Empowering Forest Owners with Simple Volume Equations for Poplar Plantations in the Órbigo River Basin (NW Spain)

Abstract

Hybrid poplar plantations are becoming increasingly important as a source of income for farmers in northwestern Spain, as rural depopulation and farmers aging prevent landowners from planting other labor-intensive crops. However, plantation owners, usually elderly and without formal forestry background, lack of simple tools to estimate the size and volume of their plantations by themselves. Therefore, farmers are usually forced to rely on the estimates made by the timber companies that are buying their trees. With the objective of providing a simple, but empowering, tool for these forest owners, simple equations based only on diameter were developed to estimate individual tree volume for the Órbigo River basin. To do so, height and diameter growth were measured for 10 years (2009–2019) in 404 trees growing in three poplar plantations in Leon province. An average growth per tree of 1.66 cm year−1 in diameter, 1.52 m year−1 in height, and 0.03 m3 year−1 in volume was estimated, which translated into annual volume increment of 13.02 m3 ha−1 year−1. However, annual volume increment was different among plots due to their fertility, with two plots reaching maximum volume growth around 11 years since planting and another at 13 years, encompassing the typical productivity range in plantations in this region. Such data allowed developing simple but representative linear, polynomial and power equations to estimate volume explaining 93%–98% of the observed variability. Such equations can be easily implemented in any cellphone with a calculator, allowing forest owners to accurately estimate their timber existences by using only a regular measuring tape to measure tree diameter. However, models for height were less successful, explaining only 75%–76% of observed variance. Our approach to generate simplified volume equations has shown to be viable for poplar, but it could be applied to any species for which several volume equations are available.

Dieback and stability loss of old-growth Populus × euramericana in urban environments: Case study Železnički park, Novi Sad

“…P × euramericana introdukovana je u Srbiju 1950-ih godina prošlog veka, a u urbanim sredinama se najčešće sreću klon "I-214" i kultivar "Robusta" atraktivne, piramidalne krošnje. Kao brzorastuća vrsta velike biomase i tolerancije na teške metale pruža izuzetne mogućnosti za sekvestraciju ugljenika, ali i za fitoremedijaciju (Galić et al 2008;Tsarev et al 2020; Blanco et al 2021). Ova topola osetljiva je na razna oboljenja lista i stabla, uključujući pegavost lišća koju uzrokuje patogena gljiva Drepanopeziza brunnea (Ellis & Everh.)…”

Forests for a Better Future: Sustainability, Innovation and Interdisciplinarity

“…Robinia pseudoacacia plantations for the rehabilitation of post-mining lignite areas in northwestern Greece were evaluated in terms of above-ground biomass and deadwood, indicating low biomass accumulation in bruised trees and deadwood, due to their young age (5-30 years) [12]. Blanco and Blanco [13] developed simple volume equations for hybrid poplar plantations in the Órbigo river basin (NW Spain), providing a simple but acceptably accurate tool to empower aging rural owners when estimating standing volume by themselves. The feasibility of a harvesting system for small-diameter trees as forest biomass was investigated in Japan [14].…”

Comparison of Scots pine growth dynamics in Polissya and Steppe zone of Ukraine

“…In the study Vysotska et al (2021) assessed the current state and evaluated the productivity of white poplar (Populus alba L.) stands per natural zones within Ukraine. Blanco and Blanco (2021) developed representative linear and polynomial equations to estimate the volume of poplar plantations within Spain.…”