in order to create stand structures resembling old-growth features which are believed to provide ecosystem services and functions, such as habitat diversity, aesthetics for recreation purposes and may enhance ecosystem resilience and stability. However, along with increasing complexity in horizontal and vertical structures of forests the growing conditions of trees become more heterogeneous. The first part of the proposed study will evaluate whether or not the applied management practices actually resulted in more complex spatial structures which resembles the spatial complexity of old-growth forests. This question will be answered by a comparison of tree/crown structures in old-growth and young managed stands. Terrestrial laser scanning will be used for a three-dimensional assessment of structural parameters that characterize the comprehensive spatial aspects of complexity in forests. Old-growth forests, traditional production oriented stands and plantations which had explicitly been managed towards more structural diversity will be contrasted in order to identify differences in their spatial structure, e.g. vertical layering of the canopy and crown profiles of individual trees. The second part of the study aims at comparing tree/crown structures in edge versus stand interior trees. It will be investigated if altered forest structure and growing conditions result in significant changes in tree habitus, crown profiles, and related wood quality attributes such as branchiness. As gaps play an important role in the management for spatial complexity, the size and shape of gaps are of special interest. Gaps will be measured in all three dimensions using terrestrial laser scanning and will be related to the tree and crown shape and external attributes of wood quality of adjacent trees.The main goal of the proposed study is to test the suitability of artificial gaps aiming at resembling the spatial structure of old-growth forests in plantations. Furthermore, it will be qualitatively described how management for complexity affects the shape and external attributes of wood quality of the remaining trees. Finally, the study will derive suggestions on how to design silvicultural measures which may balance the two possibly diverging management goals: structural diversity and high quality timber production.

直到1993年西北森林计划生效之前，美国的原始森林覆盖面积一直在以惊人的速度减少。道格拉斯冷杉（pseudozuga menziesii (Mirbel) Franco）是太平洋西北地区最重要的经济树种之一，在砍伐后种植，单种均匀年龄的林分取代了古老的森林。今天，美国的造林管理模式正在发生变化。已经提出了替代的造林制度，以创造类似旧生长特征的林分结构，这些结构被认为可以提供生态系统服务和功能，例如生境多样性，娱乐目的的美学，并可能增强生态系统的恢复力和稳定性。然而，随着森林水平和垂直结构的日益复杂，树木的生长条件变得更加异质。拟议研究的第一部分将评价所采用的管理做法是否实际上导致了类似于原始森林的空间复杂性的更复杂的空间结构。这个问题将通过对老年林和幼龄林的树/树冠结构的比较来回答。地面激光扫描将用于对结构参数进行三维评估，这些参数是森林综合空间复杂性的特征。将对原生林、传统生产导向林分和人工林进行对比，以确定其空间结构的差异，例如，单个树木的冠层和树冠剖面的垂直分层。研究的第二部分旨在比较边缘树和立地内部树的树/树冠结构。森林结构和生长条件的改变是否会导致树木习性、树冠剖面和相关木材质量属性（如分枝）的显著变化，将进行研究。由于间隙在空间复杂性管理中起着重要的作用，因此间隙的大小和形状受到人们的特别关注。将使用地面激光扫描在所有三个维度上测量间隙，并将与树木和树冠形状以及相邻树木的木材质量的外部属性有关。本研究的主要目的是测试人工林中人工林隙的适宜性，以模拟原生林的空间结构。此外，还将定性地描述复杂性管理如何影响剩余树木的形状和木材质量的外部属性。最后，该研究将得出关于如何设计造林措施的建议，这些措施可以平衡两个可能不同的管理目标：结构多样性和高质量木材生产。