A simple method for mapping woody plant cover in agricultural fields using airborne lidar / Lihtne meetod aerolidari andmete põhjal puitttaimestiku kaardistamiseks mahajäetud põllumaadel

Information about the status of agricultural land is of strategic interest in every country. In Estonia, different and even contradicting estimates of area of actively used as agricultural land exist. To solve this problem, airborne laser scanning (ALS) data can be used to map the woody plant cover (values range from 0 to 1 corresponding to the no cover and full tree canopy cover) in agricultural land and to provide digital maps for further analysis. Canopy cover was estimated from ALS data by setting reference height to 2 m from ground. Validation dataset was created from ortophotos on 442 rectangular 100 m2 elementary sampling units. The relationship was linear and determination coefficient was high (R2 = 0.795) and the model fitting residual standard error was 0.116 indicating good applicability of ALS for woody plant cover mapping. The method can be easily automated, does not require additional fieldwork and can be applied in all places where ALS data are available