Estimates of canopy height (H) and fractional canopy cover (FC) derived from lidar data collected during leaf-on and leaf-off conditions are compared with field measurements from 80 forested riparian buffer plots. The purpose is to determine if existing lidar data flown in leaf-off conditions for applications such as terrain mapping can effectively estimate forested riparian buffer H and FC wit...

For trees in tropical forests, competition for light is thought to be a central process that offers opportunities for niche differentiation through light gradient partitioning. In previous studies, a canopy index based on three-dimensional canopy census data has been shown to be a good predictor of species-specific demographic rates across the entire tree community on Barro Colorado Island, Pan...

Sampling in forests across the world has revealed clear variation in bat use across the height gradient from ground level, up through the canopy, and above the tallest trees (Francis, 1994; Bradshaw, 1996; Kalcounis et al., 1999; Hayes and Gruver, 2000; Bernard, 2001; Henry et al., 2004; Menzel et al., 2005; Pereira et al., 2010). The ways bats distribute their activities along this vertical gr...

We analyzed assumptions and measurement errors in estimating canopy transpiration (E(L)) from sap flux (J(S)) measured with Granier-type sensors, and in calculating canopy stomatal conductance (G(S)) from E(L) and vapor pressure deficit (D). The study was performed in 12-year-old Pinus taeda L. stands with a wide range in leaf area index (L) and growth rate. No systematic differences in J(S) we...

The radial increases in wood specific gravity known in many tree species have been interpreted as providing mechanical support in response to the stresses associated with wind loading. This interpretation leads to the hypothesis that individuals reaching the canopy should (1) be more likely to have radial increases in specific gravity and (2) exhibit greater increases than individuals in the su...

Dennis J. O’Dowd*, Peter T. Green† and P. S. Lake School of Biological Sciences, PO Box 18, Monash University, Melbourne, Victoria 3800, Australia †Present address: c/-CSIRO, PO Box 780, Atherton, Queensland 4883, Australia *Correspondence: E-mail: [email protected] Abstract Islands can serve as model systems for understanding how biological invasions affect community structure and ecosys...

The hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), is an exotic insect species dramatically reducing populations of eastern hemlock, Tsuga canadensis (L.) Carrieré, throughout the eastern United States. Systemic imidacloprid is one of the primary chemicals used to successfully control infestations of the hemlock woolly adelgid. The concentration levels for this systemic i...

The composition of the arthropod fauna foraging within the canopy of Argyrodendron actinophyllum Edlin (Sterculiaceae) in a subtropical rainforest near Brisbane, Australia, was investigated during a 2-year field study. Collecting methods included flight interception traps, restricted canopy fogging, and hand-collecting. Over 50 000 canopy arthropods were collected and about 760 species sorted, ...

Massive tree dieback has occurred periodically in the Hawaiian montane rain forest. The species mainly involved is Metrosideros polymorpha, which is the prevailing upper canopy tree species throughout most of this forest on all high Hawaiian islands. The canopy dieback occurs in stands over the entire spectrum of sites, from well-drained lava flows over nutritionally rich volcanic ash to perman...