Tree Height Growth in Petawawa Research Forest
Monitor through LiDAR CHMs from 2005 to 2018
Monitor through LiDAR CHMs from 2005 to 2018
Monitoring the growth of trees is important for sustainable forest management. The traditional method of monitoring forest growth at a broad level is timber cruising by humans, while modern remote sensing technology, especially Lidar, is usually used for monitoring at the single-tree level or stand-level. This project uses Light Detection and Ranging (LiDAR, i.e. airborne laser scanning (ALS)) data from 2005, 2012, 2016, and 2018 and forest survey data from 2007 from the Petawawa research forest (PRF) supersite to monitor the tree height growth through a time series and build relationships between stand ages and dominant tree heights (DH).
The PRF was established in 1918 to create and transfer knowledge that could be used to improve the quality, productivity, and health of Canada's forests, and is the oldest sustainably operated research forest in Canada. Over the 100-year history of the PRF, many ground sample plots and research experiments have been established. The data holdings, long-term infrastructure, and ease of access have made this data source an important one. More than 1900 data records, including multiple airborne laser scan datasets and associated derived data (i.e., digital terrain models, canopy height models), airborne imagery, and ground patch data, are publicly available for download from the Canadian National Forest Information System (CNIS) or its supersite.
By overlaying and intersecting every outline and 2007 inventory range, landcover classification based on stand age can be done on the areas which contains all types of data.
The areas are devided into 10x10m grids and the dominant tree height of each grid can be derived. Based on variation of height in the time series and normal tree ranges for the native species, the whole forest can be classified as healthy/disturbed and misclassified areas.
Different linear models are developed and tested for the healthy data in each landcover type.
PRF-landcover classification
multiple linear models for each landcover type
multiple linear models for the whole forest
This method represents a cost and time-efficient alternative to manually measuring the height of dominant trees in closed forests.