Quantification of Spatial Structure Characteristics of Typical Natural Secondary Forest Gaps in Northeastern China

作者：Sifu Bi, Yifan Tan, Yao Wang, Meiwei Liu, Xuegang Mao · 发表于：Research Square (Research Square) · 年份：2020 · DOI：10.21203/rs.3.rs-38728/v1 · 被引用次数：1 · 研究领域：Remote Sensing and LiDAR Applications、Forest Management and Policy、Forest ecology and management

Abstract Background: To understand the theory of forest cycle and reveal the relationship between forest gaps and forest structure, species composition and biodiversity, we need to study the spatial structure of forest gaps. However, the complexity of natural secondary forest structure makes it difficult to quantify the spatial structure characteristics of gaps in large areas by field measurement. In this study, aerial orthophotos, and light detection and ranging (LiDAR), were used as data sources. The experimental area was Maoer Mountain Forest Farm, a typical natural secondary forest in northeastern China, and we used the investigation data of forest resources as reference material. We extracted 1343 forest gaps by manual digitization combined with canopy height model correction. The spatial characteristics of the extracted gaps were quantified from the spatial characteristics (area, shape complexity index), spatial heterogeneity (gap height diversity index) and spatial distribution characteristics (Clark–Evans index) of individual gaps. Results: In the three types of natural secondary forest, the frequency distribution of gap area showed a negative exponential distribution: 90% of the gap area was less than 100 m 2 . As forests aged, the proportion of gap area decreased from young forest to near-mature forest, and increased from near-mature forest to over-mature forest. The maximum frequency range of shape index changed from 1.2 to 1.4 for young forest, middle age forest a...