Finland Weighs Risks of Introducing Non-Native Species for Climate Adaptation

As Finland grapples with climate change, authorities are urgently seeking new adaptation strategies. While adapting to changing conditions, plants, animals, and other organisms are also responding to the warming climate, with species' ranges potentially shifting northward.

One proposed adaptation measure in agriculture and forestry is the introduction of southern crop species. For instance, Douglas fir is being considered as an alternative to Norway spruce, which is susceptible to climate change-exacerbated pests. Douglas fir grows faster, tolerates drought, and is less appealing to bark beetles. However, it is vulnerable to diseases like *Phytophthora lateralis*, which has already caused damage in Central Europe and now threatens drought-stressed pines and junipers in Finland.

The introduction of non-native species, whether to forests, fields, or gardens, is inherently risky. Species brought in for beneficial purposes can evolve into harmful invasive ones, carrying their own ecosystems of microbes and fungi. These new arrivals can also create pathways for new plant pests to spread.

Plants moved beyond their natural range or to its limits are particularly susceptible to pests. When their defenses are weakened, they can provide an environment where pest populations best adapted to the local conditions can thrive and spread. The article advises caution when utilizing species of foreign origin in primary production, green construction, and even hobbies.

While using southern species and varieties might be economically attractive or necessary for drought-resistant crops, the risk of unintentional spread must be considered. Finland has identified several new non-native pest organisms in the 2020s, including pathogens found on ornamental pines and in pine nuts sold as bird feed. Pests can also be transported via imported bulbs, fruit tree saplings, and ornamental plants, posing a continuous threat.