An improved tool for the fabrication of dendrometer bands to estimate growth as function of treatments in slow growing native Prosopis stands

Abstract

Silvicultural research on slow growing hardwoods, especially hardwoods in semi-arid ecosystems is complicated by the slow growth rates that require long time periods to measure treatment responses. Difficulty in measuring small growth increments with traditional methods results in large measurement errors requiring many replications over long time spans. Permanently mounted dendrometers with a vernier scale can detect diameter changes of 0.25 mm (0.01 in.) and are useful tool for these applications. A tool described by Liming [Liming, F.G., 1957. Homemade dendrometers, J. For. 55, 555–577.] can be used to construct inexpensive, precise dendrometers. Unfortunately this tool is difficult to fabricate due to the very thin slots 0.254 mm (0.01 in.). Additionally, the stylus for this dendrometer is very narrow (<0.25 mm) and not very robust. We report a design for a dendrometer whose slots are five times as wide that is easier to fabricate. The stylus for the new dendrometer is machined on a lathe and is five times thicker and more robust. This paper reports the use of this dendrometer that can measure increase or decrease of 0.25 mm (0.01 in.) in diameter. When used in conjunction with sampling and regression equation development, this system measured significant treatment differences in growth for total biomass and volume in stands that only grew from 1.2 to 2.7 mm in basal diameter per year.