14th September: Wytham Woods
Leader: Nigel Fisher, Conservator of Wytham Woods,
This field trip was surprisingly poorly attended, presumably because of a late change of date after the leader discovered he had a prior engagement on Sunday 15th. Also there was some confusion as to which car park we were meeting at, despite a map and postcode being clearly given in the directions. However seven members did manage to meet in the right place and, on a warm sunny afternoon, we were welcomed by the Conservator of the woods, Nigel Fisher. He explained that the woods were given to the University in 1942 by the then owners in memory of their daughter who had sadly died as a young girl, and since then had become one of the three most exhaustively researched areas of woodland in the British Isles. 1700 species of plants and animals were known and there could be more as yet undiscovered.
We then embarked on a walk around the woods, stopping at places of interest. Beside one of the 1174 nest boxes that he said were in the woods, Nigel described studies of bird behaviour using small transmitters. Studies on blue and great tits showed that egg-laying was timed to coincide with maximum expected caterpillar numbers, and if there was then a shortage it was the male chicks that died first, presumably because they were less important for reproductive purposes. Also lack of predators made birds sluggish and less alert. We visited a group of ash trees which had started to suffer from Chalara fraxinea (ash die-back) and this was an alarming trend for the future. Examination of leaf litter had shown that roots produce an exudate which encourages mycorrhizal fungi. There were also tree growth ring studies which were beginning to yield interesting results connected to climate change.
The highlight of the visit was when we visited two high-level canopy walkways that had been erected in the woods. The first one was for carbon dioxide and other atmospheric gas sampling connected with climate change, and was considered too high and dangerous for us to ascend, but we were allowed to climb the second one near the top of the hill. It was an exciting experience walking through the canopy with branches growing up through the floor of the walkway, and, looking down, it was easy to imagine what it must be like for a bird or insect living up there.
Following a most interesting visit we returned to the car park where Nigel was warmly thanked by the acting organiser, Sally Gillard.
- Nigel Fisher (Conservator of Wytham Woods, University of Oxford) - leader, Sally Gillard - acting organiser, Lesley Bosley, Victoria Framolina, Denise Kozlova, Margaret Abel, Ian Smith, Michael Bloom
Report: Michael Bloom