S-Space Graduate School of Environmental Studies (환경대학원) Dept. of Environmental Planning (환경계획학과) Theses (Ph.D. / Sc.D._환경계획학과)
Modelling avian taxonomic, functional, and phylogenetic diversity in relation to 3-D forest structure : 3차원 산림 구조에 따른 조류 종다양성과 기능다양성, 계통발생학적 다양성 특성의 모형 연구
- 환경대학원 환경계획학과
- Issue Date
- 서울대학교 환경대학원
- Functional diversity ; Vertical complexity ; Canopy density ; LiDAR ; Heterogeneity-diversity theory ; Species-energy theory
- 학위논문 (박사)-- 서울대학교 환경대학원 : 환경계획학과, 2015. 8. 이도원.
- The complex 3-D structure of forests is a major determinant of species diversity. The seminal work by MacArthur and MacArthur (1961) investigating the relationship between vegetation structure and avian diversity was the starting point of an ongoing debate in ecology about the role of pure physiognomy versus plant species composition in determining the diversity and composition of birds. In general, such finding is in line with the habitat heterogeneity hypothesis predicting more different species with increasing variability in structure. The second closely related hypothesis is the species-energy hypothesis predicting more species with more energy availability such as vegetation volume. The early studies were strongly restricted by the effort in the measuring the complex 3-D structure of forest. However, as LiDAR (Light Detection and Ranging) shed light on the investigation of relation between the vegetation physiognomy and fauna diversity, numerous studies predicted fauna diversity with the physical forest structure derived from airborne LiDAR.
Despite such improvement of measuring the environmental conditions with high accuracy, ecologists also improved their ability to measure new perspectives of biodiversity. Over the last decade, biodiversity has been revealed to play a significant role in sustaining social-ecological systems, as diversity of species effects on ecosystems and their response to the environmental conditions improve adaptive capacity and resilience of the ecosystems. Following the extended recognition, quantifying biodiversity beyond species has been developed to focus on ecological differences
the two major aspects of diversity are functional diversity and phylogenetic diversity.
Over the last decade, there were remarkable advances in measuring both the complex 3-D structure of forest with an aid of LiDAR and fauna diversity with a development of functional or phylogenetic diversity. In spite of the remarkable advances in both sides, the response of avian functional or phylogenetic diversity to the forest structure was not examined yet. Furthermore, the relationship between the most influential structural attributes on bird species diversity, i.e., vegetation volume and vertical complexity, assumed to be closely related remains unexplored.
In this dissertation, the chapter two investigated the relationships between vegetation volume as one surrogate of available energy for the forest bird species and prevalent vertical complexity indices across temperate mixed forests having the wide range of forest structure attributes. Additionally, it compared the abilities of multiple vertical complexity indices in predicting the bird species diversity. Two measures of vegetation volume and six measures of vertical complexity from airborne LiDAR data were respectively compared on 560 sampling plots within Chuncheon in South Korea to examine the relationships. The predictabilities of vertical complexity indices were assessed on 40 bird survey points by using generalized linear models. The response patterns of prevalent multiple vertical complexity indices to vegetation volume were contrasting from each other and could be clearly classified into positive, negative, or hump-shaped patterns. The different patterns might come from which attributes in vertical profiles the index was mainly associated with and well represented the change of vertical complexity with vegetation volume from various angles. Although the vegetation volume and vertical complexity were closely related, the positive relationship generally assumed should be reconsidered. Additionally, the usage of vertical complexity indices should be very careful since same plots could be shown as very heterogeneous or homogenous plots depending on the chosen index for the study. Considering the dependent biological meaning of foliage height diversity subdivision on the study area, the vertical complexity indices such as vertical distribution ratio and coefficient of variation of vegetation height could work as more global indices.
The chapter three assessed standardized measures of forest structure by LiDAR and standardized measures of functional and phylogenetic diversity from four forests of three continents in order to investigate how forest structure shapes the different facets of breeding bird diversity and their mismatch in temperate forests of the Northern Hemisphere. The richness, entropy, and evenness of taxonomic, functional, and phylogenetic diversity were respectively assessed for 173 bird species on 637 sampling plots. Generalized linear mixed models were employed with canopy density and vertical complexity as predictors for bird diversity derived from airborne LiDAR data. Despite very different regional species pools, this study demonstrated a clear pattern of the complex response of birds in temperate forests of the Northern Hemisphere and closed the existing gap of LiDAR-animal diversity studies in Asia. Within temperate forest bird assemblages, canopy density better determined taxonomic, functional, and phylogenetic diversity than vertical complexity. The relationships between multiple avian diversity facets and forest structure were non-linear. Functional and phylogenetic diversity of breeding birds may be fostered by very open and dense forest stands, in contrast to taxonomic diversity which may be fostered by medium dense stands. LiDAR was an efficient and unifying tool for detecting complex forest structure across the globe and a wide range of various forests. However, the vertical complexity proxy over forest structures of different height division needs to be studied in the future. The different responses of multiple diversity facets to environmental gradients could lead to new insight in understanding community assembly mechanisms and strategies for conserving biodiversity.