4Environmental and Ecological Engineering,
Purdue University, West Lafayette, USA
ORCiD: [0000-0002-4038-9204]
Keywords: Buckthorn, Honeysuckle, Canopy Structural Diversity,
NDVI, Urban Forestry
In the Chicago region, common buckthorn and bush honeysuckle stand out
as dominant invasive species, accounting for over 40% of the regional
forest coverage. Their proliferation leads to the formation of dense
thickets that hinder sunlight penetration, resulting in diminished
native plant diversity in the understory. Detection of these species
across this region is essential for the effective management of these
invasives. Airborne LiDAR datasets show pronounced potential in
detecting the distinctive structural patterns created by these thickets.
Previous studies have utilized multi-temporal spectral imagery to track
the phenological shifts of invasive species. However, in the Chicago
region, it is difficult to employ multi-temporal spectral imagery due to
substantial cloud cover during early spring and late autumn.
Consequently, our research adopted the use of dense airborne LiDAR
datasets specific to the Chicago area. Preliminary results indicate that
invaded plots manifest less complex vertical structure, higher
vegetation area index in the subcanopy, and lower NDVI values compared
to their non-invaded plots. Notably, LiDAR-derived metrics surpass
NDVI-based ones in estimation. Using binomial logistic regression (with
an AUC of 0.97), we assessed the presence and absence of these invasive
species across Chicago’s forests, achieving an accuracy rate of 0.92.
Alarmingly, our findings suggest that these invasive species have
affected over 75% of the forested expanses in Chicago. In summary, our
research highlights the important role of LiDAR datasets in
regional-scale invasive species detection.