Estimating the mass density of fine roots of trees for minirhizotron-based estimates of productivity

2005 ◽  
Vol 35 (7) ◽  
pp. 1708-1713 ◽  
Author(s):  
Pierre Y Bernier ◽  
Gilles Robitaille ◽  
Danny Rioux
Keyword(s):  
Cross Sections ◽  
Root Length ◽  
Cell Walls ◽  
Fine Roots ◽  
Fine Root ◽  
Mass Density ◽  
Specific Root Length ◽  
Root Diameter ◽  
Soil Cores ◽  
Species Mixture

Allocation of carbon for the production of fine roots is a significant component of the carbon budget within trees. Transformation of fine-root volumes or lengths as seen with minirhizotrons into fine-root mass per unit of horizontal area requires an estimate of the mass density or specific root length of fine roots for the species of interest. We obtained values of mass density of fine roots using three different sampling strategies on temperate and boreal forested sites. The strategies examined were (1) the use of bulk root samples from soil cores, (2) the use of individual roots from seedlings, and (3) the use of individual roots from soil cores. Our results show that the mass density of fine roots taken from seedlings is strongly dependent on root diameter, as shown by the strong drop in mass density with a decrease in diameter in all species examined. However, the dependency of mass density of individual fine roots extracted from soil cores on root diameter varies with the species mixture. Examination of thin cross-sections of roots using microscopy reveals that the proportion of xylem cell walls as a percentage of total cell walls also decreases strongly as root diameter diminishes for seedling fine roots, but that this relationship is not as clear in fine roots obtained from soil cores. We conclude that using the mass density from core fine roots may yield the best estimate of fine-root productivity when deriving such a value from the analysis of minirhizotron images. We also discuss some of the problems associated with the use of specific root length.

scholarly journals The morphological and chemical properties of fine roots respond to nitrogen addition in a temperate Schrenk’s spruce (Picea schrenkiana) forest

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Haiqiang Zhu ◽  
Jingjing Zhao ◽  
Lu Gong
Keyword(s):  
Nitrogen Deposition ◽  
Root Length ◽  
Fine Roots ◽  
Fine Root ◽  
Specific Root Length ◽  
Nitrogen Addition ◽  
Nonstructural Carbohydrates ◽  
High Nitrogen ◽  
Picea Schrenkiana ◽  
Nitrogen Treatment

AbstractFine roots (< 2 mm in diameter) play an important role in belowground ecosystem processes, and their physiological ecology is easily altered by nitrogen deposition. To better understand the response of physiological and ecological processes of fine roots to nitrogen deposition, a manipulation experiment was conducted to investigate the effects of exogenous nitrogen addition (control (0 kg ha−1 a−1), low (5 kg ha−1 a−1), moderate (10 kg ha−1 a−1), and high nitrogen (20 kg ha−1 a−1)) on the biomass, morphological characteristics, chemical elements and nonstructural carbohydrates of fine roots in a Picea schrenkiana forest. We found that most fine roots were located in the 0–20 cm of soil layer across all nitrogen treatment groups (42.81–52.09% of the total biomass). Compared with the control, the biomass, specific root length and specific root area of the fine roots increased in the medium nitrogen treatment, whereas the fine roots biomass was lower in the high nitrogen treatment than in the other treatments. In fine roots, nitrogen addition promotes the absorption of nitrogen and phosphorus and their stoichiometric ratio, while reducing the content of nonstructural carbohydrates. The content of nonstructural carbohydrates in the small-diameter roots (< 1 mm in diamter) in each nitrogen treatment group was lower than that in the large-diameter roots. Correlation analysis showed that soil carbon and nitrogen were positively correlated with fine root biomass and specific root length and negatively correlated with the nonstructural carbohydrates. Our findings demonstrate that medium nitrogen addition is conducive to the development of fine root morphology, while excessive nitrogen can suppress the growth of root systems.

scholarly journals SEASONAL CHANGES IN ASPARAGUS ROOT GROWTH IN CONVENTIONAL AND NOTILL SYSTEMS

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1071b-1071
Author(s):  
Daniel Drost ◽  
Darlene Wilcox-Lee ◽  
Richard Zobel
Keyword(s):  
Root Growth ◽  
Fine Roots ◽  
Fine Root ◽  
Production Systems ◽  
Growing Season ◽  
Published Data ◽  
Soil Cores ◽  
No Till ◽  
Conventional Ct ◽  
Fibrous Roots

Published data on the spatial patterns and periodicity of root growth in asparagus are limited. During the 1989 growing season growth and distribution of both fleshy and fibrous roots were monitored in a 7 year old asparagus planting. Soil cores were removed at 15 cm intervals to a depth of 90 cm at 40 and 80 cm from the plants in asparagus beds which had been maintained under conventional (CT) and no-till (NT) production systems. Fleshy and fine roots were separated from the soil and root length densities calculated. Harvests began in late March and continued at three week intervals until early November. Fine root growth was greater in the NT than CT in all depths and at both locations in March. Greatest lengths of fine roots were at the 15-60 cm depths for both CT and NT. This pattern was consistent throughout the season. Fine root lengths decreased by one half by the middle of the year (July) and remained at those levels until the last harvest (Nov). Fleshy root lengths were more variable, however NT generally had greater lengths than CT. Greatest length of fleshy roots were located in the 15-60 cm depths for both CT and NT treatments. Few fleshy roots were found below the 60 cm depth.

scholarly journals RAINFALL REGIME ON FINE ROOT GROWTH IN A SEASONALLY DRY TROPICAL FOREST

2020 ◽  
Vol 33 (2) ◽  
pp. 458-469
Author(s):  
EUNICE MAIA DE ANDRADE ◽  
GILBERTO QUEVEDO ROSA ◽  
ALDENIA MENDES MASCENA DE ALMEIDA ◽  
ANTONIO GIVANILSON RODRIGUES DA SILVA ◽  
MARIA GINA TORRES SENA
Keyword(s):  
Root Growth ◽  
Root Length ◽  
Fine Roots ◽  
Root Biomass ◽  
Fine Root ◽  
Fine Root Biomass ◽  
Rainfall Regime ◽  
Seasonally Dry ◽  
Fine Root Length ◽  
Fine Root Growth

ABSTRACT Seasonally dry tropical forests (SDTF) usually present dry seasons of eight or more months. Considering the concerns about the resilience of SDTF to climate changes, the objective of this study was to evaluate the effect of the rainfall regime on fine root growth in a SDTF. The experiment started at the end of the wet season (July 2015), when fine roots were evaluated and ingrowth cores were implemented. The temporal growth of fine roots in the 0-30 cm soil layer was monitored, considering the 0-10, 10-20, and 20-30 cm sublayers, through six samplings from November 2015 to July 2017. The characteristics evaluated were fine root biomass, fine root length, fine root specific length, and fine root mean diameter. The significances of the root growths over time and space were tested by the Kruskal-Wallis test (p<0.05). Fine roots (Ø<2 mm) were separated and dried in an oven (65 °C) until constant weight. The root length was determined using the Giaroots software. The fine root biomass in July 2015 was 7.7±5.0 Mg ha-1 and the length was 5.0±3.2 km m-2. Fine root growth in SDTF is strongly limited by dry periods, occurring decreases in biomass and length of fine roots in all layers evaluated. Fine root growth occurs predominantly in rainy seasons, with fast response of the root system to rainfall events, mainly in root length.

Dynamics of fine-root production and mortality of Scots pine in waterlogged peat soil during the growing season

2020 ◽  
Vol 50 (5) ◽  
pp. 510-518
Author(s):  
Tapani Repo ◽  
Timo Domisch ◽  
Jouni Kilpeläinen ◽  
Sirpa Piirainen ◽  
Raimo Silvennoinen ◽  
...  
Keyword(s):  
Scots Pine ◽  
Tree Growth ◽  
Root Length ◽  
Fine Roots ◽  
Time Course ◽  
Fine Root ◽  
Peat Soil ◽  
Growing Season ◽  
Root Production ◽  
Fine Root Length

Excess water in the rooting zone critically reduces tree growth and may even kill trees; however, the relative importance of damage to roots versus aboveground parts and the time course of damage are not well understood. We studied the dynamics of fine-root growth and mortality of 7-year-old Scots pine (Pinus sylvestris L.) saplings affected by a 5-week period of waterlogging (WL) during the growing season. Two out of six WL-exposed saplings survived the treatment. After 1–2 weeks of WL, the mortality of the first-order short roots (usually mycorrhizas) started to increase and the production of these roots started to decrease. WL decreased the longevity of short and long roots. Total root length (especially of fine roots with a diameter < 0.5 mm), specific fine-root length, total root dry mass (including stump), and reverse-flow root hydraulic conductance were lower in WL saplings than in control saplings at the end of the experiment; however, several root traits were similar in control and surviving WL saplings. Because of the high importance of fine roots for tree growth and carbon sequestration, their responses to elevated water tables should be considered in sustainable use and management of boreal peatland forests, for example, by continuous cover forestry and (or) ditch network maintenance.

scholarly journals The role of fine‐root mass, specific root length and life span in tree performance: A whole‐tree exploration

2020 ◽  
Vol 34 (3) ◽  
pp. 575-585 ◽  
Author(s):  
Monique Weemstra ◽  
Natasa Kiorapostolou ◽  
Jasper Ruijven ◽  
Liesje Mommer ◽  
Jorad Vries ◽  
...  
Keyword(s):  
Life Span ◽  
Root Length ◽  
Fine Root ◽  
Specific Root Length ◽  
Root Mass ◽  
Tree Performance ◽  
Whole Tree

scholarly journals Comparative Analysis of Root System Morphology in Tomato Rootstocks

2017 ◽  
Vol 27 (3) ◽  
pp. 319-324 ◽  
Author(s):  
David H. Suchoff ◽  
Christopher C. Gunter ◽  
Frank J. Louws
Keyword(s):  
Image Analysis ◽  
Abiotic Stress ◽  
Root System ◽  
Root Length ◽  
Specific Root Length ◽  
Root Diameter ◽  
Image Analysis System ◽  
Ancillary Benefits ◽  
Main Effect ◽  
Analysis System

At its most basic, grafting is the replacement of one root system with another containing more desirable traits. Grafting of tomato (Solanum lycopersicum) onto disease-resistant rootstocks is an increasingly popular alternative for managing economically damaging soilborne diseases. Although certain rootstocks have demonstrated ancillary benefits in the form of improved tolerance to edaphic abiotic stress, the mechanisms behind the enhanced stress tolerance are not well understood. Specific traits within root system morphology (RSM), in both field crops and vegetables, can improve growth in conditions under abiotic stress. A greenhouse study was conducted to compare the RSM of 17 commercially available tomato rootstocks and one commercial field cultivar (Florida-47). Plants were grown in containers filled with a mixture of clay-based soil conditioner and pool filter sand (2:1 v/v) and harvested at 2, 3, or 4 weeks after emergence. At harvest, roots were cleaned, scanned, and analyzed with an image analysis system. Data collected included total root length (TRL), average root diameter, specific root length (SRL), and relative diameter class. The main effect of cultivar was significant (P ≤ 0.05) for all response variables and the main effect of harvest date was only significant (P ≤ 0.01) for TRL. ‘RST-106’ rootstock had the longest TRL, whereas ‘Beaufort’ had the shortest. ‘BHN-1088’ had the thickest average root diameter, which was 32% thicker than the thinnest, observed in ‘Beaufort’. SRL in ‘Beaufort’ was 60% larger than ‘BHN-1088’. This study demonstrated that gross differences exist in RSM of tomato rootstocks and that, when grown in a solid porous medium, these differences can be determined using an image analysis system.

scholarly journals The Right-Skewed Distribution of Fine-Root Size in Three Temperate Forests in Northeastern China

2022 ◽  
Vol 12 ◽  
Author(s):  
Cunguo Wang ◽  
Ivano Brunner ◽  
Junni Wang ◽  
Wei Guo ◽  
Zhenzhen Geng ◽  
...  
Keyword(s):  
Tree Species ◽  
Fine Roots ◽  
Fine Root ◽  
Root Diameter ◽  
Northeastern China ◽  
Skewed Distribution ◽  
Root Number ◽  
First Order ◽  
Fine Root Length ◽  
Root Size

Trees can build fine-root systems with high variation in root size (e.g., fine-root diameter) and root number (e.g., branching pattern) to optimize belowground resource acquisition in forest ecosystems. Compared with leaves, which are visible above ground, information about the distribution and inequality of fine-root size and about key associations between fine-root size and number is still limited. We collected 27,573 first-order fine-roots growing out of 3,848 second-order fine-roots, covering 51 tree species in three temperate forests (Changbai Mountain, CBS; Xianrendong, XRD; and Maoershan, MES) in Northeastern China. We investigated the distribution and inequality of fine-root length, diameter and area (fine-root size), and their trade-off with fine-root branching intensity and ratio (fine-root number). Our results showed a strong right-skewed distribution in first-order fine-root size across various tree species. Unimodal frequency distributions were observed in all three of the sampled forests for first-order fine-root length and area and in CBS and XRD for first-order fine-root diameter, whereas a marked bimodal frequency distribution of first-order fine-root diameter appeared in MES. Moreover, XRD had the highest and MES had the lowest inequality values (Gini coefficients) in first-order fine-root diameter. First-order fine-root size showed a consistently linear decline with increasing root number. Our findings suggest a common right-skewed distribution with unimodality or bimodality of fine-root size and a generalized trade-off between fine-root size and number across the temperate tree species. Our results will greatly improve our thorough understanding of the belowground resource acquisition strategies of temperate trees and forests.

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