Fine Root Morphological Traits Research Articles

Fine-root morphology of woody and herbaceous plants responds differently to altered precipitation: A meta-analysis

The growth of plant roots and their acquisition of resources are significantly impacted by changes in precipitation patterns. Although numerous studies have examined the impact of precipitation on fine root systems, the rooting strategies of woody and herbaceous plants under different precipitation patterns remain to be comparatively evaluated. Accordingly, in the current study, we conducted a meta-analysis of 64 peer-reviewed articles to explore the response of 17 biomass and fine-root traits of woody and herbaceous plants to precipitation changes. Our findings demonstrate that woody and herbaceous plants have developed different root strategies to cope with altered precipitation. Specifically, when precipitation increased, the fine roots of woody plants had a larger surface area and significantly increased shallow root growth. In contrast, the fine-root morphological traits of herbaceous plants showed a stronger response to increased precipitation, in which fine-root length, volume, and tissue density increased. This may result in more effective use of available water by herbaceous than woody plants. When precipitation decreased, woody plants displayed more active fine-root morphological alterations, presenting a conservative fine-root phenotype of resource acquisition, with lower specific root length and higher fine-root tissue density. Moreover, woody plants transfer absorptive fine-root structures to deep soil layers, whereas herbaceous plants are less drought-tolerant. Furthermore, woody plants may allocate biomass more optimally than herbaceous plants in precipitation-reduction scenarios. Increased precipitation may boost soil carbon sequestration and stability in woody plant-dominated forest ecosystems under future climate change scenarios, while drought may considerably reduce soil carbon storage in grassland ecosystems. In more arid environments, where woody and herbaceous plants coexist, drought may lead to the expansion of woody plants and subsequent predominance of woody plants vegetation change. our findings will fill knowledge gaps in the literature regarding the effects of precipitation changes on the fine-root dynamics of various functional plants and will improve predictions of the vegetation dynamics of forests, grasslands, and other ecosystems vegetation dynamics under changing precipitation patterns.

Fine-root traits are devoted to the allocation of foliar phosphorus fractions of desert species under water and phosphorus-poor environments.

Traits of leaves and fine roots are expected to predict the responses and adaptation of plants to their environments. Whether and how fine-root traits (FRTs) are associated with the allocation of foliar phosphorus (P) fractions of desert species in water- and P-poor environments, however, remains unclear. We exposed seedlings of Alhagi sparsifolia Shap. (hereafter Alhagi) treated with two water and four P-supply levels for three years in open-air pot experiments and measured the concentrations of foliar P fractions, foliar traits, and FRTs. The allocation proportion of foliar nucleic acid-P and acid phosphatase (APase) activity of fine roots were significantly higher by 45.94 and 53.3% in drought and no-P treatments relative to well-watered and high-P treatments, whereas foliar metabolic-P and structural-P were significantly lower by 3.70 and 5.26%. Allocation proportions of foliar structural-P and residual-P were positively correlated with fine-root P (FRP) concentration, but nucleic acid-P concentration was negatively correlated with FRP concentration. A tradeoff was found between the allocation proportion to all foliar P fractions relative to the FRP concentration, fine-root APase activity, and amounts of carboxylates, followed by fine-root morphological traits. The requirement for a link between the aboveground and underground tissues of Alhagi was generally higher in the drought than the well-watered treatment. Altering FRTs and the allocation of P to foliar nucleic acid-P were two coupled strategies of Alhagi under conditions of drought and/or low-P. These results advance our understanding of the strategies for allocating foliar P by mediating FRTs in drought and P-poor environments.

Fine root morphological traits and production in coniferous- and deciduous-tree forests with drained and naturally wet nutrient-rich organic soils in hemiboreal Latvia

Fine root production is one of the key elements of carbon (C) turnover in soil in afforested peatlands and forest lands with organic soils. We estimated variability in fine root morphology traits and annual production in hemiboreal forests dominated by coniferous trees (Norway spruce) and deciduous trees (silver birch and black alder) with nutrient-rich organic soils in Latvia. In total, 23 research sites were established in drained and naturally wet forests of different ages, and ingrowth core techniques were used to sample fine roots and subsequently determine fine root morphology traits and annual production, and calculate C input through fine root litter. Significant differences in several fine root morphological traits between coniferous- and deciduous-trees-dominated stands were found. Fine root production tended to be higher in coniferous-trees-dominated stands and positively correlated with several forest stand characteristics: stand age, average tree diameter at breast height, basal area and average tree height, but negatively correlated with nitrogen and phosphorus content in soil. C input through fine root litter ranged up to 0.46 ± 0.16 t ha-1 yr-1. It is necessary to conduct further research, including multi-annual estimates in a wider set of forest stands with diverse dominant tree species and growing conditions, to improve estimates, patterns and understanding of C flows through fine root litter in drained and naturally wet organic soils.

Temperature rather than N availability determines root exudation of alpine coniferous forests on the eastern Tibetan Plateau along elevation gradients.

Root exudation fulfills fundamental roles in regulating carbon (C)-nutrient cycling in forest ecosystems, yet the main ecological drivers of root exudation and underlying mechanisms in forests under natural gradients remain poorly understood. Here, we investigated the intraspecific variation of root exudation rates in two alpine coniferous forests (Abies faxoniana and Abies georgei) along two elevation gradients on the eastern Tibetan Plateau. Meanwhile, the fine root traits and associated climate and soil parameters were assessed to examine the effects of elevation-dependent changes in climatic and soil nutrient conditions on root exudation. Results showed that root exudation rates decreased with increasing elevation and were positively correlated with mean air temperature. However, the relationships of root exudation with soil moisture and soil N availability were not significant. The structural equation model (SEM) further revealed that air temperature affected root exudation both directly and indirectly through the effects on fine root morphology and biomass, implying that the adaption of root C allocation and fine root morphological traits to low temperatures primarily resulted in declined root exudation at higher elevations. These results highlight the perceived importance of temperature in determining the elevational variation of root exudation in alpine coniferous forests, which has foreseeably great implications for the exudate-mediated ecosystem C and nutrient processes in the face of drastic warming on the eastern Tibetan Plateau.

Response of Fine-Root Traits of Populus tomentosa to Drought in Shallow and Deep Soil

Understanding the response characteristics of fine roots to soil drought of different degrees is essential for revealing the ecological adaptability of trees to different water environments and diverse plant resource absorption strategies. This study focused on a Chinese white poplar (Populus tomentosa) plantation stand, which gradually experienced the process of deep soil drying. In 2019 and 2021, by measuring the fine-root length density (FRLD), mean root diameter (MRD), specific root length (SRL), and root tissue density (RTD) of 1920 root samples and continuously monitoring the soil water content (SWC) in 0–600 cm soil layers, we explored the response characteristics of fine-root distributions and morphological traits relative to soil drought of different degrees. The results showed that P. tomentosa primarily changed the fine-root vertical distribution rather than the total amount of fine roots for coping with soil drought of different degrees. Shallow soil drought induced more fine-root distributions in the deep soil layer, while drought in both shallow and deep soil further aggravated this trend. Shallow soil drought restrained shallow fine-root growth, yet deep soil drought promoted deep fine-root growth. The very deep fine roots (400–600 cm) were more sensitive to soil drought than shallow fine roots. The shallow soil drought significantly increased the SRL of very deep fine roots; in contrast, when deep soil drought also occurred, the MRD and SRL significantly increased and decreased, respectively. In addition, fine-root morphological traits exhibited significant vertical spatial and temporal variation. MRD increased and then decreased, and the RTD gradually decreased with depth, while SRL had an increased trend in the very deep soil layer (400–600 cm). When the rainy season came, MRD and SRL increased and decreased, respectively. In conclusion, when facing gradual deep soil drying, P. tomentosa will use a large range of rooting patterns to meet the water demand of the canopy. These patterns range from “drought tolerant strategies” by distributing more fine roots in the deeper soil layer where water is abundant to “drought tolerant strategies” by changing very deep fine-root morphological traits to improve water-absorbing and transporting efficiencies. Our findings provide insight into the ecological adaption strategy of tree root systems relative to soil drought of different degrees in arid and semi-arid regions and provide crucial theoretical support for developing water management technologies to cope with deep soil drying under climate change.

The impact of soil warming on fine root trait responses of trees, deciduous vs. coniferous: a meta-analysis

Abstract We compiled data from 149 paired observations from 43 publications and performed a meta-analysis to evaluate the variability of trees’ fine root trait responses under various global soil warming experiments. The impacts of warming magnitude, soil depth, and different tree species (deciduous vs. coniferous), on the responses of fine root biomass (FRB), and fine root morphology were assessed in this study. Our results confirmed that soil warming increased FRB while having no significant effect on fine root morphological traits, such as specific root length (SRL), specific root area (SRA), and diameter (D). The effect of warming on FRB decreased significantly at higher warming magnitude. The effect of tree species was also evident in the response of FRB to soil warming magnitude. Furthermore, warming effects on SRA and D increased in deeper soil horizons. The present meta-analysis provides an improved understanding of trees’ fine roots and the tree species-specific adaptive strategy under future soil warming episodes. Our results suggest that trees will resist the altering soil warming conditions by modifications more in fine root biomass allocation rather than morphological adjustments.

Soil properties and fine root morphological traits in relation to soil particle-size fractions in a broad-leaved beech (Fagus orientalis Lipsky) forest

Soil particle-size fractions play an important influence soil physico-chemical properties, microbial biomass processes as well as fine roots morphological traits in beech forest ecosystem. The objectives of study were to determine how soil texture interacts with soil physico-chemical properties and microbial biomass as well as fine roots traits in oriental beech forest in Guilan province, northern Iran. Five subplots of 400 m2 were randomly selected at a plot of 1 ha. At five different locations, soil samples were collected at depth of 0–20 cm and fine root samples were also taken from beech trees. Results indicated that clay content was positively correlated with carbon, carbon/nitrogen (C/N) ratio, and moisture, but negatively correlated with nitrogen (N) and phosphorous (P). Silt values had significant positive correlation with C/N, and negative correlation with N and P. The microbial biomass carbon/carbon (MBC/C) ratio in soil increased significantly with clay, but microbial biomass nitrogen (MBN) decreased significantly with increasing clay. The MBC/C ratio decreased significantly with sand values in soil at depth 0–20 cm. Results showed that silt value of soil profile was negatively correlated with MBN, but positively with MBN/N ratio. Soil acidic phosphatase concentration was negatively correlated with clay content, but soil alkaline phosphatase was positively correlated with silt. Clay and sand contents were positively correlated with fine root density, fine root biomass, fine root length, and surface root area. Sand content was negatively correlated with fine root volume. The results of research, considering the correlation between soil particle-size fractions and some soil characteristics as well as fine root traits, show that soil texture in oriental beech forest can play an important role in forest stand dynamics.

Effects of combined nitrogen and phosphorus addition on fine root traits of young Machilus pauhoi forest

Both nitrogen (N) and phosphorus (P) are the main limiting elements for plant growth in terrestrial ecosystems. Fine roots play a critical role in plant growth. To reveal the effects of combined N and P addition on fine root traits of Machilus pauhoi, we performed a field N and P addition experiment in the midmonth from April to September in 2016 and 2017 in a 3-year M. pauhoi forest (N and P supply ratios were 8:1, 10:1, 12:1, 15:1). Both fine root morphological traits (specific root length, specific root area, average diameter, root tissue density) and stoichiometric traits (total carbon content, total nitogen content and carbon-nitrogen ratio) were analyzed. The results showed that the effects of combined application of N and P on fine root raits varied with seasons. In June, fertilization significantly increased specific root area, total nitrogen content and specific root length of 0-1 mm fine root, but decreased root tissuse density, carbon-nitrogen ratio and average diameter of 0-1 mm root. The most obvious change of fine root traits in June was found under the treatment with a N and P supply ratio of 12:1. In December, combined N and P addition significantly increased root tissue density, total nitrogen content, carbon-nitrogen ratio as well as fine root biomass with the diameter of 0-1 mm. The results of principal component analysis showed that different N and P supply ratios exerted different effects on the relationships among fine root traits. Fine root traits were distributed at both ends of Axis 1 when treated with 12:1 N:P, while distributed at Axis 1 and Axis 2 under other treaments. There was a significant negative correlation between fine root average diameter variation and the relative plant growh rate. The relationship among fine root traits, and between fine root traits and the relative growth rate of plant biomass were optimally coordinated at the treament with a N:P ratio of 12:1.

Plastic responses of fine root morphology and architecture traits to nitrogen addition in ectomycorrhizal and arbuscular mycorrhizal tree species in an evergreen broadleaved forest.

We measured the morphology traits (specific root length, specific root surface area, root tissue density, average root diameter) and architecture traits (root fork, root fork ratio, increase rate of root length, root tip density, root fork density) of fine roots in two mycorrhiza tree species, Castanopsis faberi (ectomycorrhizal) and Schima superba (arbuscular mycorrhizal), in an evergreen broadleaved forest in the middle subtropical zone. Root bags method was used in an in situ nitrogen deposition experiment. The aim of this study was to reveal the differences in the plastic responses of fine root morphology and architecture traits to nitrogen deposition between the different mycorrhizal trees. The plastic responses of specific root length, specific root surface area and root fork to nitrogen addition decreased from the first-order root to the fourth-order root, while root tissue density showed an opposite pattern. Such a result indicated a trade-off between nutrient acquisition and resource maintenance of different fine root orders. Different mycorrhizal tree species adopted diffe-rent adaptation strategies to the variations of soil nitrogen availability. C. faberi adopted an opportuni-stic strategy, which relied on fine root to improve nutrient absorption efficiency, enhanced the capacity of space expansion and in-situ nutrient absorption to focus on rapid nutrient absorption strategy. S. superba did not change fine root morphological traits through the trade-off between nutrient absorption efficiency and root construction cost, but relied more on the complementarity between mycorrhizal fungi and fine root architecture traits for nutrient acquisition. The differences in the cost of maintaining and constructing fine root C between different mycorrhizal trees led to fine root adopting the most suitable nutrient capture strategy.

Wind intensity affects fine root morphological traits with consequences for plant-soil feedback effects.

Wind influences the development, architecture and morphology of plant roots and may modify subsequent interactions between plants and soil (plant–soil feedbacks—PSFs). However, information on wind effects on fine root morphology is scarce and the extent to which wind changes plant–soil interactions remains unclear. Therefore, we investigated the effects of two wind intensity levels by manipulating surrounding vegetation height in a grassland PSF field experiment. We grew four common plant species (two grasses and two non-leguminous forbs) with soil biota either previously conditioned by these or other species and tested the effect of wind on root:shoot ratio, fine root morphological traits as well as the outcome for PSFs. Wind intensity did not affect biomass allocation (i.e. root:shoot ratio) in any species. However, fine-root morphology of all species changed under high wind intensity. High wind intensity increased specific root length and surface area and decreased root tissue density, especially in the two grasses. Similarly, the direction of PSFs changed under high wind intensity in all four species, but differences in biomass production on the different soils between high and low wind intensity were marginal and most pronounced when comparing grasses with forbs. Because soils did not differ in plant-available nor total nutrient content, the results suggest that wind-induced changes in root morphology have the potential to influence plant–soil interactions. Linking wind-induced changes in fine-root morphology to effects on PSF improves our understanding of plant–soil interactions under changing environmental conditions.

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

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.

Plastic responses of fine root morphological traits of Castanopsis fabri and Castanopsis carlesii to short-term nitrogen addition

Nitrogen deposition will affect the morphology of fine roots and its absorption of nutrien-ts, resulting in changes nutrient cycling in terrestrial ecosystems. In order to understand the effects of nitrogen deposition on fine root morphological traits of Castanopsis fabri and C. carlesii, two ectomycorrhizas tree species, we carried out in situ experiment using the root bags method in an evergreen broadleaved forest in the subtropical zone. The results showed that the plastic responses of specific root length and specific root surface area of low-order roots (first to third order) to nitrogen addition was higher than that of high-order roots (fourth order). The plastic responses of root tissue density to nitrogen addition increased from the first-order to the fourth-order, while the average root diameter of each order had no significant plastic responses to nitrogen addition. There was a certain synergistic change between the plastic response of specific root length and specific surface area in the low order fine root and the plastic response of tissue density in the high order fine root. The specific root length, specific root surface area and root tissue density of the two species showed opposite plastic responses to nitrogen addition, indicating that different ectomycorrhizal tree species had different nutrient foraging strategies. C. fabri adopted rapid absorption strategy by increasing specific root length, specific root surface area, and proliferation rate of fine root length, while C. carlesii adopted a relatively conservative resource absorption strategy by increasing tissue density of fine roots.

Fine-root morphological trait variation in tropical forest ecosystems: an evidence synthesis

Key functions of fine roots are often related to their morphological traits, yet little is known about the patterns and controls on fine-root morphological traits in the tropical forest biome. In this study, we consolidated data on key root morphological traits to describe patterns of root trait variation among different tropical regions and examined the relationships among root traits and climate and soil properties. We synthesized root traits (root diameter, specific root length (SRL), specific root area (SRA) and root tissue density (RTD)) from 59 site observations from nine countries in Africa, Asia, and Central and South America to determine the patterns and variation in root traits among different tropical regions. We also examined relationships among fine-root morphological traits, climate (mean annual precipitation, MAP; mean annual temperature, MAT) and soil properties (including available phosphorus (P), base saturation and clay content) using linear mixed-effects modelling. Plant fine-root morphological traits showed systematic variation among tropical regions—Africa, Asia and the Neotropics. Across the tropical biome, SRL was positively related to MAT, suggesting that in warmer tropical sites, plants tended to produce thinner roots with high SRL. Specific root length and SRA were positively related to base saturation, while soil available P explained some of the variation in SRL. This study demonstrates that soil properties, and to a lesser extent MAT, partially explain variation in key fine-root morphological traits across tropical forests. Importantly, we also identified wide variation in fine-root morphological trait values in the tropical biome that encompasses much of the variation seen worldwide. Consequently, attempts to predict tropical forest ecosystem functioning could improve significantly if regional differences in root traits are incorporated into process-based models.

Linkage of root morphology to anatomy with increasing nitrogen availability in six temperate tree species

Fine root morphological traits are generally changed under soil nitrogen (N) enrichment, however, the underlying mechanism and functional significance are still not well understood. Our aims were to investigate the linkage of root morphology to anatomy, and its implication for root function at elevated soil N availability. Ingrowth cores were used to sample root tips (0–20 cm soil depth) from six temperate tree species growing in monoculture plantations at a common site in northeastern China. Root morphological and anatomical traits were concurrently measured, and their relationships were determined within and among species in both control and N fertilization (10 g N m−2y−1) plots. Root diameter generally increased in all six species (non-significant for Phellodendron amurense) following N fertilization, which was caused by the increased root stele radius rather than cortical thickness. Congruently, N fertilization significantly decreased the ratio of cortical thickness to stele radius, but increased the ratio of total cross-sectional area of conduits to stele area in root tips across all species. The observed anatomical changes of root tips contributed to the alternations of morphological root traits following N fertilization, with potentially important impacts on root physiological functions, like increased water and nutrient transport.

Plasticity of fine-root functional traits in the litter layer in response to nitrogen addition in a subtropical forest plantation

Fine-root traits mediate the capacity of plants to acquire soil resources in different environments. This study aimed to examine the changes of fine-root traits when roots proliferate into the litter layer vs. mineral soils, and to determine fine-root trait plasticity of these roots in response to nitrogen (N) addition. A one-year N addition experiment was conducted in a 22-year-old broadleaf Mytilaria laosensis (Hamamelidaceae) plantation in subtropical China. Newly produced fine roots were collected monthly from the litter layer and upper mineral soil (0–10 cm) layer to measure root morphological traits and nutrient concentrations. Fine-root production was determined using ingrowth mesh screens in the litter layer. Fine-root production in the litter layer in the Mytilaria laosensis plantation was 2.6 g m−2 yr.−1 but increased 3- to 5-fold with N addition. Significant differences in fine-root morphological traits and nutrient concentrations were found between the litter layer and 0–10 cm mineral soil layer. Fine roots in the litter layer were thinner, with higher specific root length (SRL), higher specific root area (SRA), a higher proportion of fine-root biomass in lower, more absorptive root orders, and lower root tissue density (RTD) than those in 0–10 cm mineral soil layer. Higher carbon (C), N, phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg) concentrations and lower C:N ratio (C/N) were also observed in fine roots in the litter layer, compared to the 0–10 cm mineral soil layer. Nitrogen addition significantly increased root P, K, and Ca concentrations, but had no effect on Mg concentration. Nitrogen addition did not affect most fine-root morphological traits but did result in decreased root diameter. Compared with the mineral soil, roots produced in the litter layer generally reflected a more absorptive strategy with smaller root diameter and lower RTD and with higher SRL, SRA, and nutrient concentrations which together are generally associated with more metabolically active, but shorter lived roots. Strong responses of fine-root production and nutrient concentrations to N addition also suggest that N may be a driving factor for fine-root growth into the litter layer. Further studies are required to identify the effect of fine-root growth into the litter layer on microbial activity.

Do ectomycorrhizal and arbuscular mycorrhizal temperate tree species systematically differ in root order-related fine root morphology and biomass?

While most temperate broad-leaved tree species form ectomycorrhizal (EM) symbioses, a few species have arbuscular mycorrhizas (AM). It is not known whether EM and AM tree species differ systematically with respect to fine root morphology, fine root system size and root functioning. In a species-rich temperate mixed forest, we studied the fine root morphology and biomass of three EM and three AM tree species from the genera Acer, Carpinus, Fagus, Fraxinus, and Tilia searching for principal differences between EM and AM trees. We further assessed the evidence of convergence or divergence in root traits among the six co-occurring species. Eight fine root morphological and chemical traits were investigated in root segments of the first to fourth root order in three different soil depths and the relative importance of the factors root order, tree species and soil depth for root morphology was determined. Root order was more influential than tree species while soil depth had only a small effect on root morphology All six species showed similar decreases in specific root length and specific root area from the 1st to the 4th root order, while the species patterns differed considerably in root tissue density, root N concentration, and particularly with respect to root tip abundance. Most root morphological traits were not significantly different between EM and AM species (except for specific root area that was larger in AM species), indicating that mycorrhiza type is not a key factor influencing fine root morphology in these species. The order-based root analysis detected species differences more clearly than the simple analysis of bulked fine root mass. Despite convergence in important root traits among AM and EM species, even congeneric species may differ in certain fine root morphological traits. This suggests that, in general, species identity has a larger influence on fine root morphology than mycorrhiza type.

Changes in arbuscular mycorrhizal associations and fine root traits in sites under different plant successional phases in southern Brazil

Fine root morphological traits and distribution, arbuscular mycorrhizal (AM) fungi, soil fertility, and nutrient concentration in fine root tissue were compared in sites under different successional phases: grass plants, secondary forest, and mature forest in Londrina county, Paraná state, southern Brazil. Soil cores were collected randomly at the 0-10- and 10-20-cm depths in three quadrants (50 m2) in each site. Plants from the different successional stages displayed high differences in fine root distribution, fine root traits, and mycorrhizal root colonization. There were increases in the concentration of nutrients both in soil and fine roots and decrease of bulk soil density along the succession. The fine root biomass and diameter increased with the succession progress. The total fine root length, specific root length, root hair length, and root hair incidence decreased with the succession advance. Similarly, the mycorrhizal root colonization and the density of AM fungi spores in the soil decreased along the succession. Mycorrhizal root colonization and spore density were positively correlated with fine root length, specific root length, root hair length, root hair incidence, and bulk density and negatively correlated with fine root diameter and concentration of some nutrients both in soil and root tissues. Nutrient concentration in root tissue and in soil was positively correlated with fine root diameter and negatively correlated with specific root length, root hair length, and root hair incidence. These results suggest different adaptation strategies of plant roots for soil exploration and mineral acquisition among the different successional stages. Early successional stages displayed plants with fine root morphology and AM fungi colonization to improve the root functional efficiencies for uptake of nutrients and faster soil resource exploration. Late successional stages displayed plants with fine root morphology and mycorrhizal symbiosis for both a lower rate of soil proliferation and soil exploration capacity to acquire nutrients.