Monitoring tree occupancy and height in the Norwegian alpine treeline using a time series of airborne laser scanner data

Our new study is out on the use of time series of airborne laser scanner (ALS) data for monitoring the alpine treeline. The paper can be accessed here:

The paper demonstrates a method for monitoring tree occupancy, i.e., the proportion of a sampled area in which trees are present, and tree height in the alpine treeline ecotone. We used field data and ALS data from three points in time (2008, 2012 and 2018) collected along a ~1100 km transect in the Scandinavian Mountain Range.

We found that time series of ALS data are highly useful for detecting and monitoring small pioneer trees. We found no significant changes in either tree occupancy nor tree height in the observed period. The proposed method can be used to monitor alpine treeline ecotones and to provide the uncertainty of the estimates which can inform whether observed changes are in fact significant.