In the fight to conserve tropical rainforests, here’s a tool you don’t often hear about:orange peels. Specifically, 12,000 tons of them, dumped (倾倒) on the land. “You don’t usually associate waste treatment with biodiversity benefits, something that’s good for the environment.

Tim Treuer is an ecologist at Princeton University. and he’s talking about a unique conservation story. It started in the early 1990s, when an orange juice producer cal led Del Oro set up a company near the Guanacaste Conservation Area in Costa Rica, a region that contains several national parks and a widlife protection zone.

Del Oro needed somewhere to dump the orange peels, and the company also owned forested land next to the parkland that it had no intention of growing crops on. So a deal was struck: if Del Oro donated its forested land, it could dump orange peel waste on degraded(退化的) land within the conservation area. Then a thousand dump trucks’ worth of orange peels were lying on the land in 1998. “And within about six months the orange peels had been turned from orange peels into this thick black rich soil.”

“I couldn’t even find the site the fist time I saw it.” He couldn’t find it because, over 16 years, the orange peel waste had sent the land on a journey to become a vine-choked jungle, with three times the diversity of tree species of the neighboring control plot, richer soil and a much thicker covering. In other words, the experiment was a success. The results appear in the journal Restoration Ecology.

Treuer says perhaps this lesson could be applied elsewhere. “It’s a shame that we live in a world with nutrient-limited degraded ecosystems and also nutrient-rich waste streams. We’d like to see those things come together a little bit. That’s not license for any agricultural company to just start dumping their waste products on protected areas, but it does mean that land managers, people involved with industrial-scale agricultural operations should start thinking about ways to do thoughtful experimentation to see if in their particular system they can have similar win-win-win results.”

The air is thin and we have to rest several times on the shore hike from camp. To our left, snow-covered mountains disappear into clouds that seem almost close enough to touch. On the plain in front of us, we can just make out a herd of graceful animals. This is why we stay here.

Tibetan antelopes live mainly on the plains of Xizang. Watching them move slowly across the green grass, I'm struck by their beauty. I'm also reminded of the danger they are in. They are being hunted illegally for their valuable fur.

My guide is Zhaxi, a villager from Changtang. He works at the Changtang National Nature Reserve. The reserve is a safe place for the animals and plants of northwestern Xizang. To Zhaxi, protecting the wildlife is a way of life. “We're not trying to save the animals,” he says. “Actually, we're trying to save ourselves.”

In the 1980s and 1990s the population of Tibetan antelopes dropped by more than 50 percent. Hunters were shooting antelopes to make money. Their living places were becoming smaller as new roads and railways were built.

In order to save Tibetan antelopes, the Chinese government placed them under national protection. Zhaxi and volunteers watched over the antelopes day and night to keep them safe from attacks. Bridges and gates were added to let the antelopes move easily and keep them safe from cars and trains.

The measures were effective. The antelope population has recovered and in June 2015, the Tibetan antelope was removed from the endangered species list. The government, however, does not intend to stop the protection program since the threat to the Tibetan antelope has not yet disappeared. Only when we learn to exist in harmony with nature can we stop being a threat to wildlife and to our planet.

REDUCING WATER POLLUTION IN THE LI RIVER

The beautiful Li River and its amazing surrounding scenery is one of the most well-known tourist destinations in China’s Guangxi Zhuang Autonomous Region. It attracts millions of domestic and foreign visitors each year. However, its reputation as a top destination has had negative effects on the river’s water quality. This report looks at the problem of water pollution and some actions that have been taken to deal with it.

Previously, water quality in the Li River had suffered greatly from an increasing volumeof tourists, many of whom frequently threw garbage into the river. Many tour boats contributed to the problem too. Kitchens on board were using lots of oil, which was often thrown into the water. The growth in tourism also meant the local population rose rapidly, as well as the number of commercial and industrial enterprises. Water pollution levels increased, with more household and commercial waste ending up in the river. In order to feed more people, more chemicals were used to increase crop production. These chemicals led to severe water quality issues, causing a decrease in the number of fish species. Local officials were concerned that the pollution was damaging the natural environment and felt that urgent steps should be taken to restore the river’s original beauty.

A comprehensive initiative was started, with a number of measures that addressed the issues. The construction of waste water treatment facilities improved the water quality and water conservation. The collection and transport of household waste was also improved. Dozens of polluting enterprises were closed or moved. The local government set up strict regulations regarding further industrial development. New rules were also introduced regarding tour boat routes and garbage disposal methods. Furthermore, the local authorities began to use the media to spread environmental awareness and encourage greater use of clean energy. At the same time, they started to carry out inspections regularly and fine tourist organisations for abuses. With these measures, it is believed that the beauty of the Li River will be preserved for generations to come.

In addition, the ambitious “Water Ten Plan” is also now tackling water pollution across the country. Other initiatives, such as the “River Chief System”, hold senior officials responsible for reducing water pollution. With such campaigns in effect, China’s waterways are heading towards a clean and sustainable future.