Pōkeno Park superintendent Leo Lornie gets an update from Robert Shearer of Native Awa, on key activities to manage the environmental development of the park.
Pest and weed control
The site of Pōkeno Park has had mixed uses over the years, including farming and being prepared for a quarry. The problem species are possums and rabbits, and weeds requiring continuous control are gorse, tobacco weed, pampas, woolly nightshade and wattle.
Seed sourcing for native planting
There is a small stand of native bush that is hundreds of years old in an elevated part of the park. This has served as a seed source for canopy species, which have been propagated in the Native Awa nursery and are now beginning to be planted.
Regeneration principles generally guide that new plants are sourced within 10-15km of a site. Rob’s experience guides that they also need to be relevant to the terrain – which is not coastal, and has a mix of wetlands and hills. With the right plant selection, there is minimal loss. But in a regeneration project like this, which also has landscaping components, different species may be desirable to achieve a design goal. The focus in the past four years has been on underplanting species such as kanuka and manuka.
These are now at heights that allow planting of canopy species including puriri, karaka, rewarewa and taiere, which are key carbon sequesters. Although it will be many decades until their maturity yields benefits, natives are a preferable carbon sequester to pine. Natives are forever, and have the benefit of consistently returning organic matter to improve soil health. The rationale for pine is generally economic – to earn carbon credits at a faster rate.
The combination of pest/weed control and continual planting is an accelerant in the regeneration process. Fertilising tablets have also boosted growth. Instead of 25 years, we’re probably able to achieve a sustainable system in 10 years. Still everything takes time, and while the need for ongoing management reduces over the years, it never goes away. If left alone for two years, all the problems will come back.
Instead of 25 years, we’re probably able to achieve a sustainable system in 10 years.
Wetlands
Initially, wetland natives were planted in the upper catchment of the property. Subsequently, the focus has been planting on slopes, as the next step to control sediment runoff into the waterways. This is likely to continue in the coming season. Koi carp are a massive problem across Waikato and impact on the potential of wetlands to do their job of filtering and cleaning. In low lying parts of the park, there is potential for koi carp to enter the wetlands and our aim is to ensure this doesn’t happen because of the damage they cause in sediment buildup and bank erosion.
Monitoring success
Observation is our primary tool. Planting over the past four years is doing really well and birdlife is increasing. Weeds and pests are under control. It’s looking good! Hynds Sustainability team assists us to assess carbon sequestration based on the tree species. Soil health improvement is a consideration, though it has limitations. Diverse uses and movement of land creates irregularity in soil profiles. Potentially, we can focus on plots and sampling at three-year intervals.
