A week into our fieldwork trip to study New Zealand's peat bogs and the North Island is done! To say our trip has been something of a whirlwind so far would probably be leaning towards understatement. Rewi met Dan and I off the plane at about 2pm last Tuesday morning, though to be honest, after 27 hours in transit, our bodies had very little of what time of day it really was. Apart from a short power nap for half an hour on my part, we managed to stay awake for the whole of the five hour drive to Kaitaia where we arrived and gratefully fell straight into a comfy bed.
There was no time to ease ourselves into the swing of things – a schedule covering six bogs from the far north to the far south in a smidgen over two weeks allowed for no such luxuries. So, bright and early, we were off to Tangonge Bog, just west of Kaitaia, where we met up with several people who joined us out in the field; a local botanist who has been central in efforts to preserve the remaining remnants of the bog over the past few years and members of the two local iwi, Te Rawara and Ngai Takoto. It was great to be able to learn about the area from them and to let them know about what we hope to learn from their site. The stories of how recently what is now a pretty dry fragment of bog used to be a large lake surrounded by extensive wetlands teeming with bird life were astonishing. The drainage of the land for agriculture has slowly sucked the water from the bog and it was heartening to learn that the iwi want to restore the wetland to its former glory in the near future. I really hope they can succeed because Tangonge is one of the final remnants of wire rush dominated bog in far Northland that deserves to be preserved for a multitude of reasons, not least its central place in the local Maori folklore and history.
After a morning on the bog we retired to the Te Rarawa marae at lunchtime to which we were kindly invited. It was a wonderful experience including lots of traditional Maori greetings (touching of foreheads) and our attempt (which went quite well if I do say so myself) to sing a Maori song as part of the welcoming ritual. Rewi gave a greeting in Maori which Dan and I were both surprised and very impressed by – in Rewi’s great modesty he had said only earlier that day when Dan asked, that his Maori was “coming on ok”! We returned to the bog in the afternoon to finish off our sampling and got caught in a massive rainstorm, which only served to fuel our discussions on the way back south towards Auckland at the end of the day about the climatic differences in terms of rainfall patterns and sources that we are trying to see if the wire rush records in its isotope record.
At each site, including at Kopouatai Bog, New Zealand’s largest and most famous peat bog where we found ourselves the next day, we are taking a range of plant and water samples to test our hypotheses. We want to see whether the oxygen isotopes in roots and shoots of the wire rush and the water sources it uses to grow reflect spatial (throughout New Zealand) and temporal (over the course of a year) variation in the oxygen isotopes in rainfall. We also want to understand whether the carbon isotopes are influenced by the moisture status of the bog, reflecting the amount of rainfall received in the past. If we can figure all of this out, it means we might be able to use isotope records from wire rush dominated peat cores to study past changes in precipitation, something that’s currently very difficult to do in New Zealand.
At Kopouatai, we’re being ably assisted in this task by Jordan, a PhD student from nearby Waikato University who is working on the site measuring gas fluxes. We met Jordan at a farm near the edge of the bog and drove along bumpy lanes as far as we could until the vegetation changed dramatically from farm paddock to something distinctly more natural. There was still a couple of kilometres of fringing vegetation to tramp through until we reached the bog itself and what a wonderful place it was. Bogs may not be everyone’s cup of tea and on the face of it might be seen as rather featureless, but I find them very beautiful places. Kopouatai was a vast open landscape, with a soft wind sending the vegetation wisping away in gentle waves. Situated in the low lying Hauraki Plains, it is hemmed in to the east and west by distant jagged hills. As we worked away, our techniques already a lot more slick than the first day, I felt a wonderful sense of peace and serenity overcoming me. It was pretty hard to feel this was my job and once we had finished I didn’t really want to leave and could easily have sat out on the bog all evening watching the sun go down and feeling at one with the world.
Our final site in the North Island was Kaipo Bog in Te Urewera National Park and it was an epic trek to get there. From the flat plains of Kopouatai we wound our way up into the hills, finally arriving at Lake Waikaremoana, camping on the lake shore (or actually, not quite on the lake shore due my slightly inept scoping of the campsite, much to Rewi and Dan’s consternation!) From the lake it was an hour of hiking through beautiful native beech forest, damp in the morning air with shafts of sunlight piercing through gaps in the canopy, to Lake Waikareti. We rowed across the lake in about an hour, saving ourselves at least a four hour tramp in the process. From our landing point at Sandy Bay hut, our accommodation for that night, it was a further two hours of tramping to the bog. This was our first meeting with the more slender species of the wire rush, the northern sites being dominated by its more robust cousin. The bog surface was an intriguing mixture of hummocks formed of vegetation and low lying watery hollows ready to trip up an unwary footstep. The sampling by now was a slick process and after a further two hours walk back to the hut, we felt we had earned a lazy evening on the veranda, overlooking the pristine lake as the sun sank over the horizon and the flames of an open fire fluttered on the beach.
Five days, three bogs and 87 samples since we touched down on New Zealand soil; let’s just hope the South Island goes as well...