Plant hydraulic transport controls transpiration sensitivity to soil water stress

نویسندگان

چکیده

Abstract. Plant transpiration downregulation in the presence of soil water stress is a critical mechanism for predicting global water, carbon, and energy cycles. Currently, many terrestrial biosphere models (TBMs) represent this with an empirical correction function (?) moisture – convenient approach that can produce large prediction uncertainties. To reduce uncertainty, TBMs have increasingly incorporated physically based plant hydraulic (PHMs). However, PHMs introduce additional parameter uncertainty computational demands. Therefore, understanding why when PHM ? predictions diverge would usefully inform model selection within TBMs. Here, we use minimalist to demonstrate coupling effects atmospheric demand leads spectrum responses controlled by soil–plant transport (conductance). Within transport-limitation spectrum, emerges as end-member scenario infinite conductance, completely decoupling on transpiration. As result, most systems low conductance (transport-limited) experience high variation moderate supply plants. We test these results using land surface at AmeriFlux site. At transport-limited site, scheme outperforms due its sensitivity variations demand. Based observation, develop new “dynamic ?” varies overcomes existing biases schemes has potential simplify parameterization implementation.

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Transpiration as a function of soil temperature and soil water stress.

An apparatus was developed for the measurement of transpiration rates of Trifolium repens. The transpiration rates were measured under controlled conditions of soil water stress and soil temperature. Other environmental parameters such as air temperature, relative humidity, light intensity and air speed were held constant. Diffusive resistances were calculated and stomatal aperture changes were...

متن کامل

Sensitivity Analysis of Hydraulic Parameters in the Simulation of Unsaturated Soil Water Dynamics

Soil water content is one of the most important parameters for estimating irrigation frequency and providing the plant’s water requirement. Since measurement of soil water content is both expensive and time consuming, water movement models are used to estimate these values. In this study, LEACHW model was used to estimate soil water content for two “dry” (20-29 Aug) and “wet” (1-6 Jul) periods ...

متن کامل

Reconciling seasonal hydraulic risk and plant water use through probabilistic soil-plant dynamics.

Current models used for predicting vegetation responses to climate change are often guided by the dichotomous needs to resolve either (i) internal plant water status as a proxy for physiological vulnerability or (ii) external water and carbon fluxes and atmospheric feedbacks. Yet, accurate representation of fluxes does not always equate to accurate predictions of vulnerability. We resolve this ...

متن کامل

Plant responses to water stress.

This Special Issue comprises a series of papers that develops the theme of plant responses to water stress, encompassing recent developments at the molecular level, through responses of photosynthesis and metabolism, to their application in crop selection and yield. The consideration of water deficits is particularly timely, given the huge developments in this area in the past decade. This issu...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Hydrology and Earth System Sciences

سال: 2021

ISSN: ['1607-7938', '1027-5606']

DOI: https://doi.org/10.5194/hess-25-4259-2021