Photos / Sounds
What
Matagouri (Discaria toumatou)Observer
cwells1Description
Matagouri (discaria toumatou) commonly occupies many drier climates on both the North and South Islands of New Zealand. It’s easily recognizable by its grey color, sharp spikey stems, and small leaves. Matagouri is a pioneer species, meaning that it often is one of the first plants to occupy an area after a disturbance. Matagouri is also shade-intolerant – once it has been succeeded by another plant as the dominant species, matagouri does not survive well in the shade of other plants. Therefore, you’ll most commonly locate matagouri in open areas where it won’t have to compete for sun.
The location in the photo is along the Hooker Valley trail near Aoraki/Mt. Cook. The rubble in the background is a remnant of a glacial moraine from the Hooker Glacier. Due to the height of the Southern Alps and their close proximity to the coast, the Alps are an extremely good spot for glaciers to form. Because of the orographic effect, also known as a rain shadow, weather fronts from the West are pushed up over the Alps. The pressure from elevation forces them to precipitate, ensuring plenty of snowfall in the high elevation of the mountains. Over time snow turns to ice and compacts under its own weight and around other materials, becoming a glacier.
When glaciers recede from a location due to changes in the climate, it often leaves behind some of its contents. Moraines most often are noticeable by the larger sections of earth that was contained in the receded glacier: rocks and cobbles. Glaciers are not only made up of ice – either slips and rock fall or the advancing of glaciers can cause them to populate with earth. These are compressed by the full weight of the glacier on the bottom, or are compressed into the glacier from the top with added snowfall and ice over many years. Smaller bits of earth like pebbles, sands, silts, and clay are usually carried further away by the runoff water in formations called alluvial fans.
Here, the Hooker Valley was carved out years ago by the Hooker glacier from the Southern Alps. The glacier still stands, although it has receded considerably from its former girth. We hiked along the river that flows from the glacier to Hooker Lake, where you can view the glacier today. The moraines we saw help us not only imagine how large the glacier was at one time, but they mark specific landmarks in time where the glacier had rapid recession.
Photos / Sounds
What
West Coast Black Fly (Austrosimulium ungulatum)Observer
cwells1Description
Austrosimulium ungulatum, are most commonly called sandflies by New Zealanders. They are also named “namu” by the Māori. Similar species found in other places in the world, mostly refered to as “blackflies.” Sandflies are considered pests among natives and tourists alike, and they plague the Fiordlands on the tip of the South Island. There are only two species of sandfly that bite, and we experienced firsthand that this is one of them.
Sandflies are related to mosquitos and other flies. Only female members of the species drink blood, as it’s a necessary component to reproduction. Subsequent to mating blood is required for the female to be able to produce her eggs. The sandflies are a menace always, but they cannot see in the dark. Hence, most visitors to the Fiordlands are safe at night.
The male sandflies, and females not in breeding season, collect organic material from the tops of running rivers to compose their diet. The male does not consume vertebrate material at all.
Eggs are then laid above or submerged in fast moving waters. Small hairs are able to snag passing bacteria, algae, and other bits for food passing through those waters when the larvae hatch. After about 10-12 days the larvae emerges from the water as a full grown sandfly and proceeds to terrorize vertebrates on the mainland. The lifespan of a sandfly lasts 6 to 7 weeks.
Our group experienced hundreds of sandfly bites on the shores of the Doubtful Sound in Deep Cove. This diagram was located in the information center on the edge of lake Manapouri. The display also provided some information surrounding the Māori myth of the sandfly.
When the god Tu-te-raki-whanoa created the Fiordlands by drawing them by hand Te-Hine-nui-to-po, the goddess of death, released the sandflies to “remind humans of their mortality,” and to ward them off from living permanently on Doubtful Sound and throughout the Fiordlands.
When Captain Cook sailed around the Fiordlands in the 1770s he encountered these sandflies as well and described them as a menace. Not only were the bites painful in the first moments, they can swell and itch in the later hours after receiving them. In rare cases recipients of the bites can suffer anaphylactic shock.
Photos / Sounds
What
Hall's Totara (Podocarpus laetus)Observer
cwells1Date
Missing DateDescription
Podocarpus cunninghamii, is also known as Hall’s tōtara, mountain tōtara, and thin-barked tōtara. It is similar to the lowland variety of tōtara, and is a smaller conifer found in drier mountain climates. It’s found on both islands and coasts of New Zealand and in different climates due to its ability to survive cold as well as lowland temperatures. Tōtara is a part of the podocarpaceae, which are mainly found in the Southern Hemisphere. New Zealand’s large collection of endemic podocarps is part of the draw for students of botany like us.
The specimen that we found today was located on the Hooker Valley Trail leading from Mt. Cook Village to Hooker Lake. Our class payed special observation noting the change in plant diversity from the start of the trek to when we reached the lake. Tōtara was fairly common along the beginning portions of the trail along with larger plants like celery pine and broadleaf. However, as we trekked further up into the sub-alpine zone the specimens we found were more stunted, or else in the juvenile stage.
The reason for this is because of the environment around Mt. Cook. In addition to being colder due to elevation, there are very strong winds that come roaring down the mountain which restrict the growth of large and spacious plants. This variety of tōtara was very dense, a trait shared by the other plant life around the harsh environment of Mt. Cook.
Shown in the photo are the distinct red cones that make tōtara easy to identify when it’s the fruiting season. When it is not the time of year for the cones to be shown, tōtara has a distinct peeling red bark in its adult form. Both the juvenile and adult forms share the small, blade-like leaves lighter in color. Against the backdrop of the other plants in the area, these leaves stand out fairly well against the other flora. They can look similar to members of the hebe genus, however the leaves of tōtara lack the rotated pairs of opposite leaves.
Tōtara were highly valued and treasured by the Māori people as the wood is incredibly strong. This was the preferred wood for canoe making, as well as for most construction due to its incredible strength.
Photos / Sounds
What
Scotch Broom (Cytisus scoparius)Observer
cwells1Description
The hillsides along the route towards Banks Peninsula holds smaller details than just the impressive hills. Alongside some of the ridges, one can observe layers of volcanic ash embedded in the rock which designate past volcanic eruptions. Volcanic ash can be formed of rock fragments, volcanic glass, and also minerals that are a key ingredient to making soil with volcanic ash extremely fertile.
The minerals trapped inside the ash is usually dissolved through rainfall. The nutrient enriched water mixes with the soil underneath and creates a layer called Andisol. This is the layer accessed by flora and used to create the lush plant life usually found in areas where current or past volcanic activity was present.
New Zealand has a unique geological system in which the Australian and Pacific tectonic plates meet on a boundary that runs directly under both islands. When a plate subducts under another, the mantle of the subducting plate heats up due to being exposed to the magma underneath. This newly melted crust is pushed upwards and can result in volcanic activity.
Banks Peninsula, where this photo was taken, is made from the remains of the two shield volcanoes Akaroa and Lyttleton as well as the Mt. Herbert Volcanic group. This peninsula is the only relic of volcanic activity on the South Island.
The Ōtepatotu Scenic Reserve, where we hiked, had a few very dense portions of trees and brush. Unfortunately, this is not the case for most of the Peninsula. The area used to be heavily forested, and was cut down due to the colonization of Akaroa at the center of one of the craters by the French. Additionally, much of the forested portion is also non-endemic, and had crops of non-native trees planted by hand in the area that took advantage of the soil. The identification on this post is one of them – Scot’s Broom. Our class has also seen signs of Scot’s Broom in Wanaka (1.17.17).
During the drive towards the hike we saw several examples of the volcanic ash embedded in the rocks running along the road. I hadn’t thought to really look at the details in the rock faces until our bus driver, Alan, mentioned that lines of ash were sometimes visible. Sure enough, after a few more minutes I too was able to spot the difference between layers of rock and snapped a few pictures.
