scholarly journals Water-Use Efficiency of Co-occurring Sky-Island Pine Species in the North American Great Basin

2021 ◽  
Vol 12 ◽  
Author(s):  
Xinsheng Liu ◽  
Emanuele Ziaco ◽  
Franco Biondi
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Growing Season ◽  
Stem Growth ◽  
Tree Level ◽  
Late Season ◽  
Limber Pine ◽  
Use Efficiency ◽  
Sky Island ◽  
The Impact

Water-use efficiency (WUE), weighing the balance between plant transpiration and growth, is a key characteristic of ecosystem functioning and a component of tree drought resistance. Seasonal dynamics of tree-level WUE and its connections with drought variability have not been previously explored in sky-island montane forests. We investigated whole-tree transpiration and stem growth of bristlecone (Pinus longaeva) and limber pine (Pinus flexilis) within a high-elevation stand in central-eastern Nevada, United States, using sub-hourly measurements over 5 years (2013–2017). A moderate drought was generally observed early in the growing season, whereas interannual variability of summer rains determined drought levels between years, i.e., reducing drought stress in 2013–2014 while enhancing it in 2015–2017. Transpiration and basal area increment (BAI) of both pines were coupled throughout June–July, resulting in a high but relatively constant early season WUE. In contrast, both pines showed high interannual plasticity in late-season WUE, with a predominant role of stem growth in driving WUE. Overall, bristlecone pine was characterized by a lower WUE compared to limber pine. Dry or wet episodes in the late growing season overrode species differences. Our results suggested thresholds of vapor pressure deficit and soil moisture that would lead to opposite responses of WUE to late-season dry or wet conditions. These findings provide novel insights and clarify potential mechanisms modulating tree-level WUE in sky-island ecosystems of semi-arid regions, thereby helping land managers to design appropriate science-based strategies and reduce uncertainties associated with the impact of future climatic changes.

Estimating the water use efficiency of spring barley using crop models

2018 ◽  
Vol 156 (5) ◽  
pp. 628-644 ◽  
Author(s):  
E. Pohanková ◽  
P. Hlavinka ◽  
M. Orság ◽  
J. Takáč ◽  
K. C. Kersebaum ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Spring Barley ◽  
Growing Season ◽  
Above Ground Biomass ◽  
Grain Yields ◽  
Crop Models ◽  
Average Value ◽  
Ground Biomass ◽  
Use Efficiency

AbstractIn the current study, simulations by five crop models (WOFOST, CERES-Barley, HERMES, DAISY and AQUACROP) were compared for 7–12 growing seasons of spring barley (Hordeum vulgare) at three sites in the Czech Republic. The aims were to compare how various process-based crop models with different calculation approaches simulate different values of transpiration (Ta) and evapotranspiration (ET) based on the same input data and compare the outputs of these simulations with reference data. From the outputs of each model, the water use efficiency (WUE) from Ta (WUETa) and from actual ET (WUEETa) was calculated for grain yields and above-ground biomass yield. The results of the first part of the study show that the model with the Penman approach for calculating ET simulates lower actual ET (ETa) sums, at an average of 250 mm during the growing season, than other models, which use the Penman–Monteith approach and simulate 330 mm on average during the growing season. In the second part of the current study, WUE reference values in the range 1.9–2.4 kg/m3were calculated for spring barley and grain yield. Values of WUETa/WUEETacalculated from the outputs of individual models for grain yields and above-ground biomass yields ranged from 2.0/1.0 to 5.9/3.8 kg/m3with an average value of 3.2/2.0 kg/m3and from 3.9/2.1 to 10.5/6.8 kg/m3with an average value of 6.5/4.0 kg/m3, respectively. The results confirm that the average values of all models are nearest to actual values.

Site-level soil moisture controls water-use efficiency improvement and climate response in sugar maple: a dual dendroisotopic study

2021 ◽  
pp. 1-12
Author(s):  
R. Dietrich ◽  
F.W. Bell ◽  
M. Anand
Keyword(s):  
Soil Moisture ◽  
Water Use Efficiency ◽  
Water Use ◽  
Tree Ring ◽  
Sugar Maple ◽  
Photosynthetic Capacity ◽  
Environmental Drivers ◽  
Tree Level ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency

Given the large contribution of forests to terrestrial carbon storage, there is a need to resolve the environmental and physiological drivers of tree-level response to rising atmospheric CO2. This study examines how site-level soil moisture influences growth and intrinsic water-use efficiency in sugar maple (Acer saccharum Marsh.). We construct tree-ring, δ18O, and Δ13C chronologies for trees across a soil moisture gradient in Ontario, Canada, and employ a structural equation modelling approach to ascertain their climatic, ontogenetic, and environmental drivers. Our results support previous evidence for the presence of strong developmental effects in tree-ring isotopic chronologies — in the range of −4.7‰ for Δ13C and +0.8‰ for δ18O — across the tree life span. Additionally, we show that the physiological response of sugar maple to increasing atmospheric CO2 depends on site-level soil moisture variability, with trees only in relatively wet plots exhibiting temporal increases in intrinsic water-use efficiency. These results suggest that trees in wet and mesic plots have experienced temporal increases in stomatal conductance and photosynthetic capacity, whereas trees in dry plots have experienced decreases in photosynthetic capacity. This study is the first to examine sugar maple physiology using a dendroisotopic approach and broadens our understanding of carbon–water interactions in temperate forests.

scholarly journals Interannual and Seasonal Variations in Ecosystem Transpiration and Water Use Efficiency in a Tropical Rainforest

Forests ◽  
2018 ◽  
Vol 10 (1) ◽  
pp. 14 ◽  
Author(s):  
Maricar Aguilos ◽  
Clément Stahl ◽  
Benoit Burban ◽  
Bruno Hérault ◽  
Elodie Courtois ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Seasonal Variations ◽  
Radiation Effects ◽  
Global Radiation ◽  
Climate Conditions ◽  
Carbon Cycles ◽  
Use Efficiency ◽  
The Impact

Warmer and drier climates over Amazonia have been predicted for the next century with expected changes in regional water and carbon cycles. We examined the impact of interannual and seasonal variations in climate conditions on ecosystem-level evapotranspiration (ET) and water use efficiency (WUE) to determine key climatic drivers and anticipate the response of these ecosystems to climate change. We used daily climate and eddyflux data recorded at the Guyaflux site in French Guiana from 2004 to 2014. ET and WUE exhibited weak interannual variability. The main climatic driver of ET and WUE was global radiation (Rg), but relative extractable water (REW) and soil temperature (Ts) did also contribute. At the seasonal scale, ET and WUE showed a modal pattern driven by Rg, with maximum values for ET in July and August and for WUE at the beginning of the year. By removing radiation effects during water depleted periods, we showed that soil water stress strongly reduced ET. In contrast, drought conditions enhanced radiation-normalized WUE in almost all the years, suggesting that the lack of soil water had a more severe effect on ecosystem evapotranspiration than on photosynthesis. Our results are of major concern for tropical ecosystem modeling because they suggest that under future climate conditions, tropical forest ecosystems will be able to simultaneously adjust CO2 and H2O fluxes. Yet, for tropical forests under future conditions, the direction of change in WUE at the ecosystem scale is hard to predict, since the impact of radiation on WUE is counterbalanced by adjustments to soil water limitations. Developing mechanistic models that fully integrate the processes associated with CO2 and H2O flux control should help researchers understand and simulate future functional adjustments in these ecosystems.

scholarly journals Evapotranspiration, crop coefficient and water use efficiency of coriander grown in tropical environment

2018 ◽  
Vol 36 (4) ◽  
pp. 446-452 ◽  
Author(s):  
Vicente de PR da Silva ◽  
Inajá Francisco de Sousa ◽  
Alexandra L Tavares ◽  
Thieres George F da Silva ◽  
Bernardo B da Silva ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Crop Production ◽  
Field Experiments ◽  
Growth Parameters ◽  
Crop Coefficient ◽  
Growing Season ◽  
Tropical Environment ◽  
Mean Values ◽  
Use Efficiency

ABSTRACT The water scarcity is expected to intensify in the future and irrigation becomes an essential component of crop production, especially in arid and semiarid regions, where the available water resources are limited. Four field experiments were carried out at tropical environment in Brazil in 2013 and 2014, in order to evaluate the effect of planting date on crop evapotranspiration (ETc), crop coefficient (Kc), growth parameters and water use efficiency (WUE) of coriander (Coriandrum sativum) plants. The planting dates occurred during winter, spring, summer and autumn growing seasons. ETc was obtained through the soil water balance method and the reference evapotranspiration (ETo) through the Penman-Monteith method, using data collected from an automatic weather station located close to the experimental area. The results of the research showed that the mean values of coriander ETc and Kc were 139.8 mm and 0.87, respectively. Coriander water demand is higher in the summer growing season and lower in the winter; however, its yield is higher in the autumn and lower in the winter. Coriander has higher yield and development of its growth variables in the autumn growing season. The results also indicated that the interannual climate variations had significant effects on most growth variables, as yield, ETc and Kc of coriander grown in tropical environment.

scholarly journals Effects of Temperature and Grafting on Yield, Nutrient Uptake, and Water Use Efficiency of a Hydroponic Sweet Pepper Crop

Agronomy ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 110 ◽  
Author(s):  
Andreas Ropokis ◽  
Georgia Ntatsi ◽  
Constantinos Kittas ◽  
Nikolaos Katsoulas ◽  
Dimitrios Savvas
Keyword(s):  
Water Use Efficiency ◽  
Nutrient Uptake ◽  
Water Use ◽  
Total Yield ◽  
Sweet Pepper ◽  
Winter Climate ◽  
Mild Winter ◽  
Yield Increase ◽  
Use Efficiency ◽  
The Impact

In areas characterized by mild winter climate, pepper is frequently cultivated in unheated greenhouses in which the temperature during the winter may drop to suboptimal levels. Under low temperature (LT) conditions, the uptake of nutrients may be altered in a different manner than that of the water and thus their uptake ratio, known as uptake concentration, may be different than in greenhouses with standard temperature (ST) conditions. In the present study, pepper plants of the cultivars “Sammy” and “Orangery”, self-grafted or grafted onto two commercial rootstocks (“Robusto” and “Terrano”), were cultivated in a greenhouse under either ST or LT temperature conditions. The aim of the study was to test the impact of grafting and greenhouse temperature on total yield, water use efficiency, and nutrient uptake. The LT regime reduced the yield by about 50% in “Sammy” and 33% in “Orangery”, irrespective of the grafting combination. Grafting of “Sammy” onto both “Robusto” and “Terrano” increased the total fruit yield by 39% and 34% compared with the self-grafted control, while grafting of “Orangery” increased the yield only when the rootstock was “Terrano”. The yield increase resulted exclusively from enhancement of the fruit number per plant. Both the water consumption and the water use efficiency were negatively affected by the LT regime, however the temperature effect interacted with the rootstock/scion combination. The LT increased the uptake concentrations (UC) of K, Ca, Mg, N, and Mn, while it decreased strongly that of P and slightly the UC of Fe and Zn. The UC of K and Mg were influenced by the rootstock/scion combination, however this effect interacted with the temperature regime. In contrast, the Ca, N, and P concentrations were not influenced by the grafting combination. The results of the present study show that the impact of grafting on yield and nutrient uptake in pepper depend not merely on the rootstock genotype, however on the rootstock/scion combination.

scholarly journals Daily dynamics of photosynthetic parameters in beech population under periodical drought conditions

2015 ◽  
Vol 10 (1) ◽  
Author(s):  
Milan Borišev ◽  
Rita Horak ◽  
Slobodanka Pajević ◽  
Saša Orlović ◽  
Nataša Nikolić ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Soil Drought ◽  
Physiological Status ◽  
Photosynthetic Parameters ◽  
Soil Layers ◽  
Photosynthetic Productivity ◽  
Early Afternoon ◽  
Use Efficiency ◽  
The Impact

AbstractThe paper presents the impact of periodic soil drought on physiological parameters important for bioproductivity of mountain beech populations. The investigated forest population was located near Fruška gora mountain peak, where water runs off quickly, and consequently lack of soil humidity develops very often. Decreasing trends of photosynthesis, transpiration, water use efficiency and stomatal conductance (gs) during the growing season were evident, in correlation with a shortage of precipitation. Diurnally, photosynthesis of beech leaves showed rhythmical changes. It was the most intensive in the morning, then decreased between noon and 1 pm, and increased again during early afternoon. High leaf temperature and water deficit in the deeper soil layers caused a decreasing trend in photosynthesis and daily rhythmic changes of the transpiration rate and water use efficiency. Although surface soil water capacity did not show a significant decreasing trend from July to September, a lack of precipitation was observed, which probably caused a lack of moisture in deeper soil layers, resulting in a decline in photosynthesis and transpiration. Physiological status, linked to primary photosynthetic productivity of forests, could be a significant indicator of environmental conditions and trends in climate changes.

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