Soil respiration (Rs) is important in the carbon cycle; it is regarded as an indicator of plant metabolism due to its close relationship with biological activity in the soil. However, this component lacks rigorous experimental studies considering its use as a drought indicator. This study evaluated the Rs and increment diameter breast height (iDBH) of Eucalyptus globulus and E. nitens x globulus (high and low yield), E. nitens, E. badjensis, E. smithii, and E. camaldulensis x globulus in drought conditions (~25% over the permanent wilting point). Measurements were carried out from 2020 to 2023 (7 to 9-year-old plants); Rs was measured monthly with a chamber LICOR-8200s; iDBH was evaluated seasonally. The results showed an annual Rs of 0.75 to 1.42 gC/m2 and iDBH of 0.4 to 14.4 mm, with maximum values in the summer (December to February) and minimum in the winter (June to August). Also, a strong correlation between Rs and DBH increment (r-value=0.88) is explained with the equation iDBH=1.29*Rs (R2=0.85, p-value=0.002). This resulted in three groups: i.) E. globulus and E. nitens x globulus (low productivity) hads high drought susceptibility with minimum Rs and iDBH values (average 0.83 gC/m2/yr and 0.85 mm/yr, respectively); ii.) E. nitens, E. badjensis, E. smithii, and E. camaldulensis x globulus with moderated drought susceptibility with average Fs of 1.08 gC/m2/yr and iDBH of 9.60 mm/yr.; and iii.) E. globulus and E. nitens x globulus (high productivity) were classified as low drought susceptible maximum Rs and iDBH (average 1.38 gC/m2/yr and 13.8 mm/yr, respectively). Our results suggest that Rs is an ideal trait to differentiate Eucalyptus genotype susceptibility to drought and its effect on growth.
Previous Article in event
Previous Article in session
Next Article in event
Use of soil respiration as a trial of drought susceptibility in Eucalyptus genotypes
Published:
19 January 2024
by MDPI
in The 3rd International Electronic Conference on Plant Sciences
session Plant Modeling and Bioinformatics
Abstract:
Keywords: Soil respiration; productivity; drought; modelation