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54. Responses of functional traits to seven-year nitrogen addition in two tree species: coordination of hydraulics, gas exchange and carbon reserves.

Author

Zhang, Hongxia, Yuan, Fenghui, Wu, Jiabing, Jin, Changjie, Pivovaroff, Alexandria L, Tian, Jinyuan, Li, Weibin, Guan, Dexin, Wang, Anzhi, and McDowell, Nate G

Subjects
HYDRAULICS, HYDRAULIC conductivity, ATMOSPHERIC nitrogen, TEMPERATE forests, PLANT-water relationships, PLANT anatomy
Abstract

Atmospheric nitrogen (N) deposition has been observed to impact plant structure and functional traits in terrestrial ecosystems. Although the effect of N deposition on plant water use has been well-evaluated in laboratories and in experimental forests, the linkages between water and carbon relations under N deposition are unclear. Here, we report on hydraulics, gas exchange and carbon reserves of two broad-leaved tree species (Quercus mongolica and Fraxinus mandshurica) in mature temperate forests after a seven-year experiment with different levels of N addition (control (CK), low (23 kg N ha−1 yr−1), medium (46 kg N ha−1 yr−1) and high (69 kg N ha−1 yr−1)). We investigated variation in hydraulic traits (xylem-specific hydraulic conductivity (K s), native percentage loss of conductivity (PLC) and leaf water potential), xylem anatomy (vessel diameter and density), gas exchange (maximum net photosynthesis rate and stomatal conductance) and carbon reserves (soluble sugars, starch and total nonstructural carbohydrates (NSC)) with different N addition levels. We found that medium N addition significantly increased K s and vessel diameter compared to control, but accompanied increasing PLC and decreasing leaf water potential, suggesting that N addition results in a greater hydraulic efficiency and higher risk of embolism. N addition promoted photosynthetic capacity via increasing foliar N concentration but did not change stomatal conductance. In addition, we found increase in foliar soluble sugar concentration and decrease in starch concentration with N addition, and positive correlations between hydraulic traits (vessel diameter and PLC) and soluble sugars. These coupled responses of tree hydraulics and carbon metabolism are consistent with a regulatory role of carbohydrates in maintaining hydraulic integrity. Our study provides an important insight into the relationship of plant water transport and carbon dynamics under increasing N deposition. [ABSTRACT FROM AUTHOR]

Published
2021
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55. Divergences in hydraulic conductance and anatomical traits of stems and leaves in three temperate tree species coping with drought, N addition and their interactions.

Author

Zhang, Hongxia, McDowell, Nate G, Adams, Henry D, Wang, Anzhi, Wu, Jiabing, Jin, Changjie, Tian, Jinyuan, Zhu, Kai, Li, Weibin, Zhang, Yushu, Yuan, Fenghui, and Guan, Dexin

Subjects
DROUGHTS, TEMPERATE climate, ATMOSPHERIC nitrogen, SPECIES, LINDENS, CYCLIC compounds, ASH (Tree)
Abstract

Drought and nitrogen (N) addition have been shown to affect tree hydraulic traits, but few studies have been made on their interactions across species with different wood types or leaf forms. We examined the responses of hydraulic conductance and xylem anatomical traits of Quercus mongolica (ring porous with simple leaves), Fraxinus mandshurica (ring porous with compound leaves) and Tilia amurensis (diffuse porous with simple leaves) to drought, N addition and their interactions. Drought stress decreased current-year xylem-specific conductivity in stems (K sx) and leaf hydraulic conductance (K leaf), but N addition affected K sx and K leaf differently among species and watering regimes. These divergent effects were associated with different responses of anatomical traits and leaf forms. Higher mean vessel diameter in stems and lower vessel density in leaves were observed with N addition. The three-way interactive effects of drought, N addition and tree species were significant for most values of anatomical traits. These results were also reflected in large differences in vessel diameter and density among species with different wood types or leaf forms. The two-way interactive effects of drought and N addition were significant on K leaf and predawn water potential, but not K sx, indicating that leaves were more sensitive than stems to a combination of drought stress and N addition. Our results provide mechanistic insight into the variable responses of xylem water transport to the interactions of drought and N availability. [ABSTRACT FROM AUTHOR]

Published
2020
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62. Simulated and In Situ Frost Heave in Seasonally Frozen Soil from a Cold Temperate Broad-leaved Korean Pine Forest

Author

Lin, Maosen, Wang, Anzhi, Guan, Dexin, Jin, Changjie, Wu, Jiabin, and Yuan, Fenghui

Subjects
environmental_sciences
Abstract

Frost heave, which is the volumetric expansion of frozen soil, has great ecological significance, since it creates water storage spaces in soils at the beginning of the growing season in cold temperate forests. To understand the characteristics of frost heave in seasonally frozen soil and the factors that impact its extent, we investigated the frost heave rates of forest soil from different depths and with different soil moisture contents, using both lab-based simulation and in situ measurementin a broadleaved Korean pine forest in the Changbai Mountains (northeastern China). We found that frost heave was mainly affected by soil moisture content, soil type, and gravitational pressure. Frost heave rate increased linearly with soil moisture content, andfor each 100% increase in soil moisture content, the frost heave rate increased by 41.6% (loam, upper layer), 17.2% (albic soil, middle layer), and 4.6% (loess, lower layer). Under the same soil moisture content,the frost heave rate of loam was highest, whereas that of loess was lowest, and the frost heave of the uppermost 15 cm, which is the biologicallyenrichedlayer, accounted for ~55% of the frost heave. As a result, we determined the empirical relationship between frost heave and freezing depth, which is important for interpreting the effects of frost heave on increases in the storage space of forest soils and for calculating changes in soil porosity.

Published
2016

68. Water use efficiency and its influential factor over Horqin Meadow

Author

井艳丽 Jing Yanli, 李辉东 Li Huidong, 关德新 Guan Dexin, 吴家兵 Wu Jiabing, 袁凤辉 Yuan Fenghui, 李峥 Li Zheng, 王安志 Wang Anzhi, and 金昌杰 Jin Changjie

Subjects
Ecology, Agroforestry, Environmental science, Water-use efficiency, Ecology, Evolution, Behavior and Systematics
Published
2015

69. Modeling canopy transpiration of young poplar trees (Populus × euramericana cv. N3016) based on Back Propagation Artificial Neural Network

Author

王安志 Wang Anzhi, 关德新 Guan Dexin, 袁凤辉 Yuan Fenghui, 李辉东 Li Huidong, 吴家兵 Wu Jiabing, and 金昌杰 Jin Changjie

Subjects
Canopy, Horticulture, Ecology, Populus euramericana, Botany, Environmental science, Poplar trees, Back propagation artificial neural network, Ecology, Evolution, Behavior and Systematics, Transpiration
Published
2015

70. Performance of Priestley–Taylor model for estimating evaporation with and without snow coverage over a temperate meadow in Inner Mongolia, China.

Author

Chen, NiNa, Zhang, YuShu, Jin, ChangJie, Wang, AnZhi, Guan, DeXin, Mi, Na, and Zhou, Bin

Subjects
MEADOWS, SNOW accumulation, SNOW, SOIL moisture
Abstract

To promote the awareness of Priestley–Taylor (PT) model and extend the knowledge of hydrological model under snow, performance of PT model was illustrated by comparing with eddy covariance (EC) measurements over a temperate meadow. The results showed that the mean half‐hourly averages and directly calculated daily value of PT parameter α is 0.47 ± 0.27 and 0.51 ± 0.32, respectively. Vapour pressure deficit VPD is the mainly factor influences α in the snow‐covered period, while soil moisture in the snow‐free period. PT method underestimated evaporation in the whole study period and showed remarkable difference in different phases. It performed best in the snow‐melting phase, better in the presnow phase, worse in the fresh snow phase and worst in the snow‐melted phase. These studies indicated that PT model could be used to estimate evaporation over temperate meadow in dormant season, but utility of a variable PT parameter α during different phases should be considered. [ABSTRACT FROM AUTHOR]

Published
2019
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71. Ecological functions of coarse woody debris in forest ecosystem

Author

Han Shi-jie, Zhang Mi, Wu Jiabing, Guan Dexin, and Jin Changjie

Subjects
Functional ecology, Productivity (ecology), Ecology, Forest ecology, Biodiversity, Environmental science, Forestry, Coarse woody debris, Structure and function
Abstract

Coarse woody debris is an important structure and function unit in forest ecosystem. This review analyzed the ecological functions of coarse woody debris in forest ecosystem and introduced several hotspots and existing problems in coarse woody debris research field. It is suggested that quantitative research should be intensified in the ecological demands of coarse woody debris for providing a technical guidelines in management of productivity, biodiversity and other ecological processes.

Published
2005

72. Dynamics of profiles and storage of carbon dioxide in broadleaved/Korean forest in Changbai Mountain

Author

Han Shi-jie, Guan Dexin, Wu Jiabing, Zhang Junhui, Lin Li-sha, Yu Gui-rui, and Zho Xiao-song

Subjects
Canopy, Forest floor, chemistry.chemical_compound, Daytime, chemistry, Co2 concentration, Infrared gas analyzer, Carbon dioxide, Eddy covariance, Environmental science, Forestry, Stratification (vegetation), Atmospheric sciences
Abstract

CO2 concentrations at different heights in a broadleaved/Korean forest (with a mean height of 26 m) were measured with infrared gas analyzer IRGA (model 2250D, LI-COR Inc. and LI-COR, 820) from Aug. to Oct. of 1999, Apr. to Jul. of 2000, and from Aug. 2002 to Sept. 2003. Based on the collected data, the diurnal and seasonal dynamics of profiles and storage of carbon dioxide in the forest were analyzed. The diurnal CO2 profiles showed that the vertical distribution of CO2 concentration were different for daytime and nighttime, and the CO2 concentration was highest close to forest floor, no matter at daytime and nighttime. The seasonal profiles of CO2 showed that stratification in the canopy was evident during growth season. CO2 concentrations at different heights (60 m to 2.5 m) had a little change in March, with a difference of 10 μmol·mol−1, but had a significant change in July, with a difference of 60 μmol·mol−1. In July, there also existed a greater gradient of CO2 concentrations at canopy (22, 26 and 32 m), with a difference of 8 μmol·mol−1. The calculated total storage (ΔC/Δt) of CO2 in the air column with height of 40 m beneath eddy covariance instrument was negative, and made a little contribution to NEE.

Published
2003

73. Wind tunnel experiment of drag of isolated tree models in surface boundary layer

Author

Zhu Tingyao, Guan Dexin, and Han Shi-jie

Subjects
Physics::Fluid Dynamics, Permeability (earth sciences), Drag coefficient, Tree (data structure), Planetary boundary layer, Parasitic drag, Drag, Forestry, Astrophysics::Earth and Planetary Astrophysics, Aerodynamics, Mechanics, Mathematics, Wind tunnel
Abstract

For very sparse tree land individual tree was the basic element of interaction between atmosphere and the surface. Drag of isolated tree was preliminary aerodynamic index for analyzing the atmospheric boundary layer of this kind of surface. A simple pendulum method was designed and carried out in wind tunnel to measure drag of isolated tree models according to balance law of moment of force. The method was easy to conduct and with small error. The results showed that the drag and drag coefficient of isolated tree increased with decreasing of its permeability or porosity. Relationship between drag coefficient and permeability of isolated tree empirically was expressed by quadric curve.

Published
2000

74. Friction velocityu⋆ and roughness length zo of atmospheric surface boundary layer in sparse-tree land

Author

Zhu Tingyao, Guan Dexin, and Han Shi-jie

Subjects
Surface (mathematics), Boundary layer, Roughness length, Scale (ratio), Surface roughness, Forestry, Geometry, Shear velocity, Surface finish, Geology, Wind tunnel
Abstract

Sparse-tree land is one of the typical lands and can be considered as one typical rough surface in boundary layer meteorology. Many lands can be classified into the kind surface in the view of scale and distribution feature of the roughness elements such as agroforest, scatter planted or growing trees, savanna and so on. The structure of surface boundary layer in sparse-tree land is analyzed and the parameters, friction velocityu⋆and roughness length zo are deduced based on energy balance law and other physical hypothesis. The models agree well with data of wind tunnel experiments and field measurements.

Published
1999

99. Impacts of climate change and land use change on runoff of forest catchment in northeast China.

Author

Zhang, Yongfang, Guan, Dexin, Jin, Changjie, Wang, Anzhi, Wu, Jiabing, and Yuan, Fenghui

Subjects
CLIMATE change, HYDROLOGIC models, METEOROLOGICAL precipitation, HYDROLOGY, REGRESSION analysis
Abstract

Hydrological processes change from the impacts of climate variability and human activities. Runoff in the upper reaches of the Hun-Taizi River basin, which is mainly covered by forests in northeast China, decreased from 1960 to 2006. The data used in this study were based on runoff records from six hydrological stations in the upper reaches of the Hun-Taizi River basin. Nonparametric Mann-Kendall statistic was used to identify change trends and abrupt change points and consequently analyze the change characteristics in hydrological processes. The abrupt change in the annual runoff in most subcatchments appeared after 1975. Finally, the effects of climate change and land cover change on water resources were identified using regression analysis and a hydrology model. Results of the regression analysis suggest that the correlation coefficients between precipitation and runoff prior to the abrupt change were higher compared with those after the abrupt change. Moreover, using hydrology model analysis, the water yield was found to increase because of the decrease in forest land. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Published
2014
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