Monitoring the Distribution and Dynamics of an Invasive Grass in Tropical Savanna Using Airborne LiDAR

Remote Sensing

Shaun R. Levick³  Samantha A. Setterfield¹  Natalie A. Rossiter-Rachor¹  Lindsay B. Hutley¹  Damien McMaster¹  Jorg M. Hacker²  Norbert Pfeifer⁴  András Zlinszky⁴  Hermann Heilmeier⁴  Heiko Balzter⁴  Bernhard H཯le⁴  Bálint Czྫྷz⁴ 

[1] Research Institute for Environment and Livelihoods, Charles Darwin University, Darwin, NT 0909, Australia; E-Mails:;Airborne Research Australia, Flinders University, Salisbury South, SA 5106, Australia; E-Mail:;Max Planck Institute for Biogeochemistry, Hans-Knoell-Str. 10, Jena 07745, Germany;id="af1-remotesensing-07-05117">1Max Planck Institute for Biogeochemistry, Hans-Knoell-Str. 10, Jena 07745, Germa

关键词: alien plant;    gamba grass;    invasion;    LiDAR;    weed mapping;   

DOI  :  10.3390/rs70505117

来源: mdpi

【 摘 要 】

The spread of an alien invasive grass (gamba grass—Andropogon gayanus) in the tropical savannas of Northern Australia is a major threat to habitat quality and biodiversity in the region, primarily through its influence on fire intensity. Effective control and eradication of this invader requires better insight into its spatial distribution and rate of spread to inform management actions. We used full-waveform airborne LiDAR to map areas of known A. gayanus invasion in the Batchelor region of the Northern Territory, Australia. Our stratified sampling campaign included wooded savanna areas with differing degrees of A. gayanus invasion and adjacent areas of native grass and woody tree mixtures. We used height and spatial contiguity based metrics to classify returns from A. gayanus and developed spatial representations of A. gayanus occurrence (1 m resolution) and canopy cover (10 m resolution). The cover classification proved robust against two independent field-based investigations at 500 m² (R² = 0.87, RMSE = 12.53) and 100 m² (R² = 0.79, RMSE = 14.13) scale. Our mapping results provide a solid benchmark for evaluating the rate and pattern of A. gayanus spread from future LiDAR campaigns. In addition, this high-resolution mapping can be used to inform satellite image analysis for the evaluation of A. gayanus invasion over broader regional scales. Our research highlights the huge potential that airborne LiDAR holds for facilitating the monitoring and management of savanna habitat condition.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.