Tree Species with Photosynthetic Stems Have Greater Nighttime Sap Flux

Prerequisite for selection of appropriate tree species in afforestation programs is to understand their water use strategy. Acacia mangium Willd., Schima wallichii Choisy, and Cunninghamia lanceolata (Lamb.) Hook are the three main vegetation restoration pioneer species in southern China, but no comparative research on the water use strategy of these three tree species have been reported. Our objective was to gain a detailed understanding of how photosynthetically active radiation (PAR), vapor pressure deficit (VPD), and soil water content (SWC) at different soil depths control the sap flux density (Js) in the dry and wet seasons. We measured the Js of these three tree species by using the thermal dissipation method in low subtropical China. We found that both S. wallichii and C. lanceolata differed clearly in their stomatal behavior from one season to another, while A. mangium did not. The canopy conductance per sapwood area of S. wallichii and C. lanceolata was very sensitive to VPD in the dry season, but not in the wet season. The Js of A. mangium was negatively correlated to SWC in all soil layers and during both seasons, while the other two species were not sensitive to SWC in the deeper layers and only positively correlated to SWC in dry season. Our results demonstrate that the three species have distinct water use strategies and may therefore respond differently to changing climate.

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Variability in radial sap flux density patterns and sapwood area among seven co-occurring temperate broad-leaved tree species

Tree Physiology ◽

10.1093/treephys/28.12.1821 ◽

2008 ◽

Vol 28 (12) ◽

pp. 1821-1830 ◽

Cited By ~ 115

Author(s):

T. Gebauer ◽

V. Horna ◽

C. Leuschner

Keyword(s):

Flux Density ◽

Tree Species ◽

Sap Flux ◽

Sap Flux Density ◽

Sapwood Area

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Urbanization intensifies tree sap flux but divergently for different tree species groups in China

Environmental Science and Pollution Research ◽

10.1007/s11356-021-17813-8 ◽

2022 ◽

Author(s):

Lei Ouyang ◽

Jie Du ◽

Zhenzhen Zhang ◽

Ping Zhao ◽

Liwei Zhu ◽

...

Keyword(s):

Tree Species ◽

Sap Flux ◽

Tree Sap ◽

Species Groups

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Capacity of Quercus robur L. and Tilia cordata Mill. trees in providing urban ecosystem services in boreal climate

10.5194/egusphere-egu21-7125 ◽

2021 ◽

Author(s):

Sofia Sushko ◽

Alexey Yaroslavtsev ◽

Nina Tsuvareva ◽

Riccardo Valentini

Keyword(s):

Ecosystem Services ◽

Energy Loss ◽

Tree Species ◽

Quercus Robur ◽

Urban Ecosystem ◽

Tilia Cordata ◽

Heat Island ◽

Sap Flux ◽

Island Effect ◽

Tree Transpiration

Trees play an important role in urban ecosystem functioning and providing many ecosystem services, in particular, water and energy balance regulation. Consequently, trees can be a tool to mitigate to run-off and heat island effect in urban areas. We quantified the possibility of urban trees to provide these ecosystem services in the northernmost city with a million population &#8211; St. Petersburg (59&#176;57&#8242; N / 30&#176;19&#8242; E; Russia). Two diffuse-porous tree species &#8211; Quercus robur L. (n=2) and Tilia cordata Mill. (n=4) &#8211; were chosen for the research. These tree species are the most common in the green infrastructure of the city despite they are not typical for this biome, i.e. south taiga. During two growing season (July-Oct. 2019, April-Oct. 2020), tree sap flux was measured by thermal dissipation method using TreeTalker device (Nature 4.0 Corp., Italy). Sap flux density (Js) was calculated with modified Granier&#8217;s empirical calibration equation. Energy loss through tree transpiration was estimated from sap flux per tree (Js &#215; sap wood area) and latent heat of vaporization. For the entire observed period, average daily Js (24 h) of Q. robur trees were almost two times higher than T. cordata trees (3.46 vs. 1.91 g cm-2 h-1). Importantly, for Q. robur Js significantly decreased with increasing tree age (from 3.75 to 1.99 g cm-2 h-1 with age alteration from 145 to 350 yrs.), while for T. cordata it did not change (1.74 and 1.69 g cm-2 h-1 for 60-80 and 100-115 yrs.). Q. robur showed a significant higher daily energy loss through tree transpiration compared to T. cordata (618 and 396 W tree-1 with 100-108 diameter at breast high) for the studying period. Thus, Q. robur compared to T. cordata was more effective in providing water regulation services, especially in shallow groundwater table typical for St. Petersburg. Moreover, this tree species also has a higher capacity in mitigate to urban heat island effect.Current research was financially supported by Russian Science Foundation, No 19-77-30012.

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Cool-Dry Season Depression in Gas Exchange of Canopy Leaves and Water Flux of Tropical Trees at the Northern Limit of Asian Tropics

10.21203/rs.3.rs-223937/v1 ◽

2021 ◽

Author(s):

Zafar Siddiq ◽

Yong-Jiang Zhang

Keyword(s):

Gas Exchange ◽

Tree Species ◽

Environmental Changes ◽

Leaf Gas Exchange ◽

Water Status ◽

Water Flux ◽

Dry Season ◽

Sap Flux ◽

Dry Seasons ◽

Cool Dry Season

Abstract Trees on the northern boundary of Asian tropics experience hot-humid and cool-dry seasons, but little is known about their seasonal dynamics in canopy physiology. We used a canopy crane to reach the canopy of nine tropical tree species and measured canopy leaf gas exchange, water status, and trunk sap flux during the hot-humid and cool-dry seasons in Xishuangbanna, China. We found that most tree species exhibited significant reductions in maximum photosynthetic rate (Amax), stomatal conductance (gsmax), predawn and midday leaf water-potentials, and maximum sap flux density in the cool-dry season. Compared to the hot-humid season, Amax declined by 19 % − 60 %, and maximum water flux declined by -14% (an increase) to 42 %. The cool-dry season decline in Amax of four species can be partly explained by an increased stomatal limitation (decreased gsmax and intercellular CO2 concentrations). Therefore, a predicted increase in drought in this region may decrease the carbon sequestration and productivity of these forests. We did not find a tradeoff between performance (Amax in the hot-humid season) and persistence through the cool-dry season; species with higher Amax in the hot-humid season did not show higher percent seasonal declines in the cool-dry season. Amax was significantly and positively associated with the trunk spa flux for both seasons but the association was weak in the cool-dry season. Thus, our results suggest that some tradeoffs and trait associations are environment-dependent. Our results are important to understand carbon and water fluxes of seasonal tropical forests and their responses to environmental changes.

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