Bedrock Vadose Zone Storage Dynamics Under Extreme Drought: Consequences for Plant Water Availability, Recharge, and Runoff

Water Resources Research, Год журнала: 2022, Номер 58(4)

Опубликована: Апрель 1, 2022

Abstract Bedrock vadose zone water storage (i.e., rock moisture) dynamics are rarely observed but potentially key to understanding drought responses. Exploiting a borehole network at Mediterranean blue oak savanna site—Rancho Venada—we document how capacity in deeply weathered bedrock profiles regulates woody plant availability and groundwater recharge. The site is the Northern California Coast Range within steeply dipping turbidites. In wet year (water 2019; 647 mm of precipitation), moisture was quickly replenished characteristic capacity, recharging that emerged springs generate streamflow. subsequent rainless summer growing season, depleted by about 93 mm. two years followed (212 121 precipitation) total amount gained each winter 54 20 mm, respectively, declines were documented exceeding these amounts, resulting progressively lower content. Oaks, which rooted into bedrock, demonstrated signs stress drought, including reduced transpiration rates extremely low potentials. 2020–2021 precipitation did not exceed variable belowground storage, increased stress, no recharge or runoff. Rock deficits (rather than soil deficits) explain

Язык: Английский

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Seasonal variations in water uptake and transpiration for plants in a karst critical zone in China

The Science of The Total Environment, Год журнала: 2022, Номер 860, С. 160424 - 160424

Опубликована: Ноя. 25, 2022

Язык: Английский

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Building Cross-Site and Cross-Network collaborations in critical zone science

Journal of Hydrology, Год журнала: 2023, Номер 618, С. 129248 - 129248

Опубликована: Фев. 9, 2023

The critical zone (CZ) includes natural and anthropogenic environments, where life, energy matter cycles combine in complex interactions time space. Critical observatories (CZOs) have been established around the world, yet their limitations space duration of observations, as well oft-existing dominant disciplinary research field(s) each CZO may limit transferability local knowledge to other settings or hinder integrative CZ understanding. In this regard, review advocates for cross-site cross-network collaborations sciences. We posit that type collaboration is becoming indispensable understanding past trends future trajectories CZ, context fast-developing widespread environmental changes. Aided by a series cyberseminars community survey, we highlight some existing initiatives, tools techniques, cross-cutting science questions could benefit from such syntheses, various types (montane, alpine, arctic, managed agricultural lakes, wetlands, streams, landscapes disturbed drought and/or wildfire, etc.). This also identifies discusses major legitimate concerns obstacles collaborative approach, including data harmonization integration social sciences, proposes tentative ways forward.

Язык: Английский

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Diagnosing evapotranspiration responses to water deficit across biomes using deep learning

New Phytologist, Год журнала: 2023, Номер 240(3), С. 968 - 983

Опубликована: Авг. 25, 2023

Summary Accounting for water limitation is key to determining vegetation sensitivity drought. Quantifying effects on evapotranspiration (ET) challenged by the heterogeneity of types, climate zones and vertically along rooting zone. Here, we train deep neural networks using flux measurements study ET responses progressing drought conditions. We determine a stress factor (fET) that isolates reductions from atmospheric aridity other covarying drivers. regress fET against cumulative deficit, which reveals control whole‐column moisture availability. find variety stress. Responses range rapid declines 10% its water‐unlimited rate at several savannah grassland sites, mild in most forests, despite substantial deficits. Most sensitive are found arid warm sites. A combination regulation stomatal hydraulic conductance access belowground reservoirs, whether groundwater or soil moisture, could explain different behaviors observed across This not captured standard land surface model, likely reflecting simplifications representation storage.

Язык: Английский

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Geologic Controls on Apparent Root‐Zone Storage Capacity

Water Resources Research, Год журнала: 2024, Номер 60(3)

Опубликована: Март 1, 2024

Abstract The water storage capacity of the root zone can determine whether plants survive dry periods and control partitioning precipitation into streamflow evapotranspiration. It is currently thought that top‐down, climatic factors are primary on this via their interaction with plant rooting adaptations. However, it remains unclear to what extent bottom‐up, geologic provide an additional constraint capacity. Here we use a machine learning approach identify regions lower than climatically expected apparent We find in seasonally California these overlap particular substrates. hypothesize patterns reflect diverse mechanisms by which substrate limit capacity, highlight case studies consistent limited weathered bedrock (melange Northern Coast Range), toxicity (ultramafic substrates Klamath‐Siskiyou region), nutrient limitation (phosphorus‐poor plutons southern Sierra Nevada), low porosity capable retaining (volcanic formations Cascades). observation at regional scales climate alone does not “size” has implications for parameterization models dynamics (and interrelated carbon cycles), also underscores importance geology considerations climate‐change induced biome migration habitat suitability.

Язык: Английский

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Bedrock: the hidden water reservoir for trees challenged by drought

Trees, Год журнала: 2024, Номер 38(1), С. 1 - 11

Опубликована: Янв. 22, 2024

Abstract Key message Bedrock can store appreciable amounts of available water, and some trees apparently use this resource to survive drought. Several forest ecosystems rely on only shallow soil layers overlying more or less compact bedrock. In such habitats, the largest water reservoir be represented by rock moisture, rather than water. Here, we review evidence for presence root uptake in types, show examples physiological ecological roles especially when are facing drought conditions. The possible magnitude rock–root exchanges is discussed frame current knowledge rock, soil, hydraulic properties. We highlight several areas uncertainty regarding role moisture preventing tree failure under drought, exact pathway(s) exchange, relative efficiencies transport different compartments rock–soil–root continuum. Overall, experimental suggests that bedrock should incorporated into any model describing seasonal responses

Язык: Английский

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Evaluating soil water dynamics and vegetation growth characteristics under different soil depths in semiarid loess areas

Geoderma, Год журнала: 2024, Номер 442, С. 116791 - 116791

Опубликована: Янв. 28, 2024

Weathered bedrock alleviating vegetation death has been gradually appreciated, yet the hydrological effects of shallow soil layers and underlying impervious on upper moisture growth are less excavated in semiarid loess areas. To demystify these variations, this study evaluated water storage (SWS) changes differences alfalfa caragana by characterizing different depths. The results showed that reservoirs changed under depths varied with types. From beginning Jun. to end Oct. 2021, SWS increased 3.5 ‰ 2.8 0.6 m 1.0 but decreased 3.6 depth 1.4 m; For caragana, 9.9 8.0 % m, while it 1.5 m. Moreover, types affected precipitation redistribution. Soil inhibited consumption accumulated within (increasing 3.9 %) 5.6 3.0 depth). These might be caused root distribution absorption zone between caragana. Furthermore, limitation was one strategy dwarfing, which had diverse systems aboveground for plants. By setting at underground parts were restricted, promoted reduced However, extended depth. due physiological response restrictions seasonal precipitation. This would provide a new understanding distinction difference herbaceous shrub

Язык: Английский

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Drought effects in Mediterranean forests are not alleviated by diversity‐driven water source partitioning

Journal of Ecology, Год журнала: 2024, Номер 112(9), С. 2107 - 2122

Опубликована: Авг. 5, 2024

Abstract Tree species diversity in forest ecosystems could reduce their vulnerability to extreme droughts through improved microclimate and below‐ground water source partitioning driven by contrasting species‐specific use patterns. However, little is known about the seasonal dynamics of belowground uptake that determine whether positively or negatively impacts tree carbon assimilation exchange. Using a network 30 permanent plots Mediterranean forests with increasing (from monospecific four‐species mixtures), we examined patterns in‐situ aboveground relations sources on 265 trees from four pine oak over 2 years using hydraulic stable isotope approaches. We found broadleaf conifer mixtures induced strong soil between species. As conditions became drier during summer mixed stands, took up deeper sources, while pines were systematically limited shallow ones. Despite significant moisture partitioning, stronger drought‐induced reductions photosynthesis, stomatal conductance, leaf potential still observed diverse compared stands for but some benefits oaks. Synthesis : Our findings reveal promoted potentially reducing competition more ecosystems. Yet, our results show it insufficient buffer adverse severe use, leading higher stress, especially pines.

Язык: Английский

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Mineral Nutrients Sourced in Deep Regolith Sustain Long‐Term Nutrition of Mountainous Temperate Forest Ecosystems

Global Biogeochemical Cycles, Год журнала: 2020, Номер 34(9)

Опубликована: Авг. 28, 2020

Abstract Primary productivity of forest ecosystems depends on the availability plant‐essential mineral nutrients. Because nutrient demand trees often exceeds supply from rock, tree nutrition is sustained by efficient reutilization organic‐bound These nutrients are continuously returned to floor in litterfall. However, over millennia limitation may develop landscapes which permanently lost drainage and erosion. Such a deficit prevented if advection unweathered bedrock toward surface as driven erosion supplies fresh Yet mechanisms depth range this deep resource accessed poorly known. We show that two montane temperate Black Forest Bavarian geogenic source was found within zone several meters. This contains large pool biologically available applied isotope ratios proxies for uptake depth, we tracked regolith at 87 Sr/ 86 Sr 10 Be(meteoric)/ 9 Be match respective values plant tissue. mapped distribution calcium‐bound form most phosphorus or even deeper defined ratios. conclude meters critical ecosystem function moderate hillslopes rainfall affected permanent loss.

Язык: Английский

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Weather underground: Subsurface hydrologic processes mediate tree vulnerability to extreme climatic drought

Global Change Biology, Год журнала: 2020, Номер 26(5), С. 3091 - 3107

Опубликована: Фев. 14, 2020

Abstract Drought extent and severity have increased are predicted to continue increase in many parts of the world. Understanding tree vulnerability drought at both individual species levels is key ongoing forest management preparation for future transitions community composition. The influence subsurface hydrologic processes particularly important water‐limited ecosystems, an under‐studied aspect vulnerability. With California's 2013–2016 extraordinary as a natural experiment, we studied four co‐occurring woodland species, blue oak ( Quercus douglasii ), valley lobata gray pine Pinus sabiniana California juniper Juniperus californica examining function climate, lithology hydrology using regional aerial dieback surveys site‐scale field surveys. We found that addition climatic (i.e., rainfall), explained variation within across scales. Regionally oak, was related bedrock lithology, with higher mortality on igneous metamorphic substrates, reductions groundwater. At site scale, access deep water, evidenced by stem water stable isotope composition, canopy condition all species. Along hillslope gradients, channel locations supported similar environments terms stress wide gradient, indicating mediates species’ experience drought, areas associated persistent resources may provide refugia xeric range edges. Despite this overall environment, showed markedly different response patterns. argue niche segregation can be useful lens through which interpret these differences climate change.

Язык: Английский

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