The McKinney Kauri

Biospatial was engaged to determine a list of the Iconic Kauri standing in New Zealand. Kauri Agathis australis is an iconic tree species itself. It resides in the northern part of the North Island of New Zealand, however it is under serious threat from die-back caused by the pathogen Phytophthora agathidicida. A methodology was established by Biospatial to determine candidates using factors such as existing lists, popularity, size and botanical importance. Some of these trees were selected by the ease of their public access. The McKinney Kauri was one such tree. It stands in a park near Warkworth on a major tourist route.

The threat of national loss of theses trees and potential actions taken to mitigate this loss was covered in the report. In particular Biospatial has designed and trialed efficient investigation and monitoring methods using UAV surveillance at the McKinney Kauri location as follows:

Biospatial scanned the entire canopy of the tree by slowly circumnavigating it in a “Point of Interest” flight. The UAV records 4K video which has a high enough resolution to have highly detailed frames that can be grabbed for analysis. These flights are pre-programmed and reproducible. The flights can be designed by the proposed analysts.

This map using Google Earth shows the planned track and waypoints determined for a flight over the McKinney Kauri in Warkworth. The “Point of Interest” can be the centre of the tree’s crown and can be predetermined or established by flying over and marking it. Its position is then determined to within centimetres. Very accurate measurements can be taken of the width, height and volume of crown and trunk etc. The UAV can also take opportunistic photographs around the tree both above and below the canopy. 

Biospatial mapped the tree and its surroundings by producing a highly detailed aerial photograph geo-referenced so that its position and dimensions are defined. Using this mapping a complete analysis of the surrounding ecology can be determined and mapped. 3D modelling can be deduced to provide accurate contour and aspect information.

A flight plan is predetermined in Google Earth to map the area around the tree.

The McKinney Kauri is shown top right and its crown is measured at: Diameter 31.0m, Area 2023 m2. The notable Kauri register listed the average crown spread of this tree at 28.0m.

The Simpson Kauri is shown centre and its crown is measured at: Diameter 23.8m, Area 895 m2.

Digital Elevation Model (DEM) can determine the height of the tree. The McKinney Kauri’s height is 35.0m (notable tree register listed as 37.8m) and the Simpson Kauri stands at 34.0m. Using a contour filter it is possible to measure accurately the height of the highest foliage of the tree.

A highly detailed Orthomosaic projection aerial photograph can be produced of the trees and their environs.

A fully interactive 3D Model can be generated from the UAV data