by
John A. Pitcher
Introduction
As reported in Forest Genetic Resources Information No. 2 (Pitcher, 1973), the second session of the FAO Panel of Experts on Forest Gene Resources (FAO, 1972), having declared Araucaria angustifolia an endangered species with urgent attention needed, recommended that seed collections be carried out within Brazil and Argentina. The joint Brazil Government/United Nations Development Programme Project BRA/45 was assigned this responsibility. FAO provided financial support from its Regular Programme.
First priority was given to the establishment within Brazil of A. angustifolia plantations of certified identity, particularly of the most endangered provenances, in order to preserve the gene resources of this species. Of second priority but very important was the objective of establishing provenance trials in other countries for the purpose of testing performance of the species and as a small gene resource pool. A third, but unmentioned objective of the trials might be included; that of focusing attention on the current condition and practices within the A. angustifolia forests which had led to its nomination as an endangered species.
As earlier reported (Pitcher, 1973), seed was collected from 18 separate locations, well distributed over the natural range extending from about latitude 19 to 31 degrees south and longitude 41 to 54 degrees west. Altitudinal ranges included a low value of 250 metres and a maximum of 1,663 metres. Seed of five representative provenances were distributed to eight countries (Argentina, Kenya, Malagasy Republic, Rhodesia, South Africa, Uganda, U.S.A. and Uruguay) for use in international provenance trials, while trials of all 18 provenances were established on several sites in Brazil itself. The origins of these 1973 collections are given in Table 1 and Map 1.
Notes on Provenances of Special Interest
Near Conselheiro Pena in the state of Minas Gerais is a very small stand of native A. angustifolia situated in the Padre Angelo mountains of the upper Rio Doce (Hueck, 1961). This is the most northerly occurrence reported in the literature. Contact was made with Mr. José Maurício Ramos, of the Rio Doce State Park, who had made a special trip into the area in 1969 to verify the existence of the stand. According to Mr. Ramos, the A. angustifolia are very old, in extremely poor vigour because of repeated fires, very sparse and few in number. The area is located some distance from any roads and is accessible only by foot or horseback. Mr. Ramos agreed to arrange a collection trip into the area but was not at all confident that any seed would be available. This, unfortunately, proved to be the case when the collection trip was made.
There is a residual stand on the lands of the Barro Branco National Coal Mining Company at Lauro Müller, Santa Catarina. This is a low elevation coastal source. Unfortunately only 11.5 kilograms of this source was available in 1973 for the IRDF/FAO provenance trials.
Near the village of Cangassu, Rio Grande do Sul, is the southernmost extension of A. angustifolia in Brazil. This outlier population consists of isolated trees in stringers on fingers along streams and cultivated fields. Less than one kilogramme of seed was collected here.
At Santa Maria, Rio Grande do Sul, Mr. Franz Andrae of the Department of Forestry, Universidade Federal do Rio Grande do Sul, provided 100 kg of A. angustifolia seed from an area near Pinhal Grande, representing an isolated outlier at the extreme southwestern extension of the natural range.
Natural stands occur in the Missiones region of Argentina. These excellent stands are not represented in the provenance trials. However, one of the test origins is from Barracão which is located on the border and may be taken as indicative of the provenance.
One other origin, Quedas do Iguaçu, demands special recognition as it represents the largest existing virgin population of A. angustifolia in Brazil. This forest covers more than 100 000 hectares in western Paraná and is in private ownership. No effort is being made to retain or preserve even a portion of this resource and it is scheduled for cutting over the next 15 – 20 years. Some reforestation will be done but a major part of this area will be converted to agriculture.
The remaining provenances represent populations of A. angustifolia that are remnants of original larger forests. Most of them are in reserve of some type, either federal, state or private and thus should be available for further seed collection in the future.
Collection and Handling Procedures
No specialized climbing or collection equipment was necessary since the “cones” of A. angustifolia are large, weighing up to two kilogrammes each, and fall from the tree when ripe. The large seeds (120 per kg) are readily gathered by hand from the ground. Loosely woven jute bags were used for transporting the seeds to Curitiba where the National Forestry School provided space in their recently constructed seed storage room. Seed was stored at three degrees Centigrade.
According to Glaser and Oliveira (1972) seeds of A. angustifolia larger than 6 cm in length produce significantly better seedlings, at least through the fourth year of plantation life. Therefore a selection by size was attempted, separating carefully by hand all insect and animal damaged seeds and keeping only the largest seeds for the trials. Unfortunately, with the limited quantities available, it was necessary to reduce the minimum acceptable length to 5.5 cm or even 5 cm in order to retain sufficient seeds to carry out the proposed trials. Strict control was maintained over the seed source throughout the processing with only one provenance being sorted at a time.
The cleaned and selected seed was placed in double-walled heavy duty plastic bags, one bag inside the other. The bags held between 30 – 40 kg each.
Following the published results of Grodski (1972) the seed was treated with methyl bromide gas at the rate of 20 oc per cubic meter of seed for 24 hours. This treatment was carried out in the plastic bags which were heat sealed with a special iron. After 24 hours, the treated bags were opened and the gas allowed to disperse. After another 24 hours, the treated seeds were returned to the laboratory where sample lots were drawn and weighed. Each lot for overseas shipment was 8 kg of seed, representing between 800 – 960 seeds. Five provenances were selected for the International Trials as representative of the entire range. Table 1 presents the entire list of provenances with a special notation for those used in the International Trials.
The seeds were also treated with a fungicide, Orthocide-50, at the rate of 2.5 g per kg of seed.
During the processing phytosanitary certificates were obtained from the Brazilian Ministry of Agriculture, Plant Protection Sector. These certificates were forwarded with the bill of lading to the port of entry along with the entry permits from the country receiving the shipment.
Provenance Trials in Brazil
After overseas shipments were dispatched, 18 provenances were available for establishing trials in Brazil. The provenance from Três Barras in the state of Santa Catarina did not have enough seed after selection for size to be included in the Brazilian trials.
Sites were prepared at Fazenda Santa Tereza, Guaragi, Paraná; at Três Barras National Forest in Santa Catarina and at Fazenda da Fábrica de Papel Sguário S/A, Rio Preto, São Paulo. The test designs for each of these trials were randomized complete blocks with four replications and one plot per replication. Plots consist of 25 trees in 5 rows and 5 columns. Spacing is 3 m × 3 m. A border of 4 rows completely surrounds the trials. At each tree location within the plots and border, three seeds were sown. Following garmination, plots will be thinned to one tree per position where necessary.
One constant density increment Nelder plot (Namkoong, 1966) was also established at each trial site to evaluate the effects of spacing on growth of different provenances. These are the first Nelder trials in Brazil using Araucaria angustifolia. Ten spacings ranging from 3 089 trees per hectare to 124 trees per hectare are represented in these plots with increments of 370 trees.
Other Provenance Trials
At the same time that the IBDF/FAO BRA/45 project was making provenance collections, the Instituto Florestal in São Paulo (1) was also collecting seed of A. angustifolia and establishing provenance trials. These collections were mostly from other origins but some provenances are common to both series of trials and should serve as a basis for comparing performances at different locations.
The IBDF/FAO provenance trials will require close attention during the initial establishment period. This work will involve careful weeding of the sites, thinning planting spots to one tree per position and possibly some replacement work.
Measurement and analysis of growth characteristics, definitely height, diameter and volume and possibly others as they appear, will need to be done at regular intervals. This data should be available to all cooperators for comparison with results of the standard provenances furnished.
The gene resource position of Araucaria angustifolia now appears reasonably strong and the concern expressed earlier by the FAO panel of experts requires reevaluation (FAO, 1973). There are capable people in Brazil conducting research in this species.
Literature Cited
FAO, 1972
Report of the second session of the FAO Panel of Experts on Forest Gene Resources.
FAO report FO:FGR/2/Rep. Rome. 68 pp.
GLASER, Gil Reinaldo and OLIVEIRA, Jesuino Almeida de, 1972
Influência do tamanho das sementes no desenvolvimento inicial dos povoamentos
florestais de Araucaria angustifolia (Bert.) O. Ktze. VII World Forestry Congress,
Buenos Aires.
GRODSKI, Romulo Mário, 1972
Pesquisa dos efeitos do CS2 e CH3Br no expurgo de sementes de Araucaria angustifolia
para o combate da lagarta de Laspeyresia araucariae. Brasil Florestal III(12):36–39.
HUECK, Kurt, 1961
Distribuição e habitat natural do pinheiro-do-Paraná (Araucaria angustifolia).
Transcrição do Boletim Geográfico (IBGE) no. 165: 709–723.
NAMKOONG, Gene, 1966
Application of Nelder's designs in tree improvement research. Proc. Eighth Southern
Conf. For. Tree Imp. pp. 24–37.
PITCHER, J.
The Araucaria angustifolia (Bert.) O. Ktze. gene resource in Brazil. Forest Genetic
Resources Information No. 2, FAO, 1973.
