Book contents
- Frontmatter
- Contents
- Foreword
- Preface
- 1 Introduction
- 2 Stochastic soil moisture dynamics and water balance
- 3 Crossing properties of soil moisture dynamics
- 4 Plant water stress
- 5 Applications to natural ecosystems
- 6 Coupled dynamics of photosynthesis, transpiration and soil water balance: from hourly to growing-season time scale
- 7 Plant strategies and water use
- 8 Seasonal and interannual fluctuations in soil moisture dynamics
- 9 Spatial scale issues in soil moisture dynamics
- 10 Hydrologic controls on nutrient cycles
- 11 Hydrologic variability and ecosystem structure
- References
- Species Index
- Subject Index
- Plate section
3 - Crossing properties of soil moisture dynamics
Published online by Cambridge University Press: 14 October 2009
- Frontmatter
- Contents
- Foreword
- Preface
- 1 Introduction
- 2 Stochastic soil moisture dynamics and water balance
- 3 Crossing properties of soil moisture dynamics
- 4 Plant water stress
- 5 Applications to natural ecosystems
- 6 Coupled dynamics of photosynthesis, transpiration and soil water balance: from hourly to growing-season time scale
- 7 Plant strategies and water use
- 8 Seasonal and interannual fluctuations in soil moisture dynamics
- 9 Spatial scale issues in soil moisture dynamics
- 10 Hydrologic controls on nutrient cycles
- 11 Hydrologic variability and ecosystem structure
- References
- Species Index
- Subject Index
- Plate section
Summary
The frequency and duration of excursions of the soil moisture process above and below some levels directly related to the physiological dynamics of plants are of crucial importance for ecohydrology. This chapter focuses on the crossing properties of specific levels of soil moisture that are important for vegetation. After a general mathematical derivation of the crossing characteristics typical of shot noise processes, attention is turned to the impact of climate, soil, and vegetation on the duration and frequency of soil moisture excursions below the wilting point, sw, and below the point where transpiration is reduced, s*. These properties will be basic for the study of plant water stress in Chapter 4.
The analysis of the crossing properties is also important for gaining insights into the transient dynamics of soil moisture, either at the beginning of the growing season, to evaluate the time to reach the stress levels after the soil winter storage is depleted, or after a drought, to estimate the time to recover from a situation of intense water stress. The expressions of the mean time to reach s* from field capacity, sfc, will be used in Chapter 7 to extend the definition of water stress to transient conditions and furthermore to analyze different strategies of water use when the winter water recharge is important. This chapter ends with the crossing analysis of the minimalistic models of soil moisture dynamics described in Section 2.6.2.
Although the results of this chapter are extensively used later, an understanding of the mathematical derivations presented in Section 3.1 is not necessary for their use.
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- Chapter
- Information
- Ecohydrology of Water-Controlled EcosystemsSoil Moisture and Plant Dynamics, pp. 59 - 85Publisher: Cambridge University PressPrint publication year: 2005