Appendix 4. Maderas Preciosas Costa Rica S.A., Reforestation Program

M.Sc. Edgar Víquez López^*[6]

Director, Forest Research Program

Precious Woods, Costa Rica

INTRODUCTION

Since 1990, Precious Woods has been investing on planting projects through his subsidiary Maderas Preciosas Costa Rica S.A. (MACORI S.A.), the administrative and executing unit for planting, management and plantation’s maintenance.

These projects have special characteristics. They are carried out in an integrated context with the environment’s conservation. Considerable efforts have been done to protect and multiple-use native species. Primary forests are preserved. After studying local wildlife, trees and native shrubs to be planted are chosen according to wildlife food necessities, ornament purposes and timber production. Every year seeds are collected, and nursery seedlings are planted, along roads, borders and sites where teak does not grow well. Some native species like pochote (Bombacopsis quinatum) are planted for commercial purposes. Until now, 1,067 ha of native species have been planted, from which 85% was pochote, and the rest of more than 20 native regional species. In 1996 the nurseries produced 160,000 seedlings of 49 native species.

MACORI is one of the few companies which had established a Forest Research Program (PIFOMA, started in 1994) that includes nurseries and plantations tests, evaluation of native species and genetic improvement of the priority species. This lead to the development of innovating systems of seedlings production, and use of high genetic quality tree as seeds sources. Plantation’s management has detailed grow data. Systems to determine the pruning and thinning year and intensity have been developed.

TECHNICAL ASPECTS

Planted Area and Species

All projects are in different five farms located in the Guanacaste Province, north-west of the country: Garza which belongs to Nicoya; Río Tabaco and Ostional in Santa Cruz; and Peñas Blancas and Santa Cecilia, in La Cruz. Total area per projects, including protected and reforested areas, are shown on the Table 1.

At present, the Garza, Ostional and Río Tabaco projects have totally planted: In Peñas Blancas 368 hectares has been planted, and 1,161 ha in Santa Cecilia, and both still have areas for planting.

Table 1. Total and Possible Area to Reforest by Project

Table 2: Planted areas by Project, year and species. Maderas Preciosas Costa Rica S.A.

Table 2 presents the data of planted areas by species. Until 1993 pochote was the most planted species. Since 1995 teak became the priority species. Up to 1997, 2, 863 ha have been planted. Of them, 63% (1,796 ha) is teak, 32% (907 ha) is pochote and 5% (160 ha) other native species (caoba (Swietenia macrophylla), cedro amargo (Cedrela odorata and Cedrela salvadorensis), ron ron (Astronium graveolens), cocobolo (Dalbergia retusa), cristóbal (Platysmicium pleistotachium), cachimbo (P.pinnatum), genízaro (Pithecolobium saman), guanacaste (Enterolobium ciclocarpum), guayaquil (Albizzia guachapele), guapinol (Hymenaea courbaril), surá (Terminalia oblonga) and roble sabana (Tabebuia rosea).

Plant Production

PIFOMA collects seeds from of previously selected trees for phenotypic superiority. There is a pochote’s clonal seed orchard, that produced all the 1995 sticks (plants) for Ostional, as well as for establishing four repetitions families trials, on which the genetic quality of each mother tree is evaluated.

The first clonal seed teak orchard was established in 1996 with buds grafted from plus trees. It is expected that it will start producing sticks by 1999. In 1998 it will start the planting of material from the best teak trees. This process will increase and improve as the clonal tests give better results.

Due to several trials of PIFOMA, the teak nurseries production system was changed. Plants are left in the nursery about 45 to 60 days after being transplanted, and then they are take to the field. This has increased the survival to over 90%, even when dry periods follow plantation. Nursery’s maintenance costs have been reduced, and plant sizes permits to use a smaller plastic bag, diminishing the transportation costs. Another important effect from this system is that plants do not have wounds which may contribute to illnesses, especially Agrobacterium or fungus. Initial growth does not show significant differences with stump materials, but reduces the costs of the initial formation pruning.

Native species are also planted in plastic bags, except pochote (sticks with pruned roots).

Establishment and plantation management

General, planting is done in formerly pastures and cattle raising areas. When conditions allow it, land preparation is done with disk plough and rippers. From 1995 on, the selected spacing between trees is 3.5 x 3.5 m. (816 trees/ha). Before distances varied, with densities between 400 to 1,000 trees/ha

PIFOMA measures the plantations every year or two, to evaluate, detect growth problems and suggest corrective measures. This data is also used to define the moment and intensity for pruning and thinning.

Recently, foliar biomass studies have been performed in plantations of different ages and site qualities. Its main objectives are to develop a pruning system where it’s possible to calculate the pruning height and frequency, to guarantee an optimum proportion of wood free of knots, and to diminish costs of this silvicultural intervention. The system is being implemented on commercial plantations. Different intensities of pruning for teak and pochote are tested to check its efficiency. Results will be published on technical or scientific magazines on 1999.

Due to the variability of tropical site conditions, (even inside a small track of land you could find areas with a high, medium and low site index), a decision was made to program thinnings based on the measurements of the permanent plots. Because of possible errors, it is not convenient to generalize frequency and intensity. Thinnings could be made too early or too late or, if it is done with a very low intensity, it will not have the desired effect on the stand. The general criteria is to reduce the basal area when it reaches the 20 m²/ha level to 14 m²/ha. This system does not work on plantations with densities of less than 600 trees/ha. To facilitate it’s implementation a matrix was developed. With a simple field measure, the technician determinates the thinning intensity, based on basal area and plantation density.

Plantation Growth

The estimated rotation age is 25 years for teak and 30 for pochote, but this may vary according to site quality and market demands.

A study is being done in 1990 and 1991 on teak and pochote plantations of the Garza’s project. Based on the particular site conditions, the establishment and management of this plantations, growth tables and production projections for thinnings and final harvest will be calculated, to be used in financial analysis to determine the moment of investment for industrialization.

Garza’s project site index has been calculated (base age of 10 years). Results show that more than 85% of the pochote’s plantations area is in medium and high Site Class. In its first years, the spacing has contributed to fast diameter growth and reduced height, so it is difficult to make thinning yields projections, in part because the growth does not correspond to values of the existing equations. However, the Company expects logs with larger diameters than the ones of Alfaro’s tables (1990) and Hughell.

In 1997 measurements of 7 years old teak plantations (Garza project 1990), with the exception of two plots with site index lower than 21 (medium) all the plots showed a high site index. It is possible that they might be influenced by spacing and initial management. The values were compared with Miller’s growth table (1969, mentioned by CATIE, 1991). The results showed great similarity in height, diameter and basal area on this age. It was decided to use this yield table to make an appraisal of the thinnings. Miller (1969) reports a very high initial density (2,196 trees/ha), but a first thinning on the third year reduces the density to 988 trees/ha. Later on, thinnings are done in years: 7, 12, 18 and 26 and, in year 37th they have only 76 trees/ha. The company evaluates site quality after the fourth or fifth year, and interventions and yields are projected. In Precious Woods, thinnings were planned up to year twelve. Periodical evaluations are done (every 2 or 3 years) to determine need and intensity of this practice. In 1997 the first thinning was done, and results were very similar to the ones reported by Miller.

Plantations are measured every 1 - 2 years, and technical report is prepared, including average values by plot and stand. The maps of the farms are being digitalized in a GIS system, with references to areas, species, planting year and site quality. The goal is to have a clearer idea of the production. Good sites require to be thinned more often than medium or low quality ones. So thinnings of areas of different quality sites and ages will produce timber of different sizes and qualities.

The oldest pochote’s (1990-91) have average diameter increments of 2.5 to 3.7 cm/year. MAI in height goes from 1.3 m to 1.8 m. For teak’s older plantations, the average diameter MAI varies from 2.7 cm and 2.8 cm, and from 2.2 m to 2.4 m of height.

MARKETS

Studies started on 1998 with estimates of thinning yields and final harvest of the oldest plantations (6 to 8 years old), and were complemented with digitalized GIS maps of the farms, the planting years, species, slopes, site quality and location of permanent plots. The goal is to project, as precisely as possible, the total volume to be cut/year in each farm, by species, as well as the dimensions of the products, and their possible uses. Studies have been started to find markets for the products, and determinate prices.

EXPANSION POTENTIAL

Presently, the Company projects to expand its planted area to twelve thousand ha. Today, 63% of the available area have been planted with teak, and the trend is to maintain, at least, this proportion. The remaining available area is 1,911 ha in Santa Cecilia and Peñas Blancas (Table 1), will allows to continue planting an average of 400 to 500/ha/year up to year 2001.

RESEARCH PROGRAM

PIFOMA’s first activity was to prepare a Research Plan and its budget. The three research lines were approved: 1. teak and pochote genetic improvement; 2. native species trials and; 3. research for help management (Víquez 1998).

Through systematic evaluation of materials from both selected species improvements on growth, stem form and wood quality, as well as a reduction of rotation age are expected at medium and long term periods (5 to 15 years). Selection and propagation of superior genotypes of vegetative material of both selected species (clonal tests and clonal orchards), are expected to produce vegetative material for pilot plantations after the third year.

At present, 17 species native species on pure and mixed plantations are been evaluated, in 6 test with 3 or 4 repetitions each one with annual or bi-annual measurements. On 1998 the process of selection superior trees of some of these species for vegetative propagation was started.

The commercial plantations are monitored through permanent plots to detect problems and silvicultural interventions. The following is a list of trials established on this line of PIFOMA’s activities:

• Pruning intensities on teak and pochote plantations
• Lime application and teak’s growth
• Teak and pochote and different types of nursery materials
• Evaluation on different containers for teak production in nursery
• Trial of Leguminosae cover on commercial plantations of pochote
• Evaluation of natural regeneration in plantations with a low site index.

Bibliography

Alfaro, M. 1990. Estudio de caso sobre la rentabilidad y el uso óptimo de recursos en plantaciones forestales en Costa Rica. Tesis M.Sc. CATIE. 181 pp.

CATIE, 1991. Teca (Tectona grandis). Especie de árbol de uso múltiple en América Central. Colección de guías silviculturales. Serie Técnica. Informe técnico No 179. 48 pp.

Víquez, E. 1998. Programa de Investigación Forestal. Precious Woods-Costa Rica. In: Memorias del Seminario. Aumento de la rentabilidad de las plantaciones forestales: un reto ligado al uso de semilla de alta calidad. Patrocinado por el Ministerio del Ambiente Energía y Minas, Oficina Nacional de Semillas y la Cámara Costarricense Forestal. Hotel Corobicí, San José. 19 de mayo de 1998. 3 pp.