Biomass Allocation and Root Characteristics of Early-Stage Poplars (Populus spp.) for Assessing Their Water-Deficit Response During SRC Establishment

Abstract

Early above- and belowground biomass fractionation, root diameter composition and allocation of cumulated fine root length per total leaf area of Populus clones have been measured for a pre-assessment of the risk for plantation establishment during spring drought conditions. Four clones of Populus × euramericana, and one P. nigra × P. maximowiczii clone (cv. Max 3), were planted in sandy mix substrate and were exposed to one normal and one deficit watering regime over 65-day greenhouse experiments conducted during early summer. The P. × euramericana hybrids showed plasticity of their root biomass fractions. Although clone Max 3 was among the productive clones, even under deficit watering, it was not able to respond plastically to deficit watering. It showed no increase in the root biomass fraction and no increase in the ratio of cumulated fine root length per total leaf area. Therefore, the clone Max 3 should not be planted under high risk for spring drought. Planting the investigated P. × euramericana clones under water deficit likely involves a lower risk, but clone differences within this group must be considered. It can be concluded that the water deficit response of biomass allocation to roots and of the ratio of fine root length per unit leaf area is suitable traits to improve drought risk assessments that are based on yield response of poplar clones to drought. Percent plant loss data and the yield at the end of the first SRC rotation will be suitable to verify the present greenhouse assessment.

Soil water availability affects the vertical distribution of fine roots in poplar short rotation coppice

“…The results of this study add new novelty data with some of the published results from poplar plantations in Europe, in particular, in the vertical distribution of ne root biomass and production under different soil moisture scenarios. Some studies have reported that drought stress can lead to a decrease in root production and in poplar trees (Meyer et al, 2021;Regier et al, 2009). As young roots generally are physiologically more active, an increase in root turnover can increase the water use e ciency, but with an additional carbon cost (Eissenstat, Wells, Yanai, & Whitbeck, 2000).…”

Manipulating grading strategy for the efficient harvesting of industrial poplar plantations

“…Both plantations were 5-year-old poplar stands established at a square spacing of 3.0 m x 2.0 m with the hybrid poplar (Populus x euramericana Dode (Guinier)). Clone 'AF16' was planted in Nivky, and clone 'AF18' in Gajary (Heilig et al 2021, Landgraf et al 2020, Meyer et al 2021.…”

A cost-benefit analysis of pre-sorting using a feller-buncher in underdeveloped short rotation poplar plantations

“…The test plantation was located in Pernek (48° 23' 55.04" N;17° 04' 43.97" E in WGS84), few kilometers northeast of the plant (48° 25' 01.81" N; 17° 02' 06.95"E). It was a 6-year-old poplar stand established at a square spacing of 3.0 m x 2.0 m with hybrid poplar (Populus x euramericana Dode (Guinier)), using the following mix of similar clones: AF13, AF 16 and AF18 (Landgraf et al 2020, Meyer et al 2021. The trees were planted on an ex-arable field, on flat and even terrain.…”