Changing Needs and Changing Policies in Tropical Forest Management

CIFOR scientists are working alongside Brazil nut harvesters to measure the production of Brazil nut trees and determine the impact of selective logging. Marco Simola/CIFOR
CIFOR scientists are working alongside Brazil nut harvesters to measure the production of Brazil nut trees and determine the impact of selective logging. Marco Simola/CIFOR

B-09B: What is the Future for Tropical Silviculture?

 

When it comes to forest management, the future of tropical forests is a high priority concern. However, the diverse demands for timber, biodiversity, non-timber products, and water quality are often at odds with one another. In order to ensure not only that these demands can be met, but also that they can continue to be met in the future, it’s imperative that management strategies properly account for multiple uses.

As Martin Mendoza emphasized, many of the traditional forestry goals have changed. There’s now more value being placed on non-timber services that forests can provide. While multi-use forestry is becoming the goal, putting it into practice can be difficult. Additionally, the diversity of forest types in the tropics means that generalized management strategies are likely to have flaws.

Sven Guenter reported that in Ecuador national forest inventories designed for REDD+ are often  in conflict with the needs of sustainable forest management.

In a large scale study of dry forests in Ecuador, he found that although dry forests did not have high potential in terms of timber harvest, there were non-timber values in these forests that were not being considered. This puts these forests at risk of being under-valued and marginalized when compared to humid forests. Guenter argued that dry forests may be more important in terms of preserving biodiversity than in sequestering carbon or providing timber, and that management in these types of forests should focus on ecosystem services, non-timber products, and increasing the area of protected lands.

Sheila Ward, on the other hand, spoke from the timber perspective. Her focus was on how best to balance the increased demand for timber production with the increased demand for tropical forests to sequester carbon. She investigated which high-value tropical timber species sequestered the most carbon by determining the average percent carbon in each species. Among the high-value species examined, each tree contained, on average, 85 to 100 kg of carbon, with  about 50 percent of that carbon captured in wood products.

Most of the carbon in the studied forests was contained in the larger diameter trees (>30cm DBH).  At the forest level, Ward found that greater tree species diversity promoted greater above and below ground carbon sequestration. She suggested that to maximize both timber value and the carbon sequestration, longer cutter cycles should be used that would allow the growth of larger trees, and that area-cover, as well as the post-harvest life in wood products, should be maximized.

While timber remains the primary forest commodity, it is important to recognize the potential of non-timber forest products. Manuel Guariguata spoke about the potential for an integrated system in Brazil in which timber and Brazil nuts could be extracted from the same concessions.  In the past, forests in Brazil were segregated into timber concessions and Brazil nut concessions, but the presence of valuable timber within the Brazil nut concessions put pressure on the government to allow some timber harvesting within these areas.

The goal of Guariguata’s research was to determine if there was an impact of selective harvesting on Brazil nut production. In a study of 499 randomly selected Brazil nut trees, he and his colleagues measured the number of fruit per tree, the total fruit weight per tree, and the distance to logging gaps. He concluded that there was no effect of timber harvesting on Brazil nut production and that the two seemed to be compatible within the same forests. However, he warned that there are still unknown thresholds that need to be determined.

Forty percent of the earth’s total carbon stocks reside in tropical forests. The future of tropical forests is a global issue, and the impacts of mismanagement could be widespread. This makes these forests both a huge resource and a huge risk. Understanding the biological complexity of these ecosystems and the diverse demands put on them will be an extremely difficult, yet necessary task in the coming years.

Written by: Allison Chan

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