193 Fine Root Turnover and Mycorrhizal Morphotypes in Loblolly Pine (Pinus taeda L.)

Loblolly pine (Pinus taeda L.) is the most widely planted tree species in the Atlantic Coastal Plain. To maximize its aboveground yield, it is vital to understand how root production, particularly fine root production, affects root carbon allocation to its root systems under various environmental conditions. Over a 2-year period (1998-99), we conducted a field study using minirhizotron technology to investigate fine root production and turn over in four families of a 6-year-old loblolly pine stand in Scotland County, N.C. A total of 144 minirhizotron tubes were installed to examine potential genetic differences in fertilizer effects on fine root turnover. Data analyses indicated an interaction between these families and fertilizer treatments for total fine root length and total fine root number. The effect of treatment on total root length was less clear in the faster-growing families. However, fertilization increased total root length in a slow-growing family but decreased total root length in a faster-growing family. Total root number was decreased by fertilizer treatment in the two fastest-growing families, but increased in the two slowest-growing families. Because ectomycorrhizae are significant carbon sinks in pine root systems and more than 90% of short roots in these loblolly pine families were colonized, ectomycorrhizal short roots (clusters) were classified into nine different morphotypes. No treatment and family interactions were found. Fertilizer treatment decreased the number of mycorrhizal clusters per unit root length. Dark and brown morphotypes were dominant mycorrhizal morphotypes among all the families. Our results suggest possible genetic differences and treatment effects on root system carbon demands of loblolly pine.

Download Full-text

CARBON AND NUTRIENT CYCLING THROUGH FINE ROOTS IN RUBBER (HEVEA BRASILIENSIS) PLANTATIONS IN INDIA

Experimental Agriculture ◽

10.1017/s0014479713000203 ◽

2013 ◽

Vol 49 (4) ◽

pp. 556-573 ◽

Cited By ~ 6

Author(s):

M. D. JESSY ◽

P. PRASANNAKUMARI ◽

JOSHUA ABRAHAM

Keyword(s):

Soil Moisture ◽

Nutrient Cycling ◽

Fine Roots ◽

Fine Root ◽

Nutrient Status ◽

Root Turnover ◽

Root Production ◽

Fine Root Production ◽

Fine Root Turnover ◽

Rubber Plantations

SUMMARYUnderstanding the growth dynamics of fine roots and their contribution to soil organic carbon and nutrient pools is crucial for estimating ecosystem carbon and nutrient cycling and how these are influenced by climate change. Rubber is cultivated in more than 10 million hectare globally and the area under rubber cultivation is fast expanding due to socio-economic reasons, apart from the importance given to this species for eco-restoration of degraded lands. An experiment was conducted to quantify fine root production, fine root turnover and carbon and nutrient cycling through fine roots in rubber plantations with different soil nutrient status and rainfall pattern. Fine root production was estimated by sequential coring and ingrowth core methods. Fine root decomposition was determined by the litter bag technique. Carbon and nutrient contents in fine roots were determined and their turnover was computed. Fine root biomass in the top 0–7.5-cm soil layer showed significant seasonal fluctuation and the fluctuations were particularly wide during the transition period from the dry season to the rainy season. Fine root production estimated by the different methods was significantly higher at the lower fertility site and during the higher soil moisture stress year. Fine root turnover ranged from 1.04 to 2.29 year−1. Root carbon and nutrient status showed seasonal variation and lower status was observed during the rainy season. The annual recycling of C, N, P, K, Ca and Mg through fine roots ranged from 590 to 1758, 30 to 85, 3 to 12, 13 to 31, 11 to 35 and 6 to 13 kg ha−1, respectively. Substantial quantities of carbon and nutrients were recycled annually in rubber plantations through fine roots. When soil moisture and nutrient stress were more severe, fine root production, turnover and carbon and nutrient recycling through fine roots were higher.

Download Full-text

Contributions of fine root production and turnover to the carbon and nitrogen cycling in taiga forests of the Alaskan interior

Canadian Journal of Forest Research ◽

10.1139/x26-148 ◽

1996 ◽

Vol 26 (8) ◽

pp. 1326-1336 ◽

Cited By ~ 159

Author(s):

R.W. Ruess ◽

K. Van Cleve ◽

J. Yarie ◽

L.A. Viereck

Keyword(s):

Fine Roots ◽

Fine Root ◽

Organic N ◽

Root Turnover ◽

Root Production ◽

Total Production ◽

Fine Root Production ◽

Litter Fall ◽

Fine Root Turnover ◽

Taiga Forests

Fine root production and turnover were studied in hardwood and coniferous taiga forests using three methods. (1) Using soil cores, fine root production ranged from 1574 ± 76 kg•ha−1•year−1 in the upland white spruce (Piceaglauca (Moench) Voss) stand to 4386 ± 322 kg•ha−1•year−1 in the floodplain balsam poplar (Populusbalsamifera L.) stand, accounting for 49% of total production for coniferous stands and 32% of total production for deciduous stands. Fine root turnover rates were higher in floodplain (0.90 ± 0.06 year−1) stands than in upland (0.42 ± 0.10 year−1) stands. Across all sites, the ratio of fine root turnover to litter fall averaged 2.2 for biomass and 2.8 for N. Both values were higher in floodplain stands than in upland stands, and in coniferous stands than in deciduous stands. (2) The C budget method showed that C allocation to fine roots varied from 150 to 425 g C•m−2•year−1 and suggested that soil respiration was more dependent on C derived from roots than from aboveground inputs. The C allocation ratio (C to roots: C to litter fall) was inversely correlated with litter-fall C and varied from 0.3 to 69.5; there was a tendency for higher proportional belowground allocation in coniferous stands than in deciduous stands and the highest levels were at the earliest successional sites. (3) Estimates of apparent N uptake (Nu), N allocation to fine roots, and fine root production based on N budget calculations showed that annual aboveground N increments exceeded Nu estimates at half the sites, indicating that the method failed to account for large amounts of N acquired by plants. This suggests that plant and (or) mycorrhizal uptake of soil organic N may be more significant to ecosystem N cycling than mineral N turnover by the soil microbial biomass.

Download Full-text

Fine root standing stock and production in young beech and spruce stands

Forestry Journal ◽

10.2478/v10114-011-0023-x ◽

2013 ◽

Vol 59 (3) ◽

Cited By ~ 1

Author(s):

Bohdan Konôpka ◽

Jozef Pajtík ◽

Miriam Maľová

Keyword(s):

Fine Roots ◽

Fine Root ◽

Soil Depth ◽

Standing Stock ◽

Maximum Diameter ◽

Root Turnover ◽

Root Production ◽

Fine Root Production ◽

Turnover Rates ◽

Fine Root Turnover

AbstractFine roots (defined by a maximum diameter of 2 mm) and assimilatory organs are the compartments which rotate carbon much faster than any other tree part. We focused on quantification of fine roots in young European beech and Norway spruce trees growing under the same ecological conditions. Standing stock of fine roots was estimated by soil coring during 2009 - 2012. Fine root production was established by the in-growth bag method. Standing stock and productions of fine roots were comparable in both tree species. The quantity of fine root biomass (at a soil depth of 0 -50 cm) varied inter-annually between 6.08 and 7.41 t per ha in the beech and from 5.10 to 6.49 t per ha in the spruce stand. Annual production of fine roots (soil depth of 0 - 30 cm) was between 1.11 and 1.63 t ha-1 in beech and between 0.95 and 1.54 t.ha-1 in spruce. We found that fine root standing stock at the beginning of each growing season was related to climatic conditions in the previous year. Annual fine root production was influenced by the climatic situation of the current year. In general, a maximum standing stock of fine roots as well as a relatively slow fine root turnover is expected in young forest stands. Whereas production of fine roots prevailed over mortality in a favorable year (sufficiency of precipitations and slightly above-average temperatures in 2010), there was a reverse situation in an unfavorable year (drought episodes in 2011). We concluded that although both forest types represented contrasting turnovers of assimilatory organs (once a year and once in 5 years in beech and spruce respectively), fine root turnover rates were very similar (approx. once per four years).

Download Full-text

Water‐phosphorus coupling enhances fine root turnover and dry matter yield of alfalfa under drip irrigation

Agronomy Journal ◽

10.1002/agj2.20782 ◽

2021 ◽

Author(s):

Xuanshuai Liu ◽

Junwei Zhao ◽

Junying Liu ◽

Weihua Lu ◽

Chunhui Ma ◽

...

Keyword(s):

Drip Irrigation ◽

Dry Matter ◽

Fine Root ◽

Root Turnover ◽

Dry Matter Yield ◽

Fine Root Turnover

Download Full-text

Measuring and modeling the spectrum of fine-root turnover times in three forests using isotopes, minirhizotrons, and the Radix model

Global Biogeochemical Cycles ◽

10.1029/2009gb003649 ◽

2010 ◽

Vol 24 (3) ◽

pp. n/a-n/a ◽

Cited By ~ 65

Author(s):

Julia B. Gaudinski ◽

M. S. Torn ◽

W. J. Riley ◽

T. E. Dawson ◽

J. D. Joslin ◽

...

Keyword(s):

Fine Root ◽

Root Turnover ◽

Fine Root Turnover

Download Full-text

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

Journal of Plant Ecology ◽

10.1093/jpe/rtz039 ◽

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.

Download Full-text

Biomass Allocation to Resource Acquisition Compartments Is Affected by Tree Density Manipulation in European Beech after Three Decades

Forests ◽

10.3390/f11090940 ◽

2020 ◽

Vol 11 (9) ◽

pp. 940

Author(s):

Bohdan Konôpka ◽

Milan Barna ◽

Michal Bosela ◽

Martin Lukac

Keyword(s):

Fine Root ◽

Standing Stock ◽

European Beech ◽

Forest Harvesting ◽

Tree Density ◽

Resource Acquisition ◽

Root Turnover ◽

Root Production ◽

Fine Root Production ◽

Mature Forest

This study reports on an investigation of fine root and foliage productivity in forest stands dominated by European beech (Fagus sylvatica L.) and exposed to contrasting intensities of mature forest harvesting. The main aim of this study was to consider the long-term effects of canopy manipulation on resource acquisition biomass compartments in beech. We made use of an experiment established in 1989, when five different light availability treatments were started in plots within a uniform forest stand, ranging from no reduction in tree density to full mature forest removal. We measured fine root standing stock in the 0–30 cm soil layer by coring in 2013 and then followed annual fine root production (in-growth cores) and foliage production (litter baskets) in 2013–2015. We found that the plot where the tree density was reduced by 30% had the lowest foliage and the highest fine root production. In 2013, this plot had the highest fine root turnover rate (0.8 year−1), while this indicator of fine root dynamics was much lower in the other four treatments (around 0.3 year−1). We also found that the annual fine root production represented around two thirds of annual foliage growth on the mass basis in all treatments. While our findings support the maintenance of source and sink balance in woody plants, we also found a long-lasting effect of tree density manipulation on investment into resource acquisition compartments in beech forests.

Download Full-text