ABSTRACT Buttresses and other natural structures modify the shape of stems in Amazonia and change the diameter at breast height (DBH) measured at 1.3 m at ground level. The lack of adequate measurement techniques affects negatively forest dynamics analyses and biomass estimating. The study evaluated an indirect method of measuring diameters in trees with DBH > 40 cm using principles of digital photogrammetry. The results obtained with two cameras (smartphone and Sony) were compared with direct measurements using diametric tape and a ladder. The technique is adequate to measure the diameters of trees with measurement point above 2 m of ground, with a confidence interval of ±1cm. The use of photogrammetry as a supplementary tool to the diametric tape (IC ± 0.24 cm) is recommended, helping to measure trees with diameter above the reach of the technician in forest inventories.

O objetivo deste trabalho foi estudar o crescimento das espécies florestais pioneiras pau-de-balsa (Ochroma lagopus Sw.) e caroba (Jacaranda copaia D. Don) para a recuperação de áreas degradadas pela agricultura. Na área, situada no km 120 da BR-174, tinha sido plantado mandioca e banana e abandonada há 8 anos, formando uma capoeira de porte baixo e rala. O experimento foi instalado em maio/98, com e sem gradagem da área. O espaçamento foi de 3x3m, em covas de 20 cm (diâmetro) x 30 cm (profundidade), com adubação de 150g/cova de NPK (4-16-8) e calcário dolomítico na proporção de 3:1. Para a avaliação do crescimento, foram medidas a altura e o diâmetro das plantas aos 2 meses (julho/98) e a cada ano aproximadamente (junho/99, setembro/00 e maio/01). Os dados foram analisados através do delineamento inteiramente casualisado. A sobrevivência do pau-de-balsa foi maior em área gradeada (97,1%) do que em area não gradeada (92,5%), após o primeiro ano do plantio; da caroba, foi cerca de 90% e sem diferenças entre as areas. A altura e diâmetro do pau-de-balsa, foram maiores em área gradeada, a partir do primeiro ano, chegando no terceiro ano a 11,85 m de altura e 11,42 cm de diâmetro. Na caroba, a diferença ocorreu a partir do segundo ano e no terceiro chegou a 8,37 m de altura e 11,18 cm de diâmetro. Além de outros fatores inerentes às espécies, o solo mais friável das áreas gradeadas, possibilitou um maior crescimento em altura e diâmetro das duas espécies estudadas.

The objective of experiment was study the growth of pioneer forest species pau-de-balsa (Ochroma lagopus) and caroba (Jacaranda copaia) to rehabilitate degraded areas from agriculture. The experiment carried out at Br-174, km 120. After the use for cassava and banana plantations the area was abandoned for 8 years. The secondary forest that took place was of low height and sparse trees. The experiment was installed at may/98 and composed by harrowed and no harrowed areas. The seedlings were planted in 3 x 3 m spacing, in 20 cm diameter by 30 cm deep holes, with 150g of fertilizer NPK (4-16-8) and dolomite limestone in the proportion 3:1. To evaluation the growth were measured the height and diameter in july/98 and each year, approximately (June/99, September/00 and May/01). The data were obtained from planted species comparing harrowed and no harrowed areas in a full random design. The survival of pau-de-balsa, was greater in harrowed area (97,1%) in relation to no harrowed area (92,5%) after one year of planting; and the survival of caroba, was 90% after one year of planting and showed no difference when compared the harrowed and no harrowed areas. The height and diameter of pau-de-balsa were greater in harrowed area after one year of planting, reaching 11.85 m and 11.42 cm, respectively. The differences occurred in caroba trees after the second year of planting, and reached, in the third year, 8.37 m of high and 11,18 cm in diameter. Besides other factors inherent to the species, the more friable soil of the harrowed area, facilitated higher growth to two studied species.

O objetivo deste trabalho foi avaliar o desempenho de mudas de caroba (Jacaranda copaia (Aubl.) D. Don.), jatobá (Hymenaea courbaril L.) e pau-de-balsa (Ochroma lagopus (Cav. ex. Lam.) Urban) sob diferentes níveis de sombreamento, em viveiro. O experimento foi realizado na Estação Experimental de Silvicultura Tropical (EEST) do Inpa, em Manaus, AM. O delineamento experimental foi em blocos ao acaso, com cinco tratamentos: dois tratamentos com 50% de sombra durante 15 e 30 dias, respectivamente, e o restante do período a pleno sol (0%), e três tratamentos com sombreamento a 30, 50 e 70%, respectivamente, obtido com o uso de telas de polipropileno, de cor preta. Foram avaliados o diâmetro do colo, a altura total da parte aérea das mudas, o comprimento das raízes, a massa de matéria seca de raízes, caule e folhas, a área foliar e as relações altura/diâmetro do colo e parte aérea/sistema radicular. Hymenaea courbaril teve seu crescimento prejudicado quando cultivada sob 70% de sombra. As mudas de Ochroma lagopus e Jacaranda copaia apresentaram maior crescimento sob sombra, porém a qualidade das mudas foi prejudicada. Na tomada de decisão sobre qual sombreamento a ser usado, devem ser considerados, principalmente, os parâmetros que refletem um crescimento equilibrado da muda como um todo e um bom desenvolvimento radicular.

The objective of this paper was to assess the development of Jacaranda copaia (Aubl.) D. Don., Hymenaea courbaril L. and Ochroma lagopus (Cav. ex. Lam.) Urban seedlings under different shade levels in the nursery. The experiment was carried out at Experimental Station of Tropical Silviculture (EEST) of Inpa, in Manaus, AM, Brazil. The experiment design was fully randomised blocks with five treatments: two treatments with 50% of shading during 15 and 30 days, respectively and the remaining period under full sun light (0%) and three treatments under 30, 50 and 70% shade, respectively by using black polypropylene screen. Stem diameter, seedling height, root length, leaf area, dry mass of leaves, root and stem, shoot/root ratio and height/diameter ratio were assessed. Hymenaea courbaril had its growth affected under 70% of shade. Ochroma lagopus and Jacaranda copaia seedlings increased their growth under shade, but seedlings quality was poor. In choosing shade levels to grow seedlings, shoot/root ratio and development of root system should be considered.