The Botanical Society field day onto army ground proved interesting. Military training grounds the world over provide opportunities for nature simply because there is no incentive to develope the land for agriculture and it therefore gets left to the plants and animals that can survive there. In this case dryland herbs and shrubs, moths, beetles, bugs and birds. Explosions and target practice, engineering exercises and tracked vehicles also provide small amounts of disturbance, an essential element to keep the pioneer species present in any natural system islandised by developed land all around and cut off from the pre-human source of disturbance.
The day before had been hot but Saturday was grey and cold. Still the forecast drizzle didn’t make it this far down the plains, even though it was damp most of the day at Sheffield just up the road. Our site was once part of the braided Waimakariri river fan and the nor-west winds have blown fine sand into dunes that extend for several kilometres to the south of the current river. So we had two soil types, low dunes dominated by introduced marram grass and gravels dominated by exotic and native grasses with many plants of interest under our feet and in between the grasses, making for a bottoms up day. Patotara, Leucopogon fraseri, was widespread otherwise the natives were in patches defined by the changing conditions relating to the braided deposits and journeys of the dunes. There was an ongoing discussion about Dichondra with 2 species present, confirmation of what was what came with discovery of a single D. brevifolia flower.
Brian, our leader again, is a bug man first. In order to understand insects that utilise plants he also needs to know his plants. Pretty much every species of native plant has invertebrates that are dependent on them at some stage of the insects life-cycle and some of the plants may even require the insects such as the celebrated case of american yucca and yucca moths , although I don’t know if there is anything this profound in NZ. Anyway for Brian, find a rare plant and chances are you’ll find a rare insect or maybe even something completely new to science. Sorry I didn’t take notes on Brian’s enthusiastic commentary, I was having enough trouble with a bunch of new plants. But I did learn that the male copper butterfly is purple-black and the caterpillars feed on Muehlenbeckia, there was a flightless moth present and somewhere he snared a couple of large rove beetles.