Pioneering LiDAR for Forestry Applications
Deforestation is increasingly clearing Earth’s surface. While there are various causes for logging, the main reason is to make room for agriculture in order to produce sufficient food and sell the wood as additional income. With forest being an essential part in regulating the carbon and water cycle this directly affects our environment and the world’s climate.
The quickest solution to deforestation would be to simply stop cutting down trees – but it is clear that such a radical solution would not be successful. A more sensible approach is to carefully manage forest resources by eliminating clear-cutting and making sure that existing environments stay intact.
As a result the United Nations Framework Convention on Climate Change initiated a mechanism called Reducing emissions from deforestation and forest degradation or short REDD/REDD+.
Fundamental for all REDD/REDD+ activities is good knowledge about the forest resources. While there are several methods of surveying the location and extent of forested areas, LiDAR allows for a more accurate analysis of the biomass structure within these forests.
Expertise from Finland to the Tropics
Roughly 75% of Finland is covered with forests and more than half of it is privately owned. Finnish forest owners are generally operating their lands with future generations in mind. Part of this is good forest management in which Finland has been amongst the most experienced countries.
Various studies have found that LiDAR has great potential for carbon stock estimations and it is therefore not a surprise that this technology is used throughout Finland to map privately owned as well as state forests.
Taking the same approach can help to accurately survey and sustainably manage forest resources in developing countries where deforestation occurs. While this might sound easy to do, some challenges need to be addressed first.
One of the major factors determining the success or failure of algorithms for forestry is always the diversity of the forest itself. With only three major tree species in Finland, tropical forest might present itself with a much wider range of different trees, plants and understory vegetation.
Pioneering the use of LiDAR technology in the Tropics
In 2010, FINNMAP was part of a consortium looking for new methodologies of mapping carbon stock in tropical forests. These forest play a significant role in mitigating global climate change as they hold more than 210 gigatonnes of carbon. Accurate estimations of the biomass in dense tropical forest has been a challenge and finding a cost-efficient and accurate way of observing carbon stock would allow for better observation and implementation of REDD methodologies.
Part of the SUFORD forest monitoring component (a bilateral co-operation between Finland and Lao PDR), a study area was selected near Vientiane. The developed staged approach utilizes advantages of different surveying technologies into an integrated solution. The capability of LiDAR technology to penetrate dense canopies and mapping forest structures is hereby used to calibrate satellite imagery collected over a wide area. Combined with field sampling to verify the results, this methodology turned out to be very successful and has since been recognized as a spotlight example on how to map biomass in tropical forests.
FINNMAP has since used this methodology in various other projects which have proven that this approach is also well suitable for other mixed tropical forests.