Nanoindentation Testing

Abstract

A simultaneous autoregressive model (SAR) was used to evaluate theamount of spatial influence juvenile loblolly pine (Pinus taeda L.)stems in a plantation have on one another. The presence of spatialautocorrelation between stems in a stand indicates that the characteristicsof one stem are related to the characteristics of neighboring stems.The stands evaluated in this study had planting densities that variedfrom 747 to 6,727 trees per hectare. The SAR model contains a spatialdependency parameter that captures the inter-tree influences. Analysison detrended diameter data showed that across ages 2 to 5 for groundlinediameter measurements and ages 5 to 11 for breast height diametermeasurements, the simultaneous autoregressive model indicated significantspatial dependency parameters in 23.2% of the plots (alpha-level 0.10). A generally increasing trend in the occurrence of significantspatial influence from 18.2% to 28.4% was noted with an increasein planting density from 747 to 3,364 trees per hectare, beyond whichthe trend decreased. Estimation of the spatial dependency parameterwill aid in describing juvenile competition processes and developinga more precise representation of juvenile forest stands.