A TEAM of ecologists and statisticians trolling through scientific observations collected in the past 20 years has revealed startling developments since farmers first teamed up with Landcare and Greening Australia to plant and preserve native trees on farmland across Australia.
Increased crop yields, better lamb survival rates and carrying capacity and biodiversity increases beyond expectations are just some of the benefits.
The findings have bolstered the scientific community’s belief that selective protection of remnant forest and planting new trees has clear economic benefits for farmers.
And it’s no mystery to farmers, who have watched the progression while new trees mature and patches they’ve fenced off grow and age.
One of the ecologists involved, Damian Michael from the Australian National University, said that systematic monitoring had revealed better economic outcomes for farmers was the most exciting benefit.
Dr Michael is part of a an ANU team lead by Professor David Lindenmayer that includes a team of post-doctoral researchers and statisticians who have spent the better part of two decades monitoring sites across the country.
Now, all the visits to tip over bits of tin, old railway sleepers and roofing tiles, the hours spent collecting hair follicles and noting different scats, the days monitoring bird numbers and interviewing farmers have added up to a story of success.
“What we’re seeing is big increases in canola yields because of insect populations blossoming, a increase in bird populations following the insects, the return of reptiles and all stock benefiting from the extra cover and a diversity of native grasses making a comeback,” he said.
“Farmers need to make money, not only for themselves but for the future of global food security, and these are very, very encouraging indications we’re on the right track.”
Gundagai farmer and former Nuffield scholar of environmental stewardship Sam Archer has seen the results for himself.
Farmers need to make money, not only for themselves but for the future of global food security, and these are very, very encouraging indications we’re on the right track.
He said the team has been monitoring sites on his place since early 2000 and about five years ago the data collected began to show strong trends of increased biodiversity and accompanying improved economic performance.
But it wasn’t anything he hadn’t seen for himself on his property ‘Kincora’.
“We had an area of about 40 hectares and we saw saline discharge lower in the landscape and so we planted trees higher up.
“If we had let it go as it was we would have had all sorts of problems that eventually would have resulted in erosion of the paddock.
“At the time the land was carrying one sheep to the acre.
“But we planted the trees and excluded stock for three years and in that time we’ve doubled our carrying capacity,” he said.
Mr Archer said during those three years native perennial grasses had returned and set seed.
“Now we have a great seed bank high among the trees and gravity is taking care of the rest,” he said.
The return of the natives microlaena stipoides, which populates cooler slopes and red grass in warmer areas had net benefits to his farm, he said.
“These are perennial grasses that respond to any rain event and they are good feed.”
The Primary Industries Department backs up Mr Archer, describing microlaena as tolerant to acid soils, drought and frost and giving livestock 10 to 27 per cent crude protein in a highly digestible form (55 to 80 per cent).
“We’re showing we can recruit native pastures,” he said.
Mr Archer is extremely enthusiastic about the results and where his farm is going.
“One of the greatest impediments to change is a lack of demonstrated success, but here is the data we need to show there are economic benefits.”
The ANU’s Dr Michael said not only were lamb survival rates bolstered by shelter from trees, but there was clear evidence they were gaining weight faster grazing around tree lines and remnant forest patches.
He said patches, or “islands” in paddocks of 30 metres wide had demonstrated the best results for biodiversity increases.
But a really encouraging finding had been that trees planted along transecting fence lines, helping to reduce fencing costs, had the same result as a 30m wide planting.
Dr Michael said there were many more benefits becoming evident from their studies.
He said anecdotal evidence from farmers suggested there had been positive mental health outcomes as a result of having green outcrops in what were inevitably at times drought-affected zones.
And he said populations of birds, such as the vulnerable superb parrot, were vigorously increasing in areas where they hadn’t been seen for years.
Mr Archer says an initial investment in the landscape is required, but then nature takes care of the rest.
He speaks of the “triple bottom line”, an increase of financial capital, social capital and natural capital.
“We’re co-locating economic and environmental outcomes, we’re sequestering carbon, increasing habitat, mitigating erosion and bolstering organic matter in soils.”
- See Cowra tree planting project, p41