Palcazu Method Strip Cutting

The Palcazu method, designed and applied in the Palcazu Valley of eastern Peru in the 1980s, was based on ecological observations of gap-phase dynamics of tropical forests. In natural forests, following gap formation, shade-intolerant species regenerate in the center of the gap, and more shade-tolerant species tend to occupy the borders. In the Palcazu method, the forest was cut in long narrow strips 30-40 m wide, simulating natural forest gaps to maximize utilization of the timber and to facilitate natural regeneration of trees. The strip clear-cuts were rotated through a production forest so that uncut primary forest or advanced secondary forest bordered a harvested strip. One strip was cut every year. Forest cutting was done using directional felling, cutting the trees so that they fell towards the already open area. Lianas were cut the year before felling. Extraction was done by oxen. A 40-year cycle was originally planned, to be done in parallel strips, leaving mature forest in between. Forest management using this strip cutting method was practiced on a total of 50,000 ha in an area with low hills. The project was based on an integrated use of products (sawn timber, poles, charcoal). There were two small sawmills on site to process the extracted timber. Initial evaluations of demonstration experiments using strip-cutting in the forest of the region were promising and showed that harvesting and extraction of wood could be done under the local conditions without serious environmental damage and that initial regeneration was rapid, abundant, and diverse (Hartshorn 1990).

The project was initially funded by the US Agency for International Development (USAID) to serve social objectives for communal lands of indigenous people living in the region, who were associated in a cooperative. The project suffered several difficulties after the withdrawal of the external financial and technical aid in 1989 due to the guerrilla activity in the region (Dawkins and Philip 1998). The cooperative continued the project for several more years but was faced with a variety of marketing and administrative difficulties. Costs exceeded revenues as timber prices were kept low under the national government policies at the time.

Yields were also lower than predicted by the pre-felling inventories. Silvi-cultural treatments were experimentally applied to the previously cut strips to test the effects on regeneration. Thinning significantly enhanced annual growth increments for stems in all regenerating categories of commercial species, with growth rates approximately twice those in the controls (Dolanc et al. 2003). However, economic sustainability of the system is still in question, as growth rates of commercial stems, even in thinned plots, were quite low (<0.3 cm/year for all categories).

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