THE ARAUCARIA ANGUSTIFOLIA (Bert.) O. Ktze. GENE RESOURCE IN BRAZIL

by

J. Pitcher, FAO

INTRODUCTION

The report of the second session of the FAO Panel of Experts on Forest Gene Resources (FAO, 1972) gave to Araucaria angustifolia the status of “endangered with extinction or severe depletion of the gene pool”. By priority “urgent attention” was needed, with work to begin immediately towards preserving this species. The joint Brazil Government/United Nations Development Programme Project (BRA 45) on Integrated Establishment of Forestry Research in Brazil undertook the task of making range-wide collections of seed during 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. Contacts were made with collectors in two outlier subpopulations, the most northerly and southerly occurrences of the species, but no seed was produced at these locations during 1973. In arranging these collections the author, FAO forest officer in charge of Tree Improvement in the above project, travelled extensively throughout the natural range of the species and observed the conditions of the existing forest. Seed of five representative provenances has been distributed to 8 countries for use in international provenance trials, while trials of all 18 provenances are to be carried out on several sites in Brazil itself.

HISTORY OF ARAUCARIA

The species does not form pure extensive stands covering vast areas of land and probably never did. Its site requirements are very rigid compared to other conifers such as Pinus elliottii Engelm. and P. taeda L., now widely planted within the Araucaria range. Deep, well-drained loessal soils provide the optimum sites at elevations between 600 and 900 meters. In mature stands there is a well-developed understory of tolerant hardwoods and very little reproduction of Araucaria. This lack of regeneration is due in large part to the influence of man. The large seeds are an annual delicacy for the rural population and find a ready market in the cities also. Hogs are allowed to roam free and these voracious animals apparently consume huge quantities of the new seeds, effectively preventing regeneration of the forests. There are many positive examples of abundant natural regeneration where man and animals have been excluded or controlled, such as in the National Forests and Parks. These examples support the contention that man's influence is responsible for the lack of regeneration in natural stands.

When the Portuguese colonised Brazil in the 1500's Araucaria angustifolia was the dominant timber tree in the southern part of the country. Old records of the early settlers attest to its omnipresence and to its value in establishing the colonies. The capital city of the state of Paraná derives its name from the numerous “pinheiros” in the area. “Curi” means pinheiro or Araucaria and “tiba” means “where there are”. Thus Curitiba, the capital literally means “where there are Araucaria”. The distinctive silhouette of the mature Araucaria with its clean bole capped by a flat-topped upswept crown, similar to an inverted umbrella, is a frequently used motif in this part of Brazil. It can be seen in paintings, carvings, jewelry, adorning entrances to buildings and even in repeated patterns in the colourful sidewalks set by hand with individual stones of contrasting tones. The common name for Araucaria angustifolia is “pinheiro do Paraná” or Paraná pine, ample evidence of its ubiquitous character.

Most of the early colonisation of southern Brazil was limited to a narrow coastal strip. Therefore vast reserves of Araucaria remained inaccessible until the latter part of the 19th century. With the development of the railroads which opened the interior, rapid exploitation of the Araucaria was inevitable. During the early 1900's there was little control over the cutting and harvesting of these virgin stands. The demand for the excellent quality lumber obtainable was insatiable and remains so even today.

Recognising the value of the pinheiro to the commerce and industrial development of southern Brazil, the Government formed the Instituto Nacional do Pinho in 1942. Several small reserves of Araucaria were set aside in 1943–44 and work was started in establishing plantations of Araucaria within these units. These reserves still exist today, totalling more than 14 000 hectares in area and containing more than 20 million trees of Araucaria. In 1967 the Instituto Brasileiro de Desenvolvimento Florestal (Brazilian Institute of Forestry Development) was created by law. The administration of the units under the Instituto Nacional do Pinho was included in the act creating this Federal Forest Service.

In addition to these IBDF reserves of Araucaria there are several national and state parks having large areas of old Araucaria. Large private holdings of virgin Araucaria still exist in the western part of the state of Paraná, one exceeding 100 000 hectares with 560 000 trees over 40 cm DBH and there are several smaller private tracts of 1–10 000 hectares (Table I).

CURRENT STATUS OF THE ARAUCARIA FOREST RESOURCE

The Inventory of Pinheiro in Paraná (van Dillewijn, 1966) separated the existing Araucaria forests into two types. Type I was virgin forest with a relatively high number of trees per hectare. Type II was cutover forest, exploited and depleted, with a relatively small number of trees per hectare. At the time of the inventory in 1963, van Dillewijn concluded that there was only sufficient volume to last another 11–16 years in Type I or until 1974–1979. In 1963, Paraná had a total forest area of 6.5 million hectares. In the decade previous, exploitation was proceeding at the rate of 270 000 hectares per year. These factors led to the conclusion that soon Araucaria would no longer exist; that it would, within a very short time, be an extinct species.

Sylvio Péllico Netto (1971) updated the situation regarding the reserves of Paraná pine and also concluded that immediate action was demanded to avoid the extermination of the reserves in the near future.

These dire predictions have value for the lumber market and are similar in concluding that at the then present rate of harvest, the Paraná pine forests would be exhausted within the foreseeable future. It was largely upon these publications and those of Heinsdijk (1960) and others that the original forecast of imminent extinction of the species was based. However, from the standpoint of the Araucaria gene resource, these predictions do not indicate elimination or even severe depletion of the gene pool. The predictions refer to merchantable timber in virgin stands. Merchantable timber and unmerchantable timber in cutover stands is not included in these predictions and this category now constitutes the major portion of the Araucaria forest resource.

These same predictions assume a straight line decline in existing reserves based upon consumption during a five-year interval (1959–1964). But consumption of a dwindling resource theoretically follows an asymptotic curve as processors operating on a low product conversion margin drop out of the picture. Thus consumption declines curvilinearly and not as a straight line. Table II illustrates consumption of Araucaria angustifolia through 1971. The fact that there has been no appreciable decline in production indicates that the threshold of raw material scarcity has not yet been experienced.

In 1966, shortly before the creation of the IBDF, a fiscal incentive law (Lei no.5.106) was enacted, This law provided, among other alternative investments, that up to 50% of the income tax obligation could be deducted and invested in approved reforestation projects. This was later reduced to 25%. In the six years since enactment, projects totalling more than one million hectares throughout Brazil have been approved for reforestation. By law, at least 1% of the area on any project had to be reforested with native species (IBDF, 1972). In the southern part of Brazil, this meant Araucaria. More recently, in 1972, this regulation was increased to 25% of the area, within the Araucaria region, meaning that one tree in four planted in Paraná, Santa Catarina, Rio Grande do Sul and Sâo Paulo, must be native. A major part of the native trees used are Araucaria. Thus the area of reforestation with Paraná pine is increasing and will continue to do so in the future as long as the fiscal incentive programme remains effective (Table III). This reforestation effort will offer little benefit to the timber interests in the immediate future but from the viewpoint of a forest gene resource it illustrates that the situation regarding extinction is far from serious.

There are a number of research projects now under way with Araucaria. Project BRA-45 is investigating thinning and management regimes to maintain optimum growth rates. A definitive study of soil-site relationships is well under way and will prove most beneficial in reforestation projects. A provenance trial with 18 origins has been established to locate better seed sources for future plantings. The Instituto Florestal de São Paulo has also been very active in studying Araucaria improvement. It established a 3-origin trial in 1954 and concluded that there is evidence of geographic races in Araucaria angustifolia (Gurgel and Gurgel Filho, 1965). In 1966, an expanded series of provenance trials was established by the Genetics Institute of Piracicaba and the São Paulo Forestry Service. These trials involved 23 origins and were installed in nine locations in Brazil (Gurgel Filho, undated).

CONCLUSIONS

There is no danger of extinction of the species or even of severe depletion of the Araucaria angustifolia gene pool. There are extensive reserves of old Araucaria that will continue to be held for many years to come. The fiscal incentive law is stimulating reforestation adding many thousands of hectares of young Araucaria to the gene pool each year. Dysgenic implications can be dismissed since the original population is still existing in many areas and the progenies retain the genetic constitution of the parent population, although favourable gene combinations may be lost for one or more generationes. At this point, their existence is not even established and the remarkably uniform development of the species suggests a rather homogeneous nature to the gene pool. The existence of geographic races is being investigated on a broader scale than previously. Aside from several small outlier groups which seem to be disappearing because of factors other than timber harvest and which may possess some useful genes, the general gene pool is strong and well distributed. In travelling throughout the Araucaria region one is rarely out of sight of a stand or pocket of Araucaria. There are literally hundreds of thousands of trees of the original population remaining within the region, providing a basis for genetic research for many years to come.

RECOMMENDATIONS

1. Based upon present conditions as discussed in this paper, Araucaria angustifolia should be removed from the endangered list and its conservation may be given a lower priority rating. Because of the value of its wood for a variety of purposes, its collection, evaluation and utilisation should retain a high priority.

2. The Brazilian government, through its Instituto Brasileiro de Desenvolvimento Florestal, should act now to create reserves of some of the more outstanding areas of Araucaria and maintain these reserves as valuable gene resources.

3. IBDF should increase the exercise of its legal authority in the regulation of cutting practices to place the remaining Araucaria forest resources upon a solid management basis for the sustained yield of this commercially valuable timber.

4. Much greater emphasis must be placed upon proper matching of the species to sites adequate for its optimum development, thereby encouraging greater reforestation efforts and providing an adequate gene pool for the future.

LITERATURE CITED

FAO, 1972
Report of the second session of the FAO Panel of Experts on Forest Gene Resources. FO:FGR/2/rep. Rome. 68 pages

Gurgel Filho, O.A. undated
Resumo do projeto de raças geográficas em pinheiro brasileiro, Araucaria angustifolia (Bert.) O.Ktze. Instituto Florestal, São Paulo

Gurgel, J.T.A. and Gurgel Filho, O.A. 1965
Evidências de raças geográficas no pinheiro brasileiro, Araucaria angustifolia (Bert.) O.Ktze. Ciência e Cultura. 17(1):33–39.

Heinsdijk, Dammis, Roberto O. Soares and Helmut Haufe. 1960
The future of the Brazilian pine forests. Fifth World Forestry Congress Proceedings (1):669–672.

Péllico Netto, Sylvio. 1971
Recursos florestais do sul do país. Revista Floresta 3(2):68–74.

van Dillewijn, F.J. 1966
Inventário do pinheiro do Paraná. CERENA. 104 pages.illus.

IBDF. 1972
Código Florestal. 2.Ed. Rio de Janeiro. 65 pages.

TABLE I
Estimated area of Araucaria Reserves

Source: Dillewijn, F.J. Inventário do Pinheiro no Paraná. Curitiba, CERENA, 1966.104 p.

TABLE II
Production (m3 and tons) of Araucaria 1966 – 1970. State of Paraná

Source: Péllico Netto, Sylvio. Recursos florestais do sul do país. Quadro 3. Floresta 3(2), 1971

TABLE III
Reforestation of Araucaria in Southern Brazil under the fiscal incentive law 1967 – 1970

Source: Instituto Brasileiro de Desenvolvimento Florestal.M.A. (Data available only through 1970)