An ecological history of Rotota
Rotota is located in the Ātiamuri ecological area (222,440 hectares), one of 268 ecological regions in New Zealand. It is a part of the Taupō basin, a huge caldera complex formed during several catastrophic volcanic eruptions. These eruptions, along with the evolution of the Tongariro and Waikato river systems, have greatly influenced the formation of the land and vegetation.
The last Taupō eruption of 186 AD blasted a column of superheated rocks, pumice and ash some 50 kilometres into the air from its vent, the Horomatangi reef east of the middle of Lake Taupō. When the column collapsed it surged sideways at speeds of up to 1000 kilometres per hour, largely incinerating all pre-existing forest over a distance of about 80 kilometres in all directions.
Successful regeneration occurred, and prior to human settlement the land was again almost entirely re-covered in forest vegetation. Reasonably extensive wetlands existed on plains and in valley floors, many of which still remain today.
Prior to deforestation, the densely forested catchment provided a natural filtration system as the water moved across the land flowing through the various wetlands, streams and waterways, eventually reaching Lake Taupō and moving on into the Waikato River as cool, clear water.
Repeated wildfires combined with harsh temperatures resulted in a landscape dominated by tussock, bracken fern and scrub, with forest generally being restricted to inaccessible steeper places and damp gullies. By 1840, much of the forest cover had been burnt.
Following forest clearance, land drainage, land use intensification and the spread of pest species, the natural filter has been disrupted. A series of hydroelectric power stations have also been built along the Waikato river, flooding many areas that would now be protected.
The Ohakuri Dam was built on the Waikato River in 1961. This was the site of the spectacular Orakei Korako geothermal area, known as “Geyserland.” The lake created for the power station submerged most of the geothermal area, destroying 200 hot springs, several silica terraces and 70 geysers, including the world’s second largest geyser. This geyser was known as Minginui, and its “fountain” reached heights of 90 metres. The scheme also destroyed wāhi tapu (sacred sites of Māori), and forced Ngāti Tahu-Ngāti Whaoa, the local iwi, to relocate their marae.
Flora at Rotota
Geothermal vegetation is adapted to tolerate extremely high temperatures and unusual water and soil chemistry.
Podocarps are a group of plants that produce pollen in cones, but their seeds are either enclosed in a fleshy cover or sit atop a fleshy ‘foot’, both of which are designed to attract birds that distribute their seeds. They include rimu, totara, kahikatea, matai and miro.
Biggest conservation risks at Rotota
- Loss of native fauna by predators and pests such as stoats, rats, pigs, hedgehogs, magpies, and wasps
- Fire
- Invasive plants species such as jasmine, wandering willy, and japanese honeysuckle dominating native species
- Loss of biodiversity from establishment of forestry plantations
- Loss of bees for pollination
- Loss of aquatic biodiversity due to weed and the effects of farming run-off
- Human interference and pollution
Be a Rotota Conservation Champion
- NEVER throw rubbish or food waste into the bush, as it attracts pests and predators. Take all rubbish and waste with you when you leave Rotota.
- Pull weeds when walking the grounds, and pick up fallen cabbage tree leaves before the caretaker mows.
- Adopt an area on a path, culvert or bush section at Rotota and keep invasive species down. Remove wandering willy (carefully and into black plastic bags), climbing jasmine, prickly blackberry, and japanese honeysuckle.
- Replant with native plants. Keep introduced species to only within allocated sites. Avoid all invasive plants that can take over, such as jasmine or asparagus fern.
- Plant locally suitable flora such as species on the Ātiamuri ecological area threatened list. Additional guidance can be found in this planting guide.
- Join in our club pest control activities.
- Join in on an arbor day planting or working bee, grow seedlings for future planting, or help out in the plant nursery.
- Tend to the club shade trees, especially in drought periods.
- Destroy wasp nests.
- Don’t pollute the water, and check for didimo on any water craft.
- Come up with a conservation idea and present it to the committee. There are lots of enthusiasts who may want to help!