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CHARACTERIZING THE VERTICAL STRUCTURE AND STRUCTURAL DIVERSITY OF FLORIDA OAK SCRUB VEGETATION USING DISCRETE-RETURN LIDAR
| Title: | CHARACTERIZING THE VERTICAL STRUCTURE AND STRUCTURAL DIVERSITY OF FLORIDA OAK SCRUB VEGETATION USING DISCRETE-RETURN LIDAR. |
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| Name(s): |
Angelo, James, Author Weishampel, John, Committee Chair University of Central Florida, Degree Grantor |
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| Type of Resource: | text | |
| Date Issued: | 2010 | |
| Publisher: | University of Central Florida | |
| Language(s): | English | |
| Abstract/Description: | Vertical structure, the top-to-bottom arrangement of aboveground vegetation, is an important component of forest and shrubland ecosystems. For many decades, ecologists have used foliage height profiles and other measures of vertical structure to identify discrete stages in post-disturbance succession and to quantify the heterogeneity of vegetation. Such studies have, however, required resource-intensive field surveys and have been limited to relatively small spatial extents (e.g., <15 ha). Light detection and ranging (lidar) is an active remote sensing technology with enormous potential to characterize the three-dimensional structure of vegetation over broad spatial scales. In this study, discrete-return lidar data were used to create vertical profiles for over 500 vegetation patches on approximately 1000 ha of an oak scrub landscape in the Kennedy Space Center/Merritt Island National Wildlife Refuge area on the east-central coast of Florida. Nonparametric multivariate analysis of variance (NPMANOVA) tests detected significant differences among the profiles belonging to the four predominant land use/land cover (LULC) types in the study area. For the dominant LULC category (Herbaceous upland non-forested), pairwise NPMANOVA comparisons indicated that there were significant differences between vertical profiles for some of the distinct time since fire (TSF) values. Measures of vertical structural diversity (VSD) were calculated from the vertical profiles and then null, linear, and quadratic models relating VSD to TSF were compared via an Akaike information criterion (AIC) model selection procedure. As predicted by the Intermediate Disturbance Hypothesis, the quadratic model was the best model for the Herbaceous upland non-forested LULC category, but it explained less than 3% of the total variation in VSD. When fire frequency was considered in conjunction with TSF for this LULC category, however, the model that was quadratic in both predictor variables was the best model among the candidates and explained over 6% of the total variation in VSD. These results support the Extended Keystone Hypothesis, which predicts that disturbance generates discrete structural patterns across landscapes, and the Intermediate Disturbance Hypothesis, since the VSD of the predominant LULC category was maximized at intermediate levels of fire disturbance (i.e., intermediate values of TSF and/or fire frequency). In addition to demonstrating the ability of discrete-return lidar to characterize the vertical structure of vegetation at the landscape scale, this research has potential management implications. Using the techniques developed in this study, practitioners can compare the vertical structure of managed ecosystems to reference natural systems to evaluate the efficacy of managed disturbance regimes. | |
| Identifier: | CFE0003254 (IID), ucf:48520 (fedora) | |
| Note(s): |
2010-08-01 M.S. Sciences, Department of Biology Masters This record was generated from author submitted information. |
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| Subject(s): |
Vertical structure structural diversity oak scrub lidar fire Intermediate Disturbance Hypothesis Extended Keystone Hypothesis |
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| Persistent Link to This Record: | http://purl.flvc.org/ucf/fd/CFE0003254 | |
| Restrictions on Access: | public 2010-07-01 | |
| Host Institution: | UCF |
