Stored carbon partly fuels fine-root respiration but is not used for production of new fine roots

Abstract Global climate change scenarios predict an increase in air temperature, precipitation, and air humidity for northern latitudes. Elevated air humidity may significantly reduce the water flux through forest canopies and affect interactions between water and nutrient uptake. However, we have limited understanding of how altered transpiration would affect root respiration and carbon (C) exudation as fine root morphology acclimates to different water flux. We investigated the effects of elevated air relative humidity (eRH) and different inorganic nitrogen sources (NO3− and NH4+) on above and belowground traits in hybrid aspen (Populus × wettsteinii Hämet-Ahti), silver birch (Betula pendula Roth.), and Scots pine (Pinus sylvestris L.) grown under controlled climate chamber conditions. The eRH significantly decreased the transpiration flux in all species, decreased root mass-specific exudation in pine, and increased root respiration in aspen. eRH also affected fine root morphology, with specific root area increasing for birch but decreasing in pine. The species comparison revealed that pine had the highest C exudation, while birch had the highest root respiration rate. Both humidity and nitrogen treatments affected the share of absorptive and pioneer roots within fine roots; however, the response was species-specific. The proportion of absorptive roots was highest in birch and aspen, the share of pioneer roots was greatest in aspen, and the share of transport roots was greatest in pine. Fine roots with lower root tissue density were associated with pioneer root tips and had a higher C exudation rate. Our findings underline the importance of considering species-specific differences in relation to air humidity and soil nitrogen availability that interactively affect the C input–output balance. We highlight the role of changes in the fine root functional distribution as an important acclimation mechanism of trees in response to environmental change.

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Insitu needle and fine root respiration in mature slash pine (Pinuselliottii) trees

Canadian Journal of Forest Research ◽

10.1139/x91-221 ◽

1991 ◽

Vol 21 (11) ◽

pp. 1589-1595 ◽

Cited By ~ 39

Author(s):

Wendell P. Cropper Jr. ◽

Henry L. Gholz

Keyword(s):

Time Series ◽

Fine Roots ◽

Root Respiration ◽

Fine Root ◽

Time Of Day ◽

Slash Pine ◽

Chamber System ◽

North Central ◽

Central Florida ◽

Respiration Rates

Respiration of needles and surface fine roots was measured in a north central Florida slash pine (Pinuselliottii Engelm. var. elliottii) plantation. A controlled temperature chamber system was used to estimate respiration rates and Q10 values of insitu tissues over a range of 10 to 35 °C. Respiration rates did not differ significantly among seasons, fertilized versus unfertilized plots, or time of day in a diurnal time series (needles). Needle respiration from the lower canopy was less than that from the upper canopy. Fine root respiration measurements were consistent with previously made estimates based on soil CO2 partitioning and trenched plots.

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Influence of Pruning and Irrigation on Root Longevity of `Concord' Vines

HortScience ◽

10.21273/hortsci.33.3.511a ◽

1998 ◽

Vol 33 (3) ◽

pp. 511a-511

Author(s):

L.H. Comas ◽

D.M. Eissenstat ◽

A.N. Lakso ◽

R. Dunst

Keyword(s):

Fine Roots ◽

Fine Root ◽

Cultural Practices ◽

Growing Season ◽

Root Production ◽

Root Dynamics ◽

Supplemental Irrigation ◽

Root Longevity ◽

Root Lifespan ◽

Median Lifespan

Improved cultural practices in grape require a better understanding of root growth and physiology. Seasonal root dynamics were examined in mature `Concord' vines with balanced or minimal-pruning, and with or without supplemental irrigation in Fredonia, N.Y. Fine roots were continuously produced during the growing season starting in mid-June around time of bloom. Roots began to die in September at verasion. Minimal-pruned vines produced more roots than balanced-pruned vines, with the minimal-pruned/unirrigated vines producing the most roots. Irrigation and pruning delayed fine root production at the beginning of the growing season. Peak fine root flush was 16 June to 21 July 1997 for the minimal-pruned/unirrigated treatment, while peak flush was 7 July to 2 Sept. 1997 for balanced-pruned/irrigated treatment. In minimal-pruned vines, many roots were observed down to depths of 120 cm. In contrast, balanced-pruned vines had very few fine roots deeper than 40 cm. From initial observations, median lifespan of fine roots was 5 to 9.5 weeks, depending on treatment and depth in soil. Fine roots lived longer in the top 15-cm than in the 16- to 30-cm layer of soil in all treatments. Both minimal pruning and irrigation increased root lifespan. Fine roots had the shortest lifespan in the balanced-pruned/unirrigated treatment and the longest lifespan in the minimal-pruned/irrigated treatment.

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Observations on early fungal infections with relevance for replant disease in fine roots of the rose rootstock Rosa corymbifera 'Laxa'

Scientific Reports ◽

10.1038/s41598-020-79878-8 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

G. Grunewaldt-Stöcker ◽

C. Popp ◽

A. Baumann ◽

S. Fricke ◽

M. Menssen ◽

...

Keyword(s):

Fine Roots ◽

Woody Plant ◽

Fine Root ◽

Fungal Infections ◽

Thin Sections ◽

Replant Disease ◽

Pot Trials ◽

Worldwide Phenomenon ◽

First Time ◽

The Rose

AbstractReplant disease is a worldwide phenomenon affecting various woody plant genera and species, especially within the Rosaceae. Compared to decades of intensive studies regarding replant disease of apple (ARD), the replant disease of roses (RRD) has hardly been investigated. The etiology of RRD is also still unclear and a remedy desperately needed. In greenhouse pot trials with seedlings of the RRD-sensitive rootstock Rosa corymbifera ‘Laxa’ cultured in replant disease affected soils from two different locations, early RRD symptom development was studied in fine roots. In microscopic analyses we found similarities to ARD symptoms with regards to structural damages, impairment in the root hair status, and necroses and blackening in the cortex tissue. Examinations of both whole mounts and thin sections of fine root segments revealed frequent conspicuous fungal infections in association with the cellular disorders. Particularly striking were fungal intracellular structures with pathogenic characteristics that are described for the first time. Isolated fungi from these tissue areas were identified by means of ITS primers, and many of them were members of the Nectriaceae. In a next step, 35 of these isolates were subjected to a multi-locus sequence analysis and the results revealed that several genera and species were involved in the development of RRD within a single rose plant. Inoculations with selected single isolates (Rugonectria rugulosa and Ilyonectria robusta) in a Perlite assay confirmed their pathogenic relationship to early necrotic host plant reactions, and symptoms were similar to those exhibited in ARD.

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Fine-root distribution of coniferous plantations in relation to site in southern Buenos Aires, Argentina

Canadian Journal of Forest Research ◽

10.1139/x92-209 ◽

1992 ◽

Vol 22 (11) ◽

pp. 1575-1582 ◽

Cited By ~ 20

Author(s):

Adrián Ares ◽

Norman Peinemann

Keyword(s):

Organic Matter ◽

Vertical Distribution ◽

Root Distribution ◽

Fine Roots ◽

Buenos Aires ◽

Fine Root ◽

Organic Matter Content ◽

Root Density ◽

Site Quality ◽

Coniferous Plantations

A study was conducted to determine the amounts and vertical distribution of fine roots <2 mm as a function of site quality in a temperate, hilly zone of Argentina. Fine roots were sampled in autumn from 0.2-ha plots established in 12 coniferous plantations of Pinushalepensis Mill., Pinusradiata D. Don, Cedrusdeodara (D. Don) G. Don, and Cupressussempervirens L.f. horizontalis, located in Sierra de la Ventana, southern Buenos Aires. Generally, root density was found to be higher under low-growth stands. The distance from a tree sometimes had an effect on root density, but no clear pattern within stands could be observed. Root density commonly decreased with depth, but slight irregularities in some profiles were observed. Site quality and soil type influenced root distribution. Belowground biomass up to a depth of 50 cm ranged from 1600 to 9800 kg•ha−1 in high-growth stands and from 5400 to 40 700 kg•ha−1 in low-growth stands. Soil organic matter content provided the best correlation with root density. A possible practical implication would be the use of indices related to vertical distribution of organic matter, among other variables, as complementary estimators of effective depth of rooting. The results strongly suggest that trees maintain a large fine-root system in poor sites at the expense of aboveground growth.

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Fine root biomass and nutrient content in a black spruce peat soil with and without alder

Canadian Journal of Soil Science ◽

10.4141/s96-097 ◽

1998 ◽

Vol 78 (1) ◽

pp. 163-169 ◽

Cited By ~ 14

Author(s):

J. S. Bhatti ◽

N. W. Foster ◽

P. W. Hazlett

Keyword(s):

Fine Roots ◽

Root Biomass ◽

Fine Root ◽

Black Spruce ◽

Peat Soil ◽

Chemical Properties ◽

Nutrient Content ◽

Fine Root Biomass ◽

Boreal Peatlands ◽

Strong Positive Relationship

Vertical distribution of fine root biomass and nutrient content was examined within a black spruce (Picea mariana) stand growing on a boreal peat soil in northeastern Ontario. The influence of site physical and chemical properties on fine root biomass production was assessed. More then 80% of the fine roots were present in moss plus the top 10 cm of peat where nutrients and aeration are most favourable. The fine root biomass (W/V) was significantly higher with alder (5.9 kg m−3) (Alnus rugosa) as understory vegetation compared to non-alder locations (2.9 kg m−3). Total nutrient content in fine roots was 54, 3.2, 5.4, 63 and 5.7 kg ha−1 on the alder site and 20, 1.4, 2.3, 28 and 4.2 kg ha−1 of N, P, K, Ca, and Mg on the non-alder site, respectively. The mass (W/V) of nutrients in fine roots was strongly dependent upon the availability of nutrients in the peat. Fine root content had a strong positive relationship with peat available P and exchangeable K contents suggesting that P and K may be limiting nutrients for black spruce in this peat soil. Key words: Nitrogen, phosphorus, potassium, boreal peatlands, aeration, water table

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Desiccation Tolerance of Green Ash and Sugar Maple Fine Roots

Journal of Environmental Horticulture ◽

10.24266/0738-2898-27.4.229 ◽

2009 ◽

Vol 27 (4) ◽

pp. 229-233 ◽

Cited By ~ 2

Author(s):

Gary W. Watson

Keyword(s):

Root Growth ◽

Fine Roots ◽

Acer Saccharum ◽

Sugar Maple ◽

Fine Root ◽

Cell Damage ◽

Fraxinus Pennsylvanica ◽

Green Ash ◽

Root Electrolyte Leakage ◽

Bare Root

Abstract Exposed fine roots are subject to desiccation, which may affect their survival as well as new root growth following bare root transplanting. Fine roots of dormant 1-year-old green ash (Fraxinus pennsylvanica) and sugar maple (Acer saccharum) seedlings, subjected to desiccation treatments of 0, 1, 2, or 3 hours in December and March, lost up to 82 percent of their water. Root electrolyte leakage, a measure of cell damage, tripled after three hours of desiccation. The increase was moderately, but significantly, greater in March for both species. Desiccation treatments had no effect on fine root survival. Growth of new roots (RGP) was also unaffected by desiccation treatments. RGP of maple was greater in March than December, but not ash.

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Carbon allocation in early successional tree species at elevated air humidity and different soil nitrogen sources

10.5194/egusphere-egu21-8217 ◽

2021 ◽

Author(s):

Marili Sell ◽

Ivika Ostonen ◽

Gristin Rohula-Okunev ◽

Azadeh Rezapour ◽

Priit Kupper

Keyword(s):

Biomass Allocation ◽

Tree Species ◽

Root Respiration ◽

Fine Root ◽

Silver Birch ◽

Organic Carbon Content ◽

Climate Change Scenarios ◽

Air Humidity ◽

Species Specific ◽

Exudation Rate

Global climate change scenarios predict increasing air temperature, enhanced precipitation and air humidity for Northern latitudes. We&#8239;investigated the effects of elevated air relative humidity (RH) and different inorganic nitrogen&#8239;sources&#8239;(NO3-, NH4+) on above- and belowground traits in different tree species, with particular emphasis on rhizodeposition rates. Silver birch, hybrid aspen and Scots pine saplings were grown in PERCIVAL growth chambers with stabile temperature, light intensity and two different air humidity conditions: moderate (mRH, 65% at day and 80% at night) and elevated (eRH, 80% at day and night). The collection of fine root exudates was conducted by a culture-based cuvette method and total organic carbon content was determined by Vario TOC analyser. Fine root respiration was measured with an infra-red gas analyser CIRAS 2.&#8239;&#160;We analysed species-specific biomass allocation, water and rhizodeposition fluxes, foliar and fine root traits in response to changing environmental conditions. The&#8239;eRH&#8239;significantly decreased the transpiration flux in all species. In birch the transpiration flux was also affected by the nitrogen source. The average carbon exudation rate for aspen, birch and pine varied from 2 to 3 &#8239;&#956;g&#8239;C g-1&#8239;day&#8239;-1. The exudation rates for deciduous tree species tended to increase at&#8239;eRH, while conversely decreased for coniferous trees (p=0.045), coinciding with the changes in biomass allocation.&#8239;C flux released by fine root respiration varied more than the fine root exudation, whereas the highest root respiration was found in silver birch and lowest in aspen. At eRH the above and belowground&#8239;biomass ratio in aspen increased, at the expense of decreased root biomass and root respiration.&#8239;&#160;Moreover,&#8239;eRH&#8239;significantly affected fine root morphology, whereas the response of specific root area was reverse for deciduous and coniferous tree species. However, fine roots with lower root tissue density had higher C exudation rate. Our findings underline the importance of considering species-specific differences by&#8239;elucidating tree&#8217;s&#8239;acclimation&#8239;to environmental factors and their&#8239;interactions.&#8239;&#8239;&#160;

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Differences in fine root traits between Norway spruce (Picea abies [L.] Karst.) and European beech (Fagus sylvatica L.) – A case study in the Kysucké Beskydy Mts

Journal of Forest Science ◽

10.17221/10/2009-jfs ◽

2009 ◽

Vol 55 (No. 12) ◽

pp. 556-566 ◽

Cited By ~ 7

Author(s):

B. Konôpka

Keyword(s):

Picea Abies ◽

Norway Spruce ◽

Fagus Sylvatica ◽

Seasonal Dynamics ◽

Fine Roots ◽

Fine Root ◽

Root Traits ◽

European Beech ◽

Root Turnover ◽

Mortality Ratio

Interspecific comparisons of the fine root “behaviour” under stressful situations may answer questions related to resistance to changing environmental conditions in the particular tree species. Our study was focused on Norway spruce (Picea abies [L.] Karst.) and European beech (Fagus sylvatica L.) grown in an acidic soil where acidity was caused by past air pollution in the Kysucké Beskydy Mts., North-Western Slovakia. Between April and October 2006, the following fine root traits were studied: biomass and necromass seasonal dynamics, vertical distribution, production, mortality, fine root turnover and production to mortality ratio. Sequential soil coring was repeatedly implemented in April, June, July, September, and October including the soil layers of 0–5, 5–15, 15–25, and 25–35 cm. Results indicated that spruce had a lower standing stock of fine roots than beech, and fine roots of spruce were more superficially distributed than those of beech. Furthermore, we estimated higher seasonal dynamics and also higher turnover of fine roots in spruce than in beech. The production to mortality ratio was higher in beech than in spruce, which was hypothetically explained as the effect of drought episodes that occurred in July and August. The results suggested that the beech root system could resist a physiological stress better than that of spruce. This conclusion was supported by different vertical distributions of fine roots in spruce and beech stands.

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