From November 2021 to February 2022 we were joined by Poppy who did her summer research placement with us, studying soil food webs and ecosystem functioning in kauri forests. Being part of the programme Ngā Rākau Taketake – Saving our Iconic Trees was an opportunity Poppy really enjoyed, and postdoc Rebecca (and later Marijke) were very happy with Poppy’s hard work and assistance.
The placement involved visiting the field sites in the Waitākere ranges to sift through leaf litter to look for invertebrates and to collect soil cores beneath both kauri and non-kauri trees. Back at the lab, they extracted the soil cores for nematodes and mesofauna. Nematodes were extracted using a Baermann funnel and mesofauna were extracted using a MacFadyen heat extractor. In the Baermann funnel, soil is placed on tissue paper submerged in water, sitting in a funnel closed off with a rubber tube and clamp at the lower end. Nematodes sink down to the bottom of the funnel, from where they can be collected. The MacFadyen heat extractor is like a fancy Tüllgren funnel. It blows heated air along the top of the soil cores, and cool humidified air along the bottom of the soil cores. This creates a temperature and moisture gradient in the soil. Microarthropods move from warmer, dryer soil into the cooler, moister soil below, where they eventually fall into a collection vessel.
This lab and fieldwork provided excellent context for Poppy’s literature review on the ecosystem impacts of global forest pathogens which she worked on during her summer placement.
Since terminating her summer placement, we are now happy to be able to keep Poppy on the project a little while longer as a research assistant.