Tree water storage and its diurnal dynamics related to sap flow and changes in stem volume in old-growth Douglas-fir trees.

Diurnal and seasonal tree water storage was studied in three large Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) trees at the Wind River Canopy Crane Research site. Changes in water storage were based on measurements of sap flow and changes in stem volume and tissue water content at different heights in the stem and branches. We measured sap flow by two variants of the heat balance method (with internal heating in stems and external heating in branches), stem volume with electronic dendrometers, and tissue water content gravimetrically. Water storage was calculated from the differences in diurnal courses of sap flow at different heights and their integration. Old-growth Douglas-fir trees contained large amounts of free water: stem sapwood was the most important storage site, followed by stem phloem, branch sapwood, branch phloem and needles. There were significant time shifts (minutes to hours) between sap flow measured at different positions within the transport system (i.e., stem base to shoot tip), suggesting a highly elastic transport system. On selected fine days between late July and early October, when daily transpiration ranged from 150 to 300 liters, the quantity of stored water used daily ranged from 25 to 55 liters, i.e., about 20% of daily total sap flow. The greatest amount of this stored water came from the lower stem; however, proportionally more water was removed from the upper parts of the tree relative to their water storage capacity. In addition to lags in sap flow from one point in the hydrolic pathway to another, the withdrawal and replacement of stored water was reflected in changes in stem volume. When point-to-point lags in sap flow (minutes to hours near the top and stem base, respectively) were considered, there was a strong linear relationship between stem volume changes and transpiration. Volume changes of the whole tree were small (equivalent to 14% of the total daily use of stored water) indicating that most stored water came from the stem and from its inelastic (sapwood) tissues. Whole tree transpiration can be maintained with stored water for about a week, but it can be maintained with stored water from the upper crown alone for no more than a few hours.

[1]  R. Häsler,et al.  Diurnal changes in the radius of a subalpine Norway spruce stem: their relation to the sap flow and their use to estimate transpiration , 1995, Trees.

[2]  J. Cermak,et al.  Water content in stem wood of large pine and spruce trees in natural forests in central Sweden , 1999 .

[3]  N. Holbrook,et al.  Diurnal variation in xylem hydraulic conductivity in white ash (Fraxinus americana L.), red maple (Acer rubrum L.) and red spruce (Picea rubens Sarg.) , 1998 .

[4]  G. Parker.  Canopy structure and light environment of an old-growth Douglas-fir/Western hemlock forest , 1997 .

[5]  E. D. Ford,et al.  Height growth and vertical development of an old-growth Pseudotsuga-Tsuga forest in southwestern Washington State, U.S.A. , 2000 .

[6]  A. Sellin.  Variation in sapwood thickness of Picea abies in Estonia depending on the tree age , 1991 .

[7]  Richard H. Waring,et al.  The contribution of stored water to transpiration in Scots pine , 1979 .

[8]  R. Ceulemans,et al.  Water flux in a hybrid poplar stand. , 1994, Tree physiology.

[9]  W. Wenkert.  Water Transport and Balance Within the Plant: An Overview , 1983 .

[10]  R. Zweifel,et al.  Dynamics of water storage in mature subalpine Picea abies: temporal and spatial patterns of change in stem radius. , 2001, Tree physiology.

[11]  M. Philip,et al.  Measuring Trees and Forests , 1994 .

[12]  J. Lassoie.  Diurnal dimensional fluctuation in a Douglas-fir stem in response to tree water status and certain environmental factors , 1973 .

[13]  H. Griffiths,et al.  Water deficits: plant responses from cell to community. , 1993 .

[14]  G. Goldstein,et al.  The role of capacitance in the water balance of Andean giant rosette species , 1984 .

[15]  R. C. Dobbs,et al.  Distribution of Diurnal Fluctuations in Stem Circumference of Douglas-fir , 1971 .

[16]  Frederick C. Meinzer,et al.  Control of transpiration in a 220-year-old Abies amabilis forest , 2001 .

[17]  J. Kucera,et al.  The canopy water relations of old-growth Douglas-fir trees , 1999, Trees.

[18]  D. Macdougal.  Reversible variations in volume, pressure, and movements of sap in trees , 1925 .

[19]  D. Woodruff,et al.  Dynamics of water transport and storage in conifers studied with deuterium and heat tracing techniques. , 2006, Plant, cell & environment.

[20]  Jerry F. Franklin,et al.  Ecological Setting of the Wind River Old-growth Forest , 2004, Ecosystems.

[21]  J. Kucera,et al.  Xylem water flow in a crack willow tree (Salix fragilis L.) in relation to diurnal changes of environment , 1984, Oecologia.

[22]  J. Domec,et al.  How do water transport and water storage differ in coniferous earlywood and latewood? , 2002, Journal of experimental botany.

[23]  Kjeld Ladefoged.  Transpiration of Forest Trees in Closed Stands , 1963 .

[24]  M. G. Ryan,et al.  Hydraulic Limits to Tree Height and Tree Growth , 1997 .

[25]  J. Sperry.  Limitations on Stem Water Transport and Their Consequences , 1995 .

[26]  R. Lemeur,et al.  An experimental system for analysis of the dynamic sap-flow characteristics in young trees: results of a beech tree. , 2004, Functional plant biology : FPB.

[27]  M. Mccully,et al.  Daily embolism and refilling of xylem vessels in the roots of field-grown maize. , 1998, The New phytologist.

[28]  V. P. Cherkashin,et al.  Daily dynamics in xylem cell radial growth of Scots pine (Pinus sylvestris L.) , 1995, Trees.

[29]  A. M. Lewis.  Plant Stems: Physiology and Functional Morphology , 1997 .

[30]  Frederick R. Adler,et al.  Limitation of plant water use by rhizosphere and xylem conductance: results from a model , 1998 .

[31]  J. Kucera,et al.  The compensation of natural temperature gradient at the measuring point during the sap flow rate determination in trees , 1981, Biologia Plantarum.

[32]  M. G. Ryan,et al.  The relationship between tree height and leaf area: sapwood area ratio , 2002, Oecologia.

[33]  B. Law,et al.  Age-related changes in ecosystem structure and function and effects on water and carbon exchange in ponderosa pine. , 2004, Tree physiology.

[34]  E. Cienciala,et al.  Sap flow by the heat balance method applied to small size Salix trees in a short-rotation forest , 1995 .

[35]  R. Oren,et al.  Radial patterns of xylem sap flow in non‐, diffuse‐ and ring‐porous tree species , 1996 .

[36]  R. Ceulemans,et al.  Crown conductance and tree and stand transpiration in a second growth **Abies amabilis** forest , 1997 .

[37]  J. Cermak,et al.  Radial variation in sap flow in five laurel forest tree species in Tenerife, Canary Islands. , 2000, Tree physiology.

[38]  M. Penka,et al.  Improved thermal method of continual recording the transpiration flow rate dynamics , 1977, Biologia Plantarum.

[39]  D. Hollinger,et al.  Transpiration and canopy conductance in a pristine broad-leaved forest of Nothofagus: an analysis of xylem sap flow and eddy correlation measurements , 1992, Oecologia.

[40]  B. Bond,et al.  Does turgor limit growth in tall trees , 2004 .

[41]  M. Tyree,et al.  A dynamic model for water flow in a single tree: evidence that models must account for hydraulic architecture. , 1988, Tree physiology.

[42]  M. Deml,et al.  A new method of sap flow rate determination in trees , 1973, Biologia Plantarum.

[43]  R. Milne,et al.  Diurnal water storage in the stems of Picea sitchensis (Bong.) Carr. , 1989 .

[44]  J. Lassoie.  Diurnal Dimensional Fluctuations in a Douglas-fir Stem in Response to Tree Water Status , 1973 .

[45]  N. Nadezhdina,et al.  Sap flow measurements with some thermodynamic methods, flow integration within trees and scaling up from sample trees to entire forest stands , 2004, Trees.

[46]  P. Berbigier,et al.  Transpiration of a 64-year-old maritime pine stand in Portugal , 1996, Oecologia.

[47]  P. Berbigier,et al.  Transpiration of a 64-year old maritime pine stand in Portugal , 1996, Oecologia.

[48]  F. Smith,et al.  The role of Douglas-fir stem sapwood and heartwood in the mechanical and physiological support of crowns and development of stem form , 1981 .

[49]  J. Grace,et al.  Continuous measurements of water tensions in the xylem of trees based on the elastic properties of wood , 1997, Planta.

[50]  M. Tyree,et al.  Water Relations and Hydraulic Architecture of a Tropical Tree (Schefflera morototoni) : Data, Models, and a Comparison with Two Temperate Species (Acer saccharum and Thuja occidentalis). , 1991, Plant physiology.

[51]  F. Molz,et al.  Rehydration versus Growth-induced Water Uptake in Plant Tissues. , 1973, Plant physiology.

[52]  R. Zweifel,et al.  Link between diurnal stem radius changes and tree water relations. , 2001, Tree physiology.

[53]  M. Zimmermann.  Xylem Structure and the Ascent of Sap , 1983, Springer Series in Wood Science.

[54]  M. Zimmermann,et al.  Trees: Structure and Function. , 1972 .

[55]  E. Nikinmaa,et al.  Time lags for xylem and stem diameter variations in a Scots pine tree , 2002 .

[56]  D. Intrigliolo,et al.  Usefulness of diurnal trunk shrinkage as a water stress indicator in plum trees. , 2006, Tree physiology.

[57]  J. Cermak,et al.  Laurel forests in Tenerife, Canary Islands , 1996, Trees.

[58]  M. Penka,et al.  Transpiration flow rate in a full-grown tree ofPrunus avium L. estimated by the method of heat balance in connection with some meteorological factors , 1976, Biologia Plantarum.

[59]  H. So.  An Analysis of the Relationship between Stem Diameter and Leaf Water Potentials1 , 1979 .

[60]  F. Tatarinov,et al.  Daily and seasonal variation of stem radius in oak , 1999 .

[61]  T Vesala,et al.  Tree stem diameter variations and transpiration in Scots pine: an analysis using a dynamic sap flow model. , 2001, Tree physiology.

[62]  Frederick C. Meinzer,et al.  Stem water storage and diurnal patterns of water use in tropical forest canopy trees , 1998 .

[63]  P. Jarvis,et al.  Vertical Gradients of Water Potential and Tissue Water Relations in Sitka Spruce Trees Measured with the Pressure Chamber , 1974 .

[64]  J. Kucera,et al.  Sap flow rate and transpiration dynamics in the full-grown oak (Quercus robus L.) in floodplain forest exposed to seasonal floods as related to potential evapotranspiration and tree dimensions , 1982, Biologia Plantarum.

[65]  N. McDowell,et al.  Does foliage on the same branch compete for the same water? Experiments on Douglas-fir trees , 2003, Trees.

[66]  Barbara L. Gartner,et al.  Cavitation and water storage capacity in bole xylem segments of mature and young Douglas-fir trees , 2001, Trees.

[67]  C. Stewart.  Moisture Content of Living Trees , 1967, Nature.

[68]  G. Goldstein,et al.  Comparative gas exchange of leaves and bark in three stem succulents of Baja California , 1990 .

[69]  N. Holbrook.  Stem Water Storage , 1995 .

[70]  Gene Silberhorn,et al.  Red Maple Acer rubrum L. , 1991 .

[71]  M. Tyree,et al.  Water-storage capacity ofThuja, Tsuga andAcer stems measured by dehydration isotherms , 1990, Planta.

[72]  J. W. Worthington,et al.  Comparison of Trunk and Branch Sap Flow with Canopy Transpiration in Pecan , 1990 .

[73]  M. G. Ryan,et al.  Transpiration and whole-tree conductance in ponderosa pine trees of different heights , 2000, Oecologia.

[74]  M. Tyree,et al.  Water Relations and Hydraulic Architecture of a Tropical , 1991 .

[75]  Thomas M. Hinckley,et al.  The effects of drought on water relations and stem shrinkage of Quercus alba , 1975 .

[76]  R. Zweifel,et al.  Stem radius changes and their relation to stored water in stems of young Norway spruce trees , 2000, Trees.

[77]  Geoffrey G Parker,et al.  Canopy light transmittance in Douglas-fir--western hemlock stands. , 2002, Tree physiology.

[78]  Anthony E. Hall,et al.  Interpreting Leaf Water Potential Measurements with a Model of the Soil‐Plant‐Atmosphere Continuum , 1972 .

[79]  H. M. Taylor,et al.  Stem diameter in relation to plant water status. , 1971, Plant physiology.

[80]  T. Kozlowski,et al.  Shrinkage and swelling of stems ofPinus resinosa andBetula papyrifera in northern Wisconsin , 1975, Plant and Soil.

[81]  N. Holbrook,et al.  The Dynamics of “Dead Wood”: Maintenance of Water Transport Through Plant Stems1 , 2002, Integrative and comparative biology.

[82]  E. Cienciala,et al.  The analysis of physical background of tree sap flow measurement based on thermal methods , 2005 .

[83]  A. Sellin,et al.  Hydraulic Conductivity of Xylem Depending on Water Saturation Level in Norway Spruce (Picea Abies (L.) Karst.) , 1991 .

[84]  John Roberts,et al.  An Examination of the Quantity of Water Stored in Mature Pinus sylvestris L. Trees , 1976 .

[85]  M. G. Ryan,et al.  Reliance on stored water increases with tree size in three species in the Pacific Northwest. , 2003, Tree physiology.

[86]  R. Borchert,et al.  Soil and Stem Water Storage Determine Phenology and Distribution of Tropical Dry Forest Trees , 1994 .

[87]  E. D. Ford,et al.  Variation in specific needle area of old-growth Douglas-fir in relation to needle age, within-crown position and epicormic shoot production. , 2002, Tree physiology.

[88]  George W. Koch,et al.  The limits to tree height , 2004, Nature.

[89]  N. Holbrook,et al.  Water balance in the arborescent palm, Sabal palmetto. I. Stem structure, tissue water release properties and leaf epidermal conductance , 1992 .

[90]  Jan Čermák,et al.  Sapwood as the scaling parameter - defining according to xylem water content or radial pattern of sap flow? , 1998 .

[91]  F. Molz,et al.  On the Mechanism of Water-Stress-Induced Stem Deformation1 , 1973 .

[92]  J. Grace,et al.  Concurrent measurements of stem density, leaf and stem water potential, stomatal conductance and cavitation on a spaling of Thuja occidentalis L. , 1984 .

[93]  Richard H. Waring,et al.  Sapwood water storage: its contribution to transpiration and effect upon water conductance through the stems of old‐growth Douglas‐fir , 1978 .

[94]  Barbara L. Gartner,et al.  Patterns of xylem variation within a tree and their hydraulic and mechanical consequences , 1995 .

[95]  R. Zimmermann,et al.  Canopy transpiration and water fluxes in the xylem of the trunk of Larix and Picea trees — a comparison of xylem flow, porometer and cuvette measurements , 1985, Oecologia.

[96]  M. Mccully,et al.  Root xylem embolisms: implications for water flow to the shoot in single-rooted maize plants , 1999 .

[97]  Mccully.  Root xylem embolisms and refilling. Relation To water potentials of soil, roots, and leaves, and osmotic potentials of root xylem Sap , 1999, Plant physiology.