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Riparian woodlands are hotspots of productivity and biodiversity on dryland landscapes, yet riparian tree species are also extremely vulnerable to catastrophic hydraulic damage caused by hydroclimatic change. Root zone water subsidies from shallow groundwater facilitate the high levels of productivity seen in riparian woodlands. Shallow groundwater provides a persistent source of root zone soil moisture that is somewhat decoupled from the local precipitation regime. As a result, riparian tree species are able to avoid water stress and maximize productivity throughout the prolonged summer dry seasons that are common in the southwestern United States. Groundwater declines caused by extreme drought conditions threaten the health and function of dryland riparian woodlands. If groundwater elevations drop below the root zones of riparian tree species, it is likely that riparian woodlands will experience widespread stress and mortality. However, the sensitivity of riparian tree species to changes in root zone water availability remains poorly constrained. This dissertation combines remote sensing, flux tower measurements, and ecological modeling to examine vegetation cover, evapotranspiration, and photosynthesis in riparian woodlands under changing environmental conditions. It also identifies critical physiological thresholds that are needed to maintain ecosystem structure and function under anthropogenic climate change.In the first chapter, I combine remote sensing data with measurements from groundwater monitoring wells to identify critical groundwater thresholds that are needed to maintain the health and function of riparian woodlands. The analysis examines the Santa Clara River in southern California, which experienced widespread groundwater declines during an extreme drought from 2012 to 2019. Spectral mixture analysis was used to estimate the fractional cover of green vegetation and non-photosynthetic vegetation (i.e., dead and woody plant material) in six riparian woodlands. The groundwater depth was characterized for each woodland using data from groundwater monitoring wells. The analysis revealed that riparian woodlands experience substantial decreases in green vegetation cover and substantial increases in dead/woody vegetation cover when the depth to groundwater exceeds ca. 5 m. The analysis also revealed a coherent spatial and temporal trend of riparian woodland mortality that proceeded downstream over six years and mirrored trends in groundwater elevation over space and time. The findings reveal that riparian woodlands depend on shallow groundwater access to maintain health and function, and that they experience substantial stress and mortality when they lose access to root zone water subsidies from shallow groundwater aquifers.In the second chapter, I develop a novel theoretical model to predict leaf temperature as a function of evapotranspiration. The model reveals that the difference between leaf temperature and air temperature varies as a linear function of the evaporative fraction. The model also reveals that leaf temperature converges to air temperature when the evaporative fraction equals one. The model predictions were validated using flux tower measurements from a riparian woodland and an upland savanna in southeastern Arizona. The flux tower measurements reveal that evaporative cooling reduced leaf temperature by ca. 1-5 °C in the middle of the growing season. Evaporative cooling also resulted in a ca. 15% reduction in leaf respiration. The impact of evaporative cooling on leaf carbon cycling represents a novel connection between plant water and carbon cycles via leaf energy balance that has received little attention in literature.In the third chapter, I develop a novel modeling framework to predict the vertical profiles of radiation and wind speed within forest canopies based on known physical principles. The predictions are then used to estimate the vertical profiles of leaf temperature and net photosynthesis for five flux tower sites spanning a large latitudinal gradient in North and South America. The model predictions reveal that leaf temperature decreases exponentially downward through forest canopies, and that the difference between top-of-canopy leaf temperature and bottom-of-canopy leaf temperature can exceed 7 °C. Unexpectedly, in many forest biomes, the highest levels of net photosynthesis often occur in the middle of the canopy. The analysis helps uncover the mechanistic basis for this behavior. The analysis also identifies the combinations of environmental conditions that result in critical leaf temperatures that cause irreversible damage to leaf photosynthetic infrastructure. Two different data sets provide evidence of trait coordination between leaf size and stomatal conductance to avoid critical leaf temperatures across global forest biomes.

Актуальность. Сегодня в разработку вводится большое количество нефтяных месторождений с трудноизвлекаемыми запасами, в частности, с низкопроницаемыми коллекторами. При проницаемости менее 1 мД система поддержания пластового давления имеет низкую эффективность, а добывающие скважины имеют высокие темпы падения и низкие дебиты даже при наличии гидроразрыва пласта. Помочь в решении данной проблемы может новая технология - водный Huff and Puff. Данная технология представляет собой циклическую закачку воды, остановку и последующий отбор жидкости на добывающей нефтяной скважине. Она позволяет инициировать процесс капиллярной пропитки в малодебитных безводных скважинах в низкопроницаемом коллекторе и увеличить добычу нефти. Цель: проанализировать мировой опыт применения и лабораторные исследования технологии Huff and Puff, определить ключевые параметры ее эффективности, сформулировать критерии применимости технологии. Объекты: процесс капиллярной пропитки в низкопроницаемом нефтенасыщенном коллекторе, результаты лабораторных исследований, отчеты о применении технологии на нефтяных месторождениях. Методы: оценка и анализ существующих лабораторных исследований технологии на керне, анализ условий и методик проведения экспериментов и их результатов, сравнение с аналогичными исследованиями, выявление общих зависимостей; обзор опыта применения технологии в США, КНР и России, сравнение их результатов с результатами лабораторных исследований. Результаты. В процессе анализа лабораторных исследований выявлены ключевые параметры эффективности применения технологии - наличие трещин в коллекторе, низкая проницаемость, гидрофильность и маленький характерный размер поровых каналов. Анализ мирового опыта применения водного Huff and Puff показал, что технология успешно применяется в КНР на малопроницаемых гидрофильных пластах на скважинах с многостадийным гидроразрывом пласта, что подтверждает лабораторные исследования. Опыт применения в США не был успешным из-за гидрофобности коллекторов. Опыт в России имеет неоднозначные результаты - из-за гидрофильности и низкой проницаемости пласта эффект капиллярной пропитки присутствует, но из-за конструкции скважин и отсутствия раскрытых трещин гидроразрыва пласта значительного эффекта не было. Результаты опыта применения согласуются с данными лабораторных испытаний. В результате данного анализа были сформированы критерии применимости технологии водного Huff and Puff. The relevance. Today, a large number of oil fields with hard-to-recover reserves, in particular, with low-permeability reservoirs, are in exploration. With a permeability of less than 1 mD, the formation pressure flow system has low efficiency, and production wells have high decline rates and low flow rates even in the presence of hydraulic fracturing. A new technology, water Huff and Puff, can help solve this problem. This technology is a cyclic water injection, shutdown and subsequent withdrawal of fluid during an oil well production. It allows us to initiate the process of capillary imbibition in marginal waterless wells in a low-permeability reservoir and increase oil production. The main aim: to analyze the world experience in the application and laboratory studies of the Huff and Puff technology, to determine the key parameters of its effectiveness, to formulate criteria for the applicability of the technology. Objects: capillary imbibition in a low-permeability oil-saturated reservoir, the results of laboratory studies, reports on the application of the technology in oil fields. Methods: evaluation and analysis of existing laboratory studies of technology on core, analysis of the conditions and methods for conducting experiments and their results, comparison with similar studies, identification of common dependencies; review of the experience of applying the technology in the USA, China and Russia, comparing their results with the results of laboratory studies. Results. During the analysis of laboratory studies, the key parameters of the effectiveness of the technology application - the presence of fractures in the reservoir, low permeability, hydrophilicity and small characteristic size of pore channels - were identified. An analysis of the world experience in the use of water Huff and Puff showed that the technology is successfully used in China in low-permeability hydrophilic formations in wells with multi-stage hydraulic fracturing, which is confirmed by laboratory studies. The US experience has not been successful due to the hydrophobicity of the reservoirs. The experience in Russia has mixed results - due to the hydrophilicity and low permeability of the reservoir, the effect of capillary impregnation is present, but due to the design of the wells and the absence of open hydraulic fractures, there was no significant effect. The results of the application experience are consistent with laboratory test data. As a result of this analysis, criteria for the applicability of water Huff and Puff technology were formed.

Characterizing variability in the global water cycle is fundamental to predicting impacts of future climate change; understanding the role of the Pacific Walker circulation (PWC) in the regional expression of global water cycle changes is critical to understanding this variability. Water isotopes are ideal tracers of the role of the PWC in global water cycling because they retain information about circulation-dependent processes including moisture source, transport, and delivery. We collated publicly available measurements of precipitationδ18O (δ18OP) and used novel data processing techniques to synthesize long (34 yr), globally distributed composite records from temporally discontinuousδ18OPmeasurements. We investigated relationships between global-scaleδ18OPvariability and PWC strength, as well as other possible drivers of globalδ18OPvariability—including El Niño–Southern Oscillation (ENSO) and global mean temperature—and used isotope-enabled climate model simulations to assess potential biases arising from uneven geographical distribution of the observations or our data processing methodology. Covariability underlying theδ18OPcomposites is more strongly correlated with the PWC (r= 0.74) than any other index of climate variability tested. We propose that the PWC imprint in globalδ18OParises from multiple complementary processes, including PWC-related changes in moisture source and transport length, and a PWC- or ENSO-driven “amount effect” in tropical regions. The clear PWC imprint in globalδ18OPimplies a strong PWC influence on the regional expression of global water cycle variability on interannual to decadal time scales, and hence that uncertainty in the future state of the PWC translates to uncertainties in future changes in the global water cycle.

The pyrite-type FeO2 and FeO2H were synthesized at the pressure-temperature conditions relevant to Earth’s deep lower mantle. Through the water-iron reaction, the pyrite-phase is a good candidate to explain the chemical heterogeneities and seismological anomalies at the bottom of the mantle. The solid solution of pyrite-type FeO2 and FeO2H, namely the FeO2Hx (0 ​≤ ​x ​≤ ​1), is particularly interesting and introduces puzzling chemical states for both the O and H atoms in the deep mantle. While the role of H in the FeO2–FeO2H system has been primarily investigated, discrepancies remain. In this work, we summarize recent progress on the pyrite-phase, including FeO2, FeO2H, and FeO2Hx, which is critical for understanding the water cycling, redox equilibria, and compositional heterogenicities in the deep lower mantle.

Rainfall partitioning is a key process in forest ecosystems, affecting evaporation, transpiration and water storage in the canopy, litter and soil. Although rainfall partitioning has been well studied in forest ecosystems, less is known about how rainfall partitioning is modified by tree species diversity. To disentangle the effects of tree species identity and diversity on rainfall partitioning, we installed 128 rain gauges in an experimental plantation, located in Zedelgem (Belgium), part of a large, multi-site forest diversity experiment in Belgium (FORBIO). With these rain gauges, we monitored throughfall for a full year, with a temporal resolution of two weeks. Based on these data, we analysed identity (i.e. whether throughfall is species-specific), non-additive (i.e. whether throughfall in mixtures is different from the expected amounts based on monocultures) and richness effects (i.e. how species richness affects throughfall). First of all, we found that rainfall partitioning highly differed between tree species, due to pronounced species identity effects. The presence of Pinus sylvestris [pine] was always associated with lower throughfall. Year-round throughfall was, for example, the lowest in mixtures of pine and Tilia cordata [lime] (43.8 +/- 14.5% of the open-field rainfall) and monocultures of pine (48.6 +/- 11.8%). Addi-tionally, non-additive effects were significant, leading to a 10% decrease of rainfall reaching the forest floor in mixtures compared to the expected throughfall based on measurements in monocultures. Tree species richness effects on rainfall partitioning acted indirectly, mostly via an increased basal area in mixed stands. Our findings suggest that mixing tree species leads to a higher than expected reduction in throughfall, which lowered soil moisture in mixed plots. Whether this reduced throughfall and soil moisture affects ecosystem functioning re-mains to be quantified.

The amount of water stored as OH-defects in nominally anhydrous minerals in the deep mantle is poorly constrained and its direct quantification can only be accessed by the analysis of mantle xenoliths. While the vast majority of xenoliths are peridotites and minor pyroxenites, some very rare xenoliths found in kimberlite pipes display an eclogitic mineral assemblage. We investigated three eclogite xenoliths from the 128 m.y. old Robert Victor kimberlite from South Africa that display an assemblage of garnet and omphacite with two samples showing additional kyanite, suggesting low-pressure gabbroic rock as protolith. Thermobarometry estimations based on Fe-Mg partitioning between garnet and pyroxene gives temperatures of 1100-1250 °C. When projected on the cratonic geotherm (Griffin & O’Reilly 2007) an equilibrium depth of 200-210 km is obtained, confirming that these rocks come from the lithosphere-asthenosphere boundary. Therefore these fragments might be key witnesses to understand the deep cycling of water in the mantle. This study focuses on the H2O quantification in the three rock-forming minerals using Fourier transform infrared spectroscopy (FTIR). Omphacite contains 50-250 ppm H2O, kyanite contains 40-60 ppm H2O and garnet of only one eclogite contains 40 ppm H2O. Garnet and omphacite with the highest OH content are enriched in Ca.The use of advanced mapping and profiling techniques enabled the investigation of the spatial repartition of the OH component in these minerals. High-resolution mapping (5.6 µm) of kyanite reveals diffusive gain of OH at the rim of the crystal that is interpreted as hydration during interaction with the kimberlitic melt. The OH plateau in the core of kyanite must therefore have been acquired previously, suggesting that this is residual OH that has been transported by subduction to the lithosphere-asthenosphere boundary by a once hydrated gabbroic protolith. Our results have implications for the retention of hydrogen over long timescale at the lithosphere-asthenosphere boundary and suggest that the deep cycling of water has been running since Archean times. Griffin, W. L., & O'Reilly, S. Y. (2007). Cratonic lithospheric mantle: is anything subducted?. Episodes, 30(1), 43-53.

The late Miocene provides the chance to assess the changing boundary conditions on a warmer world than present. While the climate variability is well understood for the oceanographic records, the water availability and dynamics in terrestrial environment in the densely populated East Asian remains enigmatic. Little is known about the precipitation response to the Antarctic ice-sheets during this time interval. To understand this critical relationship between low- and high-latitude climates, we use a new indicator based on the carbonate variability in Red Earth on the northern Chinese Loess Plateau to reconstruct water availability throughout the interval (7.5–6.9 Ma). Our high-resolution reconstructions show that the carbonate leaching/reprecipitation cycle is dominantly forced by the astronomical parameter obliquity (40-kyr) that is in accord with the Antarctic ice-volume controlled oceanography records at ~7 Ma. Supported by goethite and hematite records in the same site, soil temperatures and precipitations are fully coupled, interpreted as marking the climate pattern of Asian monsoon during the late Miocene. Cyclic correlation between the carbonate variability and the goethite, hematite data, reveal that the obliquity controlled precipitation oscillations were superimposed on a long-term increase of the Asian monsoon, which was synchronous with intensifification of climate cooling, the declining of partial pressure of carbon dioxide, and the growing of Antarctic ice-volume. Combined with the atmospheric- and oceanic-adjustments, we suggest that the cross-equatorial pressure gradient has led to the rise of Asian monsoon.

A primary source of uncertainty in terrestrial biosphere model (TBM) projection of carbon uptake and water cycling from ecosystems is the relationship between CO2 assimilation (A) and wa...

Subduction-induced deep hydration and water cycling may play significant roles in the modification and destruction of the overriding cratonic lithosphere. Two contrasting modes are generally propos...

The Tibetan Plateau is one of the most important high elevation areas on the earth, performing sensitive response to global changes. As the Asia water tower, high mountain melting water is important water supplies for human development in TP and surrounded areas, but water phase transition is less known, especially under the climatic warming. Lakes are links of water phase transition and water cycle in TP. Lake water storage variations are sensitive to precipitation differentiations in the domination of the Westerlies and Indian monsoon. However, lake water storage performs inconsistent response in different regions & time periods. Based upon water balance observation, lake water storage variations are influenced by different factors, which also changed during different time period. Lake water temperature and thermoclines vary with seasons, and change water temperature gradient which influence water-air heat exchange. Lake salinities generally decreased since 1970s in the Serling Co region due to increasing of water storage. Based upon more than 60 lakes monitoring correction, it is found that lake transparency generally increased during 2000-2017 inferred by remote sensing interpretation. To aim at the deep recognizing of interactions between lake water variations and climatic changes, we need to know lake water storages and their variations for whole region and consecutive time series. To understand how heat exchanges between changing lakes and atmosphere, we need more consecutive observation data from large lakes. Therefore, the proposed work is to finish more lake survey and water balance monitoring, and continue to improve water cycling studies in the large lake basin scale for deep understanding how water cycles accompanied with mass and nutrients under the warming climatic conditions.

The workflow for waterflood conformance improvement in a naturally fractured carbonate reservoir with polymer gel injection is presented. The workflow outlines a systematic way of identifying the conformance candidates and evaluating optimal gel volume for the job design predicated on using the regular surveillance data as well as a novel way of gel characterization with lab measurements. Economic and technical success of conformance jobs is based on successful implementation of the improved workflow demonstrated in this work. The wells in the carbonate reservoir of interest are screened for conformance issues using only the injection and production data. Using a set of Chevron analytical tools with the field injection and production data, we screened over four hundred wells and selected four candidate injectors with the most severe water cycling issue in the carbonate reservoir of interest. Inter well tracer test was part of the pilot to assess the effectiveness of the workflow by verifying the correct candidate selection and designed gel volumes by quantifying the thief zone volumes. Lab extrusion tests of selected mature polymer gels also demonstrated that the flow capacity of an open fracture could be reduced up to 4000 times even after ruptured by continuous water injection at the right concentrations. After the tracer tests confirmed the severe conformance issues for the selected injectors, conformance treatment was designed for optimum concentration using the lab results and optimal volume using the tracer interpretation. Finally, the first gel injection pilot is executed, and appropriate surveillance plan implemented to evaluate the results. During pilot execution injection pressure, polymer concentration and volumes were closely monitored. The offset producers were tested frequently as part of the surveillance plan. The analysis of the injection and production data shows positive response with more oil production for each barrel of water injection in all four treated patterns. This work exhibits a systematic approach of polymer gel injection for waterflood conformance improvement from candidate selection to lab tests for selection of the most appropriate chemical agent to field execution. The objective of this work was to establish criteria for more efficient and economic gel conformance treatments with high success rate in the carbonate field of interest.

Pre-print (óritrýnt handrit), Oceanic crust is a major transport medium of water into the mantle wedge and the convecting mantle. Yet, the water content of the oceanic crust remains uncertain. Active geothermal systems situated at on-land spreading centers provide a unique opportunity to study the hydration of the oceanic crust, with well constrained systems and boreholes reaching depths of >4 km. Here, we present hydrogen isotope data of geothermal fluids and altered basalt for three Icelandic geothermal systems: the meteoric water fed system at Krafla and the seawater fed systems at Reykjanes and Surtsey. The bulk rock δD values of altered and hydrated basalts from these localities, which exhibit significantly higher water contents (up to 8.9 wt.%) than magmatic (non-hydrated) basalts, vary greatly from −125 to −96 at Krafla, from −80 to −46 at Reykjanes and from −78 to −46 at Surtsey. The corresponding fluids have δD values of −84.1 to −81.1 at Krafla, −23.1 to −14.9 at Reykjanes and +2.1 to +4.3 at Surtsey. Comparison of isotope modeling results to the natural data reveals that hydration of the Icelandic crust and corresponding hydrogen isotopic characteristics are controlled by (1) the isotope composition of the source fluid, (2) isotope fractionation between the aqueous geothermal fluids and the alteration minerals formed, and (3) the type and quantity of alteration minerals formed. These factors in turn depend on the extent of fluid-rock interaction and temperature. Using the same modeling approach and expanding it to datasets available for the oceanic crust, we assessed the hydration state and δD values of the oceanic crust as a function of depth. We show that 1400 to 1650 Tg H2O/yr is added to the igneous oceanic crust upon alteration by seawater and that the upper part (, This project was financially supported by NordVulk, the International Continental Scientific Drilling Program (ICDP) through a grant to the SUSTAIN project, and the Icelandic Research Fund (project number: 163083-051). SAH acknowledges support from the Icelandic Research Fund (project number: 196139-051). HS Orka and Landsvirkjun kindly provided access to the drill cuttings. J. Cullen, T. Larson, R. Ólafsdóttir and Á.E. Sveinbjörnsdóttir are thanked for assistance during sample preparation and data acquisition. BIK is particularly grateful of being part of this project as without the project-related lab work she would have never met her future husband E.W. Marshall IV. We thank four anonymous reviewers for their constructive comments and suggestions to an earlier version of this manuscript. Louis Derry is thanked for careful editorial handling of this study.

The long-term research and monitoring site of Collelongo - Selva Piana has been established in 1991 (Abruzzo Region, Central Italy, 1560 m elevation) in the framework of a project on ecology and silviculture of European beech. In 1993, the site was the first forest in Europe where canopy fluxes started to be measured with the eddy covariance technique. Since then, the site has been involved in several of the most important networks and projects, including ICP Forests, Euroflux, CarboEurope-IP, FluxNet and, in 2006, joined the Long Term Ecological Research network (LTER).Measurements at the Collelongo site bridge two centuries, starting right at the end of the WMO and IPCC climate reference period (1961-1990) and extending, in continuous, over a period of great changes (the three warmest ever decades occurred since then), including a number of extreme events (heat waves, droughts, late frost). During these thirty years, more than 50 researchers from different parts of the world performed direct measurements at the site, flux datasets from the site (code IT-Col) had more than 1500 unique downloads and it is estimated that more than 300 people used the data for producing more than 150 ISI papers.We will briefly present the main results on different ecosystem processes (Phenology, Net Primary Production, Carbon Allocation, Net Ecosystem Exchange, Nutrient and Water Cycling) emphasizing responses to drivers, including legacies from the past. Over these thirty years, the growing season length increased significantly (1.33 day yr-1 from 2000 to 2015), the studied beech forests absorbed between 120 and 150 tC ha-1 and showing plasticity and resilience to changing climatic conditions. However, increasing warming, drought and extreme events may impair adaptation capacity. In this respect, modelling offers a tool to evaluate long-term responses, including possible management options to increase both adaptation and resilience capacities.

Globally, changing fire regimes due to climate is one of the greatest threats to ecosystems and society. In this paper, we present projections of future fire probability for the southcentral USA using downscaled climate projections and the Physical Chemistry Fire Frequency Model (PC2FM). Future fire probability is projected to both increase and decrease across the study region of Oklahoma, New Mexico, and Texas. Among all end-of-century projections, change in fire probabilities (CFPs) range from − 51 to + 240%. Greatest absolute increases in fire probability are shown for areas within the range of approximately 75 to 160 cm mean annual precipitation (MAP), regardless of climate model. Although fire is likely to become more frequent across the southcentral USA, spatial patterns may remain similar unless significant increases in precipitation occur, whereby more extensive areas with increased fire probability are predicted. Perhaps one of the most important results is illumination of climate changes where fire probability response (+, −) may deviate (i.e., tipping points). Fire regimes of southcentral US ecosystems occur in a geographic transition zone from reactant- to reaction-limited conditions, potentially making them uniquely responsive to different scenarios of temperature and precipitation changes. Identification and description of these conditions may help anticipate fire regime changes that will affect human health, agriculture, species conservation, and nutrient and water cycling.

Water infiltration is commonly recommended as an indicator of soil dynamic properties and water cycling on rangelands. We investigated the utility of a two-trial single-ring infiltration test by evaluating the relationship between the first and second trial, the spatial variation in infiltration rates within and between sampling locations, and the relationship between water infiltration and bulk density and soil organic carbon (SOC) in the context of texture and water content. We measured water infiltration rates at 156 sites in 14 counties in California. We found a strong correlation between first and second infiltration trials. In pairwise correlations, both first and second trials were significantly correlated with SOC and bulk density. However, we did not find a significant relationship between water infiltration and either initial water content or soil texture. Model comparison revealed that in the context of soil texture, infiltration can serve as an indicator of bulk density and SOC; shorter water infiltration time (i.e., faster rate) is associated with decreased bulk density and increased SOC. Our results suggest that a single-ring infiltration test can be a useful, but imprecise, indicator of soil dynamic properties such as SOC and bulk density.

Quantifying forest evapotranspiration (ET) is essential for understanding of climatic response of forest carbon and water cycling. However, there are still large uncertainties in forest ET predictions, especially in plant transpiration (PT). The poor estimations of forest ET and PT are largely attributed to the neglect of wet canopy evaporation and uncertainties in the stomatal conductance. Thus, by coupling a revised Ball—Woodrow–Berry (BWB) model, a precipitation intercepted algorithm and the gross primary production (GPP) model to Shuttleworth–Wallace (SW) model, this study introduced a modified SW ${\rm{(SW}}_{{\rm{m}}})$ model. The performances of this model were subsequently tested in three different forest sites with long-term observed records. Compared with previous models, ${\rm{SW}}_{{\rm{m}}}$ had a canopy stomatal scheme with stronger ecological significance and simpler GPP estimation scheme. Our analyses reveal the following. 1) ${\rm{SW}}_{{\rm{m}}}$ evidently improves the agreements between estimated and measured ET compared to original SW ( R 2 increasing by 0.19–0.68). ${\rm{SW}}_{{\rm{m}}}$ could more accurately partition PT and evaporation, when compared with an earlier BWB-based SW ( R 2 increasing by ∼0.03). This finding also supports the use of Lohammer function in semiempirical model of stomatal conductance. 2) Accurate predictions of GPP are helpful for improving ET estimations in ${\rm{SW}}_{{\rm{m}}}\,(r\,= \,{\text{0.73,\,p}}\, , suggesting that carbon and water fluxes are inherently linked. 3) In addition to GPP, leaf area index evidently affects the performances of estimated ET in ${\rm{SW}}_{{\rm{m}}}$ . These results suggest that critically coupling carbon and water cycling are very important for improving forest ET prediction.

Transpiration from the Amazon rainforest generates an essential water source at a global and local scale. However, changes in rainforest function with climate change can disrupt this process, causing significant reductions in precipitation across Amazonia, and potentially at a global scale. We report the only study of forest transpiration following a long-term (>10 year) experimental drought treatment in Amazonian forest. After 15 years of receiving half the normal rainfall, drought-related tree mortality caused total forest transpiration to decrease by 30%. However, the surviving droughted trees maintained or increased transpiration because of reduced competition for water and increased light availability, which is consistent with increased growth rates. Consequently, the amount of water supplied as rainfall reaching the soil and directly recycled as transpiration increased to 100%. This value was 25% greater than for adjacent non-droughted forest. If these drought conditions were accompanied by a modest increase in temperature (e.g. 1.5°C), water demand would exceed supply, making the forest more prone to increased tree mortality. This article is protected by copyright. All rights reserved.

To improve predictions of the future of ecosystems in a changing world, it is necessary to consider fine-scale processes. We propose that for the Mediterranean region (a hotspot of climate change and biodiversity), there are three local processes that have often been overlooked in predictive models and that are key to understanding vegetation changes: rural abandonment that increases wildlands, population changes that boost fire ignitions, and coastal degradation that enhances drought. These processes are not directly driven by global warming and act in different directions (greening and browning). The current balance is still toward greening, because land abandonment is buffering the browning drivers; however, it is likely to switch with increasing warming. The challenge is to mitigate the browning processes. Given that climatic warming is not directly driving these processes, local management can make a difference in reducing the overall impact on the landscape and society

This study compared heart rate (HR), oxygen uptake (V[Combining Dot Above]O2), percentage of maximal HR (%HRmax), percentage of maximal V[Combining Dot Above]O2, and cadence (Cad) related to the anaerobic threshold (AT) during a water cycling maximal test between heart rate deflection point (HRDP) and ventilatory (VT) methods. In addition, the correlations between both methods were assessed for all variables. The test was performed by 27 men in a cycle ergometer in an aquatic environment. The protocol started at a Cad of 100 b·min-1 for 3 minutes with subsequent increments of 15 b·min-1 every 2 minutes until exhaustion. A paired two-tailed Student's t-test was used to compare the variables between the HRDP and VT methods. The Pearson product-moment correlation test was used to correlate the same variables determined by the 2 methods. There was no difference in HR (166 ± 13 vs. 166 ± 13 b·min-1), V[Combining Dot Above]O2 (38.56 ± 6.26 vs. 39.18 ± 6.13 ml·kg-1·min-1), %HRmax (89.24 ± 3.84 vs. 89.52 ± 4.29%), V[Combining Dot Above]O2max (70.44 ± 7.99 vs. 71.64 ± 8.32%), and Cad (174 ± 14 b·min-1 vs. 171 ± 8 b·min-1) related to AT between the HRDP and VT methods. Moreover, significant relationships were found between the methods to determine the AT for all variables analyzed (r = 0.57�0.97). The estimation of the HRDP may be a noninvasive and easy method to determine the AT, which could be used to adapt individualized training intensities to practitioners during water cycling classes.

Among the most critical processes in simulating terrestrial ecosystem performance is the regulatory role of sto- mata in carbon and water cycles. Compared with field measurements, the changes in stomatal slope caused by the biophysical environment provide a simple but effective synthetic framework for studying climate-related carbon and water cycling, due to its sensitivity to CO2, vapor pressure deficit, and photosynthesis. It is also crucial in un- derstanding the effects of climate change on photosynthesis and water use efficiency. Endeavored by numerous scholastic efforts, stomatal conductance models have been improved based on experimental, semi-experimental, and mechanical processes. However, the underlying biological mechanisms and the dynamics of key parameters in these models remain unexplored, especially regarding the changes in stomatal slope. By improving the under- s tanding of the stomata's regulatory role, we reduced the uncertainty of stomatal conductance simulation. We then synthesized the recent developments and lessons in optimal stomatal behavior theory to simulate stomatal con- ductance and included an introduction to widely used stomatal conductance models and parameters, the main fac- tors influencing stomatal slopes, and applications of the mechanical stomatal conductance models in different ecosystems. Based on our literature review, we proposed that future research is needed on the optimal stomatal

The use of water production as a pressure mitigation tool in the context of CO2 storage is widely studied but the impact it might have on the migration behaviour of a buoyant CO2 plume is less well reported. To investigate this further two different scenarios were modelled. In the first, a single water production well was used to draw CO2 along the strike of an open aquifer with a regional dip. Large rates of water production (5–10 times the volume of injected CO2) were required to achieve only small displacements of the CO2 plume. The second scenario investigated to what extent an induced hydraulic gradient might spill CO2 already stored in a structural trap. Here the effects were more pronounced with over 90% of the CO2 being spilled at a water cycling rate of 10 Mt per year (corresponding to a hydraulic gradient of 1.28 bar/km). The modelling was tested by the real case at Sleipner where CO2 migration in the Utsira Sand is potentially impacted by water production at the nearby Volve field. Simulations concluded that the CO2 plume at Sleipner should not be materially affected by water production from Volve and this is supported by the time-lapse seismics.

御手洗水試験流域は、福岡県糟屋郡篠栗町の九州大学農学部附属演習林内に設置されており、2003年以降、流量および気象データが継続的に観測されている。本試験流域の地質は三郡変成岩類中層部の緑色片岩と北部九州に分布する三郡変成岩帯に部分的に含まれる蛇紋岩である。本試験地はヒノキ人工林および常緑・落葉の混交二次林で覆われており、ヒノキ人工林では2012年1月～3月にかけて本数間伐率50%の強度間伐が行われた。本試験流域の観測結果は2003年から2007年の5年分についてはすでに公開されており、本報告は間伐後の1年間を含む2008年から2012年の日単位の流量データ、気象データを取りまとめたものである。, This report presents daily meteorological and stream flow data for the Ochozu Experimental Watershed located in the Kasuya Research Forest. This watershed is covered with a plantation forest of Japanese cypress (Chamaecyparis obtusa) and underlain by green schist and serpentinite. Fifty percent thinning was conducted and stand density was reduced to halfin January 2012. Daily meteorological and stream flow data from 2003 to 2008 have already been published. This report presents the data from 2008 to 2012, including a year post-thinning.