It is a common practice in many third world countries to burn down forests and then use the tract of land which has been cleared for agriculture. But is it possible to reforest the tract after the agricultural land has been abandoned after the nutrients of the soil has been dried up? Well yes and it is the trees which will be doing it. Researchers have discovered that trees can switch on their ability to fix Nitrogen from the atmosphere with a little help from the Rhizobium bacteria. This finding has a huge implication on the ongoing projects of reforestation on denuded lands. It will also have a huge impact on the global warming.
A study was carried out on a square mile area of the Panama Canal watershed where the forest was recovering after clearing activities. Different land use options were studied and the carbon storage, runoff and biodiversity were carefully monitored. A comparison was made between mature tropical forests, native trees in forest restoration plots and abandoned pastureland.
Jefferson Hall, one of the researchers, said, “This is the first solid case showing how nitrogen fixation by tropical trees directly affects the rate of carbon recovery after agricultural fields are abandoned. Trees turn nitrogen fixation on and off according to the need for nitrogen in the system.”
It was observed that trees which were able to fix the atmospheric nitrogen were also able to add carbon nine times quicker than ordinary trees. In fact Nitrogen fixing trees were able to add 50,000 kilograms of carbon per hectare during the first 12 years of growth.
Tropical forests act as carbon sinks drawing away carbon from the air. As the scourge of the Global warming increases it is important that freed land which has been denuded by industrial or agricultural use be quickly repaired and reforested. Nitrogen fixing trees will help to quicken the pace of reforestation.