Planted native trees are not wild

Planted native trees should all be flagged as “captive/cultivated” on iNaturalist.

written Oct 1, 2018 (last updated Nov 1, 2023) • by Jon Sullivan • Category: Wild Counting

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If you're planting trees in wild areas, please be sure to always share them on iNaturalist, and turn on the "captive/cultivated" option. Let future generations of naturalists know what's planted and what's wild.

Roses are red, violets are blue; I tag them as “cultivated”, and so should you. Except if they’re wild. Keeping the wild separate from the captive and cultivated is essential when you’re observing nature. Otherwise it’s very difficult to use these observations to make sense of patterns and trends in nature.

a red rose in bud on iNaturalist violets in flower on iNaturalist
While the saying is that roses are red and violets are blue, there's a whole lot of exceptions to that, in roses and violets. Here are iNaturalist observations of a red rose (I found one) and violets (of all colours, including blue). These are cultivated plants are so are marked as "captive/cultivated" when added to iNaturalist. This gives them a "no" in the "Organism is wild" section of the observations' Data Quality Assessment section, so they can be separated from wild plants for research.

captive/cultivated check on the iNaturalist Identify page captive/cultivated check on the iNaturalist Organism is wild
You can mark observations as "captive/cultivated" when you share observations on iNaturalist, with the app or the website. When you identify other peoples' observations on the iNaturalist Identify webpage, you can also mark observations as "captive/cultivated" there (pictured above next to a red rose), or you can choose "yes" or "no" to the "Organism is wild" in the Data Quality Assessment section at bottom of every observation webpage.

That all makes intuitive sense to most people when they’re observing showy exotic plants in gardens. What seems sometimes less intuitive is that it’s exactly the same when observing native trees planted in restoration projects. These are no more wild than the roses in your grandmother’s garden, regardless of whether they were planted this year or a hundred years ago.

Here in New Zealand there have been decades of poorly documented tree planting in reserves around our cities and towns. Public enthusiasm for planting trees in wild places is only increasing. This means that exploring such reserves now is a confusing jumble of trees of unknown origin.

It’s clear that some of those trees must have been planted because they’re not locally native but are NZ natives from elsewhere in NZ. For others, it’s now very difficult to tell. They could be wild plants that tell us about the local environmental conditions when they germinated and established. Or, they could have been planted by someone and say nothing about the local conditions.

a kowhai tree in the fog in flower on iNaturalist
This kowhai tree on iNaturalist, that I found flowering along the Summit Road of the Port Hills of Ōtautahi-Christchurch, is marked as captive/cultivated. That's because it doesn't look like the local species, and it's flowering out of sync with the local species, and because I know there was historical planting of kowhai in this area. Therefore I conclude that it's not a wild tree. I'm not even sure what species it is (the ID on iNaturalist is just Sophora), and I've since learned that Department of Conservation botanists can no longer ecosource kowhai from the Port Hills Summit Road for use in restoration plantings, because there are now so many wild hybrids between the local native species and these unusual planted species and ornamental cultivars.

It’s like trying to read a story when half the paragraphs are randomly inserted from other books. It makes little sense. That’s frustrating for naturalists and ecologists who are able to read these stories.

Looking at the genetics within species will be even more confusing. Ecosourcing is the golden rule in restoration, but this rule is often (usually?) broken. Some planted natives will have been purchased from nurseries in other cities, or bred from these outsiders, or grown from seed inadvertently collected from historically planted outsiders.

Even proper ecosourcing has the potential to scramble the genetics of tree populations. I expect it to amplify the seed and seedling alleles best suited to nursery environments. Mass planting will also stifle the local tree population’s ability to adapt to the current local environments, since what genetics end up where will be determined by what we plant where, not what is best suited to where.

You’ll have picked up, I’m sure, that I’m uneasy about widespread planting. While that’s true, planting is certainly necessary in some places to kick start the return of native forest to deforested landscapes. It is fantastic that so many people are willing to volunteer their time to make this happen. I want to emphasise, though, that it’s important, now and in the future, to know which plants at a site were planted and which are truely wild.

You can help a lot by sharing observations of plants at restorations sites on the iNaturalist website or app. Be sure to log each planted plant as “captive/cultivated”. The iNaturalist app will automatically grab the location. While you’re at it, have a look to see if you can find any seedlings trying to bring some wild nature into the plantings. Most of these will be offspring of the planted plants, but also look closely for any seedlings of species not planted at the site.

Keeping what’s wild separate from what’s planted will let future generations explore in the habitats we’ve planted, and understand what species are there because of us and which dispersed in by themselves. Just knowing what was planted lifts the fog of confusion around what’s wild and what’s not and lets people read nature’s stories.