Methodology proposed for photogrammetric monitoring of the exotic species Hovenia dulcis Thunb. in the Green Belt area surrounding the city of Santa Cruz do Sul, RS, Brazil

• Published in: Environmental monitoring and assessment Vol. 192; no. 1; p. 26
• Main Authors: Fetter, Douglas, Dörr, Doris Sippel, Moraes, Jorge André Ribas, Putzke, Jair, Lobo, Eduardo A.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-01-2020; Springer Nature B.V
• Subjects: Aerial photography; Aircraft; Altitude; Area; Atmospheric Protection/Air Quality Control/Air Pollution; Brazil; Color; Colour; Data collection; Digital cameras; Earth and Environmental Science; Ecology; Ecotoxicology; Environment; Environmental Management; Environmental monitoring; Environmental Monitoring - methods; Environmental science; Field study; Fieldwork; Forest communities; Geography; Green belts; Hovenia dulcis; Introduced Species; Leaves; Methods; Monitoring; Monitoring systems; Monitoring/Environmental Analysis; Native species; Photogrammetry; Plant Dispersal; Protected areas; Raisins; Rhamnaceae - physiology; Software; Trees; Brazil; Biological invasion; Santa Cruz do Sul, RS, Brazil; Environmental monitoring; Green Belt area; Ecological corridors; Hovenia dulcis
• ISSN: 0167-6369; 1573-2959
• DOI: 10.1007/s10661-019-8018-7

The spread of the exotic species
Hovenia dulcis
known as Japanese raisin tree, coming from Asia, detected in a protected area of 465.0 ha surrounding the city of Santa Cruz do Sul, RS, Brazil, named “Green Belt.” In this context, this research aimed at developing an aerial monitoring system able to identify and quantify the extension in the Green Belt area that this species invaded, as well as describing the impacts caused on the local forest community. We collected data from an ultralight Flyer GT aircraft equipped with a vertical camera. The images were taking in June and July 2015, when
H. dulcis
trees have shed their leaves, displaying a gray color, and September and October 2015, when the leaves are young and with a light green color. Based on the methodology proposed trough aerial monitoring by photogrammetry, the results indicated that the total invaded area by
H. dulcis
in the Green Belt of Santa Cruz do Sul County, RS, was 131.8 ha, corresponding to 20.9% of the total area. To validate this method, a quantitative comparison between the result from a terrestrial fieldwork carried out and the proposed method showed no significant differences in the estimated area occupied by
H. dulcis
. We concluded that these results validate the proposed aerial assessment method.