https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:42785 Wed 28 Feb 2024 14:51:29 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:35500 Wed 15 Feb 2023 11:36:55 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:51517 90% accuracy at 0.1 m resolution. At the study site, saltmarsh colonised most suitable areas, increasing by 142% and resulting in 56 tonnes of carbon sequestered, within a 4-year period, providing insight into blue carbon regeneration trajectories. Saltmarsh growth patterns were species-specific, influenced by species’ reproductive and dispersal strategies. Our findings suggested that biotic factors and interactions were important in influencing species’ distributions and succession trajectories. This work can help improve the efficiency and effectiveness of restoration planning and monitoring at coastal wetlands and similar ecosystems worldwide, with the potential to apply this approach to other types of remote sensing imagery and to calculate other rehabilitation co-benefits. Importantly, the method can be used to calculate blue carbon habitat creation following tidal restoration of coastal wetlands.]]> Wed 07 Feb 2024 14:42:29 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:52386 Tue 10 Oct 2023 14:45:57 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39157 Tue 09 Aug 2022 14:06:40 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:34919 Hemiscyllium ocellatum) displayed sinusoidal movement patterns, while Blacktip Reef Sharks (Carcharhinus melanopterus) had more linear trajectories that were similar to those of a Lemon shark (Negaprion acutidens). Individual shark trajectory patterns and movement speeds were highly variable. Results indicate that Epaulette sharks may be more mobile during diurnal low tides than previously thought. The approach presented here allows the movements and behaviours of marine vertebrates to be analysed at resolutions not previously possible without complex and expensive acoustic arrays. This method would be useful to assess the habitat use and behaviours of sharks and rays in shallow water environments, where they are most likely to interact with humans.]]> Tue 03 Sep 2019 17:58:05 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:38302 Thu 26 Aug 2021 10:22:38 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:36707 Catostylus mosaicus, can be rapidly estimated over much larger areas than traditional field sampling and without requiring fishing effort. Estimated biomass within Smiths Lake, New South Wales, Australia was roughly 350 kg per hectare, and size frequency distributions were skewed towards larger specimens compared to previous studies in other locations. Drone counts were similar to a visual census which provides further evidence that this rapid and relatively automated method has potential to be used more widely in ecological monitoring.]]> Thu 25 Jun 2020 15:42:42 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39921 Thu 14 Jul 2022 12:15:12 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24999 Mon 17 Jun 2019 14:51:34 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39249 N_Ha) are important in characterising ecological conditions and assessing changes in forest dynamics after disturbances due to pyrogenic, anthropogenic and biotic factors. We use Unmanned Aircraft Systems (UAS) LiDAR with mean point density of 1485 points m⁻² across 39 flight sites to develop a bottom-up approach for individual tree and crown delineation (ITCD). The ITCD algorithm was evaluated across mixed species eucalypt forests (MSEF) using 2790 field measured stem locations across a broad range of dominant eucalypt species with randomly leaning trunks and highly irregular intertwined canopy structure. Two top performing ITCD algorithms in benchmarking studies resulted in poor performance when optimised to our plot data (mean F_score: 0.61 and 0.62), which emphasises the challenge posed for ITCD in the structurally complex conditions of MSEF. To address this, our novel bottom-up ITCD algorithm uses kernel densities to stratify the vegetation profile and differentiate understorey from the rest of the vegetation. For vegetation above understorey, the ITCD algorithm adopted a novel watershed clustering procedure on point density measures within horizontal slices. A Principal Component Analysis (PCA) procedure was then applied to merge the slice-specific clusters into trunks, branches, and canopy clumps, before a voxel connectivity procedure clustered these biomass segments into overstorey trees. The segmentation process only requires two parameters to be calibrated to site-specific conditions across 39 MSEF sites using a Shuffled Complex Evolution (SCE) optimiser. Across the 39 field sites, the ITCD algorithm had mean F_score of 0.91, True Positive (TP) trees represented 85% of measured trees and predicted plot-level stocking (N_P) averaged 94% of actual stocking (N_Ob). As a representation of plot-level basal area (BA), TP trees represented 87% of BA, omitted trees represented slightly smaller trees and made up 8% of BA, and a further 5% of BA had commission error. Spatial maps of N_Ha using 0.5 m grid-cells showed that omitted trees were more prevalent in high density forest stands, and that 63% of grid-cells had a perfect estimate of N_Ha, whereas a further 31% of the grid-cells overestimate or underestimate one tree within the search window. The parsimonious modelling framework allows for the two calibrated site-specific parameters to be predicted (R²: 0.87 and 0.66) using structural characteristics of vegetation clusters within sites. Using predictions of these two site-specific parameters across all sites results in mean F_Score of 0.86 and mean TP of 0.77, under circumstances where no ground observations were required for calibration. This approach generalises the algorithm across new UAS LiDAR data without undertaking time-consuming ground measurements within tall eucalypt forests with complex vegetation structure.]]> Fri 27 May 2022 15:28:37 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:42162 Fri 19 Aug 2022 09:14:12 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39324 Fri 03 Jun 2022 15:42:29 AEST ]]>