Mountain plants are not safe from rapid climate change

Plants perched high on mountain slopes often seem untouchable. Many people picture these hardy survivors persisting no matter what the world throws at them.

Jill Anderson from the University of Georgia (UGA) led a nine-year study that tracked more than 100,000 Drummond’s rockcress plants (also known as Boechera stricta), which are short-lived and grow in the mountains of North America.

The findings show that climate change is accelerating so quickly that natural processes struggle to keep up, putting even these widely distributed plants at risk.

Mountain plants face unexpected threats

Some assume that cool alpine air insulates species in higher elevations. Yet these peaks are not immune to changing weather patterns, which shift temperatures and snowpack conditions.

Scientists use the term montane to describe mountainous regions where cold temperatures shape plant and animal communities. In these settings, species must cope with short growing seasons and sudden weather swings.

Local adaptation under threat

Many species across large geographic ranges show local adaptation, meaning each population is especially fit for its specific climate. A plant growing at one elevation may thrive in cooler settings, while relatives at lower altitudes prefer warmer days.

When warming speeds up faster than these populations can adjust, their specialized genetic traits can become a burden.

Scientists have warned that climate change may shrink viable habitats before plant populations can produce new traits or spread existing genes to more favorable locations.

Gene flow in the wrong direction

Natural gene flow is the mixing of genetic material between populations when seeds or pollen move across different areas. In mountain landscapes, genes often travel downslope, which can be a problem when populations uphill need genes adapted to warmer conditions.

Once temperatures ramp up, plants at higher elevations may lag behind in acquiring the beneficial traits found at lower sites. Many experts believe that if gene flow continues to flow in the wrong direction, certain populations will lose out.

Local mountain plants are not safe

Many mountain plants live in narrow climate zones. Even small temperature changes can force them to move if suitable conditions shift uphill.

Furthermore, relocation can be slow. Limited seed dispersal and competition for newly available terrain make uphill migration a difficult gamble.

In the Colorado Rockies, researchers tested how these plants fare when the snowpack is manipulated to reflect varying future scenarios. Conditions mimicked both historical climates and predicted warmer settings.

Their data showed that populations already adapted to local sites were not safe just because they fell within the broader species range. As the weather changed, those local advantages vanished.

Why gene flow alone is not enough

If some high-altitude plants cannot access the genetic diversity they need, their survival chances drop. Rising temperatures also move faster than seeds can scatter uphill.

It is possible that downhill gene exchange will leave upper populations stuck with less-suitable traits. Over time, that mismatch poses a real problem for any species in a fast-warming world.

Researchers suggest assisted gene flow, which involves moving seeds or plants from warmer-adapted locations to cooler zones. The aim is to insert heat-tolerant genes into colder populations before it is too late.

Such action requires careful planning to avoid harming the resident community. It can help maintain enough genetic variation for future climate scenarios.

Mountain plants may not adapt in time

Sally Aitken, a professor at the University of British Columbia, elaborated on the research in a related perspective.

“The lessons from Anderson et al. are sobering with respect to the ability of natural populations to adapt to, and persist under, rapid global warming,” she wrote.

This warning echoes broader concerns that standard models often miss how real populations respond. Simple range maps do not reveal the underlying genetic limits that influence whether plants can hang on.

Implications for conservation

Some protected areas might not serve as reliable safe havens if warming outpaces adaptation. That’s especially worrisome for species already confined to mountaintops, where there is nowhere higher to go.

Those who manage conservation efforts might include assisted gene flow when other approaches are too slow. But balancing interventions with natural processes is tricky business.

Plants form the backbone of many mountain ecosystems. If they fade away, pollinators and seed-eating animals lose vital resources.

Such ripple effects can spread downhill, affecting everyone relying on mountain watersheds for irrigation and drinking water. Decreased plant cover can alter soil stability, which influences runoff and erosion patterns.

Some species will need a helping hand

There is no universal fix. Solutions must address local challenges and take into account how quickly climates are shifting uphill.

Short-lived species can adapt quickly under the right conditions, but only if gene flow and the environment align. That makes thoughtful conservation choices even more urgent.

Some plants will persist if we reduce greenhouse gas emissions and give them time to adjust. Others may need a helping hand when relocation or genetic mixing becomes their best option.

Experts believe that mountain environments could lose more species if assistance does not arrive. Adaptive capacity has its limits when conditions change too fast.

The study is published in the journal Science.

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