scholarly journals The response of fine root morphological and physiological traits to added nitrogen in Schrenk’s spruce (Picea schrenkiana) of the Tianshan mountains, China

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8194 ◽  
Author(s):  
Lu Gong ◽  
Jingjing Zhao
Keyword(s):  
Fine Roots ◽  
Fine Root ◽  
Root Traits ◽  
Nitrogen Addition ◽  
Tianshan Mountains ◽  
Physiological Traits ◽  
Control Group ◽  
N Addition ◽  
Soil Layers ◽  
Morphological And Physiological Traits

Fine roots are essential for water and nutrient uptake in plants, but little is known about the variation in fine root traits and the underlying mechanisms that drive it. Understanding the responses of fine root function traits to changing environmental conditions and the role of fine root traits as drivers of forest ecosystem processes are critical for informing physiological and ecological theory as well as ecosystem management. We measured morphological and physiological traits of fine roots from six soil layers and three diameter classes in Schrenk’s spruce (Picea shrenkiana) forests of the Tianshan mountains, China. We found significant effects of nitrogen addition on these morphological and physiological traits, which varied by soil layer and root diameter. Specifically, specific root length (SRL) was higher in medium N addition group (N2) than in control group (N0). Specific root area (SRA) was higher in the control group (N0) than fertilized groups (N1, N2 and N3). Root tissue density (RTD) was higher in low N addition group (N1) than in the other group. Root dry matter content had no significant difference among four treatment groups. SRL, SRA, and RTD of fine roots in different diameter classes were all significantly different between high N addition (N3) and the control (N0) groups. The physiological characteristics of fine roots showed that soluble sugar (SS), fine root vitality (FRV), and tissue water content (TWC) in different soil layers were higher in the control group than in the fertilized groups. While soluble protein (SP), malondialdehyde (MDA) and free proline (FP) were lower in the control group (N0) than in the fertilized groups. In addition, SS, FRV, SP, TWC, FP, and MDA in all N addition treatments groups were significantly different from the control group. Fine root morphological traits were closely related to physiological traits, and added nitrogen inputs change these correlations. Our study confirms that nitrogen addition has specific effects on the morphological and physiological traits of fine roots of Schrenk’s spruce, and the effects of N addition vary according to the amount added.

scholarly journals 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

2009 ◽  
Vol 55 (No. 12) ◽  
pp. 556-566 ◽  
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 (<I>Picea abies</I> [L.] Karst.) and European beech (<I>Fagus sylvatica</I> 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.

scholarly journals Functional Trait Plasticity but Not Coordination Differs in Absorptive and Transport Fine Roots in Response to Soil Depth

Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 42
Author(s):  
Yan Wang ◽  
Zhongyue Li ◽  
Zhengquan Wang ◽  
Jiacun Gu
Keyword(s):  
Fine Roots ◽  
Environmental Changes ◽  
Soil Depth ◽  
Specific Root Length ◽  
Root Traits ◽  
Functional Trait ◽  
Resource Exploitation ◽  
Soil Layers ◽  
Root Branching ◽  
Trait Plasticity

Absorptive and transport fine roots (diameter ≤ 2 mm) differ greatly in anatomy, morphology, and physiology, as well as their responses to environmental changes. However, it is still not well understood how their functional traits and biomass repartition respond to resource variability associated with increasing soil depth. Herein, we sampled the first five order roots of three hardwoods, i.e., Juglans mandshurica Maxim., Fraxinus mandshurica Rupr., and Phellodendron amurense Rupr. at surface (0–10 cm) and subsurface (20–30 cm) soil layers, respectively, and measured root biomass, anatomy, morphology, chemistry, and physiology at the branch-order level. Based on the anatomical characteristics, absorptive and transport fine roots were identified within each order, and their amounts and functional trait plasticity to soil depth were examined. The results showed that across soil layers, the first three order roots were mainly absorptive roots, while the fourth- and fifth-order roots were transport ones. From surface to subsurface soil layers, both the number and biomass proportion of absorptive fine roots decreased but those of transport fine roots increased. Transport fine root traits were more plastic to soil depth than absorptive ones, especially for the conduit-related traits. Absorptive fine roots in surface soil generally had stronger potential for resource acquisition than those in deeper soil, as indicated by their longer specific root length and greater root branching density. In comparison, transport fine roots in deeper soil were generally enhanced in their transportation function, with wider stele and higher hydraulic conductivity. Our findings suggest that functional specialization via multi-trait plasticity and coordination in both absorptive and transport fine roots along the soil depth would benefit the efficient soil resource exploitation of trees in forest ecosystems.

scholarly journals Differential variation of NSCs in root branch orders of Fraxinus mandshurica Rupr. seedlings across different drought intensities and soil substrates

2021 ◽  
Author(s):  
Li Ji ◽  
Yue Liu ◽  
Jun Wang ◽  
Zhimin Lu ◽  
Yuchun Yang ◽  
...  
Keyword(s):  
Fine Roots ◽  
Fine Root ◽  
Sandy Loam ◽  
Starch Content ◽  
Soluble Sugar ◽  
Root Traits ◽  
Drought Intensity ◽  
Branch Order ◽  
Root Branch Order ◽  
Loam Soil

Non-structural carbohydrates (NSCs) facilitate plants adapt to drought stress, could characterize trees growth and survival ability and buffer against external disturbances. Previous studies have focused on the distribution and dynamics of NSCs among different plant organs under drought conditions. However, discussion about the NSC levels of fine roots in different root branch order were little, especially the relationship between fine root trait variation and NSCs content. The aim of the study is to shed light into the synergistic variation of fine root traits and NSC content in different root branch order under different drought and soil substrate conditions. 2-year-old Fraxinus mandshurica Rupr. potted seedlings were planted in three different soil substrates (humus, loam and sandy-loam soil) and conducted to four drought intensities (CK, mild drought, moderate drought and severe drought) for two months. With the increase of drought intensity, the biomass of fine roots decreased significantly. Under the same drought intensity, seedlings in sandy-loam soil have higher root biomass, and the coefficient of variation of fifth-order roots (37.4%, 44.5% and 53.0% in humus, loam and sandy loam, respectively) is higher than that of lower-order roots. With the increase of drought intensity, the specific root length (SRL) and average diameter (AD) of all five orders increased and decreased, respectively. The fine roots in humus soil had higher soluble sugar content and lower starch content. Also, the soluble sugar and starch content of fine roots showed decreasing and increasing tendency respectively. Soluble sugar and starch explain the highest degree of total variation of fine root traits, that is 32.0% and 32.1% respectively. With ascending root order, the explanation of the variation of root traits by starch decreased (only 6.8% for fifth-order roots). The response of different root branch order fine root morphological traits of F. mandshurica seedlings to resource fluctuations ensures that plants maintain and constructure the root development by an economical way to obtain more resources.

scholarly journals Root biomass of Fagus sylvatica L. stands depending on the climatic conditions

2016 ◽  
Vol 58 (4) ◽  
pp. 220-227 ◽  
Author(s):  
Dorota Grygoruk
Keyword(s):  
Fagus Sylvatica ◽  
Fine Roots ◽  
Root Biomass ◽  
Fine Root ◽  
Soil Layer ◽  
Fine Root Biomass ◽  
Climatic Conditions ◽  
Forest Trees ◽  
Soil Layers ◽  
Fagus Sylvatica L

Abstract Fine root biomass of forest trees is a recognised indicator of environmental changes in the conditions of global climate change. The present study was carried out in six old-growth beech forests (112-140 years) located in different climatic conditions on the range border of Fagus sylvatica L. in Poland. The root biomass was investigated by soil coring method in the upper soil layers (0-5 cm, 5-15 cm and total layer 0-15 cm). The significantly greater total root biomass was found in the beech stands, which characterised by higher average precipitation and lower average annual temperatures in the period 2000-2005. The share of roots of diameter > 5 mm increased with increasing depth of top soils. Biomass of fine roots (diameter ≤ 2 mm) decreased with increasing depth of upper soil layers. The average biomass of fine roots ranged from 175.36 to 418.16 g m-2 in the soil layer 0-15 cm. The significant differences of fine root biomass were found between studied stands in the soil layers 0-5 cm and 0-15 cm. Also, it was found significant positive correlation between fine root biomass in the soil layer 0-15 cm and precipitation during the growing season in 2006. Precipitation in the study period was connected with very high rainfall in August 2006, repeatedly exceeding the long-term monthly levels. Regional climatic conditions, in that extreme weather events in growing seasons can significantly to affect changes of fine root biomass of forest trees, consequently, changes of relationships between the growth of above- and below-ground of the old-growth forest stands.

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 Intraspecific Fine-Root Trait-Environment Relationships across Interior Douglas-Fir Forests of Western Canada

Plants ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 199 ◽  
Author(s):  
Camille E. Defrenne ◽  
M. Luke McCormack ◽  
W. Jean Roach ◽  
Shalom D. Addo-Danso ◽  
Suzanne W. Simard
Keyword(s):  
Fine Roots ◽  
Fine Root ◽  
Plant Traits ◽  
Regional Scale ◽  
Root Traits ◽  
Specific Area ◽  
Douglas Fir ◽  
Western Canada ◽  
Chemical Traits ◽  
Architectural Traits

Variation in resource acquisition strategies enables plants to adapt to different environments and may partly determine their responses to climate change. However, little is known about how belowground plant traits vary across climate and soil gradients. Focusing on interior Douglas-fir (Pseudotsuga menziesii var. glauca) in western Canada, we tested whether fine-root traits relate to the environment at the intraspecific level. We quantified the variation in commonly measured functional root traits (morphological, chemical, and architectural traits) among the first three fine-root orders (i.e., absorptive fine roots) and across biogeographic gradients in climate and soil factors. Moderate but consistent trait-environment linkages occurred across populations of Douglas-fir, despite high levels of within-site variation. Shifts in morphological traits across regions were decoupled from those in chemical traits. Fine roots in colder/drier climates were characterized by a lower tissue density, higher specific area, larger diameter, and lower carbon-to-nitrogen ratio than those in warmer/wetter climates. Our results showed that Douglas-fir fine roots do not rely on adjustments in architectural traits to adapt rooting strategies in different environments. Intraspecific fine-root adjustments at the regional scale do not fit along a single axis of root economic strategy and are concordant with an increase in root acquisitive potential in colder/drier environments.

scholarly journals Differential Variation in Non-structural Carbohydrates in Root Branch Orders of Fraxinus mandshurica Rupr. Seedlings Across Different Drought Intensities and Soil Substrates

2021 ◽  
Vol 12 ◽  
Author(s):  
Li Ji ◽  
Yue Liu ◽  
Jun Wang ◽  
Zhimin Lu ◽  
Lijie Zhang ◽  
...  
Keyword(s):  
Fine Roots ◽  
Fine Root ◽  
Sandy Loam ◽  
Root Traits ◽  
Sandy Loam Soil ◽  
Fraxinus Mandshurica ◽  
Drought Intensity ◽  
Loam Soil ◽  
Soil Substrates ◽  
Humus Soil

Non-structural carbohydrates (NSCs) facilitate plant adaptation to drought stress, characterize tree growth and survival ability, and buffer against external disturbances. Previous studies have focused on the distribution and dynamics of NSCs among different plant organs under drought conditions. However, discussion about the NSC levels of fine roots in different root branch orders is limited, especially the relationship between fine root trait variation and NSC content. The objective of the study was to shed light on the synergistic variation in fine root traits and NSC content in different root branch orders under different drought and soil substrate conditions. The 2-year-old Fraxinus mandshurica Rupr. potted seedlings were planted in three different soil substrates (humus, loam, and sandy–loam soil) and subjected to four drought intensities (CK, mild drought, moderate drought, and severe drought) for 2 months. With increasing drought intensity, the biomass of fine roots decreased significantly. Under the same drought intensity, seedlings in sandy–loam soil had higher root biomass, and the coefficient of variation of 5th-order roots (37.4, 44.5, and 53% in humus, loam, and sandy–loam soil, respectively) was higher than that of lower-order roots. All branch order roots of seedlings in humus soil had the largest specific root length (SRL) and specific root surface area (SRA), in addition to the lowest diameter. With increasing drought intensity, the SRL and average diameter (AD) of all root branch orders increased and decreased, respectively. The fine roots in humus soil had a higher soluble sugar (SS) content and lower starch (ST) content compared to the loam and sandy–loam soil. Additionally, the SS and ST contents of fine roots showed decreasing and increasing tendencies with increasing drought intensities, respectively. SS and ST explained the highest degree of the total variation in fine root traits, which were 32 and 32.1%, respectively. With increasing root order, the explanation of the variation in root traits by ST decreased (only 6.8% for 5th-order roots). The observed response in terms of morphological traits of different fine root branch orders of F. mandshurica seedlings to resource fluctuations ensures the maintenance of a low cost-benefit ratio in the root system development.

scholarly journals Influence of Fertilizer Management on Sanded Soil and Its Response on Spatial Distribution of fine Roots

2021 ◽  
Vol 9 (2) ◽  
pp. 323
Author(s):  
Huan Pablo De Souza ◽  
Dione Richer Momolli ◽  
Mauro Valdir Schumacher ◽  
Aline Aparecida Ludvichak ◽  
Angélica Costa Malheiros ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Fine Roots ◽  
Fine Root ◽  
Fertilizer Management ◽  
Line Position ◽  
Nutrient Input ◽  
Soil Layers ◽  
Significant Difference ◽  
Physiological Quality

The fine root component, although it represents the lowest proportional biomass in a tree, has an important function in obtaining water and nutrients. In addition, it is an indicator of the physiological quality and growth of a tree. Thus, the objective of the study was to evaluate the spatial distribution of biomass and the density of fine roots in five different fertilizer treatments. The five treatments received increasing amounts of fertilizers. The collections were made between trees in the planting line and between the planting lines. Soil layers of 25 cm x 25 cm x 20 cm (length x width x depth) were collected until reaching a depth of 1 meter. Treatments that had less nutrient input via fertilization showed higher production of fine roots. In general, the line position in the superficial layers showed a higher density of fine roots. There was significant difference between the positions of the land monoliths and between the different layers. Strategically, the lower supply of nutrients via fertilization provided greater investment in the production of fine roots by trees in order to increase the area of absorption and exploration of the soil.

scholarly journals Plasticity of Root Traits under Competition for a Nutrient-Rich Patch Depends on Tree Species and Possesses a Large Congruency between Intra- and Interspecific Situations

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 528
Author(s):  
Zana A. Lak ◽  
Hans Sandén ◽  
Mathias Mayer ◽  
Douglas L. Godbold ◽  
Boris Rewald
Keyword(s):  
Root Growth ◽  
Interspecific Competition ◽  
Intraspecific Competition ◽  
Fine Roots ◽  
Root Biomass ◽  
Extracellular Enzymes ◽  
Fine Root ◽  
Root Traits ◽  
Acer Pseudoplatanus ◽  
High Plasticity

Belowground competition is an important structuring force in terrestrial plant communities. Uncertainties remain about the plasticity of functional root traits under competition, especially comparing interspecific vs. intraspecific situations. This study addresses the plasticity of fine root traits of competing Acer pseudoplatanus L. and Fagus sylvatica L. seedlings in nutrient-rich soil patches. Seedlings’ roots were grown in a competition chamber experiment in which root growth (biomass), morphological and architectural fine roots traits, and potential activities of four extracellular enzymes were analyzed. Competition chambers with one, two conspecific, or two allospecific roots were established, and fertilized to create a nutrient ‘hotspot’. Interspecific competition significantly reduced fine root growth in Fagus only, while intraspecific competition had no significant effect on the fine root biomass of either species. Competition reduced root nitrogen concentration and specific root respiration of both species. Potential extracellular enzymatic activities of β-glucosidase (BG) and N-acetyl-glucosaminidase (NAG) were lower in ectomycorrhizal Fagus roots competing with Acer. Acer fine roots had greater diameter and tip densities under intraspecific competition. Fagus root traits were generally more plastic than those of Acer, but no differences in trait plasticity were found between competitive situations. Compared to Acer, Fagus roots possessed a greater plasticity of all studied traits but coarse root biomass. However, this high plasticity did not result in directed trait value changes under interspecific competition, but Fagus roots grew less and realized lower N concentrations in comparison to competing Acer roots. The plasticity of root traits of both species was thus found to be highly species- but not competitor-specific. By showing that both con- and allospecific roots had similar effects on target root growth and most trait values, our data sheds light on the paradigm that the intensity of intraspecific competition is greater than those of interspecific competition belowground.

Five-year nitrogen addition affects fine root exudation and its correlation with root respiration in a dominant species, Quercus crispula, of a cool temperate forest, Japan

2020 ◽  
Vol 40 (3) ◽  
pp. 367-376 ◽  
Author(s):  
Mioko Ataka ◽  
Lijuan Sun ◽  
Tatsuro Nakaji ◽  
Ayumi Katayama ◽  
Tsutom Hiura
Keyword(s):  
Temperate Forest ◽  
Root Respiration ◽  
Fine Root ◽  
Root Exudation ◽  
Nitrogen Addition ◽  
N Addition ◽  
Quercus Crispula ◽  
C Cycling ◽  
Cool Temperate ◽  
Cool Temperate Forest

Abstract In forest ecosystems, fine root respiration directly contributes to belowground carbon (C) cycling. Exudation from fine roots indirectly affects C cycling via enhanced microbial decomposition of soil organic matter. Although these root-derived C fluxes are essential components of belowground C cycling, how nitrogen (N) addition affects these fluxes and their correlations remains unclear. In this study, fine root exudation, respiration and chemical/morphological traits were measured in a dominant canopy species, Quercus crispula Blume, found in a cool temperate forest, the Tomakomai Experimental Forest, Hokkaido University, which has undergone 5-year N addition. Soil-dissolved organic carbon (DOC) was also measured in both bulk and rhizosphere soils to evaluate the impact of fine root exudation on soil C cycling. Compared with a control plot with no N treatment, fine roots in the N addition plot exhibited larger diameters and higher N concentrations, but lower specific root lengths and areas. On a root-weight basis, respiration was not different between plots, but exudation was slightly higher under N addition. On a root-area basis, exudation was significantly higher in the N addition plot. Additionally, differences in DOC between rhizosphere and bulk soils were two times higher in the N addition plot than the control plot. Although fine root respiration was positively correlated with exudation in both the control and N addition plots, the ratio of exudation C to respiration C decreased after 5-year N addition. Nitrogen addition also affected absolute C allocation to fine root exudation and changed the C allocation strategy between exudation and respiration fluxes. These findings will help enhance predictions of belowground C allocation and C cycling under N-rich conditions in the future.

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