Ideology doesn’t make forests resilient

Ideological thinking involves following certain norms that someone else has developed, or worse, some group of people. Beliefs held by groups tend to become ideologies, and they are not necessarily rational or scientifically validated.

About 300 years ago, when people started planting trees to replace the ones they felled, it was noticed that the planted trees sometimes did not grow as well as the ones that were there before. One possible reason seemed to be that the seed source was far from the planting site. At the time, there was no scientific knowledge of forest genetics and only a limited understanding of adaptation. Nevertheless, it seemed reasonable to conclude that using local seed was less risky than using material from far away. “Local is best” became a rule of thumb and was taught to generations of foresters, even though there was no science supporting it.

Scientific understanding gradually improved with evolutionary biology, genetics, provenance trials, and most recently, climate science. When we actually do the science, it turns out that local is rarely the best, often no better than average. It also turns out that adaptation is a set of measurable traits that evolve and can be selected for, not some magic that happens when something lives in a place long enough. Where scientific knowledge exists, which includes most of Europe, people planting trees now have a choice of many species and provenances that are better than local material. They even have a choice of how they are better – better in growth rate, form, pest resistance, or any of several adaptive traits.

Not only is local seldom the best, it is also not “local”. Climate science has made us realise better than before that conditions change. “Local”, defined as a set of conditions that trees are adapted to, is not something that necessarily lasts very long. Trees (and all other organisms) are in a never-ending race to keep up with these changes through adaptation via natural selection. This also explains why local is almost never best —trees never achieve perfect adaptation.

Unfortunately, not everyone has kept up with the science. The “local is best” myth is still something that many believe to be true. It has even been adopted within the biodiversity discourse, not as science but as ideology. Ideologies are taken as given by their adherents. Opinions that do not conform to the ideology are simply wrong in their minds. Objections are seen as attacks rather than rational arguments. Ironically, adherents of ideologies often accuse others of narrow-mindedness.

Nativism is a recent ideology. No one is against natives (people or other organisms), but nativism also means being against non-natives. Native species are “good”, while non-native species are looked upon with suspicion. They are framed in a negative light, called “alien” and “invasive”. They do not “belong” while native species have a “right” to be where they originated (but not to go elsewhere), although it is in fact a characteristic of organisms to move around in one way or another; it is part of their adaptation to changeable environments. Nativism is no more based on science than “local is best”. Definitions are fluid, ideas are nebulous, and there is no logical context. It is unfortunate that it has made its way into official policy in many countries and the EU.

Nativism is not an ideology that will serve forests or humans well going forward. Climate change is happening at an increasing rate and will become extreme in many parts of the world. Forests are incredibly important, both in mitigating and adapting to climate change. At the same time, they are often slow movers and slow to recover after disturbance. Sometimes they need help, which sometimes needs to be in the form of introducing provenances or species that are likely to be better adapted and more resilient than the local or native ones. Science, rather than ideology, should inform policy.

• Article originally published on the EUFORGEN website

Text: Throstur Eysteinsson, Director, Icelandic Forestry Service