A New research has found that on average, about half of trees planted in tropical and sub-tropical forest restoration efforts do not survive more than five years, even though there is enormous variation in outcomes.
About 15% of the world’s tropical forests are said to be found in Southeast Asia and they are amongst the most carbon-dense and species-rich in the world, providing habitat for tigers, primates and elephants. But in recent decades, the region has also seen major deforestation, with forest cover reducing by an estimated 32 million hectares between 1990 and 2010.
The study which analyzed tree survival and growth data from 176 restoration sites in tropical and sub-tropical Asia where natural forests have suffered degradation, found that, on average, 18% of planted saplings died within the first year, rising to 44% after five years.
It, however, found that survival rates were different amongst sites and species, with some sites seeing over 80% of trees still alive after five years, whereas at others, a similar percentage had died.
Findings from the study further showed that forest restoration is a powerful tool to tackle biodiversity loss and climate change, by locking away carbon and supporting important habitats while reforestation projects are also used widely for carbon offsetting.
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The research showed that many of these trees are not surviving long-term, while the main measurement used for many projects is the number of trees initially planted. In some sites, survival rates were high, showing that with the right approach, restoration has the potential to be successful.
The study team also found that when an area had been fully deforested, reforestation efforts were less successful than in areas where some trees remained and that saplings planted in areas with existing mature trees had roughly a 20% higher chance of survival. In areas that are frequently disturbed, however, more intensive measures for protection and maintenance may be needed.
Furthermore, the study found some evidence that active restoration provides faster results than simply letting nature take its course even as sites which included tree-planting activities gained forest cover more quickly than sites which were left to regenerate naturally.
Stoey was adapted from Phys.org
