Wow… it has been a long time since I’ve posted anything. There were some good reasons for this, but I’ll save that discussion for a dedicated post. For now let’s just revel in some beautiful alpine scenery.
On Saturday, December 19th the Botanical Society of Otago had a joint field trip with some other conservation organizations to the Old Man Range in the Central Otago region. The weather was nothing short of spectacular – all sunshine all day. There were many cool plants, insects, geology, and science discussed while we explored the area.
Professor Emeritus Sir Alan Mark was along for the trip as our naturalist guide. He provided a number of interesting stories, as he has been conducting field research on the range for many years. The oldest field experiment in New Zealand is an introduced snow bank treatment using a snow bank fence. The fence creates a drift area, so a snow bank is present behind it long after the spring sun has melted the surrounding cover. The snow cover creates different environmental conditions, which result in a different plant community beneath it. This suggests that there are a group a species specially adapted to snow bank creating areas, though the exact environmental factors and associated plant traits that involved in this are unknown as I understand.
Another interesting example of environmental conditions affecting plant community structure was observed at a site where 60 sheep died due to an extreme weather event ~80 years ago. Much of their skeletons are still present at the site, but that is not the only legacy they have left. Soil analyses have demonstrated that soil nitrogen and phosphorus concentrations are higher where the sheep died than in surrounding areas. This is because the nutrients from the sheep leeched into the soil and have since been stored in the soil microbial community or in the plants that have soaked them up. These altered soil conditions have also created a distinct high fertility plant community, with plants that have higher nutrient content and faster growth rates replacing the typical residents. I didn’t get any cool photos of this one, though I’ll see if I can borrow one.
Historic indicators of the last glaciation event are evident in the Old Man Range in the forms of massive deposited boulders, glacially etched chasms, and sculpted topography. But ice still works to shape the landscape. Depicted is a field of hummocks, or little soil mounds, that have formed naturally through the freeze-thaw cycle. Measurements show that the hill tops, which freeze through during winter, are on average colder than the hollows, which are insulated with snow pack and do not freeze completely. This temperature difference, oscillating through summer and winter conditions, creates a soil wave action effect which drives the shape and movement of the hummocks like waves through water but on a much longer time scale. The hummocks also create microclimate conditions similar to the snowbanks. This seems to drive differences in the hollow vs. hill top plant species present.
We spotted many insects enjoying the summer feast of plants. There were mostly grasshoppers and beetles, but also arachnids like mites and spiders.
All in all it was a great day to be outside with cool people.
Happy holidays and all the best in the new year. I hope it’s filled with adventure, intrigue, and everything else you are keen on.