LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 14

Search options

  1. Article ; Online: Decoupling of tree height and root depth across the globe and the implications for tree mortality during drought events

    Xiangyan Feng / Wenzhi Zhao / Qiyue Yang / Hai Zhou

    Ecological Indicators, Vol 147, Iss , Pp 109944- (2023)

    2023  

    Abstract: Tree height (Htree) and root depth (Droot) are the two most critical functional traits for plant ecological strategies. However, the global varying patterns of Htree and Droot and the ecological significance for tree survival under changed climate ... ...

    Abstract Tree height (Htree) and root depth (Droot) are the two most critical functional traits for plant ecological strategies. However, the global varying patterns of Htree and Droot and the ecological significance for tree survival under changed climate conditions are less understood. Here, we compiled Htree, Droot, and six root traits related to soil resource absorption for 301 field-grown tree species distributed 776 sites worldwide. The relationships between Htree and Droot across different climate conditions and the implications for tree mortality during drought events were investigated. We found Htree and Droot were often decoupled in angiosperms and gymnosperms among different climate conditions. Greater Htree was prone to occur in warm and moist climates, while greater Droot tended to occur in warm and dry climates with low soil water availability. Phylogenetic analysis revealed that trees have evolved towards smaller Htree but deeper Droot from the deep time. Although dense root structures to some extent contributed to sustaining the resource supply–demand balance of large trees with shallow roots (great Htree/ Droot), the large trees with greater Htree/ Droot were more vulnerable to drought-induced mortality. The findings suggest that the linkage of below- and above-ground reaches has a pivotal role in understanding tree mortality during drought events. The insight will allow more accurate vegetation model prediction for tree sorting processes under climate change scenarios.
    Keywords Functional traits ; Supply–demand balance ; Evolution ; Drought stress ; Ecological strategy ; Ecology ; QH540-549.5
    Subject code 580
    Language English
    Publishing date 2023-03-01T00:00:00Z
    Publisher Elsevier
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

  2. Article ; Online: Effects of precipitation changes and land-use alteration on streamflow

    Xuelian Bai / Wenzhi Zhao / Hu Liu / Yongyong Zhang / Qiyue Yang / Jintao Liu / Xueli Chang

    Frontiers in Environmental Science, Vol

    A comparative analysis from two adjacent catchments in the Qilian Mountains, arid northwestern China

    2023  Volume 11

    Abstract: Comparative analysis of the impacts of precipitation and land use on streamflow from adjacent catchments is critical to exploring pathways toward water security and sustainable development. In this work, two adjacent catchments (the Mayinghe and Xidahe, ... ...

    Abstract Comparative analysis of the impacts of precipitation and land use on streamflow from adjacent catchments is critical to exploring pathways toward water security and sustainable development. In this work, two adjacent catchments (the Mayinghe and Xidahe, abbreviated as MYC and XDC, respectively) in northwestern China were selected to compare the impacts of precipitation change and land use alteration on streamflow change during 1956–2019 using field observation streamflow data and satellite data. An opposite trend of streamflow was found for the two catchments from 1956 to 2019: the streamflow decreased significantly in the MYC (-0.63 × 107m3/10a, p < 0.05), while it increased in the XDC (0.71 × 107m3/10a, p < 0.05). Land conversion dominated the streamflow reduction in the MYC, with a contribution of about 68.3%. In the XDC, precipitation was confirmed to be the major factor driving the increase in streamflow. The streamflow for farmland irrigation reached 27.97 × 104 m3/km2 in the MYC, which was the leading factor of streamflow reduction in the basin. The findings obtained from this work can shed light on the quantitative understanding of streamflow changes in small catchments and offer a scientific basis for sustainable water management in other inland river basins.
    Keywords streamflow ; inland river basin ; northwestern China ; land use alteration ; precipitation change ; Environmental sciences ; GE1-350
    Subject code 550
    Language English
    Publishing date 2023-02-01T00:00:00Z
    Publisher Frontiers Media S.A.
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

  3. Article ; Online: Spatial pattern variation of artificial sand-binding vegetation based on UAV imagery and its influencing factors in an oasis–desert transitional zone

    Ying Zheng / Qiyue Yang / Heng Ren / Dejin Wang / Changming Zhao / Wenzhi Zhao

    Ecological Indicators, Vol 141, Iss , Pp 109068- (2022)

    2022  

    Abstract: The spatial pattern of vegetation can reflect the impacts of the environment on plants and the response of plants to the environment, which can promote a deep understanding of the potential driving mechanisms of vegetation evolution and community ... ...

    Abstract The spatial pattern of vegetation can reflect the impacts of the environment on plants and the response of plants to the environment, which can promote a deep understanding of the potential driving mechanisms of vegetation evolution and community maintenance. A sand-binding vegetation system without irrigation has been implemented in the oasis–desert transitional zone since the 1970 s, where the annual precipitation has been approximately 120 mm. While the mobile dunes have been effectively stabilized, a patchy pattern of sand-binding vegetation has been observed. However, we do not understand why the pattern of sand-binding vegetation changed from the initial uniform distribution to the current patchy pattern. In this study, low-altitude UAV remote sensing technology and imaging-based quantification techniques were used to explore the effects of biotic and abiotic factors on the spatial patterns of sand-binding vegetation over 50 years. The spatial pattern of Haloxylon ammodendron changed gradually from a uniform distribution to an aggregated distribution, and the degree of patch fragmentation of H. ammodendron at the landscape scale gradually increased with the age of the sand-binding vegetation. The artificial sand-binding vegetation composed of H. ammodendron showed discontinuous change in which the system state reached a transition point after 30 years and changed to another state after 40 years. There were no significant correlations between the landscape indices and soil water content in the shallow layers (0–10 cm, 10–50 cm), while the soil water content in the 50–100 cm layers was significantly negatively correlated with the class area, percentage of landscape, largest patch index, percentage of like adjacencies and aggregation index and was positively correlated with the normalized landscape shape index. The soil water content in the 100–200 cm layers was positively correlated with the number of patches and patch density. Competition intensity at the individual level had a more significant effect on ...
    Keywords Oasis–desert transitional zone ; Artificial sand-binding vegetation ; Spatial pattern variation ; Landscape indices ; UAV imagery ; Ecology ; QH540-549.5
    Subject code 910 ; 580
    Language English
    Publishing date 2022-08-01T00:00:00Z
    Publisher Elsevier
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

  4. Article ; Online: Effect of Huang-Lian Jie-Du Decoction on Glucose and Lipid Metabolism in Type 2 Diabetes Mellitus

    Zhipeng Hu / Maoyi Yang / Ya Liu / Qiyue Yang / Hongyan Xie / Sihan Peng / Juan Gao / Chunguang Xie

    Frontiers in Pharmacology, Vol

    A Systematic Review and Meta-Analysis

    2021  Volume 12

    Abstract: Background: Type 2 diabetes mellitus (T2DM) is a heterogeneous disease characterized by persistent hyperglycemia. Huang-Lian Jie-Du decoction (HLJDD) is a traditional Chinese medicine formula which is widely used in treating T2DM in China. A thorough ... ...

    Abstract Background: Type 2 diabetes mellitus (T2DM) is a heterogeneous disease characterized by persistent hyperglycemia. Huang-Lian Jie-Du decoction (HLJDD) is a traditional Chinese medicine formula which is widely used in treating T2DM in China. A thorough understanding of current body of evidence is needed.Objective: this study aims to summarize the clinical evidence of HLJDD for T2DM to provide an up-to-date and accurate understanding of this issue for research and clinical practice.Methods: Six databases were searched from inception to June 27, 2020 without language and publication status restrictions and randomized controlled trials about HLJDD on T2DM were included. Two evaluators searched and screened citations independently. Risk of bias was assessed by 2019 version 2 of the Cochrane risk-of-bias tool for randomized trials (RoB2). Risk ratio (RR) with 95% confidence interval (CI) was used as an effect measure for dichotomous outcomes and mean difference (MD) with 95% CI was used for continuous outcomes. Subgroup analyses and sensitivity analyses were carried out.Results: Nine studies including 811 participants were included in this study. The overall risk of bias was high risk. Compared with metformin alone, combination treatment of HLJDD and metformin may result in a reduction in HbA1c, FBG, 2hPG, HOMA-IR and an improved lipid metabolism. Evidence comparing HLJDD and metformin or no intervention or placebo was insufficient. The quality of evidence was low.Conclusions: Current evidence about HLJDD on T2DM is still uncertain and more high-quality studies are needed to firmly establish the clinical efficacy and safety of HLJJD.
    Keywords meta-analysis ; systematic review ; type diabetes mellitus ; traditional Chinese medicine ; huang-lian jie-du decoction ; Therapeutics. Pharmacology ; RM1-950
    Subject code 610
    Language English
    Publishing date 2021-04-01T00:00:00Z
    Publisher Frontiers Media S.A.
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

  5. Article ; Online: Estimating Deep Drainage Using Deep Soil Moisture Data under Young Irrigated Cropland in a Desert-Oasis Ecotone, Northwest China

    Yongyong Zhang / Wenzhi Zhao / Tyson E. Ochsner / Briana M. Wyatt / Hu Liu / Qiyue Yang

    Vadose Zone Journal, Vol 18, Iss

    2019  Volume 1

    Abstract: Deep drainage reduces agricultural water productivity under cropland recently converted from native desert soils (i.e., young cropland) and increases the risks of nutrient and pesticide leaching into groundwater in the desert-oasis ecotone. However, the ... ...

    Abstract Deep drainage reduces agricultural water productivity under cropland recently converted from native desert soils (i.e., young cropland) and increases the risks of nutrient and pesticide leaching into groundwater in the desert-oasis ecotone. However, the deep drainage rates under young cropland in these oasis environments remain unclear, especially for winter irrigation, a common practice in Northwest China. The objective of this study was to estimate the deep drainage rate using the HYDRUS-1D model based on soil moisture data in the deep vadose zone. Soil moisture at depths ranging from 0 to 200 cm was measured using HydraProbe II soil sensors in maize ( L.) and wheat ( L.) fields in 2015 and 2017, respectively. Using a novel simulation approach based on soil moisture data in the deep vadose zone, the HYDRUS-1D model provided reliable estimates of deep drainage as confirmed by comparison with estimates from the soil water balance method and prior studies in the region. The annual deep drainage averaged 468 mm, and the annual deep drainage coefficient averaged 43% in the young croplands. The winter irrigation amount averaged 265 mm, and the deep drainage coefficient during winter averaged 21% in the young croplands. The sandy soil of the young cropland and inefficient irrigation scheduling are detrimental to water conservation, causing relatively large deep drainage losses and enhancing the risks of groundwater pollution.
    Keywords Environmental sciences ; GE1-350 ; Geology ; QE1-996.5
    Subject code 550
    Language English
    Publishing date 2019-03-01T00:00:00Z
    Publisher Wiley
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

  6. Article: Extensive investigation of the sap flow of maize plants in an oasis farmland in the middle reach of the Heihe River, Northwest China

    Zhao, Liwen / Zhibin He / Wenzhi Zhao / Qiyue Yang

    Journal of plant research. 2016 Sept., v. 129, no. 5

    2016  

    Abstract: A better understanding of the sap flow characteristics of maize plants is critical for improving irrigation water-use efficiency, especially for regions facing water resource shortages. In this study, sap flow rates, related soil-physics and plant-growth ...

    Abstract A better understanding of the sap flow characteristics of maize plants is critical for improving irrigation water-use efficiency, especially for regions facing water resource shortages. In this study, sap flow rates, related soil-physics and plant-growth parameters, and meteorological factors, were simultaneously monitored in a maize field in two consecutive years, 2011 and 2012, and the sap flow rates of the maize plants were extensively analyzed based on the monitored data. Seasonal and daily variational characteristics were identified at different growth stages and under different weather conditions, respectively. The analyses on the relationships between sap flow rate and reference evapotranspiration (ET₀), as well as several plant-growth parameters, indicate that the irrigation schedule can exert an influence on sap flow, and can consequently affect crop yield. The ranking of the main meteorological factors affecting the sap flow rate was: net radiation > air temperature > vapor pressure deficit > wind speed. For a quick estimation of sap flow rates, an empirical formula based on the two top influencing factors was put forward and verified to be reliable. The sap flow rate appeared to show little response to irrigation when the water content was relatively high, implying that some of the irrigation in recent years may have been wasted. These results may help to reveal the bio-physical processes of maize plants related to plant transpiration, which could be beneficial for establishing an efficient irrigation management system in this region and also for providing a reference for other maize-planting regions.
    Keywords agricultural land ; air temperature ; corn ; crop yield ; developmental stages ; evapotranspiration ; irrigation scheduling ; oases ; plant growth ; rivers ; sap flow ; soil physics ; transpiration ; vapor pressure ; water content ; water use efficiency ; wind speed ; China
    Language English
    Dates of publication 2016-09
    Size p. 841-851.
    Publishing place Springer Japan
    Document type Article
    ZDB-ID 2077362-6
    ISSN 1618-0860 ; 0918-9440
    ISSN (online) 1618-0860
    ISSN 0918-9440
    DOI 10.1007/s10265-016-0835-y
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  7. Article: Root biomass distribution of planted Haloxylon ammodendron in a duplex soil in an oasis: desert boundary area

    Zhou, Hai / Wenzhi Zhao / Qiyue Yang

    Ecological research. 2016 Sept., v. 31, no. 5

    2016  

    Abstract: Duplex soils, consisting of a sandy surface soil (A-horizon) and silty-clay subsoil (B-horizon), occur in a boundary area between oasis and desert in northwestern China and create a challenging habitat for restoration of plant growth. We conducted an ... ...

    Abstract Duplex soils, consisting of a sandy surface soil (A-horizon) and silty-clay subsoil (B-horizon), occur in a boundary area between oasis and desert in northwestern China and create a challenging habitat for restoration of plant growth. We conducted an experiment in a 10-year-old H. ammodendron plantation forest to determine the influence of physical properties of duplex soil on water infiltration and plant root growth. We used a trenching method to assess root biomass, and classified roots into two diameter classes: fine (<2 mm) and coarse (>2 mm). Following a 26.7 mm rain event, water infiltrated to the B- horizon; further deep percolation was hindered by low hydraulic conductivity, so that B horizon remained at high available soil moisture for an extended period of time. Root biomass increased rapidly in, or very close to the B horizon, especially for coarse roots. The subsoil formed a barrier to root penetration, but may also reflect the accumulation of water resources at the boundary between the A- and B-horizon. Shoot growth and root distribution, shrub height and canopy area, and total root biomass were negatively correlation with depth to the B horizon, and that was reflected by quadratic functions. We conclude that the texture and structure of duplex soils influenced the soil environment for water infiltration and storage, indicating that the B-horizon underlying sand in duplex soils is advantageous for the growth, and development of planted sand-stabilizing vegetation. These results have important implications for sustainable development of sand-fixing plantations in desert ecosystems.
    Keywords A horizons ; B horizons ; Haloxylon ammodendron ; biomass ; canopy ; ecosystems ; edaphic factors ; forest plantations ; habitat conservation ; hydraulic conductivity ; infiltration (hydrology) ; oases ; rain ; root growth ; roots ; sand ; shrubs ; soil water ; sustainable development ; texture ; trenching ; vegetation ; water resources ; China
    Language English
    Dates of publication 2016-09
    Size p. 673-681.
    Publishing place Springer Japan
    Document type Article
    ZDB-ID 233459-8
    ISSN 0912-3814
    ISSN 0912-3814
    DOI 10.1007/s11284-016-1376-5
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  8. Article: (with research data) Extreme drought stress shifts net facilitation to neutral interactions between shrubs and sub‐canopy plants in an arid desert

    Zhang, Gefei / Wenzhi Zhao / Hai Zhou / Qiyue Yang / Xiaofen Wang

    Oikos. 2018 Mar., v. 127, no. 3

    2018  

    Abstract: The stress gradient hypothesis (SGH) predicts that the importance or intensity of competition and facilitation will change inversely along abiotic stress gradients. It was originally postulated that increasing environmental stress can induce a monotonic ... ...

    Abstract The stress gradient hypothesis (SGH) predicts that the importance or intensity of competition and facilitation will change inversely along abiotic stress gradients. It was originally postulated that increasing environmental stress can induce a monotonic increase in facilitation. However, more recent models predicted that the relationship between severity and interaction exhibits a hump‐shaped pattern, in which positive interactions prevail under moderate stress but decline at the extreme ends of stress gradients. In the present study, we conducted a field experiment along a temporal rainfall gradient for five consecutive years, in order to investigate interactions in a shrub‐herbaceous plant community at the southern edge of the Badain Jaran Desert, and, more specifically, investigated the effects of Calligonum mongolicum, a dominant shrub species, on both abiotic environmental variables and the performance of sub‐canopy plant species. We found that shrubs can improve sub‐canopy water regimes, soil properties, plant biomass, density, cover, and richness and, more importantly, that the positive effect of shrubs on sub‐canopy soil moisture during the summer diminishes as rainfall decreases, a pattern that partly explains the collapse of the positive interaction between shrubs and their understory plants. These results provide empirical evidence that the positive effect of shrubs on understory plant communities in extreme arid environments may decline and become neutral with increasing drought stress.
    Keywords Calligonum ; dry environmental conditions ; field experimentation ; models ; phytomass ; plant communities ; rain ; shrubs ; soil properties ; soil water ; summer ; understory ; water stress
    Language English
    Dates of publication 2018-03
    Size p. 381-391.
    Publishing place Blackwell Publishing Ltd
    Document type Article
    Note JOURNAL ARTICLE
    ZDB-ID 207359-6
    ISSN 0030-1299
    ISSN 0030-1299
    DOI 10.1111/oik.04630
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  9. Article: Size-related change in Nitraria sphaerocarpa patches shifts the shrub-annual interaction in an arid desert, northwestern China

    Zhang, Gefei / Qiyue Yang / Wenzhi Zhao / Xiaofen Wang

    Acta oecologica. 2015 Nov., v. 69

    2015  

    Abstract: In arid and semi-arid ecosystems, the effect of shrubs on their understory plants has been frequently reported. Many previous studies have shown that both facilitation and competition act simultaneously, and their balance changes in response to spatial ... ...

    Abstract In arid and semi-arid ecosystems, the effect of shrubs on their understory plants has been frequently reported. Many previous studies have shown that both facilitation and competition act simultaneously, and their balance changes in response to spatial or temporal variations in environmental stresses. Yet, we know little about how the interaction varies between shrubs and their understory plants in vegetation patches with different characteristics. Here, an empirical investigation was conducted in Hexi desert region of northwest China, to evaluate how the net effect of Nitraria sphaerocarpa shrubs on the herbaceous species varies across different sizes of N. sphaerocarpa patches. Our study showed that herbaceous species perform better on small shrub patches. But the magnitude of this facilitative effect decreased with increasing patch size, and finally shifted to interference in large patches. The results indicated that these negative shifts in plant interactions were not clearly related to ‘shrub-island effect’ in terms of nutrient accumulation or soil properties improvement, but may be explained by the variation in other abiotic factors, such as soil moisture and available light. Changes in root distribution and canopy structure of N. sphaerocarpa shrubs with the increase of patch size seem to also partly explain the variation in shrub-understory species interactions, as a result of increased above- and below-ground niche overlaps.
    Keywords canopy ; ecosystems ; environmental factors ; Nitraria ; shrubs ; soil properties ; soil water ; temporal variation ; understory ; vegetation ; China
    Language English
    Dates of publication 2015-11
    Size p. 121-128.
    Publishing place Elsevier Masson SAS
    Document type Article
    ZDB-ID 1033625-4
    ISSN 1146-609X
    ISSN 1146-609X
    DOI 10.1016/j.actao.2015.10.004
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  10. Article: Mechanisms and feedbacks for evapotranspiration-induced salt accumulation and precipitation in an arid wetland of China

    Liu, Bing / Chan Liu / Qiyue Yang / Wenzhi Zhao / Xuexiang Chang / YangYang Meng / Yuting Yang / Zijuan Wen

    Journal of hydrology. 2019 Jan., v. 568

    2019  

    Abstract: Salt dissolved in soil water is transported upward to the soil surface through capillary rise from shallow groundwater, leading to salt accumulation near the surface and salinization of wetlands in arid regions. However, it is not clear how the mechanism ...

    Abstract Salt dissolved in soil water is transported upward to the soil surface through capillary rise from shallow groundwater, leading to salt accumulation near the surface and salinization of wetlands in arid regions. However, it is not clear how the mechanism and feedback for evapotranspiration induces salt accumulation and precipitation. Here, we developed a model to simulate the transport of water, solutes, and heat, and measured the meteorological, hydrological, and hydraulic parameters of soil using field experiments to calibrate the model for riparian and saltmarsh wetlands in northwestern China. The results showed that the annual atmospheric precipitation averaged 125.3 ± 10.2 mm in two types of wetlands, the evapotranspiration, depth to the groundwater and soil salinity averaged 587.7 mm yr−1, 85.4 ± 5.4 cm and 29.80 g kg−1 in the riparian wetland, while 637.2 mmyr−1, 129.7 ± 15.1 cm and 63.64 g kg−1 in the saltmarsh wetland, respectively. We found that the flux of liquid water, flux of water vapor, salinity, and efflorescence had maximum values of 1.23 mm day−1, 0.22 mm day−1, 104.16 g kg−1, and 2.10 cm in the riparian wetland, respectively, versus 1.28 mm day−1, 0.32 mm day−1, 202.02 g kg−1, and 3.70 cm in the saltmarsh wetland. Our simulations show that the salinity increases significantly with increasing evapotranspiration, soil temperature, saturated water content, and groundwater depth in the saltmarsh wetland, but that the effects of saturated water content and groundwater depth were small in the riparian wetland. As a result of these factors, the efflorescence pattern exhibited characteristic seasonal and inter-annual variability in which complex interactions among atmospheric precipitation, evapotranspiration, groundwater, and river water provided the long-term driving forces for water flow and salt transport. We found that the increasing efflorescence disrupted evaporation more than subflorescence, which reduced the soil porosity and possibly affected water vapor transport.
    Keywords arid zones ; atmospheric precipitation ; capillarity ; evaporation ; evapotranspiration ; field experimentation ; groundwater ; heat ; liquids ; porosity ; river water ; salinity ; salt marshes ; simulation models ; soil salinity ; soil temperature ; soil water ; solutes ; water content ; water flow ; water table ; water vapor ; China
    Language English
    Dates of publication 2019-01
    Size p. 403-415.
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 1473173-3
    ISSN 0022-1694
    ISSN 0022-1694
    DOI 10.1016/j.jhydrol.2018.11.004
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

To top