Restoring More Than Species: Why Ecological Function Must Guide Pest Control Strategies

Protection and conservation of the many unique native species found in Aotearoa is one of the main goals of pest control. However, simply removing introduced predators or competitors is not a catch-all solution. The whole ecosystem is impacted by the presence of foreign invaders. It is important to consider the ecological function of the whole system when targeting a pest species. 

What is Ecological Function?

Within an ecosystem there are many members, from plant life to insects to animals. The ways in which each of these members interact, the role that each species plays within the community, add up to form the processes by which that ecosystem functions. 

This collaborative effort is what “ecological function” refers to: all the different parts coming together to keep the whole community operational. However, due to this shared responsibility, when one species declines, it affects the whole system. 

The Human Factor

Naturally, ecological function is impacted by human interference. Deforestation, logging, and clearing to make space for human settlements and farms have reduced the footprint of our native forests. By 2005, forest cover had been reduced to less than 25% of the total land mass. 

The introduction of non-native animals to this carefully balanced system (whether intentionally brought as food sources or accidental stowaways like rats) influences the processes in ecosystems. This is particularly evident when they prey on previously predator-free species, not to mention the impact of the parasites and diseases brought with new crop plants and animals. 

The diminishing of native species has been an unfortunate side effect of the habitation of Aotearoa, but this is where it gets tricky. Introduced or invasive species can work their way into the ecosystem. While forcing out certain competing species, the invasive species may end up participating in the community to survive, taking over the function of the native species. 

For example, an introduced species may help with pollination. This could mean a plant that attracts pollinators to the area, or an animal that performs the pollination itself. This integration of the invasive species into the operation of the ecosystem is crucial to take into account when working to remove invasive species. 

Restoration & Reintegration

In the tangled web of the inner workings of an ecosystem, nothing is straight forward. Everything intermingles with each other. This means that, even when removing an invasive species (an objectively positive goal), there are repercussions to the wider environment. This removal may also remove some key functions, such as pollination as in the example above. 

Luckily there are steps you can take while rooting out invasive species to ensure the ecosystem adapts and continues on. The best way is the simplest: reintroducing the native species to the area. 

Having been previously established there, at least you know that the species will take to the ecosystem. This method of filling the void left by eradicating the pest species not only reintegrates the native species to its natural habitat, it also restores the ecosystem to one resembling what it had been originally. 

This reintroduction is an important step in the conservation process. If there is no attempt to restore what was lost, the removal of the invasive species – and key ecological processes that may be removed along with it – can result in the downfall of the native ecosystem in that area altogether. 

Pest Control & the Wider Ecosystem

When performing everyday pest control, it is important to consider what effects those pests may be having on the natural environment – both negative and positive. Most pests will be contributing to the surrounding environment in some way, generally at least by dispersing spores and seeds or aiding with pollination. 

When working to clear the pest species from an area, there needs to be an effort to maintain the functions that they enacted. Encouraging native wildlife to resume those roles is the most beneficial way of ensuring continued functionality: 

• Creating shelters to encourage bees, butterflies, native insects and lizards
• Hanging or standing bird feeders to foster native bird involvement
• Planting native flowers (and trees where space is available) that will attract pollinators

Before laying traps or bait for your known pests, it can be helpful to put out trackers first. This not only helps narrow down what kinds of pest control tools will best suit you, but also aids in identifying what other species you already have around that you can encourage to flourish alongside your pest control efforts.