https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 5 Urban green and blue space changes: A spatiotemporal evaluation of impacts on ecosystem service value in Bangladesh https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:52550 Tue 17 Oct 2023 15:27:27 AEDT ]]> Environmental DNA metabarcoding describes biodiversity across marine gradients https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:52381 Tue 10 Oct 2023 14:46:55 AEDT ]]> A proposed extension to the soil moisture and ocean salinity level 2 algorithm for mixed forest and moderate vegetation pixels https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:17522 Sat 24 Mar 2018 08:03:53 AEDT ]]> Estimating tree and stand sapwood area in spatially heterogeneous southeastern Australian forests https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:24993 1.3) in a large number of trees to understand the spatial heterogeneity of tree and stand sapwood area within and between forest communities, and develop allometric relationships that predict SA1.3 with forest inventory data. We also apply tree competition models to determine the degree to which the relationship between SA1.3 and tree basal area at 1.3 m height (BA1.3) is influenced by competition. Methods: We visited 25 recently harvested southeastern Australian forest sites consisting of 1379 trees and 5 Eucalyptus species to evaluate a new efficient data collection method for estimating SA1.3 with tree taper and stump dimensions data using mixed effects models. The locations of 784 stumps within one 5-ha site were accurately mapped using an unmanned aerial vehicle (UAV), and four distance-dependent tree competition models were applied across the site to explain within-stand variation in the ratio of SA1.3 to BA1.3. Data from 24 additional sites, consisting of ten 15 m radial plots per site, were used to analyse within-site variation in RHa (the ratio of stand sapwood area SAHa to stand basal area BAHa). The radial plots were merged within each site to evaluate between-site variations in RHa across the landscape. For predicting SAHa with forest inventory data, we computed the relationship between SAHa and a new index of total stem perimeter per hectare, defined as √BAHaNT, where NT is tree stocking density. Important Findings: Our 1379 measured stems represent the most comprehensive measure of sapwood area, surpassing the 757 measured stems in native eucalypt forests published in literature. The species-specific RHa varied considerably across sites and therefore extrapolating SAHa with spatially distributed BAHa maps and a generalized RHa would introduce local uncertainty. We found that the species-specific stem perimeter index was more effective at capturing variability in SAHa across the landscape using forest composition, structure and density data (R²: 0.72–0.77). The strong correlation between tree SA1.3 and BA1.3 improved slightly using tree competition models (R² increased from 0.86 to 0.88). Relating SAHa to routinely measured forest inventory attributes within permanent plots and Light Detection and Ranging (LiDAR) data may provide opportunities to map forest water use in time and space across large areas disturbed by wildfire and logging.]]> Sat 24 Mar 2018 07:09:55 AEDT ]]> Investigating environmental stressors to mitigate chytridiomycosis in the environment of threatened amphibians https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:32750 Mon 23 Sep 2019 13:16:28 AEST ]]>