Even environmentally conscious hikers are neglecting to clean their boots before heading for the mountains and thus may be introducing alien plants to the environment, according to a survey.

“Visitors' environmental awareness is significantly heightened but they do not take proper precautions,” said a member of the team of scientists from such institutes as the Tokyo University of Agriculture and Technology, which conducted the study.

As many people go climbing and trekking in autumn, mountaineers are being warned to be careful not to damage precious local ecosystems with seeds carried on the soles of their boots.

Each hiker is now supposed to reflect on their “acts” once again to preserve the mountains’ original natural surroundings.

The research team this past summer released the results of its survey examining individuals who came to the Chubusangaku National Park, which is home to the Tateyama mountain range, and straddles Toyama, Nagano, Gifu and Niigata prefectures.

The gap between ideal and reality was underscored when about 350 people were asked about non-native species brought in by visitors from other places.

A total of 93.3 percent of respondents described the invasive variants’ impact as “very” or “relatively” problematic. Those who said they know the possibility that people’s movements can lead to introducing non-endemic species elsewhere accounted for 81.4 percent.

Despite all that, only 3.8 percent said they suitably cleaned their boots before entering mountains to protect the environment. Even if individuals who spruced up their shoes for maintenance and repair purposes are included, the ratio was 43.9 percent.

Looking into the soil sampled from their soles, the team found six alien variants that should not be found in Tateyama among 27 of the surveyed people. The collected seeds of sticky chickweed and other such species that retained the ability to sprout totaled 44.

Even plants and animals native to Japan are considered as non-native when they are introduced into areas outside their habitats. It can be said that the findings underline the risk of hikers and others helping spread alien species.

PREVENTIVE MEASURES BEING TAKEN

To stop invasive varieties from becoming settled, Chichijima and Hahajima islands in the Ogasawara island chain off Tokyo, a UNESCO World Natural Heritage site, have visitors step on special mats to purify the bottom of their shoes when boarding and disembarking from ferries.

Some national parks managed by the Environment Ministry alike set up mats and brushes to remove dangerous species at the entrance to mountains and other spots.

“It may be difficult to pay enough attention to one’s own soles while traveling in town, but we would like people to be wary of your soles when going to the World Heritage sites, national parks and other locations home to valuable ecosystems,” said a ministry representative, calling for the use of anti-invasion gimmicks.

With support and cooperation of volunteers, many national park operators are getting rid of introduced non-native plants as well, though they are still struggling to contain invasive species’ spread or eradicate as many as realistically possible.

TOURISTS TO MT. FUJI ASKED TO HELP

Proliferation of invasive botanical variants poses an especially serious problem on Mount Fuji, where more than 200,000 hikers show up annually.

Dandelion and lance-leaved tickseed, a designated invasive alien species, combined with many other non-native plants, have been spotted in wider areas around the fifth station and along the Mount Fuji Skyline road, where many people pop up, over the last few years.

As a result, indigenous botanical varieties are driven out of their habitats.

The Fujisan Network, a group working to conserve the environment on Mount Fuji, sends local volunteers on two to three occasions a year to clear the mountain of invasive plants.

Those plants are removed with their roots with such tools as shovels. The participants’ shoe bottoms are cleaned, while used cotton work gloves and other tools are discarded after the cleaning operations.

However, invasive plants have yet to be eradicated, because some seeds and roots remain. Another reason for this is that non-native species are constantly being brought in.

An official of the Fujisan Network’s secretariat noted raising visitors’ awareness of the issue is essential likewise to overcome the challenge, admitting that killing off all the invasive species “may be difficult.”

“Leaving the plants just as they are will result in their quick spread,” said the official. “People’s ability to distinguish alien variants is needed for their early detection.”

For that objective, the Fujisan Network is making efforts, including distributing a handbook on non-native plants, to seek help from tourists.

In a similar attempt, local tour provider Grandeco Resort included a cleaning drive in its trekking package to visit the Goshikinuma ponds in the Bandai-Asahi National Park, which sits on the border between Fukushima, Yamagata and Niigata prefectures.

Cut-leaf coneflower, which is designated an invasive alien species, thrives around Goshikinuma. The variety stands tall, threatening shrubs’ growth and exerting other negative effects.

Working with local officials, Grandeco Resort started a verification experiment for the new tour in September.

“We hope participants will not only enjoy the beautiful landscape but also go a step forward to gain a deeper insight through the cleaning campaign in order to increase their environmental awareness,” said a Grandeco Resort representative.

HIKERS ASKED TO CHECK BOOTS

What precautions should sightseers take in particular so they will not deliver invasive species to mountains via their boot soles?

According to Munemitsu Akasaka, an associate professor of conservation ecology at the Tokyo University of Agriculture and Technology, who specializes in alien plant species and biodiversity conservation, an effective countermeasure is confirming whether one’s shoes are free from mud or seeds.

As mountaineering boots have taller lugs on the ridges of their soles than those of sneakers, seeds and other objects are more easily caught between them.

Small difficult-to-find seeds could remain on the soles, so what is important is watering and brushing the shoe bottoms at home before going to mountains.

Not returning home with alien species is as significant as visiting natural environments free from non-native plants. Worn boots should be washed as soon as possible after descending from peaks.

“The acts of each individual will determine whether the biodiversity can be preserved,” said Akasaka. “People should deem the issue as their own problem first of all to take the maximum possible countermeasures. Cleaning hiking boots is among the options.”