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New Advances in Forest Mapping

Having an up-to-date forest description is a key requirement for effective forest resource management.

Traditionally aerial photography has been routinely used to provide accurate forest area descriptions. Visual interpretation and digitising of boundaries from high resolution aerial photography (~0.25 m) has provided the most accurate definition of boundaries, gaps and changes following silvicultural tending or harvesting.

Recent advances in satellite technology mean that this technology now offers a range of benefits to resource managers who require timely information for broad-scale (1: 25 000 scale) forest planning. It is especially effective when combined with existing stand boundaries that have been mapped from ortho-photography and managed within a Geographic Information System (GIS). In this environment satellite imagery can now provide a cost-effective option for frequent monitoring and updating of forest maps.

Future Forests Research has recently demonstrated that Rapid Eye satellite imagery can now be used to identify establishment within 2 years of planting and can be used for mapping purposes within 3-5 years of planting.

The March 2011 imagery below shows a range of stands established from 2005 to 2010. Bare ground or disturbed soil appears bright blue (2010 example) and green vegetation appears in shades of red, orange and brown. As the canopy closes the transition from bare ground (blue) to plantation (orange to brown) becomes quite apparent (2005 showing 5 years' growth).