scholarly journals Seasonal drought may alter N availability but not water use efficiency of dominant trees in a subtropical forest

2018 ◽  
Vol 16 ◽  
pp. e00475 ◽  
Author(s):  
Songbo Tang ◽  
Yimin Xu ◽  
Yongbiao Lin ◽  
Enqing Hou ◽  
Weijun Shen ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Subtropical Forest ◽  
N Availability ◽  
Seasonal Drought ◽  
Use Efficiency

scholarly journals Net Carbon Dioxide Assimilation, Carbon Isotope Discrimination, Growth, and Water-use Efficiency of Citrus Trees in Response to Nitrogen Status

1997 ◽  
Vol 122 (2) ◽  
pp. 226-232 ◽  
Author(s):  
J.P. Syvertsen ◽  
M.L. Smith ◽  
J. Lloyd ◽  
G.D. Farquhar
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Leaf Tissue ◽  
N Availability ◽  
Isotope Discrimination ◽  
Volkamer Lemon ◽  
Woody Root ◽  
Use Efficiency ◽  
Whole Tree ◽  
Leaf N

Five- to six-year-old `Redblush' grapefruit (Citrus paradisi Macf.) trees on `Volkamer' lemon [VL = C. volkameriana (Ten. & Pasq.)] or sour orange (SO = C. aurantium L.) rootstock, were grown individually in 7.9-m3 lysimeters for 2.5 years using low to high rates of fertilizer N. Net CO2 assimilation (ACO2) of leaves and leaf dry mass per area (DM/a) increased with leaf N concentration, whereas leaf tissue C isotope discrimination (Δ) decreased. Leaf tissue Δ was negatively related to ACO2 and DM/a. Transient effects of rootstock on leaf N were reflected by similar effects on Δ. There was no effect of leaf N on water-use efficiency (WUE) of leaves (WUEL = ACO2/transpiration); WUEL was not correlated with Δ. Although photosynthetic N use efficiency (ACO2/N) consistently decreased with increased leaf N, Δ was not consistently related to ACO2/N. Annual canopy growth, tree evapotranspiration (ET), and fruit yield increased with whole tree N uptake. Leaf tissue Δ was negatively related to all of these tree measurements at the end of the second year. By that time, whole-tree WUE (WUET, annual canopy growth per ET) also was negatively related to Δ. Larger trees on VL had higher ET than trees on SO, but there were no rootstock effects on WUET or on Δ. Leaf tissue Δ was consistently higher than Δ values of trunk and woody root tissues. Citrus leaf tissue Δ can be a useful indicator of leaf N, characteristics of leaf gas exchange, tree growth, yield, and WUET in response to N availability.

scholarly journals Evaluating the response of ẟ<sup>13</sup>C in <i>Haloxylon ammodendron</i>, a dominant C<sub>4</sub> species in Asian desert ecosystem, to water and nitrogen addition as well as the availability of its ẟ<sup>13</sup>C as the indicator of water use-efficiency

2020 ◽  
Author(s):  
Zixun Chen ◽  
Xuejun Liu ◽  
Xiaoqing Cui ◽  
Yaowen Han ◽  
Guoan Wang ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Water Use Efficiency ◽  
Water Use ◽  
N Deposition ◽  
Desert Ecosystem ◽  
N Availability ◽  
Water Addition ◽  
Haloxylon Ammodendron ◽  
Atmospheric N Deposition ◽  
Use Efficiency

Abstract. Variations in precipitation and atmospheric N deposition affect water and N availability in desert, and thus may have significant effects on desert ecosystems. Haloxylon ammodendron is a dominant plant in Asian desert, and addressing its physiological acclimatization to the changes in precipitation and N deposition can provide an insight into how desert plants adapt extreme environment by physiological adjustment. Carbon isotope ratio (ẟ13C) in plants has been suggested as a sensitive long-term indicator of physiological acclimatization. Therefore, this study evaluated the effect of precipitation change and increasing atmospheric N depositon on ẟ13C of H. ammodendron. Furthermore, Haloxylon ammodendron is a C4 plant, whether its ẟ13C can indicate water use-efficiency (WUE) has not been addressed. In the present study, we designed a field experiment with a completely randomized factorial combination of N and water, and measured ẟ13C, gas exchange and WUE of the assimilating branches of H. ammodendron. ẟ13C in H. ammodendron remained stable under N and water supply, while N addition, water addition and their interaction affected gas exchange and WUE in H. ammodendron. In addition, ẟ13C had no correlation with WUE. This result are associated with the irrelevance between ẟ13C and ci/ca, which might be caused by a special value (0.37) of the degree of bundle-sheath leakiness (φ) or a lower activity of carbonic anhydrase (CA) of H. ammodendron. Thus, ẟ13C of H. ammodendron cannot be used for indicating its WUE.

scholarly journals Evaluating the response of <i>δ</i><sup>13</sup>C in <i>Haloxylon ammodendron</i>, a dominant C<sub>4</sub> species in Asian desert ecosystems, to water and nitrogen addition as well as the availability of its <i>δ</i><sup>13</sup>C as an indicator of water use efficiency

2021 ◽  
Vol 18 (9) ◽  
pp. 2859-2870
Author(s):  
Zixun Chen ◽  
Xuejun Liu ◽  
Xiaoqing Cui ◽  
Yaowen Han ◽  
Guoan Wang ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Water Use Efficiency ◽  
Water Use ◽  
N Deposition ◽  
Bundle Sheath ◽  
N Availability ◽  
Haloxylon Ammodendron ◽  
Atmospheric N Deposition ◽  
Desert Ecosystems ◽  
Use Efficiency

Abstract. Variations in precipitation and atmospheric N deposition affect water and N availability in desert and thus may have significant effects on desert ecosystems. Haloxylon ammodendron is a dominant plant in Asian desert, and addressing its physiological acclimatization to the changes in precipitation and N deposition can provide insight into how desert plants adapt to extreme environments by physiological adjustment. Carbon isotope ratio (δ13C) in plants has been suggested as a sensitive long-term indicator of physiological acclimatization. Therefore, this study evaluated the effect of precipitation change and increasing atmospheric N deposition on δ13C of H. ammodendron. Furthermore, H. ammodendron is a C4 plant; whether its δ13C can indicate water use efficiency (WUE) has not been addressed. In the present study, we designed a field experiment with a completely randomized factorial combination of N and water and measured δ13C and gas exchange of H. ammodendron. Then we calculated the degree of bundle-sheath leakiness (φ) and WUE of the assimilating branches of H. ammodendron. δ13C and φ remained stable under N and water supply, while N addition, water addition and their interaction affected gas exchange and WUE in H. ammodendron. In addition, δ13C had no correlation with WUE. These results were associated with the irrelevance between δ13C and the ratio of intercellular to ambient CO2 concentration (ci / ca), which might be caused by a special value (0.37) of the degree of bundle-sheath leakiness (φ) or a lower activity of carbonic anhydrase (CA) of H. ammodendron. In conclusion, δ13C of H. ammodendron is not sensitive to global change in precipitation and atmospheric N deposition and cannot be used for indicating its WUE.

scholarly journals Drought Affected Ecosystem Water Use Efficiency of a Natural Oak Forest in Central China

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 839
Author(s):  
Xiaodong Niu ◽  
Shirong Liu
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Central China ◽  
Surface Conductance ◽  
Oak Forest ◽  
Summer Drought ◽  
Water Regulation ◽  
Seasonal Drought ◽  
Ecosystem Water Use Efficiency ◽  
Use Efficiency

Global climate models project more frequent drought events in Central China. However, the effect of seasonal drought on ecosystem water use efficiency (WUE) and water regulation strategy in Central China’s natural forests is poorly understood. This study investigated variations in WUE associated with drought in a natural oak (Quercus aliena) forest in Central China from 2017 to 2020 at several timescales based on continuous CO2 and water vapor flux measurements. Results showed that the 4-year mean gross ecosystem production (GEP), evapotranspiration (ET) and WUE of the natural oak forest was 1613.2 ± 116 g Cm−2, 637.8 ± 163.3 mm and 2.6 ± 0.68 g Ckg−1 H2O, with a coefficient of variation (CV) of 7.2%, 25.6% and 26.4%, respectively. The inter-annual variation in WUE was large, primarily due to the variation in ET caused by seasonal drought. Drought increased WUE distinctly in summer and decreased it slightly in autumn. During summer drought, surface conductance (gs) usually decreased with an increase in VPD, but the ratios of stomatal sensitivity (m) and reference conductance (gsref) were 0.21 and 0.3 molm−2s−1ln(kPa)−1 in the summer of 2019 and 2020. Strong drought can also affect ecosystem WUE and water regulation strategy in the next year. Decrease in precipitation in spring increased annual WUE. These results suggested that drought in different seasons had different effects on ecosystem WUE. Overall, our findings suggest that the natural oak forest did not reduce GEP by increasing WUE (i.e., reducing ET) under spring and summer drought, which could be due to its typical anisohydric characteristics, although it can also reduce stomatal opening during long-term drought.

Increasing intrinsic water-use efficiency over the past 160 years does not stimulate tree growth in southeastern China

2018 ◽  
Vol 76 (2) ◽  
pp. 115-130 ◽  
Author(s):  
G Guo ◽  
K Fang ◽  
J Li ◽  
HW Linderholm ◽  
D Li ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Tree Growth ◽  
Southeastern China ◽  
The Past ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency

A comparative appraisal of urea super granule application in raised bed and prilled urea application in conventional planting for transplanted boro rice (Oryza sativa)

2016 ◽  
Vol 6 (1) ◽  
pp. 822-832
Author(s):  
Halim Mahmud Bhuyan ◽  
Most. Razina Ferdousi ◽  
Mohammad Toufiq Iqbal ◽  
Ahmed Khairul Hasan
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
N Fertilizer ◽  
Deep Placement ◽  
Prilled Urea ◽  
Planting Methods ◽  
Weed Infestation ◽  
Use Efficiency ◽  
Raised Bed ◽  
Boro Rice

Utilization of urea super granule (USG) with raised bed cultivation system for transplanted boro (winter, irrigated) rice production is a major concern now days. A field experiment was conducted in the chuadanga district of Bangladesh to compare the two cultivation methods: deep placement of USG on raised bed with boro rice, and prilled urea (PU) broadcasting in conventional planting. Results showed that USG in raised bed planting increased grain yields of transplanted boro rice by up to 18.18% over PU in conventional planting. Deep placement of USG in raised bed planting increased the number of panicle m-2, number of grains panicle-1 and 1000-grains weight of boro rice than the PU in conventional planting. Better plant growth was observed by deep placement of USG in raised bed planting compared to PU in conventional planting. Sterility percentage and weed infestation were lower on USG in raised bed planting compared to the PU in conventional planting methods. Forty seven percent irrigation water and application time could be saved by USG in raised bed planting than PU in conventional planting. Deep placement of USG in bed saved N fertilizer consumption over conventional planting. Water use efficiency for grain and biomass production was higher with deep placement of USG in bed planting than the PU broadcasting in conventional planting methods. Similarly, agronomic efficiency of N fertilizer by USG in bed planting was significantly higher than the PU broadcasting in conventional planting. This study concluded that deep placement of USG in raised bed planting for transplanted boro rice is a new approach to achieve fertilizer and water use efficiency as well as higher yield and less water input compared to existing agronomic practices in Bangladesh.

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