Analyzing canopy structure in Pacific Northwest old-growth forests with a stand-scale crown model

Abstract

In fofe\ts.the cmopt is the locxle of critical ccoslslcrn procc\ses such as photos) nthesi\ xnd evapotranspifation, rnd it prolides essential habitat ibr .highl] dilcrsc ana! of animal!. plants, and other organisms.Despite it\ impofirnce.the structure of the canopy as a $hole has had lildc quantiratirc nudy because limited acce\s makes quantificatl1r| difficuh and irtegfaiion of det.riled nersures of nary individual trcc cro$ns is nccsssar\'.A inodel is presented fof simulaiing the cro\ln architectufe of individual tree\ in the Prcific Nofihwest to unalyze their collcclilc nilucncc on canopv sirucrure at the ltand scale.Ihe model ules ground-based mer\ufements of tree height.height to crown basc.lnd crown radii.Crown shapcs are modeled as \olid gcometric shapes based on these measures.Tur exanples.rcused to illuslrare thc nodcl s applicalionsi an cslimadon ol thc venical disribution of foliage in an old-grorv{h Douglas-lir^vestem hennock ibr.sl: and m cstrmarion ol undcrslory ljgh! condi tions in an exferimental gap, made by appLying fty trtrcirg rechnology ro a modcl ol rhc o!!'rstor!lrcc cro$ns.Bolh examples illurrate ho\r the N)del can increase del|il in the descipdm ol canopy slr'ucturc.Furlher application and luture testing of the nmdel $ i11 helD reliDe its Drecision.