Photosynthetic water use efficiency in tree crowns of Shorea beccariana and Dryobalanops aromatica in a tropical rain forest in Sarawak, East Malaysia

<p>Functional group-specific water use strategies are vital in understanding plant performance under current and future global climate change related drought scenarios. Different functional groups have different strategies to regulate their above ground water use and loss in order to respond to drought stress. Here, we studied the ecohydrological response of a controlled rain forest system to a 10-week lasting experimental drought (Biosphere 2 Water, Atmosphere, and Life Dynamics, B2 WALD project). Using gas exchange chambers, we specifically investigated the response of the two main rain forest functional groups - three canopy tree species and two understory species - in their above ground water use efficiency. Rates and isotopic fluxes of transpiration, assimilation and night respiration were monitored in high temporal resolution. In combination with plant physiological information (i.e., leaf water potential) a complete picture of their above ground water use could be gained. We expect that the deep rooting canopy tree species will be able to keep their above ground water use constant while the shallow rooting understory species will have to adapt their water use efficiency to budget their water reserves and resources.</p>

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Brachiaria physiological parameters in agroforestry systems

Ciência Rural ◽

10.1590/0103-8478cr20160150 ◽

2017 ◽

Vol 47 (5) ◽

Cited By ~ 1

Author(s):

Márcia Vitória Santos ◽

Evander Alves Ferreira ◽

Daniel Valadão ◽

Fabiana Lopes Ramos de Oliveira ◽

Vitor Diniz Machado ◽

...

Keyword(s):

Stomatal Conductance ◽

Water Use Efficiency ◽

Water Use ◽

Transpiration Rate ◽

Agroforestry Systems ◽

Physiological Parameters ◽

Tree Crowns ◽

Full Sunlight ◽

Use Efficiency ◽

Plot Design

ABSTRACT: This study aimed to assess the effects of Eucalyptus and maize shading on characteristics related to water use by Brachiaria in agroforestry systems. Treatments were arranged in a split-split-plot design, with plots consisting of different spacing between Eucalyptus plants (12.0×2.0m and 12.0×4.0m), split-plots of different distances between Brachiaria and Eucalyptus (6.0, 4.0, and 2.0m), and split-split-plots of Brachiaria sowing sites (maize row and inter-row). One treatment with Brachiaria under full sunlight was included. Bread grass intercropping in maize inter-rows associated with the densest Eucalyptus spacing and bread grass proximity to Eucalyptus tree crowns adversely affected the stomatal conductance, internal carbon, and transpiration rate of bread grass. Water use efficiency of bread grass intercropped in maize rows decreased, regardless of the Eucalyptus plot design and distance between forages and trees.

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Is distribution of hydraulic constraints within tree crowns reflected in photosynthetic water-use efficiency? An example of Betula pendula

Ecological Research ◽

10.1007/s11284-009-0641-2 ◽

2009 ◽

Vol 25 (1) ◽

pp. 173-183 ◽

Cited By ~ 22

Author(s):

Arne Sellin ◽

Eve Eensalu ◽

Aigar Niglas

Keyword(s):

Water Use Efficiency ◽

Water Use ◽

Betula Pendula ◽

Tree Crowns ◽

Use Efficiency

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Growth, gas exchange and water use efficiency of the facultative hemiparasite Rhinanthus minor associated with hosts differing in foliar nitrogen concentration

Physiologia Plantarum ◽

10.1034/j.1399-3054.1993.890110.x ◽

1993 ◽

Vol 89 (1) ◽

pp. 64-70 ◽

Cited By ~ 13

Author(s):

W.E. Seel ◽

R.E. Cooper ◽

M.C. Press

Keyword(s):

Gas Exchange ◽

Water Use Efficiency ◽

Water Use ◽

Nitrogen Concentration ◽

Foliar Nitrogen ◽

Use Efficiency ◽

Rhinanthus Minor

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

Climate Research ◽

10.3354/cr01526 ◽

2018 ◽

Vol 76 (2) ◽

pp. 115-130 ◽

Cited By ~ 5

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

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

JOURNAL OF ADVANCES IN AGRICULTURE ◽

10.24297/jaa.v6i1.5388 ◽

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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