Posted by Ben Cranston

On the morning of 20 March 2018, a crew of University of Auckland researchers, professional arborists, and volunteers set out for Huapai Scientific Reserve in the northern Waitākere range with a few objectives in mind: most notably, to collect 24-hr transpiration and leaf water potential values for kauri (Agathis australis). We were equipped for an overnight stay in the forest and spirits were high. Climbing, gear-and-sample running, eating, and sleeping shifts were divided up between participants and the plan was laid out…

The first day was mostly meant to familiarize new climbers with the protocol as well as replace some older, ailing equipment in the canopy. In effect, we ended up using day 1 to ease into an appropriate mindset for the overnight campaign which was to begin early on the second day. In addition, we were able to snag a bit of press and drone footage of the science going on at Huapai which was very cool!

I also was able to obtain a great vantage point of the throughfall exclusion shelters which were recently installed at the site. In this frame, it is slightly discernible that soil under the tarps is staying dry relative to outside. Preliminary results from sapflow measurements are showing no clear distinction between droughted and non-droughted trees, but that should hopefully change over the course of the year(s) owing to these tarps.. stay tuned.

Our resident arborist, Freddie Hjelm, had his enthusiasm for New Zealand forests on full display throughout the whole trip. On behalf of everyone in the Macinnis-Ng lab, I offer our sincerest appreciation to him and the rest of The Living Tree Company crew for helping us stay safe and problem-solve when the going got tough!

Apart from a trove of data (currently being processed), over the course of the collection period we were all treated to views like these. Climbing up the stems of my study trees  revealed a cathedral among the canopy not to soon be forgotten.

It was a lot of work from a lot of people but we made it to the next day. The volunteers did an amazing job hanging in there well into the night and I can only hope that the experience was worth the toil.

 

Ben Cranston is a PhD student at The University of Auckland. His project is part of the Kauri Drought Experiment under the supervision of Cate Macinnis-Ng.