Friday, May 16, 2008

New research from Australia: agroforestry and reforestation are an important carbon sink

There is an ongoing debate on the effectiveness of trees planting operations as a tool mitigate global warming. A new research from Australia adds more input into it, showing that agroforestry and reforestation are an important carbon sink.

The research, as reported on The Age, was conducted by researchers from Meat & Livestock Australia (MLA), Queensland Climate Change Centre of Excellence, and Queensland Department of Primary Industries & Fisheries. It was presented to an agriculture, greenhouse gases and emissions trading conference on the Gold Coast.

Dr. Beverley Henry from MLA, who presented the research, showed that different forms of land management had a variety of effects on soil carbon. She said, according to the article, that researchers, analysing data from 74 publications on land-use changes, had made several conclusions:

A change from native forest to crops decreased soil carbon by 42%; pasture to crop (59% decrease); native forest or pasture to broad-leaved plantation (no big change); native forest or pasture to pine plantation (12-15% decrease); native forest to pasture (8% increase); crop to pasture (18% increase); crop to secondary forest (53% increase); and crop to pasture (19% increase).

Some of the conclusions of the research presented by Dr Henry were:
  • Introducing cropping into uncleared land or pasture in good condition decreased soil carbon.
  • There was thus potential to sequester carbon in soils if cropping lands were converted to pasture or forest.

  • Conservation tillage practices might retain up to 25% more carbon in soils than conventional tillage.

  • Removing grazing pressure would in theory be expected to improve below-ground carbon stocks. However, under low disturbance regimes, grasses may become moribund, producing less root biomass.

This is only one research out of many researches that focus on this important issue, but it definitely gives some interesting input to think about when coming to plan how to fight global warming most effectively.

In any case, we have to remember that the value of tree planting operations, such as the the UNEP planting campaign, which as we reported set a goal of having 7 billion trees planted by the end of 2009, is not just because of carbon sequestering. Trees are one of the most important natural resources we have and have many other significant benefits, such as decreasing the chances for natural disasters such as floods, protection of important water resources, reduction of soil erosion, etc.

Raz @ Eco-Libris

Eco-Libris: plant a tree for every book you read!

Picture Courtesy of Sustainable Harvest international

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