(This is the seventh in a 10-part series intended to look at some of the issues surrounding Guyana’s bid for funds from the World Bank-administered Forest Carbon Partnership Fund (FCPF) and from Norway, and for the President’s Low Carbon Development Strategy.)
By Janette Bulkan
In the last article I looked at uncertainties in the weight of carbon in the standing forest of Guyana. In this article I will look at the more difficult estimation of the gains and losses in carbon sequestered in our forests. Apart from the obvious physical difficulties in estimating changes in biomass from one time period to the next in remote, muddy, wet forests, there are mathematical problems in estimating relatively small changes when the standing stock (or “carbon capital” in money terms) is itself not easy to estimate with accuracy or precision – accuracy being a measure of how closely we approximate to the true value, and precision being our ability to repeat measurements and obtain the same or nearly the same answer each time.
David Hammond, former director of research at Iwokrama, said “With only small quantities of nutrients to be gained through atmospheric deposition, rock weathering, fluvial deposition and biological fixation, conservation through adept internal cycling appears to be the only plausible mechanism sustaining standing forest biomass across most parts of the Guiana Shield” (Tropical Forests of the Guiana Shield: ancient forests in a modern world, 2005, page 355). In other words, with so little plant nutrients available, the scope is very limited for growing trees faster or growing more trees per hectare. Without inputs of nitrogen, phosphorus, calcium and other elements needed for plant growth, having abundant sunshine and a good supply of water does not lead to denser forest or more carbon per hectare. Experiments in other tropical rain forests have shown that they can respond positively to inorganic farm-type fertilizer applied “from the bag” but this is not financially worthwhile outside a plantation context.
Simple observation shows that trees do not continue to grow in size for ever, nor do forests become denser and denser without limit. There are natural limits determined by the genetic potential of the trees and by the restricted supplies of plant nutrients and water which the tree roots can access. In a natural forest, undisturbed by human activity or natural disasters such as windstorms or accidental fires, a steady state is reached in which the natural gains in carbon fixed by photosynthesis and net of respiration are balanced by natural decay and death of trees.
A multi-country study – the Amazon Forest Inventory Network (RAINFOR) – has since the mid-1970s shown that catastrophe affects intact Amazonian forests only very rarely and apparently at very long intervals. However, rainforests which have been logged, and especially those which have been repeatedly logged at short intervals, become much drier at ground level and much more susceptible to fire damage. In Guyana, this is exemplified by the poorly managed and much burned wallaba (Eperua falcata) forests on the white sand soils in the Intermediate Savannas of Berbice.
Gains in forest carbon
Mostly, in intact Amazonian rainforests, trees die and decay singly or in small clumps, and annual growth balances annual death and decay. But RAINFOR now shows that Amazonian forest growth has apparently increased in the last three decades, giving us an extra 0.45 tonnes of carbon per hectare per year (tC/ha/yr). Exhaustive checks across this network have shown that this is not an artifact of measurements or calculations but a real increase found on ¾ of the study sites, including the four sample plots in Guyana which contribute to RAINFOR. The severe drought in 2005 which affected much of Amazonia caused a sharp reduction in this extra growth and a sharp increase in tree mortality, especially of the trees with lower wood density.
The Guyana Forestry Commission (GFC) well recognizes the difficulties of estimating standing stocks of carbon and dynamic rates of change. In its R-PLAN proposals to the World Bank’s Forest Carbon Partnership Fund, the GFC is requesting funding for a great increase in its forest monitoring capability. This would include the establishment of 900 sample plots distributed across Guyana, to be repeatedly measured. Unfortunately, the GFC has proved incapable of taking over, using and protecting the 52 plots established by the Edinburgh Centre for Tropical Forestry on contract to Barama in the early 1990s (plots now allegedly lost because of illegal logging or mining damage) or the Pibiri observational and experimental plots at Mabura established during the University of Utrecht and Tropenbos exercises over 15 years from the mid-1980s. It is thus unclear how the GFC would cope with such a large new programme.
This is not to doubt the potential value of such a sample plot programme to evaluate forest-based carbon emissions, among many other objectives, or the technical soundness of the sample plot plan devised by consultant Denis Alder.
Apart from this unexpected natural increase in sequestered forest carbon, what carbon-stimulating activities have been undertaken by the GFC?
► afforestation (new forests where forests have not grown naturally in the past)? – No.
► reforestation (replacement of previous forest)? – No.
► silviculture (making trees grow faster, or survive longer)? – No.
Losses in forest carbon
What does the GFC do to reduce loss and wastage of carbon?
► increasing the wind resistance of forests? – not relevant. Guyana is south of the paths of Caribbean hurricanes.
► decreasing susceptibility of forests to fire? – the main way is to reduce tree damage during felling and logging and consequent piles of drying wood which could catch fire during lightning strikes or arson in the forest. The GFC’s Code of Practice for Timber Harvesting (second edition, November 2002, and available on the GFC website) is not obligatory because the GFC failed to amend the Forest Regulations 1953 to make it so. Nor, in spite of Ministerial promises since December 2006 about recruiting 50-60 new Forest Rangers (see Guyana Chronicle, February 28, 2009), has there been any public evidence of improved logging practices or less wastage by concession holders and their contractors. This is not surprising as Guyana’s forest taxes continue to be among the world’s lowest, in spite of over 15 years of external recommendations for increases at least to cover devaluation by inflation. So the GFC, responsible for administering the State Forest on behalf of the citizens, is almost giving away the public property, including the forest carbon, free of charge; the best timbers are forest-taxed at c.US$ 4 per cubic metre, when the CIF landed price for logs of equivalent timbers in Asia is US$ 750 per cubic metre.
In my next article I will continue to explore the carbon losses from Guyana’s forests.
