Publications by authors named "Zhiqun Huang"

19 Publications

  • Page 1 of 1

Clinical Efficacy and Possible Mechanism of Endoscopic Vidian Neurectomy for House Dust Mite-Sensitive Allergic Rhinitis.

ORL J Otorhinolaryngol Relat Spec 2021 Jan 4:1-10. Epub 2021 Jan 4.

Department of Allergology, The First Affiliated Hospital of Nanchang University, Nanchang, China,

Background/aims: Endoscopic vidian neurectomy (EVN) for allergic rhinitis (AR) has good clinical effects. However, the pathophysiological basis of the effect of EVN on AR is still poorly understood. This study aimed to investigate the efficacy of EVN on house dust mite (HDM)-sensitive AR and the dynamic changes of serum immunoglobulin E and some immune regulatory factors.

Methods: Twenty HDM-sensitive AR patients were treated with bilateral EVN (EVN group), 15 HDM-sensitive AR patients were treated with subcutaneous immunotherapy (SCIT group), and 15 healthy subjects served as healthy controls. Quality of daily life was assessed by the scores of the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQs). The visual analog scale was used to assess clinical efficacy. Serum molecules were measured by ELISA and the UNICAP system.

Results: Compared with the SCIT group, the RQLQs in the EVN group were lower 12 months after treatment (both p < 0.05). There was no significant difference in improving nasal itching and sneezing (both p > 0.05), but the clinical efficacy of bilateral EVN was greater than SCIT in improving nasal obstruction, rhinorrhea, eye itching, and lachrymation 12 months after treatment (all p < 0.05). Compared with before treatment, the serum levels of total immunoglobulin E (tIgE), Dermatophagoides pteronyssinus- and Dermatophagoides farinae-specific immunoglobulin E (sIgE), and tumor necrosis factor (TNF)-α in the EVN group and the serum levels of TNF-α and interleukin-4 in the SCIT group were lower 12 months after treatment (all p < 0.05).

Conclusion: The short-term efficacy of bilateral EVN is more effective than SCIT in treating HDM-sensitive AR. This may be because the surgery reduced the tIgE and sIgE levels. TNF-α may be involved in the therapeutic mechanism.
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http://dx.doi.org/10.1159/000511711DOI Listing
January 2021

Different responses of soil bacterial and fungal communities to nitrogen deposition in a subtropical forest.

Sci Total Environ 2021 Feb 22;755(Pt 1):142449. Epub 2020 Sep 22.

Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou 350007, China; School of Geographical Science, Fujian Normal University, Fuzhou 350007, 00China. Electronic address:

China has experienced a widespread increase in N deposition due to intensive anthropogenic activities, particularly in the subtropical regions. However, the effects of long-term N deposition on soil bacterial and fungal abundance, diversity, and community composition remain largely unclear. We assessed the effects of N deposition on soil microbial communities in summer and winter, using quantitative polymerase chain reaction and Illumina Miseq sequencing of bacterial 16S rRNA and fungal ITS genes from subtropical natural forest soils. The abundance of both soil bacteria and fungi exhibited a decreasing pattern with increasing N deposition rates. Nitrogen deposition increased bacterial diversity in both summer and winter, whereas fungal diversity was significantly decreased in summer, but greatly increased under the highest level of N deposition (150 kg N ha yr) in winter. Nitrogen deposition significantly increased the relative abundance of bacterial phyla Actinobacteria, Chloroflexi, and WPS-2, but decreased that of Acidobacteria and Verrucomicrobia. In addition, N deposition significantly decreased the relative abundance of Ascomycetes, but did not exert any significant effect on Basidiomycetes. The bacterial and fungal community compositions were greatly influenced by N deposition, with soil N availability and soil pH identified as the two most influential soil properties. This study demonstrates that the fungal community was more sensitive than the bacterial community to N deposition, and further emphasizes the importance of simultaneously evaluating soil bacterial and fungal communities in response to global environmental changes.
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http://dx.doi.org/10.1016/j.scitotenv.2020.142449DOI Listing
February 2021

Role of environmental factors in shaping the soil microbiome.

Environ Sci Pollut Res Int 2020 Nov 23;27(33):41225-41247. Epub 2020 Aug 23.

Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, 350007, China.

The soil microbiome comprises one of the most important and complex components of all terrestrial ecosystems as it harbors millions of microbes including bacteria, fungi, archaea, viruses, and protozoa. Together, these microbes and environmental factors contribute to shaping the soil microbiome, both spatially and temporally. Recent advances in genomic and metagenomic analyses have enabled a more comprehensive elucidation of the soil microbiome. However, most studies have described major modulators such as fungi and bacteria while overlooking other soil microbes. This review encompasses all known microbes that may exist in a particular soil microbiome by describing their occurrence, abundance, diversity, distribution, communication, and functions. Finally, we examined the role of several abiotic factors involved in the shaping of the soil microbiome.
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http://dx.doi.org/10.1007/s11356-020-10471-2DOI Listing
November 2020

Silicon-mediated plant defense against pathogens and insect pests.

Pestic Biochem Physiol 2020 Sep 26;168:104641. Epub 2020 Jun 26.

Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou 350007, China; Institute of Geography, Fujian Normal University, Fuzhou 350007, China; Faculty of Natural Resources Management, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7B 5E1, Canada. Electronic address:

Plant diseases and insect pests are one of the major limiting factors that reduce crop production worldwide. Silicon (Si) is one of the most abundant elements in the lithosphere and has a positive impact on plant health by effectively mitigating biotic and abiotic stresses. It also enhances plant resistance against insect pests and fungal, bacterial, and viral diseases. Therefore, this review critically converges its focus upon Si-mediated physical, biochemical, and molecular mechanisms in plant defense against pathogens and insect pests. It further explains Si-modulated interactive phytohormone signaling and enzymatic production and their involvement in inducing resistance against biotic stresses. Furthermore, this review highlights the recent research accomplishments which have successfully revealed the active role of Si in protecting plants against insect herbivory and various viral, bacterial, and fungal diseases. The article explores the potential in enhancing Si-mediated plant resistance against various economically important diseases and insect pests, further shedding light upon future issues regarding the role of Si in defense against pathogens and insect pests.
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http://dx.doi.org/10.1016/j.pestbp.2020.104641DOI Listing
September 2020

Carbon dynamics in three subtropical forest ecosystems in China.

Environ Sci Pollut Res Int 2020 May 20;27(13):15552-15564. Epub 2020 Feb 20.

Guangdong Provincial Key Laboratory of Bio-Control for the Forest Disease and Pest, Guangdong Academy of Forestry, Guangzhou, 510520, Guangdong Province, China.

The carbon sequestration capacity of the forest ecosystem normally increases overage due to the carbon dynamic in below canopy and soil. The carbon dynamic is reflective of the forest characteristics and their interactions with climate, topographic, and soil conditions. In this study, we measured the carbon content and carbon density of canopy, shrub, understory vegetation, litter, and soil, and assessed carbon dynamics in three forest ecosystems (Cunninghamia lanceolate, Pinus massoniana, and Evergreen broad-leaved forests) with a combination of data from Fujian Provincial forest resource inventory. This study showed that the carbon content of the canopy layers increased over time, and the carbon content of the topsoil (0-30 cm) in the young forests was significantly higher than that in other age groups in Cunninghamia lanceolata forest and Pinus massoniana forest. Due to the carbon differences in the soil layer, the carbon stocks of the C. lanceolata forest and the P. massoniana forest declined from 1996 to 2007, but the carbon stocks of Evergreen broad-leaved forest increased. Besides, using the traditional carbon content coefficient (0.5) might underestimate the carbon sequestration potential of these forest ecosystems, especially for the mature forests. The coniferous forests displayed a short-term reduction in the carbon stocks of ecosystems between 10 and 20 years after afforestation, and the decline cannot be ignored in the carbon budget.
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http://dx.doi.org/10.1007/s11356-019-06991-1DOI Listing
May 2020

Plant-insect vector-virus interactions under environmental change.

Sci Total Environ 2020 Jan 28;701:135044. Epub 2019 Oct 28.

College of Geographical Sciences, Fujian Normal University, Fuzhou, Fujian 350007, China; Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou 350007, China; Faculty of Natural Resources Management, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7B 5E1, Canada. Electronic address:

Insects play an important role in the spread of viruses from infected plants to healthy hosts through a variety of transmission strategies. Environmental factors continuously influence virus transmission and result in the establishment of infection or disease. Plant virus diseases become epidemic when viruses successfully dominate the surrounding ecosystem. Plant-insect vector-virus interactions influence each other; pushing each other for their benefit and survival. These interactions are modulated through environmental factors, though environmental influences are not readily predictable. This review focuses on exploiting the diverse relationships, embedded in the plant-insect vector-virus triangle by highlighting recent research findings. We examined the interactions between viruses, insect vectors, and host plants, and explored how these interactions affect their behavior.
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http://dx.doi.org/10.1016/j.scitotenv.2019.135044DOI Listing
January 2020

Effects of plant diversity on soil carbon in diverse ecosystems: a global meta-analysis.

Biol Rev Camb Philos Soc 2019 Oct 18. Epub 2019 Oct 18.

Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, 32 Shangshan Rd, Fuzhou, 350007, China.

Soil organic carbon (SOC) is a valuable resource for mediating global climate change and securing food production. Despite an alarming rate of global plant diversity loss, uncertainties concerning the effects of plant diversity on SOC remain, because plant diversity not only stimulates litter inputs via increased productivity, thus enhancing SOC, but also stimulates microbial respiration, thus reducing SOC. By analysing 1001 paired observations of plant mixtures and corresponding monocultures from 121 publications, we show that both SOC content and stock are on average 5 and 8% higher in species mixtures than in monocultures. These positive mixture effects increase over time and are more pronounced in deeper soils. Microbial biomass carbon, an indicator of SOC release and formation, also increases, but the proportion of microbial biomass carbon in SOC is lower in mixtures. Moreover, these species-mixture effects are consistent across forest, grassland, and cropland systems and are independent of background climates. Our results indicate that converting 50% of global forests from mixtures to monocultures would release an average of 2.70 Pg C from soil annually over a period of 20 years: about 30% of global annual fossil-fuel emissions. Our study highlights the importance of plant diversity preservation for the maintenance of soil carbon sequestration in discussions of global climate change policy.
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http://dx.doi.org/10.1111/brv.12554DOI Listing
October 2019

Plant defense against virus diseases; growth hormones in highlights.

Plant Signal Behav 2019 8;14(6):1596719. Epub 2019 Apr 8.

a Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education , Fujian Normal University , Fuzhou , China.

Phytohormones are critical in various aspects of plant biology such as growth regulations and defense strategies against pathogens. Plant-virus interactions retard plant growth through rapid alterations in phytohormones and their signaling pathways. Recent research findings show evidence of how viruses impact upon modulation of various phytohormones affecting plant growth regulations. The opinion is getting stronger that virus-mediated phytohormone disruption and alteration weaken plant defense strategies through enhanced replication and systemic spread of viral particles. These hormones regulate plant-virus interactions in various ways that may involve antagonism and cross talk to modulate small RNA (sRNA) systems. The article aims to highlight the recent research findings elaborating the impact of viruses upon manipulation of phytohormones and virus biology.
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http://dx.doi.org/10.1080/15592324.2019.1596719DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6546145PMC
April 2020

Meta-analysis shows positive effects of plant diversity on microbial biomass and respiration.

Nat Commun 2019 03 22;10(1):1332. Epub 2019 Mar 22.

Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, 350007, China.

Soil microorganisms are key to biological diversity and many ecosystem processes in terrestrial ecosystems. Despite the current alarming loss of plant diversity, it is unclear how plant species diversity affects soil microorganisms. By conducting a global meta-analysis with paired observations of plant mixtures and monocultures from 106 studies, we show that microbial biomass, bacterial biomass, fungal biomass, fungi:bacteria ratio, and microbial respiration increase, while Gram-positive to Gram-negative bacteria ratio decrease in response to plant mixtures. The increases in microbial biomass and respiration are more pronounced in older and more diverse mixtures. The effects of plant mixtures on all microbial attributes are consistent across ecosystem types including natural forests, planted forests, planted grasslands, croplands, and planted containers. Our study underlines strong relationships between plant diversity and soil microorganisms across global terrestrial ecosystems and suggests the importance of plant diversity in maintaining belowground ecosystem functioning.
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http://dx.doi.org/10.1038/s41467-019-09258-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6430801PMC
March 2019

Plant defense against fungal pathogens by antagonistic fungi with Trichoderma in focus.

Microb Pathog 2019 Apr 30;129:7-18. Epub 2019 Jan 30.

State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Fujian Agriculture and Forestry University, Fuzhou, 350002, China. Electronic address:

Fungal diseases cause considerable damage to the economically important crops worldwide thus posing continuous threat to global food security. Management of these diseases is normally done via utilization of chemicals that have severe negative impact upon human health and surrounding ecosystems. Finding eco-friendly alternatives has led the researchers to focus towards biological control of fungal diseases through biocontrol agents such as antagonistic fungi (AF) and other microorganisms. AF include various genera of fungi that cure the fungal diseases on plants effectively. Furthermore, they play a regulatory role in various plant physiological pathways and interactions. AF are highly host specific having negligible effects on non-target organisms and have fast mass production capability. However, understanding the mechanisms of the effects of AF on plant diseases is a prerequisite for their effective utilization as biocontrol agent. Trichoderma is one of the most important fungal genera known for its antagonistic activity against disease causing fungal pathogens. Therefore, in this review, we have focused upon Trichoderma-mediated fungal diseases management via illustrating its taxonomy, important strains, biodiversity and mode of action. Furthermore, we have assessed the criteria to be followed for selection of AF and the factors influencing their efficiency. Finally, we evaluated the advantages and limitations of Trichoderma as AF. We conclude that effective AF utilization against fungal pathogens can serve as a safe strategy for our Planet.
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http://dx.doi.org/10.1016/j.micpath.2019.01.042DOI Listing
April 2019

Home environment and diseases in early life are associated with allergic rhinitis.

Int J Pediatr Otorhinolaryngol 2019 Mar 14;118:47-52. Epub 2018 Dec 14.

Department of Otorhinolaryngology Head and Neck Surgery, First Affiliated Hospital of Nanchang University, Nanchang, China. Electronic address:

Objective: Risk factors in relation to allergic rhinitis (AR) remain unclear despite considerable interest. This study aimed to analysis the relationship between home environment and diseases in early life and AR.

Methods: In a case-control survey, 242 AR patients and 258 healthy persons responded to questionnaires designed to capture pre-pregnancy/pregnancy diseases, maternal medication usage, diseases in early life of participants, family allergic history and home environmental factors. Forty risk factors potentially connected with AR were investigated and analyzed with chi-square test and logistic regression.

Results: There was no correlation between mother's disorders such as periodontitis, chronic rhinitis, diabetes etc. and AR (p > 0.05). A logistic regression analysis showed that neonatal jaundice (p < 0.001), respiratory system infection (p < 0.001), diarrhea (p < 0.01), eczema (p < 0.01) in the early life and home environmental factors such as house decoration (p < 0.01), mold environment (p < 0.001), keeping flowers and plants (p < 0.001), passive smoking (p < 0.01) were associated with AR.

Conclusion: Diseases in early life and home environment are closely associated with AR.
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http://dx.doi.org/10.1016/j.ijporl.2018.12.015DOI Listing
March 2019

Traits drive global wood decomposition rates more than climate.

Glob Chang Biol 2018 11 3;24(11):5259-5269. Epub 2018 Jul 3.

Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico.

Wood decomposition is a major component of the global carbon cycle. Decomposition rates vary across climate gradients, which is thought to reflect the effects of temperature and moisture on the metabolic kinetics of decomposers. However, decomposition rates also vary with wood traits, which may reflect the influence of stoichiometry on decomposer metabolism as well as geometry relating the surface areas that decomposers colonize with the volumes they consume. In this paper, we combined metabolic and geometric scaling theories to formalize hypotheses regarding the drivers of wood decomposition rates, and assessed these hypotheses using a global compilation of data on climate, wood traits, and wood decomposition rates. Our results are consistent with predictions from both metabolic and geometric scaling theories. Approximately half of the global variation in decomposition rates was explained by wood traits (nitrogen content and diameter), whereas only a fifth was explained by climate variables (air temperature, precipitation, and relative humidity). These results indicate that global variation in wood decomposition rates is best explained by stoichiometric and geometric wood traits. Our findings suggest that inclusion of wood traits in global carbon cycle models can improve predictions of carbon fluxes from wood decomposition.
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http://dx.doi.org/10.1111/gcb.14357DOI Listing
November 2018

Temporal changes in soil C-N-P stoichiometry over the past 60 years across subtropical China.

Glob Chang Biol 2018 03 30;24(3):1308-1320. Epub 2017 Oct 30.

Faculty of Natural Resources Management, Lakehead University, Thunder Bay, ON, Canada.

Controlled experiments have shown that global changes decouple the biogeochemical cycles of carbon (C), nitrogen (N), and phosphorus (P), resulting in shifting stoichiometry that lies at the core of ecosystem functioning. However, the response of soil stoichiometry to global changes in natural ecosystems with different soil depths, vegetation types, and climate gradients remains poorly understood. Based on 2,736 observations along soil profiles of 0-150 cm depth from 1955 to 2016, we evaluated the temporal changes in soil C-N-P stoichiometry across subtropical China, where soils are P-impoverished, with diverse vegetation, soil, and parent material types and a wide range of climate gradients. We found a significant overall increase in soil total C concentration and a decrease in soil total P concentration, resulting in increasing soil C:P and N:P ratios during the past 60 years across all soil depths. Although average soil N concentration did not change, soil C:N increased in topsoil while decreasing in deeper soil. The temporal trends in soil C-N-P stoichiometry differed among vegetation, soil, parent material types, and spatial climate variations, with significantly increased C:P and N:P ratios for evergreen broadleaf forest and highly weathered Ultisols, and more pronounced temporal changes in soil C:N, N:P, and C:P ratios at low elevations. Our sensitivity analysis suggests that the temporal changes in soil stoichiometry resulted from elevated N deposition, rising atmospheric CO concentration and regional warming. Our findings revealed that the responses of soil C-N-P and stoichiometry to long-term global changes have occurred across the whole soil depth in subtropical China and the magnitudes of the changes in soil stoichiometry are dependent on vegetation types, soil types, and spatial climate variations.
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http://dx.doi.org/10.1111/gcb.13939DOI Listing
March 2018

Long-term nitrogen deposition linked to reduced water use efficiency in forests with low phosphorus availability.

New Phytol 2016 Apr 11;210(2):431-42. Epub 2015 Dec 11.

Department of Ecology and Evolutionary Biology, Kansas Biological Survey, University of Kansas, Lawrence, KS, 66047, USA.

The impact of long-term nitrogen (N) deposition is under-studied in phosphorus (P)-limited subtropical forests. We exploited historically collected herbarium specimens to investigate potential physiological responses of trees in three subtropical forests representing an urban-to-rural gradient, across which N deposition has probably varied over the past six decades. We measured foliar [N] and [P] and stable carbon (δ(13) C), oxygen (δ(18) O) and nitrogen (δ(15) N) isotopic compositions in tissue from herbarium specimens of plant species collected from 1947 to 2014. Foliar [N] and N : P increased, and δ(15) N and [P] decreased in the two forests close to urban centers. Consistent with recent studies demonstrating that N deposition in the region is (15) N-depleted, these data suggest that the increased foliar [N] and N : P, and decreased [P], may be attributable to atmospheric deposition and associated enhancement of P limitation. Estimates of intrinsic water use efficiency calculated from foliar δ(13) C decreased by c. 30% from the 1950s to 2014, contrasting with multiple studies investigating similar parameters in N-limited forests. This effect may reflect decreased photosynthesis, as suggested by a conceptual model of foliar δ(13) C and δ(18) O. Long-term N deposition may exacerbate P limitation and mitigate projected increases in carbon stocks driven by elevated CO2 in forests on P-limited soils.
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http://dx.doi.org/10.1111/nph.13785DOI Listing
April 2016

Foliar delta(13)C and delta(18)O reveal differential physiological responses of canopy foliage to pre-planting weed control in a young spotted gum (Corymbia citriodora subsp. Variegata) plantation.

Tree Physiol 2008 Oct;28(10):1535-43

Griffith School of Environment, Griffith University, Nathan, QLD 4111, Australia.

Weed control may improve the growth of forest plantations by influencing soil water and nutrient availability, but our knowledge of leaf-level physiological responses to weed control at different within-canopy positions is limited for tropical and subtropical plantations. Foliar carbon (delta(13)C) and oxygen (delta(18)O) isotope compositions, gas exchange, and nitrogen (N(mass)) and phosphorus (P(mass)) concentrations at four canopy positions were assessed in a young spotted gum (Corymbia citriodora subsp. Variegata (F. Muell.) A.R. Bean & M.W. McDonald) plantation subjected to either weed control or no weed control treatment, to test if leaves at different positions within the tree canopy had the same physiological responses to the weed control treatment. Weed control increased foliar delta(13)C but lowered delta(18)O in the upper-outer and upper-inner canopy, indicating that weed control resulted in a higher foliar photosynthetic capacity at upper-canopy positions, a conclusion confirmed by gas exchange measurements. The increased photosynthetic capacity resulting from weed control can be explained by an increase in foliar N(mass). In the lower-outer canopy, weed control reduced foliar delta(13)C while lowering delta(18)O even more than in the upper-canopy, suggesting strong enhancement of the partial pressure of CO(2) in the leaf intercellular spaces and of foliar stomatal conductance in lower-canopy foliage. This conclusion was supported by gas exchange measurements. Foliar photosynthesis in the lower-inner canopy showed no significant response to weed control. The finding that leaves at different canopy positions differ in their physiological responses to weed control highlights the need to consider the canopy position effect when examining competition for soil nutrient and water resources between weeds and trees.
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http://dx.doi.org/10.1093/treephys/28.10.1535DOI Listing
October 2008

Variations in relative stomatal and biochemical limitations to photosynthesis in a young blackbutt (Eucalyptus pilularis) plantation subjected to different weed control regimes.

Tree Physiol 2008 Jul;28(7):997-1005

Griffith School of Environment, Griffith University, Nathan, QLD 4111, Australia.

Foliar gas exchange and carbon (delta(13)C) and oxygen (delta(18)O) isotope ratios were measured in a young blackbutt (Eucalyptus pilularis Sm.) plantation subjected to four weed control treatments defined by the width of the weed-free strip maintained for the first 12 months after planting. Treatments were: 2-m-wide weed-free strip (50% of plot area, 2.0MWC), 1.5-m-wide weed-free strip (37.5% of plot area, 1.5MWC), 1-m-wide weed-free strip (25% of plot area, 1.0MWC) and no weed control (NWC). Our objectives were to determine (1) if decreasing the width of the weed control strip (decreasing herbicide use) affected growth and leaf photosynthesis of the plantation, and (2) the effects of the weed control regimes on variations in relative stomatal and biochemical limitations to photosynthesis. Trees in the 1.0MWC treatment had lower foliar light-saturated photosynthetic rate (A(sat)) than trees in the 2.0MWC treatment. An increase in metabolic limitation was responsible for the decrease in A(sat) in the 1.0MWC trees, which was also partly confirmed by the isotopic data. Compared with trees in the 1.0MWC, 1.5MWC and 2.0MWC treatments, A(sat) of NWC trees was significantly lower, a difference that was attributable mainly to stomatal limitation and to a lesser extent to biochemical limitation. The results support the conclusion that different weed control regimes cause differences in relative stomatal and biochemical limitations to plantation photosynthesis. This report contributes to a growing body of literature on competition for soil resources between trees and weeds. Our results highlight the usefulness of the stable isotopic method in supporting analysis of the response of net photosynthesis to varying intercellular CO(2) concentration for determining the relative stomatal and non-stomatal limitations to photosynthesis under experimental conditions in the field.
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http://dx.doi.org/10.1093/treephys/28.7.997DOI Listing
July 2008

Correlation between phytotoxicity on annual ryegirass (Lolium rigidum) and production dynamics of allelochemicals within root exudates of an allelopathic wheat.

J Chem Ecol 2003 Oct;29(10):2263-79

Institute of Applied Ecology, The Chinese Academy of Sciences, PO BOX 417, 110016, Shenyang, China.

An improved allelopathic correlation between phytotoxicity measured in root growth bioassay upon annual ryegrass (Lolium rigidum Gaud.) and the concentrations of a selection of dynamically produced allelochemicals quantified in the root exudates of cv. Khapli wheat (Triticum turgidum ssp. durum (Desf.) Husn.) monitored during the first 15 days of wheat seedling growth in a sterile, agar-water medium, has been established. Changes over the 15-day growth period in the quantities of five exuded benzoxazinones and seven phenolic acids were measured simultaneously using GC/MS/MS. Substantiating pure compound dose-response measurements were conducted over a range of concentrations for the putative allelochemicals within the wheat exudates. One synergism-based proposal using the monitored compounds to explain the observed low-exudate-concentration phytotoxicity was explored, but was found to be experimentally inadequate.
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http://dx.doi.org/10.1023/a:1026222414059DOI Listing
October 2003

[Effect of vanillin and P-hydroxybenzoic acid on physiological characteristics of Chinese fir seedlings].

Ying Yong Sheng Tai Xue Bao 2002 Oct;13(10):1291-4

Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016.

Effects of vanillin and P-hydroxybenzoic acid at different concentrations on physiological characteristic of Chinese fir seedlings were studied by potted experiment. The results showed that 10 mmol.L-1 and 1 mmol.L-1 of two kinds of phenolics significantly reduced the content of chlorophyll, rate of photosynthesis and root activity, and that the higher the concentration of vanillin and P-hydroxybenzoic acid, the more the physiological activities was inhibited. By treatment with 1 and 10 mmol.L-1 vanillin, Chinese fir seedlings reduced its photosynthesis rate 25.1% and 37.0%, transpiration rate 20.3% and 37.0%, stomata conductance 33.7% and 46.8% and root activity 51.6% and 78.8%, respectively. The results suggested that vanillin and P-hydroxybenzoic acid accumulated in the soil by continuous cropping of Chinese fir may have some allelopathic effect on the seedlings of Chinese fir and the effect is one of the factors leading to the low productivity of continuously cropped Chinese fir forest.
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October 2002

[Effects of plant foliar litter diversity on the growth of Chinese fir seedling and the absorption of (15NH4)2SO4].

Ying Yong Sheng Tai Xue Bao 2002 Oct;13(10):1287-90

Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016.

Effects of plant foliar litter species composition on the growth of the potted Chinese fir seedling and the absorption of (15NH4)2SO4 was studied. The result showed that there were significant growth responses to foliar litter treatments. A very noticeable trend was that as the tree species of foliar litter placed on pots increases, the growth of Chinese fir seedlings increases steadily. Seedling growth in four-species mixed foliar litter were the largest and that in Cunninghamia lanceolata + Michelia macclurei + Kalooanax septemlobus foliar litter mixture were the second. The others were in order of seedlings in C. lanceolata + M. macclurei + Castanopsis carlesii foliar litter mixture > C. lanceolata + K. septemlobus foliar litter mixture > C. lanceolata + C. carlesii > control (no foliar litter) > C. lanceolata + M. macclurei foliar litter mixture > Chinese fir foliar litter treatment. The recovery of (15NH4)2SO4 by Chinese fir seedlings in no foliar litter treatment was maximum, and seedlings grown in four foliar litter mixture was the second, then it was in order of C. lanceolata + C. carlesii + K. septemlobus = C. lanceolata + C. carlesii + M. macclurei > C. lanceolata + K. septemlobus > C. lanceolata + C. carlesii > C. lanceolata + M. macclurei > C. lanceolata foliar litter treatment. In addition, the residue of (15NH4)2SO4 was greater in soil with foliar litter treatment than in no foliar litter soil. Both of the residual amount of (15NH4)2SO4 in soil and the total recovery of (15NH4)2SO4 increased with the increasing tree species of applied foliar litter.
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October 2002