NARRATOR：

Now listen to part of a lecture on the topic you just read about.

FEMALE PROFESSOR：

You’ve just read about three ways to save Torreya taxifolia.

Unfortunately, none of these three options provides a satisfactory solution.

About the first solution, reestablishing Torreya in the same location.

That’s unlikely to be successful because of what’s happening to the coolest, dampest areas within Torreya’s microclimate.

These areas are being strongly affected by changes in the climate of the larger region.

This could be because global warming has contributed to an increase in overall temperatures in the region or because wetlands throughout Florida have been drained.

Either way, many areas across the region are becoming drier.

So it’s unlikely that Torreya would have the conditions it needs to survive anywhere within its original Florida microclimate.

Now, about the second solution, relocating Torreya far from where it currently grows.

Well, let’s look at what happened when humans helped another tree, the black locust tree, move north to a new environment.

When they did this, the black locust tree spread so quickly that it killed off many plants and trees in the new environment—and some of these plants and trees were themselves already in danger of becoming extinct.

So assisted migration can have unpredicted outcomes for the new environment.

Third, research centers are probably not a solution either.

That’s because the population of Torreya trees that can be kept in the centers will probably not be able to resist diseases.

For a population of trees to survive a disease, it needs to be relatively large and it needs to be genetically diverse.

Tree populations in the wild usually satisfy those criteria.

But research centers would simply not have enough capacity to keep a large and diverse population of Torreya trees, so trees in such centers will not be capable of surviving diseases in the long term.