Conversations about my book often come around to the question of: ‘What to do about introduced species?’ (especially in Australia). Or, about the benefits (or otherwise) of tree-planting. Here are my responses to two recent questions from readers. So, should we kill pests or plant trees? It’s simple really … ask: are we helping restore wildlife diversity by doing either?
From Ashleigh on Cane Toads
Should I kill cane toads?
- I was wondering what your thoughts are on the invasive Cane Toad, here in Queensland? Your book advocates to preserve wildlife, so it got me wondering whether I should try to remove these toads.
Answer
On the whole we jump to killing animals to solve all problems but it’s rarely the solution. It’s really buying time for the restoration of natural processes. Sure, it would be great to get rid of introduced animals but that seems a distant (if not impossible) outcome.
The golden rule is never to kill animals where this may result in destruction of other wildlife. But if reducing the burden on other wildlife means controlling some animals, then we have to be absolutely respectful and certain it’s the right thing to do. In this way, it’s remarkable what local efforts can achieve. Here are some of my thoughts in response to this difficult question.
- Do what you think is right, while always respecting the animal. No animal is a pest, it’s only doing what comes naturally to itself. We are usually the cause of the problem;
- Play your part and don’t worry about the rest of the world. Your biggest impact is where you are, and that counts for everything. So, your local impact can have massive benefits; and
- Tell the story about why animals matter! Tell everyone about the importance of animals to the world. When you’re involved in some lethal control, make sure people don’t become part of the vendetta against nature.
To summarise killing pests
Rebuilding diversity and not destroying it are the rules for any lethal intervention. For example, kangaroos are considered pests but removing them has caused decline of other wildlife, leading to things like mouse plagues. Cane Toads are a bit different. Somehow we need to nurture the landscape through this period of peril. We have to preserve as much as we can … but it’ll only work if we rebuild everything around them at the same time.
From Emma on Planting Trees
Should I plant trees?
- In your book you say that planting trees may cause more harm than good. I plant lots of trees. Am I doing the wrong thing?
Answer
Planting trees is not wrong if it’s being done to enhance or connect habitat. Of course it has to be done in the right way, for the right reasons and in the right place.
- Tree planting cannot be used to offset loss of valuable habitat. BiodiversityWhat is the definition of biodiversity? When we ask, what is the definition of biodiversity? It depends on what we want to do with it. The term is widely and commonly misused, leading to significant misinterpretation of the importance of how animals function on Earth and why they matter a great deal, to human survival. Here I will try to More is the part of Earth that enables it to be habitable for humans. But you cannot offset biodiversity if you’re destroying something else important and established. If the money to plant trees comes from schemes that have destroyed pristine ecosystemsHow ecosystems function An ecosystem is a community of lifeforms that interact in such an optimal way that how ecosystems function best, is when all components (including humans and other animals) can persist and live alongside each other for the longest time possible. Ecosystems are fuelled by the energy created by plants (primary producers) that convert the Sun's heat energy More elsewhere, it can never–practically–replace the value of what was lost. This is like seeking an ethical pension fund, only to find it’s investing your money in brown coal.
- Is it enhancing biodiversity? Many of our local parks are regularly mown to the point that there are no saplings. But in a natural system, there are younger trees ready to take over or fill gaps caused by storm fall. So, planting may be needed, to fix a problem that we have created in situ. Or, it may be to connect pieces of habitat and create cover for animals to move between. These would be worthwhile reasons to plant trees.
- Planting for carbon storage alone may not be worthwhile. If trees are planted simply to grow carbon as fast as possible, many schemes create monocultures of little or no value to wildlife. Therefore, such schemes can result in increased risk of surplus energy and lead to greater pollution problems.
- What is the survival rate? Many tree planting schemes around the world have been heavily criticised for low survival rates and don’t always help people.
Planting trees in Borneo. The reforestation project pictured is a local initiative to restore an area of clear fell in southern Kalimantan. This preserves freshwater and habitat for orangutans.
To summarise planting trees
The rule is, plant trees if it restores opportunities for wildlife. Because that way, you’re also contributing to the stability and habitability of Earth. Don’t do it just for carbon. As I discussed in a recent post, ‘the difference between those two figures is also the difference between a world that is habitable and one that is not.’ Before tree planting, or indeed any scheme to restore functioning ecosystems can succeed, we desperately need a change in human values. We have to recognise that it fails if the environment isn’t wildlife-rich.
How do you know if you’re doing the right thing?
- Become part of the rewilding generation! Start this conversation everywhere. Animals only become ‘pests’ in our minds because we create a less dynamic world, by breaking ecosystems (even if that’s by introducing an animal). Tree planting only works if animals are there to start with. By restoring wildlife populations we are giving nature the chance to fix things as we become part of the ecosystem, rather than imposing ourselves on nature.
Overall, therefore, be part of the mission to promote the critical importance of wildlife for humanity’s future. That way you can always know you’re doing the right thing.
