Influence of vegetation structure on lidar-derived canopy height and fractional cover in forested riparian buffers during leaf-off and leaf-on conditions

PLoS One. 2013;8(1):e54776. doi: 10.1371/journal.pone.0054776. Epub 2013 Jan 31.

Abstract

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 within a range of riparian vegetation types. Results illustrate that: 1) leaf-off and leaf-on lidar percentile estimates are similar to measured heights in all plots except those dominated by deciduous compound-leaved trees where lidar underestimates H during leaf off periods; 2) canopy height models (CHMs) underestimate H by a larger margin compared to percentile methods and are influenced by vegetation type (conifer needle, deciduous simple leaf or deciduous compound leaf) and canopy height variability, 3) lidar estimates of FC are within 10% of plot measurements during leaf-on periods, but are underestimated during leaf-off periods except in mixed and conifer plots; and 4) depth of laser pulse penetration lower in the canopy is more variable compared to top of the canopy penetration which may influence within canopy vegetation structure estimates. This study demonstrates that leaf-off lidar data can be used to estimate forested riparian buffer canopy height within diverse vegetation conditions and fractional canopy cover within mixed and conifer forests when leaf-on lidar data are not available.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ecosystem*
  • Lasers
  • Plant Leaves
  • Trees*

Grants and funding

LAW has been supported in part by a grant from the National Consortium for Rural Geospatial Innovations in America (www.ruralgis.org) and the Penn State Geospatial Technology Program housed in the Department of Crop and Soil Sciences at Penn State and by the Penn State Forest Vegetation Dynamics Laboratory (http://www.geog.psu.edu/research/physical-geography/vegetation-dynamics-lab). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.