Growth and Ages of Regenerating Native Species Under Plantation of Araucaria angustifolia in Parana State

ABSTRACT This study aimed to use dendrocronology techniques to recover the diameter growth and the average age of tree species established under an Araucaria angustifolia stand, planted in 1949 in the Irati National Forest, Paraná state. We obtained samples of 30 regenerating trees of the species Araucaria angustifolia, 24 regenerating trees of the species Cedrela fissilis, 24 regenerating trees of the species Clethra scabra, 22 regenerating trees of the species Ilex paraguariensis and 18 regenerating trees of the species Ocotea puberula. The Chapman-Richards model was used to describe the growth curves in diameter by species and curves of mean annual increment (MAI) and current annual increment (CAI) were constructed. Species showed a great potential for dendrochronological studies and the use of this technique allowed determining that natural regeneration began in 1958 and it had an average of 34 years old. The technique also allowed restore growth by species, generating annual growth rates, which identified the characteristic years of high and low growth.

摘要 本研究旨在借助树木年代学（Dendrochronology）技术，恢复1949年栽植于巴西巴拉那州伊拉蒂国家森林的巴西松（Araucaria angustifolia）人工林内定植树种的直径生长量与平均树龄。本研究共采集30株天然更新的巴西松、24株天然更新的洋椿（Cedrela fissilis）、24株天然更新的糙叶山柳（Clethra scabra）、22株天然更新的巴拉圭冬青（Ilex paraguariensis）以及18株天然更新的柔毛奥寇梯木（Ocotea puberula）样本。本研究采用Chapman-Richards模型（Chapman-Richards model）描述各树种的直径生长曲线，并构建了平均年增长量（Mean Annual Increment, MAI）与连年年增长量（Current Annual Increment, CAI）曲线。研究结果显示，各树种均具备开展树木年代学研究的巨大潜力；通过该技术可确定该人工林的天然更新始于1958年，林木平均树龄为34年。此外，该技术还可还原各树种的生长过程，生成年度生长速率，进而识别出生长高低峰的特征年份。