scholarly journals Fine Root Mortality Increased by Earthquake Induced Landslides

2016 ◽  
Vol 05 (03) ◽  
pp. 172-176 ◽  
Author(s):  
Yinping Bai ◽  
Gang Yang
Keyword(s):  
Fine Root ◽  
Root Mortality

Impact of tephra deposition on growth in conifers: the year of the eruption

1984 ◽  
Vol 14 (5) ◽  
pp. 731-739 ◽  
Author(s):  
Thomas M. Hinckley ◽  
Hiromi Imoto ◽  
Katharine Lee ◽  
Susan Lacker ◽  
Yasushi Morikawa ◽  
...  
Keyword(s):  
Fine Root ◽  
Height Growth ◽  
Diameter Growth ◽  
Growth Reduction ◽  
Root Mortality ◽  
Foliar Damage ◽  
Associated Species ◽  
The Impact ◽  
Total Tree ◽  
Mount St Helens

Seven sites ranging from 15 to 135 km from Mount St. Helens were selected to study the impact of air-fall tephra on the growth of Abiesamabilis (Dougl.) Forbes, A. procera Rehd., Pseudotsugamenziesii (Mirb.) Franco, Tsugaheterophylla (Raf.) Sarg., and T. mertensiana (Bong.) Carr. As tephra depth increased, there was a corresponding increase in visible foliar damage and associated decreases in diameter and height growth. Reduction in diameter growth was greater than reduction in height growth. The reduction in diameter growth approached 50% in both trees and saplings of A. amabilis. Growth reduction in true firs was greater than in associated species. This difference was related to their greater capacity for interception and retention of air-fall tephra. Damage to trees, and resulting growth reductions, were due to tephra coverage of both the foliage and the soil. Coverage of the foliage resulted in foliar damage, foliage abscission and reduction of total tree foliar area, and increased fine root mortality. Tephra coverage of the soil had the potential to restrict oxygen diffusion into the soil. However, soil oxygen concentrations less than 10% were measured only once over a 2-year period.

Root production, mortality and turnover in soil profiles as affected by clipping in a temperate grassland on the Loess Plateau

2019 ◽  
Vol 12 (6) ◽  
pp. 1059-1072
Author(s):  
Lin Wei ◽  
Pengwei Yao ◽  
Guanghua Jing ◽  
Xiefeng Ye ◽  
Jimin Cheng
Keyword(s):  
Loess Plateau ◽  
Soil Profile ◽  
Root Length ◽  
Root Biomass ◽  
Turnover Rate ◽  
Fine Root ◽  
Root Production ◽  
The Loess Plateau ◽  
Soil Layers ◽  
Root Mortality

Abstract Aims Clipping or mowing for hay, as a prevalent land-use practice, is considered to be an important component of global change. Root production and turnover in response to clipping have great implications for the plant survival strategy and grassland ecosystem carbon processes. However, our knowledge about the clipping effect on root dynamics is mainly based on root living biomass, and limited by the lack of spatial and temporal observations. The study aim was to investigate the effect of clipping on seasonal variations in root length production and mortality and their distribution patterns in different soil layers in semiarid grassland on the Loess Plateau. Methods Clipping was performed once a year in June to mimic the local spring livestock grazing beginning from 2014. The minirhizotron technique was used to monitor the root production, mortality and turnover rate at various soil depths (0–10, 10–20, 20–30 and 30–50 cm) in 2014 (from 30 May to 29 October) and 2015 (from 22 April to 25 October). Soil temperature and moisture in different soil layers were also measured during the study period. Important Findings Our results showed that: (i) Clipping significantly decreased the cumulative root production (P < 0.05) and increased the cumulative root mortality and turnover rates of the 0–50 cm soil profile for both years. (ii) Clipping induced an immediate and sharp decrease in root length production and an increase in root length mortality in all soil layers. However, with plant regrowth, root production increased and root mortality decreased gradually, with the root production at a depth of 30–50 cm even exceeding the control in September–October 2014 and April–May 2015. (iii) Clipping mainly reduced root length production and increased root length mortality in the upper 0–20 cm soil profile with rapid root turnover. However, roots at deeper soil layers were either little influenced by clipping or exhibited an opposite trend with slower turnover rate compared with the upper soil profile, leading to the downward transport of root production and living root biomass. These findings indicate that roots in deeper soil layers tend to favour higher root biomass and longer fine root life spans to maximize the water absorption efficiency under environmental stress, and also suggest that short-term clipping would reduce the amount of carbon through fine root litter into the soil, especially in the shallow soil profile.

scholarly journals Changes in the risk of fine-root mortality with age: a case study in peach, Prunus persica (Rosaceae)

2002 ◽  
Vol 89 (1) ◽  
pp. 79-87 ◽  
Author(s):  
Christina E. Wells ◽  
D. Michael Glenn ◽  
David M. Eissenstat
Keyword(s):  
Prunus Persica ◽  
Fine Root ◽  
Root Mortality

scholarly journals Fine Root Production and Mortality in Apple over Winter

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 603d-603
Author(s):  
Christina E. Wells ◽  
David M. Eissenstat
Keyword(s):  
Fine Roots ◽  
Fine Root ◽  
Cortical Cell ◽  
Root Production ◽  
Bud Burst ◽  
Apple Trees ◽  
Root Mortality ◽  
Root Lifespan ◽  
Central Pennsylvania ◽  
Allocation Patterns

Fine root lifespan has previously been estimated at 3 to 4 weeks for apple trees growing in England. We used nondestructive belowground imaging technology to investigate the accuracy of this estimate for apple trees growing in central Pennsylvania. Eight root observation tubes (minirhizotrons) were installed beneath each of six 20-year-old `Red Delicious' apple trees on M26 rootstock. Videos of roots growing against the tubes were taken at intervals of 14 to 28 days between October to June, depending on the amount of root activity. Images were used to construct a database of life history information for over 500 individual roots. A flush of fine roots was produced in the early fall, followed by a period of low but constant mortality that lasted through December. Roots that survived to this time were generally maintained throughout the winter and following spring. A second flush of root production occurred in the spring, coinciding with bud burst and flowering. Root mortality was highest in late spring following this flush. In contrast to earlier estimates of apple root lifespan, we found that >30% of the fine roots produced in the fall lived for ≥200 days. Most of these roots developed red-brown pigmentation, a feature that previously has been associated with cortical cell death. However, the ability of these pigmented roots to produce new white laterals in the spring argues against categorizing these as dead roots. The information on root demographics provided by this study adds to our understanding of seasonal carbon and nutrient allocation patterns in apple.

scholarly journals Fine-root mortality rates in a temperate forest: estimates using radiocarbon data and numerical modeling

2009 ◽  
Vol 184 (2) ◽  
pp. 387-398 ◽  
Author(s):  
W. J. Riley ◽  
J. B. Gaudinski ◽  
M. S. Torn ◽  
J. D. Joslin ◽  
P. J. Hanson
Keyword(s):  
Numerical Modeling ◽  
Temperate Forest ◽  
Fine Root ◽  
Mortality Rates ◽  
Root Mortality ◽  
Radiocarbon Data

Infection of Douglas-fir by Leptographium wageneri

2000 ◽  
Vol 78 (10) ◽  
pp. 1254-1261 ◽  
Author(s):  
Paul F Hessburg ◽  
Everett M Hansen
Keyword(s):  
Coming Out ◽  
Phase Contrast ◽  
Fine Root ◽  
Douglas Fir ◽  
Infection Frequency ◽  
Vascular Wilt ◽  
Direct Path ◽  
Root Mortality ◽  
Lateral Root Initiation ◽  
Potting Medium

In three related experiments, root systems of 2-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were dip-inoculated with a viscous blend of Leptographium wageneri var. pseudotsugae Harrington and Cobb spores and hyphal fragments and planted in a sterile potting medium. Infection frequency and points of entry were evaluated for dormant seedlings and seedlings that had been active for 4 and 8 weeks. All putative black stain infections and other areas of sapwood discoloration were free-hand sectioned and examined with a bright-field microscope and phase-contrast optics. This technique was shown to be 100% reliable in a prior experiment with 223 inoculated Douglas-fir seedlings that paired microscope examinations with pathogen isolation. In this study, all lesions were sectioned and examined at 250-1000 diameters magnification for the presence of L. wageneri var. pseudotsugae hyphae and characteristic pathological anatomy. Complete root system dissections revealed that L. wageneri var. pseudotsugae infected roots through wounds and natural openings where a direct path to the xylem was exposed and never penetrated living cortical or cambial tissues to infect its host. Among the dormant inoculated seedlings, 63% of infections occurred through wounds associated with nursery handling. Wound infection frequency decreased to zero in seedlings inoculated 8 weeks after coming out of dormancy. Seedlings inoculated 4 and 8 weeks after coming out of dormancy were most frequently infected through openings occurring at sites of new lateral root initiation. Infection of dead fine root stubs suggested that during periods of increased fine root mortality, these sites may be important for the new infection of healthy trees and egress from already diseased trees.Key words: Black-stain root disease, Leptographium wageneri, Verticicladiella wagnerii, infection courts, wounding, vascular wilt.

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