Over The Horizon

Bringing High-altitude Moss Down

Scientists have recreated typical Indonesian climatic conditions in a New Zealand laboratory as part of a major environmental project in Irian Jaya. HortResearch scientist Jill Stanley and colleague Rowan Buxton from Landcare are looking at the possibility of using moss to help return land affected by copper mining to its natural state.

Field trials are being carried out 2,200m above sea level at the mine, but the scientists are also using the National Climate Laboratory at Palmerston North to fast-track the project.

The computer-controlled Climate Lab can replicate conditions from sub-Antarctic to tropical at the touch of a button, so weather conditions at the mine posed no problem. Despite being near the tropics, high altitude brings the ambient temperature down, light levels are low and there's rain almost every day.

The mine operators, PT Freeport Indonesia, are committed to restoring 2,000 acres to natural native vegetation but the rock-strewn ground is low in nutrients and organic matter, so revegetation is difficult and slow. Transplanting native species is time consuming and there is a low survival rate.

Mosses are often the first plants to establish on the surface and other plants grow up through them. PT Freeport Indonesia thought it would be a good idea to deliberately establish mosses in an attempt to speed up the revegetation process.

The Climate Lab trials will help to establish protocols for speeding up moss development. Samples were sent from Irian Jaya and planted out in the lab. So far a number of species have shown good early growth on a number of rock types and there are indications that application of phosphorus encouraged moss growth.

"The fast growth on some plots is very encouraging," says Stanley. "The fact that trends are already emerging suggests we are on track for selecting a restricted number of protocols for moss revegetation for field testing at the end of this trial.

"It appears that there may be interactions between individual moss species and the fertilisers, propagation methods and covers used. These interactions will need to be considered carefully when combinations are selected for each rock type."

The New Zealand scientists visited the mine last year to see experimental plots and also to visit nearby glaciers.

"It was the most exciting field trip I've ever had," says Stanley. "It's important and interesting work. If we can help to restore the landscape then that's a very positive thing."