Applicability of Sap Flux Measurements in Moso Bamboo (Phyllostachys pubescens): Relationship between Water Absorption and Whole-tree Water Use Utilizing Granier Sensor Sap Flux Measurements.

The influence of heat treatment on the physico-mechanical properties, water resistance, and creep behavior of moso bamboo (Phyllostachys pubescens) was determined in this study. The results revealed that the density, moisture content, and flexural properties showed negative relationships with the heat treatment temperature, while an improvement in the dimensional stability (anti-swelling efficiency and anti-water absorption efficiency) of heat-treated samples was observed during water absorption tests. Additionally, the creep master curves of the untreated and heat-treated samples were successfully constructed using the stepped isostress method (SSM) at a series of elevated stresses. Furthermore, the SSM-predicted creep compliance curves fit well with the 90-day full-scale experimental data. When the heat treatment temperature increased to 180 °C, the degradation ratio of the creep resistance (rd) significantly increased over all periods. However, the rd of the tested bamboo decreased as the heat treatment temperature increased up to 220 °C.

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Stand-scale transpiration estimates in a Moso bamboo forest: (I) Applicability of sap flux measurements

Forest Ecology and Management ◽

10.1016/j.foreco.2010.07.012 ◽

2010 ◽

Vol 260 (8) ◽

pp. 1287-1294 ◽

Cited By ~ 40

Author(s):

Tomonori Kume ◽

Yuka Onozawa ◽

Hikaru Komatsu ◽

Kenji Tsuruta ◽

Yoshinori Shinohara ◽

...

Keyword(s):

Moso Bamboo ◽

Bamboo Forest ◽

Sap Flux ◽

Flux Measurements ◽

Moso Bamboo Forest

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Airborne Tree Crown Detection for Predicting Spatial Heterogeneity of Canopy Transpiration in a Tropical Rainforest

Remote Sensing ◽

10.3390/rs12040651 ◽

2020 ◽

Vol 12 (4) ◽

pp. 651

Author(s):

Joyson Ahongshangbam ◽

Alexander Röll ◽

Florian Ellsäßer ◽

Hendrayanto ◽

Dirk Hölscher

Keyword(s):

Spatial Heterogeneity ◽

Water Use ◽

Tropical Rainforests ◽

Sap Flux ◽

Tree Crown ◽

Individual Tree ◽

Canopy Transpiration ◽

Tree Water Use ◽

Climate Regulation ◽

The Relationship

Tropical rainforests comprise complex 3D structures and encompass heterogeneous site conditions; their transpiration contributes to climate regulation. The objectives of our study were to test the relationship between tree water use and crown metrics and to predict spatial variability of canopy transpiration across sites. In a lowland rainforest of Sumatra, we measured tree water use with sap flux techniques and simultaneously assessed crown metrics with drone-based photogrammetry. We observed a close linear relationship between individual tree water use and crown surface area (R2 = 0.76, n = 42 trees). Uncertainties in predicting stand-level canopy transpiration were much lower using tree crown metrics than the more conventionally used stem diameter. 3D canopy segmentation analyses in combination with the tree crown–water use relationship predict substantial spatial heterogeneity in canopy transpiration. Among our eight study plots, there was a more than two-fold difference, with lower transpiration at riparian than at upland sites. In conclusion, we regard drone-based canopy segmentation and crown metrics to be very useful tools for the scaling of transpiration from tree- to stand-level. Our results indicate substantial spatial variation in crown packing and thus canopy transpiration of tropical rainforests.

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