Transpiration and canopy stomatal conductance dynamics of Mongolian pine plantations in semiarid deserts, Northern China

2021 ◽  
Vol 249 ◽  
pp. 106806
Author(s):  
Jifeng Deng ◽  
Jiaqi Yao ◽  
Xiao Zheng ◽  
Guanglei Gao
Keyword(s):  
Stomatal Conductance ◽  
Northern China ◽  
Pine Plantations ◽  
Canopy Stomatal Conductance

scholarly journals Drought-Induced Reductions and Limited Recovery in the Radial Growth, Transpiration, and Canopy Stomatal Conductance of Mongolian Scots Pine (Pinus sylvestris var. mongolica Litv): A Five-Year Observation

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1143 ◽  
Author(s):  
Hongzhong Dang ◽  
Ping Lu ◽  
Wenbin Yang ◽  
Hui Han ◽  
Jun Zhang
Keyword(s):  
Stomatal Conductance ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Radial Growth ◽  
Northern China ◽  
Drought Period ◽  
Before And After ◽  
Pine Trees ◽  
Canopy Stomatal Conductance ◽  
Tree Radial Growth

Determining plant–water relationships in response to drought events can provide important information about the adaptation of trees to climate change. The Mongolian Scots pine (Pinus sylvestris var. mongolica Litv), as one of the major tree species to control soil loss and desertification in northern China, has experienced severe degradation in recent decades. Here, we aimed to examine the impacts of a two-year consecutive drought and another year of drought on the radial growth, transpiration, and canopy stomatal conductance of Mongolian Scots pine over a five-year period, especially in terms of its recovery after drought. The study period during 2013–2017 consisted of a ‘normal’ year, a ‘dry year’, a ‘very dry’ year, a ‘wet’ year, and a ‘dry’ year, according to annual precipitation and soil moisture conditions. Based on measurements of the sap flow and diameters at breast height of 11 sample trees as well as the concurrent environmental factors, we quantified the reductions in tree radial growth, transpiration, and canopy stomatal conductance during the drought development as well as their recovery after the drought. The results showed that the tree radial growth, transpiration, and canopy stomatal conductance of Mongolian Scots pines decreased by 33.8%, 51.9%, and 51.5%, respectively, due to the two consecutive years of drought. Moreover, these reductions did not fully recover after the two-year drought was relieved. The minimum difference of these parameters between before and after the two-year consecutive drought period was 8.5% in tree radial growth, 45.1% in transpiration levels, and 42.4% in canopy stomatal conductance. We concluded that the two consecutive years of drought resulted in not only large reductions in tree radial growth and water use, but also their lagged and limited recoveries after drought. The study also highlighted the limited resilience of Mongolian Scots pine trees to prolonged drought in semi-arid sandy environmental conditions.

scholarly journals Stomatal conductance limited the CO2 response of grassland in the last century

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Juan C. Baca Cabrera ◽  
Regina T. Hirl ◽  
Rudi Schäufele ◽  
Andy Macdonald ◽  
Hans Schnyder
Keyword(s):  
Climate Change ◽  
Stomatal Conductance ◽  
Nitrogen Nutrition ◽  
Physiological Control ◽  
Co2 Response ◽  
Nitrogen Acquisition ◽  
Wide Range ◽  
Park Grass Experiment ◽  
Conductance Changes ◽  
Canopy Stomatal Conductance

Abstract Background The anthropogenic increase of atmospheric CO2 concentration (ca) is impacting carbon (C), water, and nitrogen (N) cycles in grassland and other terrestrial biomes. Plant canopy stomatal conductance is a key player in these coupled cycles: it is a physiological control of vegetation water use efficiency (the ratio of C gain by photosynthesis to water loss by transpiration), and it responds to photosynthetic activity, which is influenced by vegetation N status. It is unknown if the ca-increase and climate change over the last century have already affected canopy stomatal conductance and its links with C and N processes in grassland. Results Here, we assessed two independent proxies of (growing season-integrating canopy-scale) stomatal conductance changes over the last century: trends of δ18O in cellulose (δ18Ocellulose) in archived herbage from a wide range of grassland communities on the Park Grass Experiment at Rothamsted (U.K.) and changes of the ratio of yields to the CO2 concentration gradient between the atmosphere and the leaf internal gas space (ca – ci). The two proxies correlated closely (R2 = 0.70), in agreement with the hypothesis. In addition, the sensitivity of δ18Ocellulose changes to estimated stomatal conductance changes agreed broadly with published sensitivities across a range of contemporary field and controlled environment studies, further supporting the utility of δ18Ocellulose changes for historical reconstruction of stomatal conductance changes at Park Grass. Trends of δ18Ocellulose differed strongly between plots and indicated much greater reductions of stomatal conductance in grass-rich than dicot-rich communities. Reductions of stomatal conductance were connected with reductions of yield trends, nitrogen acquisition, and nitrogen nutrition index. Although all plots were nitrogen-limited or phosphorus- and nitrogen-co-limited to different degrees, long-term reductions of stomatal conductance were largely independent of fertilizer regimes and soil pH, except for nitrogen fertilizer supply which promoted the abundance of grasses. Conclusions Our data indicate that some types of temperate grassland may have attained saturation of C sink activity more than one century ago. Increasing N fertilizer supply may not be an effective climate change mitigation strategy in many grasslands, as it promotes the expansion of grasses at the disadvantage of the more CO2 responsive forbs and N-fixing legumes.

Assessment of canopy stomatal conductance models using flux measurements

2009 ◽  
Vol 220 (17) ◽  
pp. 2115-2118 ◽  
Author(s):  
Shusen Wang ◽  
Yan Yang ◽  
Alexander P. Trishchenko
Keyword(s):  
Stomatal Conductance ◽  
Flux Measurements ◽  
Canopy Stomatal Conductance

Greater risk of hydraulic failure due to increased drought threatens pine plantations in Horqin Sandy Land of northern China

2020 ◽  
Vol 461 ◽  
pp. 117980 ◽  
Author(s):  
Ming-Yong Li ◽  
Li-Dong Fang ◽  
Chun-Yang Duan ◽  
Yu Cao ◽  
Hong Yin ◽  
...  
Keyword(s):  
Northern China ◽  
Pine Plantations ◽  
Horqin Sandy Land ◽  
Sandy Land ◽  
Hydraulic Failure

scholarly journals Dynamics of canopy stomatal conductance, transpiration, and evaporation in a temperate deciduous forest, validated by carbonyl sulfide uptake

2017 ◽  
Vol 14 (2) ◽  
pp. 389-401 ◽  
Author(s):  
Richard Wehr ◽  
Róisín Commane ◽  
J. William Munger ◽  
J. Barry McManus ◽  
David D. Nelson ◽  
...  
Keyword(s):  
Water Vapor ◽  
Stomatal Conductance ◽  
Eddy Covariance ◽  
Deciduous Forest ◽  
Carbonyl Sulfide ◽  
Temperate Deciduous Forest ◽  
Ecosystem Models ◽  
Eddy Covariance Method ◽  
Temperate Deciduous ◽  
Canopy Stomatal Conductance

Abstract. Stomatal conductance influences both photosynthesis and transpiration, thereby coupling the carbon and water cycles and affecting surface–atmosphere energy exchange. The environmental response of stomatal conductance has been measured mainly on the leaf scale, and theoretical canopy models are relied on to upscale stomatal conductance for application in terrestrial ecosystem models and climate prediction. Here we estimate stomatal conductance and associated transpiration in a temperate deciduous forest directly on the canopy scale via two independent approaches: (i) from heat and water vapor exchange and (ii) from carbonyl sulfide (OCS) uptake. We use the eddy covariance method to measure the net ecosystem–atmosphere exchange of OCS, and we use a flux-gradient approach to separate canopy OCS uptake from soil OCS uptake. We find that the seasonal and diurnal patterns of canopy stomatal conductance obtained by the two approaches agree (to within ±6 % diurnally), validating both methods. Canopy stomatal conductance increases linearly with above-canopy light intensity (in contrast to the leaf scale, where stomatal conductance shows declining marginal increases) and otherwise depends only on the diffuse light fraction, the canopy-average leaf-to-air water vapor gradient, and the total leaf area. Based on stomatal conductance, we partition evapotranspiration (ET) and find that evaporation increases from 0 to 40 % of ET as the growing season progresses, driven primarily by rising soil temperature and secondarily by rainfall. Counterintuitively, evaporation peaks at the time of year when the soil is dry and the air is moist. Our method of ET partitioning avoids concerns about mismatched scales or measurement types because both ET and transpiration are derived from eddy covariance data. Neither of the two ecosystem models tested predicts the observed dynamics of evaporation or transpiration, indicating that ET partitioning such as that provided here is needed to further model development and improve our understanding of carbon and water cycling.

scholarly journals Determining an Accurate and Cost-Effective Individual Height-Diameter Model for Mongolian Pine on Sandy Land

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1144
Author(s):  
Yangang Han ◽  
Zeyong Lei ◽  
Albert Ciceu ◽  
Yanping Zhou ◽  
Fengyan Zhou ◽  
...  
Keyword(s):  
Management Practice ◽  
Predictor Variable ◽  
Tree Height ◽  
Cost Effective ◽  
Northern China ◽  
Mixed Effects ◽  
Pine Plantations ◽  
Sampling Effort ◽  
Individual Tree ◽  
D Model

Height-diameter (H-D) models are important tools for forest management practice. Sandy Mongolian pine plantations (Pinus sylvestris var. mongolica) are a major component of the Three-North Afforestation Shelterbelt in Northern China. However, few H-D models are available for Mongolian pine plantations. In this paper we compared different equations found in the literature for predicting tree height, using diameter at breast height and additional stand-level predictor variables. We tested if the additional stand-level predictor variable is necessary to produce more accurate results. The dominant height was used as a stand-level predictor variable to describe the variation of the H-D relationship among plots. We found that the basic mixed-effects H-D model provided a similar predictive accuracy as the generalized mixed-effects H-D model. Moreover, it had the advantage of reducing the sampling effort. The basic mixed-effects H-D model calibration, in which the heights of the two thickest trees in the plot were included to calibrate the random effects, resulted in accurate and reliable individual tree height estimations. Thus, the basic mixed-effects H-D model with the above-described calibration design can be an accurate and cost-effective solution for estimating the heights of Mongolian pine trees in northern China.

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