Amostragem para inventário florestal em sistemas silvipastoris

Abstract

RESUMO -O inventário florestal, segundo diversos processos de amostragem, fornece estimativas de produção para todo povoamento florestal. Neste trabalho, testaram-se diferentes processos de amostragem em um sistema silvipastoril com arranjo em faixas de Eucalyptus grandis, no Município de Umuarama, noroeste do Paraná. A distribuição das plantas de E. grandis foi explotada para mapa em escala da área, no qual aplicaram-se diferentes técnicas de amostragem: amostragem aleatória simples (com parcelas retangulares paralelas -ALS-RPA, perpendiculares às faixas -ALS-RPE, e parcelas circulares -ALS-AC) e amostragem sistemática (com 5%, 10% e 20% de intensidade, respectivamente, AS-5, AS-10 e AS-20). Para comparação dos processos de amostragem, foi considerado o erro de amostragem (E%), segundo o qual verificou-se a melhor metodologia. Os resultados observados, demonstraram que os maiores E% foram obtidos na amostragem aleatória simples: ALS-C (61,64%), ALS-RPA (47,30%) e ALS-RPE (31,19%). Para a amostragem sistemática, o E% observado foi baixo: AS-10 (6,05%), AS-20 (7,04%) e AS-5 (12,49%). Desta forma, a amostragem sistemática foi eficiente em inventário florestal de sistemas silvipastoris por seu baixo E%.Palavras-chave: Silvicultura, Amostra e Estimadores. (with 5%, 10% and 20% of intensity, respectively,. For comparison among sampling processes, the sampling error (E%) was considered, according to which it was verified to be the best methodology. The observed results showed that the greatest E% were obtained in the simple random sampling: ALS-C (61.64%), and . For the systematic sampling, it was observed smaller E% values: , and . The systematic sampling is efficient in forest inventory in silvopastoral system due to its low E%. SAMPLING FOR FOREST INVENTORY IN SILVIPASTORAL SYSTEMS ABSTRACT -Forest inventory, according to many sampling processes, produces production estimates for the entire forest stand. In this work, it was tested many sampling processes in a silvopastoral system with band arrangements of Eucalyptus grandis in Umuarama, northeastern Paraná. The distribution of E. grandis bands were plotted in a map in aerial scale, in which it was applied some different sampling techniques: simple random sampling (with parallel rectangular plots -ALS-RPA, perpendicular to the bands -ALS-RPE, and circular plots -ALS-C), and systematic sampling

Sampling Alternatives for Eucalyptus Trees in Integrated Crop-Livestock-Forest System

“…There was precision superiority in the fixed-area method based on systematic sampling and smaller sample units holding few measurable trees. This result corroborated Fick (2011) and Dias (2014), who noticed that small sample units can be used in forest inventories in ICLF systems.…”

“…The time saved due to the adoption of proportional distance selection methods allows applying a larger sample and it provides better forest area coverage (Gomes et al, 2011). However, circular samples (as used in the Prodan's Method) are not the most suitable for ICLF because the most part of its area is not occupied by forest species (Fick, 2011). The advantage of having a smaller perimeter and of minimizing marginal-tree occurrences (Loetsch et al, 1973) is of little importance for the commonly adopted arrangements in ICLF systems, since the problem concerning marginal trees planted in rows, with one or more lines is irrelevant.…”

“…Few studies have focused on the inventory of trees in ICFL systems. Authors such as Fick (2011) and Dias (2014) were pioneers in studying tree sampling in these production systems. Fick (2011) recommended applying the systematic sampling to 10% of the trees in a silvopastoral system by considering each tree as a sampling unit.…”

“…Authors such as Fick (2011) and Dias (2014) were pioneers in studying tree sampling in these production systems. Fick (2011) recommended applying the systematic sampling to 10% of the trees in a silvopastoral system by considering each tree as a sampling unit. Dias (2014) used the modified method of maximum curvature of the coefficient of variation and recommended adopting sample units with seven to eight eucalyptus trees planted in double and triple row arrangements.…”

Sampling methods for titica vine (Heteropsis spp.) inventory in a tropical forest

“…Studies sampling approaches for inventory are typically focused on analysis and ecological processes in the form of phenological or regeneration evaluations (D'Eça-Neves and Morellato 2004;Gama et al 2001) and/or the stock of wood in natural forests (Cavalcanti et al 2011;Piqué et al 2011) and plantations (Druszcz et al 2010;Fick 2011).…”