Spatial variability of xylem sap flow in mature beech (Fagus sylvatica) and its diurnal dynamics in relation to microclimate

Botany ◽  
2008 ◽  
Vol 86 (12) ◽  
pp. 1440-1448 ◽  
Author(s):  
An Saveyn ◽  
Kathy Steppe ◽  
Raoul Lemeur
Keyword(s):  
Fagus Sylvatica ◽  
Sap Flow ◽  
Xylem Sap ◽  
Radial Profile ◽  
Vapour Pressure Deficit ◽  
Climatic Conditions ◽  
General Function ◽  
Sap Flux Density ◽  
Sapwood Area ◽  
Diurnal Variability

The spatial and diurnal variability of sap flow in a mature beech tree ( Fagus sylvatica L.) was investigated on days with different climatic conditions (sunny, cloudy, rainy), during the summer. Sap flux density (v) was measured with six heat field deformation probes placed around the stem circumference. Each probe measured v at six sapwood depths. Daily v exhibited clear radial variation, and the shape of the radial profile of v differed substantially among circumferential positions. At some positions, daily v decreased monotonically towards the stem centre, whereas at others it showed an almost monotonic increase. Hence, the conducting sapwood area of the beech was highly asymmetrical. At all positions, conducting sapwood reached beyond the deepest sampled sapwood depth, precluding correct estimations of total sap flow. The radial profile of v also differed among measuring days. A general trend was that the inner sapwood contributed relatively more to total sap flow under better weather conditions. Besides variations among days, the shape of the radial profile of v also showed within-day variations. The contribution of the inner sapwood to total sap flow increased in the afternoon, with increasing vapour pressure deficit and photosynthetic active radiation. Because of large circumferential and temporal variability, no general function for the radial profile of v could be developed.

scholarly journals Radial variations in xylem sap flux in a temperate red pine plantation forest

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Alanna V. Bodo ◽  
M. Altaf Arain
Keyword(s):  
Flux Density ◽  
Water Use ◽  
Sap Flow ◽  
Xylem Sap ◽  
Red Pine ◽  
Sap Flux ◽  
Plantation Forest ◽  
Sap Flux Density ◽  
Flow Measurements ◽  
Sapwood Area

Abstract Background Scaling sap flux measurements to whole-tree water use or stand-level transpiration is often done using measurements conducted at a single point in the sapwood of the tree and has the potential to cause significant errors. Previous studies have shown that much of this uncertainty is related to (i) measurement of sapwood area and (ii) variations in sap flow at different depths within the tree sapwood. Results This study measured sap flux density at three depth intervals in the sapwood of 88-year-old red pine (Pinus resinosa) trees to more accurately estimate water-use at the tree- and stand-level in a plantation forest near Lake Erie in Southern Ontario, Canada. Results showed that most of the water transport (65%) occurred in the outermost sapwood, while only 26% and 9% of water was transported in the middle and innermost depths of sapwood, respectively. Conclusions These results suggest that failing to consider radial variations in sap flux density within trees can lead to an overestimation of transpiration by as much as 81%, which may cause large uncertainties in water budgets at the ecosystem and catchment scale. This study will help to improve our understanding of water use dynamics and reduce uncertainties in sap flow measurements in the temperate pine forest ecosystems in the Great Lakes region and help in protecting these forests in the face of climate change.

scholarly journals Sap Flow in Aleppo Pine in Greece in Relation to Sapwood Radial Gradient, Temporal and Climatic Variability

Forests ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 2
Author(s):  
Evangelia Korakaki ◽  
Mariangela N. Fotelli
Keyword(s):  
Sap Flow ◽  
Eastern Mediterranean ◽  
Climatic Variability ◽  
Radial Profile ◽  
Climatic Conditions ◽  
Aleppo Pine ◽  
Sap Flux ◽  
Sap Flux Density ◽  
Radial Gradient ◽  
Seasonal Basis

Research Highlights: The radial gradient of sap flux density (Js) and the effects of climatic factors on sap flow of Aleppo pine were assessed at different time scales in an eastern Mediterranean ecosystem to improve our understanding of the species water balance. Background and Objectives: Aleppo pine’s sap flow radial profile and responses to environmental parameters in the eastern Mediterranean were, to our best knowledge, originating to date from more arid planted forests. Information from natural forests in this region was lacking. Our objectives were to (a) determine the species’ radial variability in Js on a diurnal and seasonal basis and under different climatic conditions, (b) scale up to tree sap flow taking into account the radial profile of Js and (c) determine the responses of Aleppo pine’s sap flow over the year to climatic variability. Materials and Methods: Js was monitored in Aleppo pine in a natural forest in northern Greece with Granier’s method using sensors at three sapwood depths (21, 51, and 81 mm) during two periods differing in climatic conditions, particularly in soil water availability. Results: Js was the highest at 21 mm sapwood depth, and it declined with increasing depth. A steeper gradient of Js in deep sapwood was observed under drier conditions. The same patterns of radial variability in Js were maintained throughout the year, but the contribution of inner sapwood to sap flow was the highest in autumn when the lower seasonal Js was recorded in both study periods. Not taking into account the radial gradient of Js in the studied Aleppo pine would result in a c. 20.2–27.7 % overestimation of total sap flow on a sapwood basis (Qs), irrespective of climatic conditions. On a diurnal and seasonal basis, VPD was the strongest determinant of sap flux density, while at a larger temporal scale, the effect of soil water content was evident. At SWC > 20% sap flow responded positively to increasing solar radiation and VPD, indicating the decisive role of water availability in the studied region. Moreover, in drier days with VPD > 0.7 KPa, SWC controlled the variation of sap flow. Conclusions: There is a considerable radial variability in Js of the studied Aleppo pine and a considerable fluctuation of sap flow with environmental dynamics that should be taken into account when addressing the species water balance.

Regulation of canopy conductance and transpiration and their modelling in irrigated grapevines

2003 ◽  
Vol 30 (6) ◽  
pp. 689 ◽  
Author(s):  
Ping Lu ◽  
Isa A. M. Yunusa ◽  
Rob R. Walker ◽  
Warren J. Müller
Keyword(s):  
Solar Radiation ◽  
Sap Flow ◽  
Heat Dissipation ◽  
Xylem Sap ◽  
Vapour Pressure Deficit ◽  
Vitis Vinifera L ◽  
Canopy Conductance ◽  
Xylem Sap Flow ◽  
Highly Correlated ◽  
Monteith Equation

Whole-vine transpiration was estimated for well-watered nine-year-old Sultana grapevines (Vitis vinifera L. cv. Sultana) from xylem sap flow measured with Granier's heat-dissipation probes. Canopy conductance of the grapevine was calculated by inverting the Penman–Monteith equation. Transpiration from grapevine canopies was strongly controlled by the canopy conductance. Canopy conductance decreased exponentially with increasing vapour pressure deficit (VPD) except in the morning when solar radiation was less than 200 W m–2 and the canopy conductance was predominantly limited by the solar radiation. A non-linear model of canopy conductance as a function of the solar radiation and VPD explained > 90% of the variation observed in canopy conductance. Under contrasting VPD conditions (daytime maximum of 3 kPa vs 8 kPa), grapevines were able to regulate their canopy conductance from 0.006 to 0.001 m s–1 to maintain a near constant transpiration. Whole-canopy transpiration calculated from modelled canopy conductance using the Penman–Monteith equation was highly correlated with the measured transpiration (sap flow) values over the range of 0–0.20 mm h–1 (R2 > 0.85). Cross-validation shows that these mechanistic models based on solar radiation and VPD provide good predictions of canopy conductance and transpiration under the conditions of the study.

scholarly journals Estimation of water use of Pinus tabulaeformis Carr. in Loess Plateau of Northwest China

2019 ◽  
Vol 67 (3) ◽  
pp. 271-279
Author(s):  
Shengqi Jian ◽  
Zening Wu ◽  
Caihong Hu
Keyword(s):  
Water Use ◽  
Loess Plateau ◽  
Sap Flow ◽  
Northwest China ◽  
Climatic Conditions ◽  
Pinus Tabulaeformis ◽  
Forest Stands ◽  
Sapwood Area ◽  
Stand Transpiration ◽  
The Mean

Abstract Tree transpiration plays a determining role in the water balance of forest stands and in seepage water yields from forested catchments, especially in arid and semiarid regions where climatic conditions are dry with severe water shortage, forestry development is limited by water availability. To clarify the response of water use to climatic conditions, sap flow was monitored by heat pulse velocity method from May to September, 2014, in a 40–year–old Pinus tabulaeformis Carr. plantation forest stands in the semiarid Loess Plateau region of Northwest China. We extrapolated the measurements of water use by individual plants to determine the area–averaged transpiration of the woodlands. The method used for the extrapolation assumes that the transpiration of a tree was proportional to its sapwood area. Stand transpiration was mainly controlled by photosynthetically active radiation and vapor pressure deficit, whereas soil moisture had more influence on monthly change in stand transpiration. The mean sap flow rates for individual P. tabulaeformis trees ranged from 9 to 54 L d−1. During the study period, the mean daily stand transpiration was 1.9 mm day−1 (maximum 2.9 and minimum 0.8 mm day−1) and total stand transpiration from May to September was 294.1 mm, representing 76% of the incoming precipitation over this period. Similar results were found when comparing transpiration estimated with sap flow measurements to the Penman–Monteith method (relative error: 16%), indicating that the scaling procedure can be used to provide reliable estimates of stand transpiration. These results suggested that P. tabulaeformis is highly effective at utilizing scarce water resources in semiarid environments.

scholarly journals Tree diversity and the temporal stability of mountain forest productivity: testing the effect of species composition, through asynchrony and overyielding

2020 ◽  
Author(s):  
Marion Jourdan ◽  
Christian Piedallu ◽  
Jonas Baudry ◽  
Xavier Morin
Keyword(s):  
Climate Change ◽  
Fagus Sylvatica ◽  
Stress Gradient ◽  
Abies Alba ◽  
Forest Productivity ◽  
Climatic Conditions ◽  
Mixed Stands ◽  
Tree Ring Data ◽  
Diversity Effect ◽  
Over Time

ABSTRACTClimate change modifies ecosystem processes directly through its effect on environmental conditions, but also indirectly by changing community composition. Theoretical studies and grassland experiments suggest that diversity may increase and stabilize communities’ productivity over time. Few recent studies on forest ecosystems suggested the same pattern but with a larger variability between the results. In this paper, we aimed to test stabilizing diversity effect for two kinds of mixtures (Fagus sylvatica - Quercus pubescens and Fagus sylvatica - Abies alba), and to assess how climate may affect the patterns. We used tree ring data from forest plots distributed along a latitudinal gradient across French Alps. We found that diversity effect on stability in productivity varies with stand composition. Most beech–fir stands showed a greater stability in productivity over time than monocultures, while beech–oak stands showed a less stable productivity. Considering non-additive effects, no significant trends were found, regardless the type of mixed stands considered. We further highlighted that these patterns could be partially explained by asynchrony between species responses to annual climatic conditions (notably to variation in temperature or precipitation), overyielding, and climatic conditions. We also showed that the intensity of the diversity effect on stability varies along the ecological gradient, consistently with the stress gradient hypothesis for beech-oak forests, but not for beech-fir forests. This study showed the importance of the species identity on the relationships between diversity, climate and stability of forest productivity. Better depicting diversity and composition effects on forest ecosystem functioning appears to be crucial for forest managers to promote forest adaptation and maintain timber resource in the context of on-going climate change.

scholarly journals Assessing variation in the radial profile of sap flux density in Pinus species and its effect on daily water use

2004 ◽  
Vol 24 (3) ◽  
pp. 241-249 ◽  
Author(s):  
C. R. Ford ◽  
M. A. McGuire ◽  
R. J. Mitchell ◽  
R. O. Teskey
Keyword(s):  
Flux Density ◽  
Water Use ◽  
Radial Profile ◽  
Sap Flux ◽  
Sap Flux Density ◽  
Pinus Species ◽  
Daily Water

scholarly journals Microscale Xylem Sap Flow Sensor Facilitating the Simultaneous Measurement of Flow Velocity and Direction

Proceedings ◽  
2019 ◽  
Vol 2 (13) ◽  
pp. 824
Author(s):  
Yuki Hara ◽  
Naoki Hara ◽  
Hiroki Ishizuka ◽  
Kyohei Terao ◽  
Hidekuni Takao ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Simultaneous Measurement ◽  
Sap Flow ◽  
Xylem Sap ◽  
Flow Sensor ◽  
Functional Verification ◽  
Thermal Flow Sensor ◽  
Quantitative Monitoring ◽  
Mems Technology ◽  
Xylem Sap Flow

In this study, we focused on direct and quantitative monitoring of sap dynamics in plant stems, and proposed the microscale xylem sap flow sensor. This sensor facilitates the simultaneous measurement of flow velocity and direction by combining the principles of a Granier sensor and a thermal flow sensor. We fabricated micro-sensor chips for functional verification by using MEMS technology, and assembled them on a resin film to facilitate mounting on the epidermis of plants. Furthermore, we measured the sap dynamics by using an experimental setup, and succeeded in measuring the flow velocity and direction at the same time.

scholarly journals Sap flow, xylem anatomy and photosynthetic variables of three Persea species in response to laurel wilt

2020 ◽  
Author(s):  
Raiza Castillo-Argaez ◽  
Aime Vazquez ◽  
Joshua L Konkol ◽  
Ana I Vargas ◽  
Randy C Ploetz ◽  
...  
Keyword(s):  
Tree Species ◽  
Sap Flow ◽  
Xylem Sap ◽  
Forest Tree ◽  
Persea Americana ◽  
Xylem Vessel ◽  
Xylem Anatomy ◽  
Laurel Wilt ◽  
Raffaelea Lauricola ◽  
Leaf Chlorophyll

Abstract Laurel wilt, a lethal vascular wilt disease caused by the fungus Raffaelea lauricola, affects several tree species in the Lauraceae, including three Persea species. The susceptibility to laurel wilt of two forest tree species native to the southern United States, Persea borbonia and Persea palustris, and avocado, Persea americana cv Waldin, was examined and related to tree physiology and xylem anatomy. Net CO2 assimilation (A), stomatal conductance (gs), leaf chlorophyll index (LCI), leaf chlorophyll fluorescence (Fv/Fm), xylem sap flow, theoretical stem hydraulic conductivity (Kh) and xylem vessel anatomy were assessed in trees of each species that were inoculated with R. lauricola and in control trees. Laurel wilt caused a reduction in A, gs, LCI, Fv/Fm, and blockage of xylem vessels by tyloses formation that negatively impacted Kh, and sap flow in all Persea species. However, disease susceptibility as indicated by canopy wilting and sapwood discoloration was less pronounced in P. americana cv Waldin than in the two forest species. Xylem vessel diameter was significantly smaller in P. borbonia and P. palustris than in P. americana cv Waldin. Differences in laurel wilt susceptibility among species appears to be influenced by physiological and anatomical tree responses.

scholarly journals Radial profile of sap flow velocity in mature Xinjiang poplar (Populus alba L. var. pyramidalis) in Northwest China

2014 ◽  
Vol 6 (5) ◽  
pp. 612-627 ◽  
Author(s):  
HongZhong Dang ◽  
TianShan Zha ◽  
JinSong Zhang ◽  
Wei Li ◽  
ShiZeng Liu
Keyword(s):  
Flow Velocity ◽  
Sap Flow ◽  
Radial Profile ◽  
Northwest China ◽  
Populus Alba ◽  
Sap Flow Velocity
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