Introduction
Tropical deforestation often occurs on soils that cannot sustain in- tensive agriculture. The seemingly inexorable advance of the agricultural frontier on forest lands not only destroys vast quantities of wood, it also rapidly exhausts the natural productivity of the soil, usually leading to abandonment or conversion to extensive pasture. Wherever virgin lands are accessible (e.g. roads for oil exploration, logging, etc.), strong socio-economic and political pressures often promote spontaneous or directed colonization; invariably this means deforestation.
Peru's Pichis-PalcazG Special Project (PEPP), with the financial and technical support of the United States Agency for International Devel- opment (USAID), is addressing the problems of inappropriate land use and uncontrolled agricultural colonization through an innovative ap- proach to rural development (JRB, Inc., 1981): The Central Selva Resources Management Project which is implementing sustained yield management of natural forests as the principal development activity in the PalcazG Valley, while protecting the traditional culture of the local Amuesha Indians. By integrating intensive forest exploitation, local processing of timber and natural regeneration of native trees, the forest management project is expected to maximize sustainable productivity of the forest resources and to increase the income and social well-being of the indigenous communities and farmers in the lower valley. In general terms, this practice is known as production forestry.
The Tropical Science Center (TSC) provides technical assistance to the forestry and land-use components of the PalcazG development
project. TSC designed a vertically integrated system for local transfor- mation and national marketing of wood products, with management of native forests based on natural regeneration and sustained yield (Tosi 1982). The PalcazG project promoted the formation of the Yanesha Forestry Cooperative, a local indigenous organization, and is developing a wood processing center for the Indian cooperative.
The Area
The small Palcaz6 Valley (140,000 hectares (ha)) is at the eastern base of the Peruvian Andes. The Palcaz6 watershed (189,200 ha) is formed by the rugged Yanachaga range (3,800 m above sea level) to the west and the lower San Matias range (1,200 m) to the east. The Palcazd river flows north, where it joins the Pozuzo river, both of which are tributaries of the Pachitea river. Base elevations vary from approximately 270 m at the northern end of the valley to 350 m in the southern foothills. Forestry development activities are limited to the lower end of the valley, generally below 500 m in elevation.
As part of the Central Selva Resources Management Project, USAID is assisting with the creation and consolidation of the Yanachaga- ChemillCn National Park (122,000 ha) and the San Matias Protection Zone (33,000 ha). These conservation units (Aguilar 1986) include considerable areas of protection forests on the steep slopes of the upper Palcaz6 watershed.
The population of the Palcazix Valley is estimated to be 6,000 inhabitants, including 3,500 Amuesha (Yanesha) Indians. Most of the Amueshas live in 12 native communities, where they practice traditional shifting cultivation of manioc, maize, and upland rice on small holdings, alternating these short-term crops with longer periods of bush or forest fallow. As part of the Palcazix project, the 12 native communities have been officially recognized and granted property titles by the Peruvian government. The rest of the valley's population is made up of mestizo settlers, some Campa Indians, and a significant component of cattle ranchers descended from German, Swiss, and Austrian immigrants attracted to the region by the turn-of-the-century rubber boom.
Detailed mapping of life zones indicates that 85% of the lower valley is in the tropical wet forest life zone (Bolaiios and Watson 1981).
Average precipitation in the lower valley is about 6,300 mm/yr (about 250 inches). Such high rainfall and the lack of an effective dry season produce natural vegetation commonly called tropical rain forest.
Approximately 75% of the lower valley retains its coverage of primary forests. Most of the deforested areas are along the rivers and on the low hills close to these rivers. The Palcaz6 Valley appears to be
especially rich in native plant species. R. Foster and A. Gentry of the Missouri Botanical Garden (pers. comm.) are discovering an impressive number of plant species with medicinal or pharmaceutical uses. I estimate that there are at least 1,000 native tree species in the Palcazii Valley.
The Palcazii Valley's soils, like most soils supporting tropical forests, are unsuited for conventional commercial farming. The red clay soils of the extensive rolling hills in the lower valley are highly acidic (pH 3.8-4.5), with an abundance of aluminum. Furthermore, these soils are highly leached and almost devoid of major nutrients, especially calcium, phosphorus, and potassium. Also present in the valley are old riverine terraces with white sandy-clay loam soils that are even less fertile than the red clay soils. The Amueshas do not use these old terraces for shifting cultivation, hence these poor soils generally have well-developed primary forests (Hartshorn 1981) with an abundance of valuable trees such as rubber (Hevea brasiliensis, Euphorbiaceae), and tornillo (Ced- relinga catenaeformis, Mimosaceae).
Because of the high rainfall and rolling-to-steep terrain, the red clay soils are highly erodible when cleared of their protective forests and used for agriculture or pasture. A survey of the land-use capability in the lower valley indicates the following distribution of maximum sus- tainable use: 7.6% suitable for annual or seasonal crops; 13.3% for pasture; 14.4% for perennial crops; 46.2% for production forestry; and 18.6% should be kept in undisturbed protection forests (Tosi 1981). In this classification system, less intensive uses are permissible, such as production forestry on lands suitable for agriculture or grazing. But the opposite (pasture on forestry land, for example) is not sustainable, and should be avoided. The project includes a program for mapping land- use capability of the lower valley, as well as actual land-use, with a view to adjusting current land-use practices to sustainable use of the natural resources. Thus, some 44,000 ha of remaining forests in the lower Palcazii Valley could be under permanent management for pro- duction forestry.
Background
Numerous efforts to manage heterogeneous tropical forests have failed due to difficulties such as: 1) the low volume of commercial woods per unit area, there being as many as 200 tree species in one hectare; 2) very high extraction costs associated with the practice of high-grading only the quality timber; 3) lack of understanding about the dynamic nature of most tropical forests; 4) a general lack of information about the regeneration requirements and silvics of canopy tree species; 5)
government policies (e.g., short-term concessions for large volumes, minimum diameters for cutting) that discourage sustained yield forest management or make it economically unattractive; 6) national and international agencies that promote agricultural colonization on lands that cannot sustain agriculture or cattle ranching; and 7) agencies in charge of forestry that do not define and protect permanent forest lands for timber production.
This complex array of factors has given rise to a pervasive attitude among forestry professionals, development agencies, and the public in general that it is economically unjustifiable and ecologically impossible to manage tropical forests (Leslie 1977). Nonetheless, significant eco- nomic changes in the demand for tropical woods and recent advances in our understanding of tropical forest dynamics have reawakened interest in the potential for managing tropical forests for sustained production of wood, without resorting to plantation forestry.
Perhaps the most important change has been the dramatic opening of national markets to a much wider range of Amazon timber species.
National markets traditionally accepted only the finest tropical woods, which often meant only 10 to 50 of the thousands of native tree species.
However, in the past decade as high-grading depleted stocks of premium timber and deforestation destroyed substitute species, national markets are opening up to more timber species that were heretofore commer- cially unacceptable. Where timber is scarce, as in much of Central America and the Andean highlands, local markets now accept any log of adequate size and decent form. Generally, many tree species are marketed under a single generic name, for example "common oak" in Chanchamayo, Peru, or "mountain oak" in central Ecuador. Market acceptance of a large number of native species literally opens the door to intensive management of tropical forests as an alternative to the selective exploitation of a few species.
The incredible richness and diversity of tree species in tropical forests have long been formidable obstacles to economic management of these forests. Most previous attempts at forest management failed because they focused on one or a few quality timbers (e.g., cedar, ebony, mahogany), which are even scarce in undisturbed primary forest. Due to the great complexity of most tropical forests, the competition of one species against hundreds of others was doomed ecologically, or was prohibitively expensive to control.
Forest Dynamics
During the last decade, some researchers working independently in Southeast Asia and in tropical America discovered that tropical forests
are very dynamic (Hartshorn 1978; Oldeman 1978; Whitmore 1978).
This means that rapid renewal of the primary forest generally occurs with the fall of large trees, and their replacement with young, fast- growing trees. One of the key components of this natural renewal is a surprisingly high dependency of tree species on natural openings (gaps) in the canopy for successful regeneration (Hartshorn 1980). At the La Selva Biological Station in northeastern Costa Rica, 50% of the native tree species require gaps for regeneration. If we consider only the tree species that form the forest canopy, 63% are gap species. The shade intolerant species that colonize gaps are fast-growing trees that fill a gap within a few years and reach the forest canopy in 20-30 years. In the La Selva primary forest in Costa Rica, the median life-span of trees greater than 10 cm (diameter at breast height) is just 34 years (Lieberman et al. 1985). Forest renewal through gap-phase dynamics, the principle pattern of natural regeneration in most tropical forests, is the key to our management plan for natural forests in the PalcazG Valley.
Management Plan
TSC designed a forest management plan based on the above-men- tioned ecological factors (Tosi 1982). Timber exploitation is limited to long, narrow clear-cuts interspersed in the natural forest. Considering topography, each new strip will be 30 to 40 m wide. Where feasible, strips 200-500 m in length will be oriented with the topography to minimize crossing ridges and streams. In effect, each strip is an elon- gated gap, bordered on each side by intact forest, which is the source of seeds for natural regeneration of trees in each clear-cut strip. In successive years, the new strips will be located at least lOOm from recently cut strips. TSC is projecting a 30 to 40 year rotation between the successive harvests of a specific strip in this strip shelterbelt system.
Two demonstration strips were harvested in 1985, the first (20X 75 m) in April-May and the second (50X 100 m) in October-December.
The natural regeneration of trees within a few months of harvest was striking. In addition to abundant regeneration from seed, many stumps displayed vigorous sprouts; even some of the very dense and beautifbl hardwoods like Tabebuia obscura (Bignoniaceae), Myrocarpus sp. and Vatairea sp. (both Fabaceae) had abundant stump sprouts on the dem- onstration strips. In a complete inventory of regeneration of the first strip 15 months after harvest, we found approximately 1,500 individuals (>50 cm tall), representing 132 tree species. At 27 months, there were 155 tree species with saplings more than 1 m tall. This wealth of tree species regenerating is more than double the number of tree species
harvested from the first demonstration strip (.I5 ha). We think that the proximity of excellent seed sources and the absence of burning and cropping are critical factors in the diversity and abundance of natural regeneration of trees on the demonstration strips.
The management plan also includes the possibility of silvicultural treatments. Once the young trees have formed a closed canopy (at about 5 m), the competitive equilibrium can be adjusted to favor particularly desirable individuals, or to eliminate undesirable individuals. In year 2 or 3, the number of stump sprouts was reduced to 1 or 2, depending on the size of the stump. As the canopy closes, climbers are cut to prevent lianas from overtopping or damaging the young trees. Thinning of trees will not be initiated until the canopy is hlly closed, in order to allow the natural suppression of weeds and vines.
Wood Uses
The harvesting and processing of timber are integral components of forest management. In order to promote natural regeneration of shade intolerant tree species, the canopy opening must be sufficient to allow sunlight to reach the forest floor. Thus the management plan requires clear-cutting and the use of almost all of the cut biomass. All trunks and large branches are extracted, leaving only the small branches and leaves on the ground to provide nutrients for the regenerating forest.
Draft animals (such as oxen or water buffalo) are used to extract the logs, poles, posts, and fbelwood. The few exceptionally large logs can be sawn lengthwise to facilitate the extraction. The logs are moved by draft animal to a road head for transport to a local processing center. The use of such simple technology to extract logs is feasible because extraction is concentrated in a small area and the distances are not great. Hence, extraction of logs is considerably cheaper with draft animals than with articulated tractors or skidders. In addition, the negative impact of extraction on .the soil is much less with draft animals than with heavy machinery, and the investment is minimal.
Processing of the wood is done locally in the valley, at an integrated processing center organized cooperatively by the producers of the raw materials. This set-up will ensure that the added-value from processing remains in the hands of the owners of the forest. The Yanesha Forestry Cooperative consists of five native communities and 96 individual members. The cooperative has identified approximately 1,000 ha of production forests and is developing operational plans for each pro- duction block (Sanchoma et al. 1986). The Yanesha Forestry Cooper- ative is the first forestry cooperative ever organized among indigenous groups in the Amazon Basin. The Cooperative plans to involve all the
native communities of the valley and bring their 25,000 hectares of natural production forests under sustained yield management.
Economic Aspects
Inventories of the lower valley forests carried out by the PEPP forestry unit indicate that there is an average of 150 m3/ha of timber in saw logs, plus 90 m3/ha of roundwood for poles and posts. The inventory data do not include branchwood, which can be sawn for specialty items or converted to charcoal. Much of the smaller dimension timber is marketable as utility poles and posts, which will be treated with a preservative to increase longevity and value. Much of the non- resistant sawnwood will also be treated with a preservative for use as form lumber in construction. The untreated hardwoods are sold in specialized markets based on their specific wood properties and work- ability, which are determined by laboratory tests and trial in a local carpentry shop. Timber that cannot be transformed into sawn products or preserved poles and posts will be converted to charcoal, for which there is a considerable demand wherever energy sources are scarce, such as the high Andes and the coastal deserts of Peru.
The first processing center located in Shiringamazti has a "Mighty- Mite" portable sawmill and a bank of 44 Pres-caps for preserving roundwood (Krones 1987). At this first stage, the cooperative can process 12 hectares of timber per year. For 1989, there are plans to diversify and expand the processing center's productive capacity by adding a band resaw, an automatic sharpener, 2 miter saws, 1 table saw, 1 molder, 2 driers, 3 duplicating lathes, 2 sanders, 50 Pres-caps, and a complete "slurry seal" system for preserving sawnwood.
Given the current unstable economic situation in Peru, any long- range projection of the financial performance of the Palcazti project would be unrealistic. Over the short term, TSC economic calculations indicate that the limited capability of the current processing center (portable sawmill, 44 Pres-caps, and a portable charcoal kiln) will produce net returns of about US $3,500 per hectare of forest harvested and processed locally. Under full development, the planned diversifi- cation and expansion of the local processing center at Shiringamazti should increase net returns to an estimated US $27,555 per hectare worked (Simeone et al. 1986). These values are the net return captured once during a proposed 30 to 40 year cycle. Assuming a 35-year rotation, annual net income at full development would be US $786 per hectare worked. At full development, about 20,000 ha would be ex- ploited over a 35 year period (about 570 hectares per year). It is
important to emphasize that these estimated profits to the Yanesha Forestry Cooperative are based on current market values and transport costs for wood products in Peru which are likely to change radically even over the short-term. Nevertheless, once local processing is avail- able, this integrated forest management system will produce attractive profits beginning in the first year of operation, while guaranteeing the sustained production of timber from managed natural forests.
Conclusions
Several factors may affect the long-term success of the Palcazd project. First, the project still depends heavily on foreign financial assistance. If this initial start-up aid were cut-off or reduced before the project reaches full-development, then the Yanesha Forestry Coopera- tive, as a local development organization, would be seriously jeopar- dized.
The strength of the Cooperative is essential for two other reasons that may influence the project's viability. A strong cooperative reinforces the commitment of individual Amuesha to abide by the concept of collectively enforced sustained use. Without a strong cooperative, Amuesha may be tempted to sell off their land-rights to loggers or accelerate harvesting rates to unsustainable levels in order to get larger profits in the short-term. Increasing pressure from "outsiders" to do just this is putting the Cooperative to an early and critical test.
Finally, the Palcazd project, not to mention any strategy for sustain- able development among the Amuesha, depends on continuing govern- ment recognition of Indian land rights. A strong and effective coop- erative increases the chances of political support for such land rights.
Clearly, the most important aspect of the Palcazd project is the opportunity and potential for sustainable development of tropical for- ests. Instead of the typical pattern of temporary prosperity for a few years based on traditional high-grading of the forest followed by ex- pansion of the agricultural frontier, sustained yield forest management will generate incomes adequate for local communities to realize their development priorities. If the Palcazd project is successful, the exploi- tation and integrated management of natural forests should become a powerfbl development model for tropical forests that are suitable only for production forestry. Sustained yield management of tropical forests would considerably diminish the growing pressures to convert forests to agricultural lands or pastures, at the same time reducing the rate of tropical deforestation.
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