THE DEGRADATION OF RAINFORESTS through felling for timber or to create land for agriculture has been going on for many years.
It is considered that deforestation contributes to around 20% of human-generated carbon emissions. And it is well known that mature rainforests are the biggest terrestrial store of carbon worldwide, hence the importance of maintaining them.
Cut them down and burn them and all that carbon goes up into the air, plus there is no forest left to capture further carbon from the atmosphere. Land turned over to agriculture comes a very poor second in terms of its carbon capture potential.
The encouraging thing is that this process is reversible and researchers from Holland and the USA have recently looked at the potential for rainforest regeneration and the effect that this has on removing carbon from the atmosphere.
They have published the results of their study in Nature magazine and it makes interesting reading. What it shows is that rainforests in the process of regeneration are able to sequestrate up to 11 times the amount of carbon from the atmosphere per hectare of land as old, established forests. The simple reason for this is that young trees grow more rapidly in order to maximise their utilisation of water, nutrients and above all sunlight. It’s basically a race to survive and requires a lot of carbon to build the biomass that gives them the edge over their competitors.
The research team has been working mainly in Central and South America and has produced a map of the carbon sequestration potential of the area. The map can be used to encourage policies to halt forestry in areas where the potential for regrowth is low, and also to encourage regeneration in those areas already cleared, where the conditions are favourable for rapid regeneration. It is these areas that will give the biggest and fastest carbon capture returns for the money invested.
Artificially regenerating rainforests is not a cheap option and in many cases, the study shows, is not necessary. Areas with relatively low levels of degradation can just be left to “get on with it” and will regenerate naturally if the young forests are protected from encroachment by grazing herbivores such as cattle and goats. In many areas this would be the best option and by far the cheapest.
Developing habitats
Regenerating rainforests isn’t just about carbon capture. Allowing new forest habitats to develop provides the environment for animals and birds to spread and, over time, join up with other populations. This encourages and maintains genetic diversity within a species which is essential for its long-term survival.
There is a lot of positive news on the overall change in attitudes to wildlife in many parts of the world and this was beautifully demonstrated recently when a grown leopard entered the grounds of a school in the Indian city of Bangalore. Fortunately it was not a school day but the situation was nevertheless very dangerous.
Some years ago I think the animal would have been shot without question but in this instance, and at great personal risk (several people were mauled, fortunately not seriously), the animal was eventually tranquilised and released in a wildlife sanctuary some distance away.
The fact that preserving the life of the animal took such high priority is of real encouragement. It is not that long ago that putting the skins of dead leopards and tigers on the floor as rugs was generally acceptable, indeed even considered desirable.
There is of course a long way to go and the problem of habitat loss and human-animal conflict is a major issue to be resolved.
But it does seem to be moving higher up the agenda with each passing year and I for one am hopeful that solutions will be found to all but the most intractable of problems.
