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Species survival and carbon retention in commercially exploited tropical rainforest Ghillean T. Prance Phil. Trans. R. Soc. Lond. A 2002 360, 1777-1785 doi: 10.1098/rsta.2002.1041

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This journal is © 2002 The Royal Society


10.1098/rsta.2002.1041

Species survival and carbon retention in commercially exploited tropical rainforest By Ghillean T. P r a n c e School of Plant Sciences, University of Reading, Whiteknights RG6 2AS, UK Published online 27 June 2002

Since deforestation is one of the sources of carbon dioxide increase in the atmosphere, any measures that prevent or reduce the amount of forest removal are beneficial to the environment and to conservation of biodiversity. In recent years, there has been considerable research on the value of standing forests and many researchers have promoted the management of tropical forests as the best type of land use. On the other hand, the enormous diversity is a serious obstacle to management and use of tropical rainforest. A single hectare of forest can have up to 306 species of trees of 10 cm diameter or more. Here we present a brief review of some of the research and programmes that have tried to promote the use and conservation of tropical forest without clear felling. The sustainable use of the standing forest has usually been promoted as a means of species conservation; however, it is also a way to maintain the carbon fixed in the ecosystem. Here we review some of the pros and cons of extraction of non-timber forest products. Keywords: ecosystem value; rainforests; non-timber forest products; extractive reserves

1. Ecosystem services There have been many recent attempts to place a value on areas of tropical forest. Costanza et al . (1997) attempted to place a value on the whole world’s ecosystem and natural capital. They based their estimate on 17 different ecosystem services of 16 biomes and calculated a value of $16–$54 trillion (1012 ) per year, with an average of $33 trillion. This compares with a global gross national product of $18 trillion. Estimates like this that fall outside the market are hard to calculate, but it is appropriate to consider this vital aspect of value of ecosystem services before looking at a few, in comparison, very minor market-driven approaches to forest conservation. The ecosystems services used by Costanza et al . to make their calculations included gas regulation such as CO2 /O2 balance, as well as climate regulation and control of greenhouse gas. We should not underestimate the value of rainforest for the services as well as for the enormous genetic resources of its biodiversity. There might be more forest standing if an accounting had been made of the value of ecosystem benefits One contribution of 20 to a special Theme Issue ‘Carbon, biodiversity, conservation and income: an analysis of a free-market approach to land-use change and forestry in developing and developed countries’. Phil. Trans. R. Soc. Lond. A (2002) 360, 1777–1785

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before alteration. Purely on ecosystem service value, a non-use option is often more beneficial than the alternative use to which forest land has been put. The total economic value of ecosystems is discussed well in Pearce et al . (1989) and that of rainforests in Pearce (1990). In the latter, Pearce estimated that the indirect carbon credit due to a single hectare of conserved forest was $1300 in 1990. This was based on a value of $13.00 per tonne of carbon. Many aspects of nature’s services are summed up in Daily (1997). Ruitenbeek (1989) calculated the value of £5.8 million for the role of the Korup rainforest in Cameroon in supporting fisheries and in flood control. The proposed alternative land use was valued at slightly more than £3 million. Much deforestation could have been avoided if adequate cost–benefit analysis had been made prior to felling the trees. Any free-market approach to conservation must include much more than an analysis of the direct costs of, and profits from, forest products. Tropical forests must be valued for their role in carbon storage, flood control, watershed protection and many other ecosystem services.

2. Marketing and valuing rainforests During the past 15 years or so there has been much effort to place value on areas of forest and to promote the extraction of non-timber forest products (NTFPs). This has been motivated by the desire to conserve the standing forest rather than replacement by alternative systems. There is not space here to review this vast literature, but good summaries are given by Ros-Tonen et al . (1995), Richards (1993), the FAO (1991) and Panayotou & Ashton (1993). Much interest in the market value of standing forests was generated by Peters et al . (1989a) when they calculated a net present value (NPV) of $6330 per hectare for a forest at Mishana in Peru. This was based on an annual possible income of $697.79 from the extraction of latex, fruits and a limited amount of timber. Pi˜ nedo-Vasquez et al . (1990a) and many other authors have challenged this high estimate. Some of the constraints are (1) the fluctuation of commodity prices (the fall in rubber prices since that work was done is a good example), (2) the fact that most individuals and rural communities lack land tenure, and (3) decisions about use of land in the region are based on both subsistence and market-oriented considerations and the calculations did not allow for subsistence needs. This was followed up in greater detail by Pi˜ nedo-Vasquez et al . (1990b) in a study of use-values of tree species in a reserve in Peru. They found that 60.1% of tree species in their 7.5 ha sample were used, representing 66.4% of individual trees. Their study, based on the methods of Prance et al . (1987) used for indigenous peoples, did not attempt to place a value on the forest, but it did place a use-value index on all trees used. Pi˜ nedo-Vasquez et al . (1992) compared the economic returns from extraction of NTFPs with forest conversion to swidden agriculture. They concluded that rural populations of Amazonian Peru can be expected to continue converting forested land to swidden agriculture unless alternative land uses become more attractive economically. Phil. Trans. R. Soc. Lond. A (2002)


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At the other end of the Amazon, Anderson (1988, 1990) and Anderson & Ioris (1992, 1994) studied the use of forest in the Amazon delta region. Their study at Combu Island near to Belém is an example of highly profitable living from extraction of ‘hearts of palm’ from a¸ca´ı (Euterpe oleracea), cacao fruits and seeds, rubber latex and shrimp. This system works for a number of reasons: (1) proximity to a large market in Belém; (2) the high natural density of the palms in the ecosystem; (3) the stability of the local population; and (4) the high degree of forest conservation. The average annual household income of a family in 1989–1990 was $4195, which is far greater than other Amazon communities at that time (e.g. Florschutz 1983; Schwartzman 1989). Anderson is careful to point out that the study at Combu is under highly specific favourable conditions and cannot be used to make general extrapolations on the viability of harvesting NTFPs elsewhere. The a¸ca´ı market was further discussed in Smith (2001). One reason for success at Combu is the natural density of palm trees in the estuarine ecosystem. Peters et al . (1989b) termed this type of forest, where one or few species dominate, ‘oligarchic forests’. They gave several examples of these in addition to Euterpe-palm-dominated forests, where extraction is likely to prove economically profitable and sustainable: (1) Grias peruviana in Amazonian Peru (sacha mangua, see Peters & Hammond (1990)); (2) Myrciaria dubia (camu camu, see Peters & Vasquez (1987)) in the floodplain; (3) Orbignya phalerata (babassu, now Attalea phalerata, see Balick (1987)); and (4) Jessenia bataua (see Balick 1986; Balick & Gershoff 1981). Because the forests have dominant species rather than the more typical speciesdiverse rainforest (Gentry 1988; Prance et al . 1987; Valencia et al . 1994), they can generate viable economic returns from market-oriented extraction. Grimes et al . (1994) calculated the value of three hectares of primary rainforest in the Upper Rio Napo region of Ecuador, inhabited by Quijos Quichua peoples. They separately valued trees on an individual basis for productivity rather that at the per-species level of Peters et al . (1989a). They excluded trees that were too young to produce, too tall or dangerous to climb or non-productive. This meant that only 72 out of 105 trees of harvestable species were counted. They came to NPVs of $2939 and $2721 for upland forest plots and $1257 for a floodplain alluvial plot. This was compared with NPVs of less than $500 for agriculture, $188 for timber extraction and $57–$287 for cattle ranching 30 km from a good market in that area of Ecuador. Balick & Mendelsohn (1992) assessed the economic value of traditional medicines gathered in the rainforests of Belize. Their study suggests that the revenue from their two sample hectares was $564 and $3064, respectively. The NPV of $3327 ha−1 was Phil. Trans. R. Soc. Lond. A (2002)


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calculated on the basis of a 50 year rotation. Melnyk & Bell (1996) calculated the value of forest as a flood resource to the Huottuja Indians of Venezuela. The monetary value of the food they could gather from the forest compared favourably with revenue received from other land uses, timber extraction and working as labourers to earn money to buy food. Godoy et al . (2000) studied the use of rainforest by the Tawahlea of Honduras. They studied both consumption of food and sale of forest goods to establish a value of the forest. Their study falls at the lower end of those cited. They found the annual value of a hectare of rainforest to vary from $49–$1089. They suggested that at this low value the local people are more likely to clear forests for alternative uses. These and many other papers show that valuing the forest and promoting the use of NTFPs has been a popular pursuit in the Neotropics. Following the assassination of Chico Mendes, leader of the rubber trappers in Acre State, Brazil has established a number of extractive reserves especially in the states of Acre, Amapá and Rondˆ onia (see Schwartzman 1989, 1992; Allegretti 1990). In Brazil, more than 3 million hectares are now in extractive reserves (Nepstad & Schwartzman 1992). In these reserves it is permitted to extract NTFPs, but not to clear cut the majority of the forest. While they have slowed down deforestation in some places, the inhabitants have had a difficult existence with the fall in the price of rubber latex and the fluctuating price of brazil nuts on the commodity market. In order to sustain extractive reserves, they must be based on much more than two commodities. Conservation International worked on the promotion of vegetable ivory or tagua from the forests of Ecuador and Colombia as a means of income from this hotspot of biodiversity. While they sold a considerable amount of tagua (900 t) at double the previous market price, this project ran into a number of difficulties. Tagua buttons cracked after repeated washing in washing machines. It was then necessary to make buttons of sturdier shapes. Low-priced buttons from other synthetic sources also presented problems to the tagua project. The development and marketing of new NTFPs is not without its difficulties! There have been several examples of trying to add value to NTFPs to strengthen the extraction industry. The Body Shop in the UK buys various products directly from the extractionists and can thereby pay a respectable price because this process avoids a long chain of intermediaries. Both brazil nut oil and babassu palm oil are supplied in this way. The author recently visited a cooperative in the town of Altamira in Par´ a State, Brazil, which is owned and run by the local people, mostly of tribal origin. Amazoncoop (see www.amazoncoop.org) processes brazil nuts in Altamira to produce the oil and sell it directly to The Body Shop. This combination of a cooperative and a direct purchaser needs to be expanded for other NTFPs in other places. We have concentrated on examples from the Neotropics, but the promotion of NTFPs and the valuation of forests has been done in many other countries, for example, in India (Appasamy 1993; Ganesan 1993) and Sri Lanka (Gunatilake et al . 1993). The volume of Economic Botany (vol. 47) in which these papers were published is a good analysis of the economic valuation and sustainable management of NTFPs. Peluso (1992) described the rattan trade in Indonesia, which has been carried on for centuries through extraction, although in this case wild sources are overexploited and cultivation seems a more promising of way of sustaining production (Dransfield 1988). An excellent analysis of the use of NTFPs in India is given by Phil. Trans. R. Soc. Lond. A (2002)



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Tewari (1994), where, in addition to such aspects as value, more emphasis is placed on expanding local processing to add value, clarifying aspects of property rights and studying and understanding the sociological aspects of the extraction process.

3. Ecotourism One way of marketing the standing forest is through ecotourism. Like extraction of products, there are successful and sustainable examples of ecotourism and ones that are damaging to the forest ecosystem. Some of the same constraints apply, especially that the market demand should not lead to over-exploitation by allowing too many people into a site. The Galapagos Islands are reaching this point. There the number of tourists and their itineraries have been well controlled, but each year their numbers are allowed to increase. In Amazonia, especially in Peru, there are an increasing number of lodges and camps, and also boats, that carry out environmentally sensitive ecotourism. It is essential to encourage local initiatives, where the money spent benefits local peoples and not just large foreign tour operators. If this is not done, the system is unsustainable. A good guide to some of the places available in Central and South America is Castner (1990). Increasingly, guide books are available to encourage sensitive ecotourism (e.g. Pearson & Beletsky 2001). The Amazon Cooperative mentioned above runs Tataquara Lodge on the Xingu River in Brazil. A most exciting destination for the naturalist and ethnobotanist.

4. The impact of extraction The examples of extraction of NTFPs cited here vary from theoretical estimates such as Peters et al . (1989a) to highly practical analyses of actual extraction (e.g. Godoy et al .). Some of these are likely to be sustainable, especially those in oligarchic forests (Peters et al . 1989b; Peters 1992), and others are over-exploiting the resource (Peluso 1992). It is therefore important to assess the pros and cons of allowing the marketing of rainforest or, indeed, any other ecosystem. To be viable, extraction must be sustainable and at the same time yield a viable livelihood for those people involved that outcompetes alternative land uses. In many places, extraction has resulted in extinction or local extinction of species. This has happened in many island communities; for example, the extraction of the Saint Helena ebony (Trochetiopsis melanoxylon) for its wood, where only two individuals remained in the wild. In some parts of its range, quinine species (Cinchona) became locally extinct through over collection. In Brazil, in some areas of Amazonia, rosewood (Aniba rosaeodora) has been completely eliminated. The method of extraction can cause extinction. In Peru, the aguaje palm (Mauritia flexuosa) has an important marketable fruit. However, the fruits have often been collected by felling the female trees of this dioecious species. There are vast stands of male trees remaining, which do not produce fruit and have no means of reproduction. Even if a species is not made extinct by extraction, there can be enormous genetic erosion of its population. In an inventory we made of forest in Rondˆ onia, nearly all the mahogany trees had been extracted. Any that remained were either diseased or with twisted trunks and not the genetic material one would select for further timber production (Lisboa et al . 1987, 1991). Phil. Trans. R. Soc. Lond. A (2002)


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Heinzman & Reining (1988) studied the extraction of the leaves of Chamaedora palms for decorative purposes in Guatemala. They found a lower population density and flowering intensity in harvested areas than in areas where no harvesting took place. Padoch & de Jong (1989) found that there is a huge difference between the potential harvest from an area of forest and the actual quantities extracted. They found that, on average, only 2.5–3.5% of the potential amount of products that could be harvested are actually used. This contradicts the optimistic valuations of Peters et al . (1989a), but it could be a good thing because it means that resources are not over-exploited. However, when demand for a product increases, driven by the market forces, over-exploitation and non-sustainable methods of harvesting often occur. One of the greatest difficulties of extraction is that often it is not compatible with a free-market approach. So many products have gone through a boom-andbust cycle. When a product becomes acceptable on the market, the demand can soon exceed the sustainable supply or, alternatively, commercial pressure leads to the manufacture of synthetic substitutes (Torres & Martine 1991). A good analysis showing that extractive products are not always compatible with the market’s need for standardization and continual growth by expansion is that of Homma (1989). One result of success is that it can then lead to cultivation of the species concerned. This cultivation will lead to habitat destruction rather than conservation of the species of the forest as a carbon sink. The study by Peters & Hammond (1990) of several fruits that are extracted in the Peruvian Amazon estimated the quantity of fruits that could be taken while maintaining the population of the species. This type of study is needed to protect a product from over-exploitation. Another problem with extraction can be the loss of nutrients from the ecosystem, especially where the soils are poor. Some products remove more essential nutrients than others and this always needs to be taken into consideration. Nutrient loss is far more likely to occur on the upland soils of Amazonia than in lowland alluvial soils, where the nutrients are replaced annually through the flooding. The fruits studied by Peters & Hammond (1990), such as camu camu (Myrciaria dubia) and sacha mangua (Grias peruviana), both occur in large natural stands in alluvial soils and are ideal for extractivism. The process of extraction of a product may modify the ecosystem in a way that effects other organisms that depend upon the extracted product or its species for their survival. The hoarded brazil nuts are a vital food for agoutis during the dry season, when other food is scarce. If too many brazil nuts are removed from the forest, it could affect the population of agoutis. Another difficulty is that the production of a product can be highly variable from year to year, yet the market demands a constant supply of a product. Many tropical trees have unusual phenological patterns and flower and fruit irregularly or only once every two or more years. The brazil nut tends to produce abundantly only every second year. The market finds this sort of product hard to accommodate. It is for these sorts of reasons that local peoples have often found alternative land uses, such as swidden agriculture, more attractive. This is particularly true when they depend upon the land for their subsistence. Many of these peoples turn the land over to agroforestry systems, which, while not helping conservation of wild species, do store a considerable amount of carbon. For analysis of such a system amongst the Bora Indians of Peru, see Denevan et al . (1984) and Denevan & Padoch (1988), and for the Huastec in Mexico, Alcorn (1984, 1989). Phil. Trans. R. Soc. Lond. A (2002)



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5. Conclusion There are many difficulties with using extractive reserves as a means of conservation and many people have questioned its validity as a method (e.g. Anderson 1990; Browder 1992; Fearnside 1989). However, there is no doubt that the establishment of extractive reserves in Amazonia has slowed the rate of deforestation in some areas. Extractivism cannot cope well with price fluctuations of the commodity market, the rising demands of products through a growth economy and also the chain of intermediaries between the extractor and the final buyer, which means that the extractor receives a pittance for his work. Where this chain of middlemen is eliminated, extraction is more likely to succeed. It is also important to note that, quite apart from the marketing of products and the issues of carbon sinks, it is essential to conserve forest because of the dependence of so many people, both indigenous and non-indigenous, on it for their own subsistence. Forest ecosystems provide food for many local peoples and produce products and employment that enable people to buy food.

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