Understanding bark thickness variations for Araucaria angustifolia in southern Brazil  

作　　者：Emanuel Arnoni Costa Veraldo Liesenberg César Augusto Guimaraes Finger AndréFelipe Hess Cristine Tagliapietra Schons 

机构地区：[1]Graduate Program in Forest Engineering,Santa Catarina State University(UDESC),Lages,SC 88520-000,Brazil [2]Department of Forest Engineering,Federal University of Uberlandia(UFU),Monte Carmelo,MG 38500-000,Brazil [3]Graduate Program in Forest Engineering,Federal University of Santa Maria(UFSM),Santa Maria,RS 97105-900,Brazil [4]Graduate Program in Agroecosystems,Federal Technological University of Parana(UFTPR),Dois Vizinhos,PR 85660-000,Brazil

出　　处：《Journal of Forestry Research》2021年第3期1077-1087,共11页林业研究（英文版）

基　　金：This study is supported by the Graduate Program in Forest Engineering of the Santa Catarina State University(UDESC);the Santa Catarina Research Foundation(FAPESC;2017TR1762,2017TR639,2019TR816);the Brazilian National Council for Scientifi c and Technological Development(CNPq;313887/2018-7);the Coordination for the Improvement of Higher Education Personnel(CAPES).

摘　　要：This study aimed to understand bark thickness variations of Araucaria angustifolia(Bertol.)Kuntze trees growing in natural forest remnants in southern Brazil,and their relationship with quantitative and qualitative attributes.Bark thickness must be accurately estimated in order to determine timber volume stocks.This is an important variable for the sustainable management and conservation of araucaria forests.In spite of its importance and visibility,bark thickness variations have not been evaluated for this key species in southern Brazil.A total of 104 trees were selected,and their qualitative and quantitative attributes such as diameter at breast height(D_(BH)),height(H),crown base height(C_(BH)),crown length(C_(L)),social position(S_(P)),stoniness(S_(T)),position on the relief(P_(R)),vitality(V_T)and branch arrangement(B_(A))were measured.The trees were categorized into two groups:red bark or gray bark.Regression analysis and artificial neural networks(ANN)were used for modelling bark thickness.The results indicate that:(1)bark thickness showed good correlation to D_(BH),with 0.76 as coefficient of determination(RS_P),0.540 as Mean Absolute Error(M_(AE))and 22.4 root-meansquare error in percentage(R_(MSE%));(2)the trend changed according to bark colour,with significant differences for the intersection(_0–Pr>F:p=0.0124)and slope(β_(1)–Pr>F:p=0.0126)of bark thickness curves between groups;(3)the highest correlation of bark thickness was found with:D_(BH)(ρ=0.88),H(ρ=0.58),C_(BH)(ρ=0.46),S_(P)(ρ=-0.52),and B_(A)(ρ=-0.32);(4)modelling with ANN confirmed high adjustment(R^(2)=0.99)and accuracy(R_(MSE%)=3.0)of the estimates.ANN is an efficient and robust technique for the modelling of various qualitative and quantitative attributes commonly used in forest mensuration.The effective use of ANN to estimate araucaria bark in natural forests reinforces its potential,besides the possibility of application for other forest species.

关 键 词：Dendrometry attributes Crown characteristics Prediction models Bark factor Parana-pine 

分 类 号：S758[农业科学—森林经理学]