Variations in the first-order root diameter in 89 woody species in a subtropical evergreen broadleaved forest

We studied the early root growth of fourSetariataxa: giant foxtail (Setaria faberiHerrm.), giant green foxtail [Setaria viridisvar.major(Gaud.) Posp.], robust white foxtail (Setaria viridisvar.robusta-albaSchreiber), robust purple foxtail (Setaria viridisvar.robusta-purpureaSchreiber). Growth studies in controlled environments showed significant differences in root elongation among the taxa at three photoperiods. Seminal root lengths after 4 days followed the order presented for selectivity and metabolism of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] and propazine [2-chloro-4,6-bis(isopropylamino)-s-triazine] (robust white foxtail > giant green foxtail = robust purple foxtail > giant foxtail). Giant foxtail had the greatest root diameter, resulting in the greatest surface area and volume when lengths were equated. The order of seminal root lengths or diameters changed little after 7 days. Robust white foxtail had the most and longest first order lateral roots. Diameter of first order laterals showed giant foxtail > giant green foxtail = robust purple foxtail > robust white foxtail.

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Effects of root diameter, branch order, root depth, season and warming on root longevity in an alpine meadow

Ecological Research ◽

10.1007/s11284-016-1385-4 ◽

2016 ◽

Vol 31 (5) ◽

pp. 739-747 ◽

Cited By ~ 7

Author(s):

Zhikai Wang ◽

Lubin Ding ◽

Jingsheng Wang ◽

Xiaolong Zuo ◽

Shuaichen Yao ◽

...

Keyword(s):

Alpine Meadow ◽

Root Diameter ◽

Root Depth ◽

Branch Order ◽

Root Longevity ◽

Order Root

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Relationships among arbuscular mycorrhizas, root morphology and seedling growth of tropical native woody species in southern Brazil

Journal of Tropical Ecology ◽

10.1017/s0266467405002555 ◽

2005 ◽

Vol 21 (5) ◽

pp. 529-540 ◽

Cited By ~ 44

Author(s):

Waldemar Zangaro ◽

Fabio Rodrigo Nishidate ◽

Flavia Regina Spago Camargo ◽

Graziela Gorete Romagnoli ◽

Julia Vandressen

Keyword(s):

Root Hair ◽

Fine Root ◽

Root Hairs ◽

Woody Species ◽

Root Traits ◽

Arbuscular Mycorrhizas ◽

Root Diameter ◽

Mycorrhizal Colonization ◽

Native Woody Species ◽

Mycorrhizal Response

The relationships between arbuscular mycorrhizal fungi and root morphological characteristics were studied under greenhouse conditions of 78 tropical native woody species and 47 seedling species collected in the field. Seedlings of native woody pioneer and early secondary species that generally exhibited fine roots with a dense cover of long root hairs showed higher mycorrhizal response and root mycorrhizal colonization than late-secondary and climax species with coarse roots with a sparse cover of short root hairs. Root-hair length and incidence decreased with the progression among the successional groups while fine-root diameter increased, both in the greenhouse and in the field. The mycorrhizal response was highly correlated to root mycorrhizal colonization in the greenhouse and in the field. These parameters were inversely correlated with the seed mass and fine-root diameter, but directly correlated with root-hair incidence, both in the greenhouse and in the field. Mycorrhizal response and root mycorrhizal colonization were also directly correlated with the root-hair length and root/shoot ratio of uninoculated plants. The seedling mycorrhizal status of the early successional woody species suggests that the root traits of these fast-growing species can be more receptive to attraction, infection and colonization by arbuscular mycorrhizas than root traits of late-successional species.

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Contrasting dynamics and trait controls in first-order root compared with leaf litter decomposition

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1716595115 ◽

2018 ◽

Vol 115 (41) ◽

pp. 10392-10397 ◽

Cited By ~ 49

Author(s):

Tao Sun ◽

Sarah E. Hobbie ◽

Björn Berg ◽

Hongguang Zhang ◽

Qingkui Wang ◽

...

Keyword(s):

Leaf Litter ◽

Arbuscular Mycorrhizal ◽

Interspecific Variation ◽

Root Decomposition ◽

Control Mechanisms ◽

First Order ◽

C Cycle ◽

Order Root ◽

Dynamics And Control ◽

Decomposition Models

Decomposition is a key component of the global carbon (C) cycle, yet current ecosystem C models do not adequately represent the contributions of plant roots and their mycorrhizae to this process. The understanding of decomposition dynamics and their control by traits is particularly limited for the most distal first-order roots. Here we followed decomposition of first-order roots and leaf litter from 35 woody plant species differing in mycorrhizal type over 6 years in a Chinese temperate forest. First-order roots decomposed more slowly (k = 0.11 ± 0.01 years−1) than did leaf litter (0.35 ± 0.02 years−1), losing only 35% of initial mass on average after 6 years of exposure in the field. In contrast to leaf litter, nonlignin root C chemistry (nonstructural carbohydrates, polyphenols) accounted for 82% of the large interspecific variation in first-order root decomposition. Leaf litter from ectomycorrhizal (EM) species decomposed more slowly than that from arbuscular mycorrhizal (AM) species, whereas first-order roots of EM species switched, after 2 years, from having slower to faster decomposition compared with those from AM species. The fundamentally different dynamics and control mechanisms of first-order root decomposition compared with those of leaf litter challenge current ecosystem C models, the recently suggested dichotomy between EM and AM plants, and the idea that common traits can predict decomposition across roots and leaves. Aspects of C chemistry unrelated to lignin or nitrogen, and not presently considered in decomposition models, controlled first-order root decomposition; thus, current paradigms of ecosystem C dynamics and model parameterization require revision.

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Large branch and leaf hydraulic safety margins in subtropical evergreen broadleaved forest

Tree Physiology ◽

10.1093/treephys/tpz028 ◽

2019 ◽

Vol 39 (8) ◽

pp. 1405-1415

Author(s):

Shi-Dan Zhu ◽

Rong-Hua Li ◽

Peng-Cheng He ◽

Zafar Siddiq ◽

Kun-Fang Cao ◽

...

Keyword(s):

Southern China ◽

Woody Species ◽

Atmospheric Temperature ◽

Dry Season ◽

Sapwood Area ◽

Evergreen Broadleaved Forest ◽

Safety Margins ◽

Hot Dry Season ◽

Hydraulic Safety ◽

Dry Seasons

Abstract As a global biodiversity hotspot, the subtropical evergreen broadleaved forest (SEBF) in southern China is strongly influenced by the humid monsoon climate, with distinct hot-wet and cool-dry seasons. However, the hydraulic strategies of this forest are not well understood. Branch and leaf hydraulic safety margins (HSMbranch and HSMleaf, respectively), as well as seasonal changes in predawn and midday leaf water potential (Ψpd and Ψmd), stomatal conductance (Gs), leaf to sapwood area ratio (AL/AS) and turgor loss point (Ψtlp), were examined for woody species in a mature SEBF. For comparison, we compiled these traits of tropical dry forests (TDFs) and Mediterranean-type woodlands (MWs) from the literature because they experience a hot-dry season. We found that on average, SEBF showed larger HSMbranch and HSMleaf than TDF and MW. During the dry season, TDF and MW species displayed a significant decrease in Ψpd and Ψmd. However, SEBF species showed a slight decrease in Ψpd but an increase in Ψmd. Similar to TDF and MW species, Gs was substantially lower in the dry season for SEBF species, but this might be primarily because of the low atmospheric temperature (low vapor pressure deficit). On the other hand, AL/AS and Ψtlp were not significant different between seasons for any SEBF species. Most SEBF species had leaves that were more resistant to cavitation than branches. Additionally, species with stronger leaf-to-branch vulnerability segmentation tended to have smaller HSMleaf but larger HSMbranch. Our results suggest that SEBF is at low hydraulic risk under the current climate.

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Variation of first-order root traits across climatic gradients and evolutionary trends in geological time

Global Ecology and Biogeography ◽

10.1111/geb.12048 ◽

2013 ◽

Vol 22 (7) ◽

pp. 846-856 ◽

Cited By ~ 100

Author(s):

Weile Chen ◽

Hui Zeng ◽

David M. Eissenstat ◽

Dali Guo

Keyword(s):

Root Traits ◽

Evolutionary Trends ◽

Geological Time ◽

First Order ◽

Order Root

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The Right-Skewed Distribution of Fine-Root Size in Three Temperate Forests in Northeastern China

Frontiers in Plant Science ◽

10.3389/fpls.2021.772463 ◽

2022 ◽

Vol 12 ◽

Author(s):

Cunguo Wang ◽

Ivano Brunner ◽

Junni Wang ◽

Wei Guo ◽

Zhenzhen Geng ◽

...

Keyword(s):

Tree Species ◽

Fine Roots ◽

Fine Root ◽

Root Diameter ◽

Northeastern China ◽

Skewed Distribution ◽

Root Number ◽

First Order ◽

Fine Root Length ◽

Root Size

Trees can build fine-root systems with high variation in root size (e.g., fine-root diameter) and root number (e.g., branching pattern) to optimize belowground resource acquisition in forest ecosystems. Compared with leaves, which are visible above ground, information about the distribution and inequality of fine-root size and about key associations between fine-root size and number is still limited. We collected 27,573 first-order fine-roots growing out of 3,848 second-order fine-roots, covering 51 tree species in three temperate forests (Changbai Mountain, CBS; Xianrendong, XRD; and Maoershan, MES) in Northeastern China. We investigated the distribution and inequality of fine-root length, diameter and area (fine-root size), and their trade-off with fine-root branching intensity and ratio (fine-root number). Our results showed a strong right-skewed distribution in first-order fine-root size across various tree species. Unimodal frequency distributions were observed in all three of the sampled forests for first-order fine-root length and area and in CBS and XRD for first-order fine-root diameter, whereas a marked bimodal frequency distribution of first-order fine-root diameter appeared in MES. Moreover, XRD had the highest and MES had the lowest inequality values (Gini coefficients) in first-order fine-root diameter. First-order fine-root size showed a consistently linear decline with increasing root number. Our findings suggest a common right-skewed distribution with unimodality or bimodality of fine-root size and a generalized trade-off between fine-root size and number across the temperate tree species. Our results will greatly improve our thorough understanding of the belowground resource acquisition strategies of temperate trees and forests.

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