An optimized fine root sampling methodology balancing accuracy and time investment

• Published in: Plant and soil Vol. 366; no. 1/2; pp. 351 - 361
• Main Authors: Berhongaray, G., King, J. S., Janssens, I. A., Ceulemans, R.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01-05-2013; Springer Netherlands; Springer Nature B.V
• Subjects: Agricultural research; Agronomy. Soil science and plant productions; Animal, plant and microbial ecology; Biological and medical sciences; Biomass; Biomedical and Life Sciences; Ecology; Error rates; Forest ecosystems; Forest soils; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Life Sciences; Physiological aspects; Plant Physiology; Plant roots; Plant Sciences; Plant-soil relationships; Planting density; Populus; Proportions; Regular Article; Root biomass; Roots; Roots (Botany); Sampling techniques; Seasons; Soil ecology; Soil samples; Soil Science & Conservation; Soil sciences; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Standard error; Summer; Trees; Winter; Belgium; Spatial error; Root picking time; Sampling time; Auger sampling; Temporal error; Methodology; Harvesting date; Samplings; Error; Optimization; Accuracy; Fine root; Sampling; Soil plant relation; Investment
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-012-1438-6

Aims Tree roots are spatially highly heterogeneous and it thus requires large numbers of samples to detect statistically significant changes in root biomass. The objectives of this study were to understand and quantify the sources of error in the assessment of fine root biomass (<2 mm) during the second year of a highdensity Populus plantation. Methods Soil cores were collected in winter (n=35) and in summer (n=20), and fine roots were picked by hand for varying lengths of time: 1, 2, 5, 20, 40, and 60 min. The root biomass data were used to identify the best combination of the time spent for root picking and the number of samples collected, that minimizes the overall uncertainty (i.e. the combination of the spatial error due to the incomplete sampling and the temporal error due to the incomplete core processing). Results On average, 25 min was enough time to pick 90 % of the fine root biomass in winter, while in summer only 10 min were needed. In winter fewer samples were needed, but more time for picking was necessary as compared to summer when root biomass was higher. Conclusions Fine root sampling can be optimized by minimizing the uncertainty of the biomass estimates and simultaneously decreasing root sampling time investment.