September 24, 2013
“Best practice” tree planting that considers more than just the carbon in trees is needed if the full benefits of trees in the landscape are to be realised by farmers, landholders, and the community, according to the CSIRO.
Tree plantings in rural lands have significant potential to remove carbon dioxide from the atmosphere but, if done well, can also provide a stream of other benefits to farmers, local communities and the environment.
“By revegetating unused, marginal or degraded cropping land, using multiple species of trees and shrubs, we could see improvements to pest control, pollination and water quality, increased wind protection and reduced soil erosion and salinity,” Dr Brenda Lin, from the CSIRO, said.
“For example, we know that remnant native vegetation patches that currently persist in agricultural landscapes, if they are well managed and contain few weed species, support a range of insect and spider predators and parasitic wasps that can attack grain crop pests.”
The benefits for local communities and the public could include increased water quality, reduced pesticide use, more habitat for species such as birds, and other cultural benefits.
“Schemes which offer economic incentives for growing trees for carbon present an opportunity to reverse trends in land clearing,” Dr Lin said.
But if done properly, she said they could also restore ecosystem services – such as pest control, pollination, soil and water conservation – that provide important benefits to farmers and the broader community.
“The ability of carbon tree plantings to restore some of these other benefits that support agricultural production may be a key factor in encouraging farmers and landholders to take up this type of carbon farming,” Dr Lin said.
CSIRO land-use models have shown that policies aimed solely at maximising carbon storage may not produce these additional agricultural and environmental benefits and may even produce unwanted outcomes.
“For example, studies of past revegetation in agricultural landscapes show that in some locations intensive single-species (or monoculture) plantations can affect water flows, increase invasive pests and lead to biodiversity loss, be fire prone and have poor growth rates,” Dr Lin said.
“Poorly located vegetation could reduce the availability of land for food production.”
The research, published in the American BioScience journal, suggests future policies and initiatives encourage “best practice” tree plantings that maximize the positives while also storing carbon.
