Allometric Equations between Stem Diameter and Sapwood Area of Japanese Cedar and Japanese Cypress for Stand Transpiration Estimates Using Sap Flow Measurement

Allometric equations were developed relating aboveground biomass, coarse root biomass, and sapwood area to stem diameter at 17 study sites located in the boreal forests near Thompson, Man. The six species studied were trembling aspen (Populus tremuloides Michx.), paper birch (Betula papyrifera Marsh.), black spruce (Picea mariana (Mill.) BSP), jack pine (Pinus banksiana Lamb.), tamarack (Larix laricina (Du Roi) Koch.), and willow (Salix spp.). Stands ranged in age from 4 to 130 years and were categorized as well or poorly drained. Stem diameter ranged from 0.1 to 23.7 cm. Stem diameter was measured at both the soil surface (D0) and breast height (DBH). The relationship between biomass and diameter, fitted on a loglog scale, changed significantly at ~3 cm DBH, suggesting that allometry differed between saplings and older trees. To eliminate this nonlinearity, a model of form log10 Y = a + b(log10 D) + c(AGE) + d(log10 D × AGE) was used, where D is stem diameter, AGE is stand age, and the cross product is the interaction between diameter and age. Most aboveground biomass equations (N = 326) exhibited excellent fits (R2 > 0.95). Coarse root biomass equations (N = 205) exhibited good fits (R2 > 0.90). Both D0 and DBH were excellent (R2 > 0.95) sapwood area predictors (N = 413). Faster growing species had significantly higher ratios of sapwood area to stem area than did slower growing species. Nonlinear aspects of some of the pooled biomass equations serve as a caution against extrapolating allometric equations beyond the original sample diameter range.

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

Journal of Hydrology and Hydromechanics ◽

10.2478/johh-2019-0013 ◽

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.

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Interannual variation in stand transpiration estimated by sap flow measurement in a semi-arid black locust plantation, Loess Plateau, China

Ecohydrology ◽

10.1002/eco.1495 ◽

2014 ◽

Vol 8 (1) ◽

pp. 137-147 ◽

Cited By ~ 35

Author(s):

Jian-Guo Zhang ◽

Jin-Hong Guan ◽

Wei-Yu Shi ◽

Norikazu Yamanaka ◽

Sheng Du

Keyword(s):

Loess Plateau ◽

Sap Flow ◽

Flow Measurement ◽

Interannual Variation ◽

Black Locust ◽

Stand Transpiration ◽

Semi Arid

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Differences in seasonality and temperature dependency of stand transpiration and canopy conductance between Japanese cypress (Hinoki) and Japanese cedar (Sugi) in a plantation

Hydrological Processes ◽

10.1002/hyp.11162 ◽

2017 ◽

Vol 31 (10) ◽

pp. 1952-1965 ◽

Cited By ~ 4

Author(s):

Takami Saito ◽

Tomo'omi Kumagai ◽

Makiko Tateishi ◽

Nakako Kobayashi ◽

Kyoichi Otsuki ◽

...

Keyword(s):

Japanese Cedar ◽

Canopy Conductance ◽

Temperature Dependency ◽

Japanese Cypress ◽

Stand Transpiration

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Dominant controls of transpiration along a hillslope transect inferred from ecohydrological measurements and thermodynamic limits

Hydrology and Earth System Sciences ◽

10.5194/hess-20-2063-2016 ◽

2016 ◽

Vol 20 (5) ◽

pp. 2063-2083 ◽

Cited By ~ 19

Author(s):

Maik Renner ◽

Sibylle K. Hassler ◽

Theresa Blume ◽

Markus Weiler ◽

Anke Hildebrandt ◽

...

Keyword(s):

Soil Moisture ◽

Solar Radiation ◽

Land Surface ◽

Sap Flow ◽

Stand Structure ◽

Surface Energy Budget ◽

Turbulent Heat ◽

Evaporative Demand ◽

Sapwood Area ◽

Stand Transpiration

Abstract. We combine ecohydrological observations of sap flow and soil moisture with thermodynamically constrained estimates of atmospheric evaporative demand to infer the dominant controls of forest transpiration in complex terrain. We hypothesize that daily variations in transpiration are dominated by variations in atmospheric demand, while site-specific controls, including limiting soil moisture, act on longer timescales. We test these hypotheses with data of a measurement setup consisting of five sites along a valley cross section in Luxembourg. Both hillslopes are covered by forest dominated by European beech (Fagus sylvatica L.). Two independent measurements are used to estimate stand transpiration: (i) sap flow and (ii) diurnal variations in soil moisture, which were used to estimate the daily root water uptake. Atmospheric evaporative demand is estimated through thermodynamically constrained evaporation, which only requires absorbed solar radiation and temperature as input data without any empirical parameters. Both transpiration estimates are strongly correlated to atmospheric demand at the daily timescale. We find that neither vapor pressure deficit nor wind speed add to the explained variance, supporting the idea that they are dependent variables on land–atmosphere exchange and the surface energy budget. Estimated stand transpiration was in a similar range at the north-facing and the south-facing hillslopes despite the different aspect and the largely different stand composition. We identified an inverse relationship between sap flux density and the site-average sapwood area per tree as estimated by the site forest inventories. This suggests that tree hydraulic adaptation can compensate for heterogeneous conditions. However, during dry summer periods differences in topographic factors and stand structure can cause spatially variable transpiration rates. We conclude that absorption of solar radiation at the surface forms a dominant control for turbulent heat and mass exchange and that vegetation across the hillslope adjusts to this constraint at the tree and stand level. These findings should help to improve the description of land-surface–atmosphere exchange at regional scales.

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