Planting NZ native trees is an important responsibility for all New Zealanders. It is not unusual to hear someone advocating the protection or planting of native trees, but why is this? Surely a tree is a tree and all trees will benefit the environment…
Trees do benefit the atmosphere in terms of storing carbon and producing oxygen. They can impact the environment both positively and negatively in other ways. This blog post will discuss the role native plants play in enhancing the local environment and why it is important to protect them.
Planting NZ native trees has a critical role in the NZ landscape and environment.
Native plants have grown in balance with their local environment over a long period of time and as such are equipped to live with the local climate, soil types, and animals. Relationships develop between the native plants and animals forming a harmonious web known as an ecosystem.
Certain plants may rely on certain animals for pollination or seed dispersal and in return the animal may receive food and shelter. These symbiotic unions take many years to evolve and help to support the biodiversity of an area.
Approximately 750 plants are native to the Auckland region.
321 of these are classified as nationally or regionally threatened. 80% of our trees, ferns and flowering plants are endemic (found only in New Zealand). If these plants are lost from NZ many will be gone forever, taking the other species that rely on them with them. To prevent further losses it important to protect the ecosystem as a whole.
Plants rely on each other as a community to survive and flourish. By having a wide range of native plants growing together they can support each other through their relationships providing habitat to the animal species that are associated with them.
The demands that native plants place on their local environment has also evolved into a harmonious balance.
Plants need water and nutrients in order to grow. Native species use these resources in levels that are sustainable to the local environment and support the wider ecosystem. When species are brought in from outside of these environments the balance can be lost. These plants have often evolved under different circumstances with different challenges and may use resources at rates that are no sustainable, depleting the local ecosystem.
Non-native species may also have evolved with different pressures in terms of predators.
When they are introduced to areas where these predators do not exist they have nothing to keep them in check and they grow wild, swamping the native species. The local animals have not evolved with these plants so they do not always recognise them as a food source which further compounds the problem.
In some cases it can be the environment in terms of sunlight or weather that keeps a plant in balance with its surrounding. When the plant is moved to a new environment with different growing conditions the results can be dramatic.
A good example of this is the Radiata Pine.
In its native environment of California conditions are very dry and it has grazing animals. In New Zealand the climate is much wetter and there are less animas that graze on young pine trees (those that do have also been introduced from overseas but that is another issue).
As a result, the trees grow rapidly and there is little to keep them under control. Many parts of the country are infested with them and a lot of time and money is spent on trying to keep the problem at bay.
So, what can you do?
Where possible planting NZ native trees species that are local to your area. If you have native species already, protect the land around them by applying mulch and ensuring the ground stays free from contaminants. Identify any pest species on site, if possible remove them, and treat the stumps to prevent regrowth. More information about native trees and removing pest species can be found at the following links
Also read Creating edible gardens…