scholarly journals Water Use by Chinese Pine Is Less Conservative but More Closely Regulated Than in Mongolian Scots Pine in a Plantation Forest, on Sandy Soil, in a Semi-Arid Climate

2021 ◽  
Vol 12 ◽  
Author(s):  
Hongzhong Dang ◽  
Xueli Zhang ◽  
Hui Han ◽  
Shuai Chen ◽  
Mingyang Li
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Scots Pine ◽  
Xylem Sap ◽  
Soil Layer ◽  
Northern China ◽  
Plantation Forest ◽  
Sap Flux Density ◽  
Chinese Pine ◽  
Dry Conditions

The diversity of plant water use patterns among species and ecosystems is a matter of widespread debate. In this study, Chinese pine (Pinus tabuliformis, CP) and Mongolian Scots pine (Pinus sylvestris var. mongolica, MP), which is co-exist in the shelterbelt plantations in the Horqin Sandyland in northern China, were chosen for comparison of water use traits by monitoring xylem sap flow alongside recordings of the associated environmental factors over four growing seasons. Continuous sap flux density measurements were converted into crown projected area transpiration intensity (Tr) and canopy stomatal conductance (Gs). The results indicated that MP showed a higher canopy transpiration intensity than in CP, with Tr daily means (±standard deviation) of 0.84 ± 0.36 and 0.79 ± 0.43 mm⋅d–1, respectively (p = 0.07). However, the inter-annual variability of daily Tr in MP was not significant, varying only approximately a 1.1-fold (p = 0.29), while inter-annual variation was significant for CP, with 1.24-fold variation (p < 0.01). In particular, the daily mean Tr value for CP was approximately 1.7-times higher than that of MP under favorable soil moisture conditions, with values for relative extractable soil water within the 0–1.0 m soil layer (REW) being above 0.4. However, as the soil dried out, the value of Tr for CP decreased more sharply, falling to only approximately 0.5-times the value for MP when REW fell to < 0.2. The stronger sensitivity of Tr and/or Gs to REW, together with the more sensitive response of Gs to VPD in CP, confirms that CP exhibits less conservation of soil water utilization but features a stronger ability to regulate water use. Compared with MP, CP can better adapt to the dry conditions associated with climate change.

scholarly journals Radial variations in xylem sap flux in a temperate red pine plantation forest

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Alanna V. Bodo ◽  
M. Altaf Arain
Keyword(s):  
Flux Density ◽  
Water Use ◽  
Sap Flow ◽  
Xylem Sap ◽  
Red Pine ◽  
Sap Flux ◽  
Plantation Forest ◽  
Sap Flux Density ◽  
Flow Measurements ◽  
Sapwood Area

Abstract Background Scaling sap flux measurements to whole-tree water use or stand-level transpiration is often done using measurements conducted at a single point in the sapwood of the tree and has the potential to cause significant errors. Previous studies have shown that much of this uncertainty is related to (i) measurement of sapwood area and (ii) variations in sap flow at different depths within the tree sapwood. Results This study measured sap flux density at three depth intervals in the sapwood of 88-year-old red pine (Pinus resinosa) trees to more accurately estimate water-use at the tree- and stand-level in a plantation forest near Lake Erie in Southern Ontario, Canada. Results showed that most of the water transport (65%) occurred in the outermost sapwood, while only 26% and 9% of water was transported in the middle and innermost depths of sapwood, respectively. Conclusions These results suggest that failing to consider radial variations in sap flux density within trees can lead to an overestimation of transpiration by as much as 81%, which may cause large uncertainties in water budgets at the ecosystem and catchment scale. This study will help to improve our understanding of water use dynamics and reduce uncertainties in sap flow measurements in the temperate pine forest ecosystems in the Great Lakes region and help in protecting these forests in the face of climate change.

scholarly journals Effects of row spacing on soil water and water consumption of winter wheat under irrigated and rainfed conditions

2011 ◽  
Vol 57 (No. 3) ◽  
pp. 115-121 ◽  
Author(s):  
X.B. Zhou ◽  
Y.H. Chen ◽  
Z. Ouyang
Keyword(s):  
Soil Water ◽  
Field Experiments ◽  
Soil Layer ◽  
Northern China ◽  
Planting Density ◽  
Row Spacing ◽  
Use Efficiency ◽  
Set Up ◽  
Jointing Stage ◽  
High Yields

The results of two seasons' work on soil water content (SWC), evapotranspiration (ET), total dry matter (TDM), and harvest index (HI) of crops under different row spacing (RS), as well as possible ways to improve water utilization, have been reported. Field experiments were carried out at the Experimental Farm of Shandong Agricultural University (36°09'N, 117°09'E) in 2006–2007 and 2007–2008. Four types of RS were treated under two different water conditions (rainfed and irrigated) and set up in a randomized plot design. RS did not exhibit any obvious effects on SWC during the study period. SWC was enhanced evidently by irrigation, especially in the 10–60 cm soil layer. Irrigation increased the ET of crop. At the seeding-jointing stage, the ET of RS14 was significantly higher than those during other treatments (P < 0.05). Irrigation increased yields, ET, and TDM, while it decreased water use efficiency and HI. There were significantly negative correlations between TDM and RS (P < 0.05). The HI of the rainfed crop was higher than that of the irrigated crop. Results showed that high yields of wheat could be achieved in northern China by reducing RS under uniform planting density conditions.

scholarly journals Source apportionment of water use during vegetation succession on the Loess Plateau, China

2018 ◽  
Author(s):  
Chang Enhao ◽  
Li Peng ◽  
Li Zhanbin ◽  
Xiao Lie ◽  
Xu Guoce ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Loess Plateau ◽  
Soil Layer ◽  
Dry Season ◽  
Chinese Government ◽  
The Loess Plateau ◽  
Bothriochloa Ischaemum ◽  
Vegetation Communities ◽  
Successional Development

Background. The Chinese government implemented the largest environmental recovery plan in the 1990s, the Grain for Green Project, on the Loess Plateau to prevent soil erosion. Extensive areas of cultivated land were abandoned and then gradually restored with communities of native vegetation. Little is known, however, about the successional development of these communities and their strategies of water use. Methods. We collected soil and root samples from four vegetation communities at different stages of succession (Artemisia capillaris, A. sacrorum, Bothriochloa ischaemum and Lespedeza davurica) in the dry and wet seasons of 2015 in the Wangmaogou watershed of the Wuding River. Results. Both the root systems and soil-water contents tended to increase with successional development and fluctuated with changes of the dry and wet seasons. Isotopic analysis indicated that the thawing of winter snow during the dry season in April provided sufficient soil water. The vegetation communities only used the water in the 0-20 cm soil layer during the early successional stage. This range increased to 0-100 cm as the succession developed, with strong seasonal variation; water was accessed from deeper soil during the dry season, and water was accessed from shallower soil during the wet season. Discussion. Antecedent rainfall, soil-water content and root distribution strongly influenced the use of water in all four vegetation communities. In the process of restoration and succession of vegetation communities, the behavior characteristics and water absorption strategies of the root system are the important theoretical basis for optimizing the selection of species and accelerating the speed of ecological restoration in Chinese Loess Plateau.

scholarly journals Divergent water sources of three dominant plant species following precipitation events in enclosed and mowing grassland steppes

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7737
Author(s):  
Tiejun Bao ◽  
Yunnuan Zheng ◽  
Ze Zhang ◽  
Heyang Sun ◽  
Ran Chao ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Plant Species ◽  
Water Use ◽  
Soil Layer ◽  
Deep Soil ◽  
Soil Layers ◽  
Typical Steppe ◽  
Dominant Plant Species ◽  
Precipitation Events

Understanding of the dynamic patterns of plant water use in a changing environment is one of foci in plant ecology, and can provide basis for the development of best practice in restoration and protection of ecosystem. We studied the water use sources of three coexisting dominant plant species Leymus chinensis, Stipa grandis and Cleistogenes squarrosa growing in both enclosed and mowing grassland in a typical steppe. The oxygen stable isotope ratios (δ18O) of soil water and stem water of these three species were determined, along with soil moisture, before and after precipitation events. The results showed that (1) mowing had no significant effect on the soil moisture and its δ18O, whereas precipitation significantly changed the soil moisture though no significant effect detected on its δ18O. (2) C. squarrosa took up water majorly from top soil layer due to its shaollow root system; L. chinensis took up relative more water from deep soil layer, and S. grandis took up water from the middle to deep soil layers. (3) L. chinensis and S. grandis in mowing grassland tended to take up more water from the upper soil layers following precipitation events, but showed no sensitive change in water source from soil profile following the precipitation in the enclosed grassland, indicating a more sensitive change of soil water sources for the two species in mowing than enclosed grassland. The differences in root morphology and precipitation distribution may partly explain the differences in their water uptake from different soil layers. Our results have important theoretical values for understanding the water competition among plants in fluctuating environment and under different land use in the typical steppe.

Hydraulic and chemical signalling in the regulation of stomatal conductance and plant water use in field grapevines growing under deficit irrigation

2008 ◽  
Vol 35 (7) ◽  
pp. 565 ◽  
Author(s):  
M. Lucília Rodrigues ◽  
Tiago P. Santos ◽  
Ana P. Rodrigues ◽  
Claudia R. de Souza ◽  
Carlos M. Lopes ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Water Availability ◽  
Dominant Role ◽  
Xylem Sap ◽  
Soil Water Availability ◽  
Vitis Vinifera L ◽  
Plant Water ◽  
Chemical Signalling ◽  
Plant Water Use

Effects of irrigation strategies on stomata and plant water use were studied in field-grown grapevines (Vitis vinifera L.). We assessed the importance of root-derived chemical signals vs. hydraulic signalling in stomatal regulation. The experiment included two treatments with the same water added to the soil (50% ETc) applied either to the whole root system (DI) or to half of the roots, alternating irrigation side every 15 days (PRD). Well-watered plants (FI) (100% ETc) and non-irrigated grapevines (NI) were also studied. Partial stomata closure occurred in both PRD and DI plants. [ABA] of xylem sap remained constant during the day and was maintained throughout the season, with higher values in NI plants. Xylem sap pH was not affected by soil water availability. A positive correlation between ψpd and maximum g s was found, indicating that grapevine stomata strongly respond to plant water status. In contrast, ABA did not explain stomatal control at veraison. At mid-ripening g s was significantly correlated with ABA, apparently interacting with the rise in xylem sap pH. Therefore, our data suggest that hydraulic feedback and feed-forward root-to-shoot chemical signalling mechanisms might be involved in the control of stomata in response to decreased soil water availability, hydraulic signals playing the dominant role.

scholarly journals Quantification of dynamic soil – vegetation feedbacks following an isotopically labelled precipitation pulse

2016 ◽  
Author(s):  
Arndt Piayda ◽  
Maren Dubbert ◽  
Rolf Siegwolf ◽  
Matthias Cuntz ◽  
Christiane Werner
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Water Uptake ◽  
Water Loss ◽  
Cork Oak ◽  
Water Isotopes ◽  
Stable Water Isotopes ◽  
Herbaceous Vegetation ◽  
Understory Plants ◽  
Dry Conditions

Abstract. The presence of vegetation alters hydrological cycles of ecosystems. Complex plant – soil interactions govern the fate of precipitation input and water transitions through ecosystem compartments. Disentangling these interactions is a major challenge in the field of ecohydrology and pivotal foundation for understanding the carbon cycle of semi – arid ecosystems. Stable water isotopes can be used in this context as tracer to quantify water movement through soil – vegetation – atmosphere interfaces. The aim of this study is to disentangle vegetation effects on soil water infiltration and distribution as well as dynamics of soil evaporation and grassland water – use in a Mediterranean cork – oak woodland during dry conditions. An irrigation experiment using δ18O labeled water was carried out in order to quantify distinct effects of tree and herbaceous vegetation on infiltration and distribution of event water in the soil profile. Dynamic responses of soil and herbaceous vegetation fluxes to precipitation regarding event water – use, water uptake depth plasticity and contribution to ecosystem evapotranspiration were quantified. Total water loss to the atmosphere from bare soil was as high as from vegetated soil, utilizing large amounts of unproductive water loss for biomass production, carbon sequestration and nitrogen fixation. During the experiment no adjustments of main root water uptake depth to changes of water availability could be observed, rendering light to medium precipitation events under dry conditions useless. This forces understory plants to compete with adjacent trees for soil water in deeper soil layers. Thus understory plants are faster subject to chronic drought, leading to premature senescence at the onset of drought. Despite this water competition, the presence of Cork oak trees fosters infiltration to large degrees. That reduces drought stress, caused by evapotranspiration, due to favourable micro climatic conditions under tree crown shading. This study highlights complex soil – plant – atmosphere and inter – species interactions in both space and time controlling the fate of rain pulse transitions through a typical Mediterranean savannah ecosystem, disentangled by the use of stable water isotopes.

scholarly journals Source apportionment of water use during vegetation succession on the Loess Plateau, China

2018 ◽  
Author(s):  
Chang Enhao ◽  
Li Peng ◽  
Li Zhanbin ◽  
Xiao Lie ◽  
Xu Guoce ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Loess Plateau ◽  
Soil Layer ◽  
Dry Season ◽  
Chinese Government ◽  
The Loess Plateau ◽  
Bothriochloa Ischaemum ◽  
Vegetation Communities ◽  
Successional Development

Background. The Chinese government implemented the largest environmental recovery plan in the 1990s, the Grain for Green Project, on the Loess Plateau to prevent soil erosion. Extensive areas of cultivated land were abandoned and then gradually restored with communities of native vegetation. Little is known, however, about the successional development of these communities and their strategies of water use. Methods. We collected soil and root samples from four vegetation communities at different stages of succession (Artemisia capillaris, A. sacrorum, Bothriochloa ischaemum and Lespedeza davurica) in the dry and wet seasons of 2015 in the Wangmaogou watershed of the Wuding River. Results. Both the root systems and soil-water contents tended to increase with successional development and fluctuated with changes of the dry and wet seasons. Isotopic analysis indicated that the thawing of winter snow during the dry season in April provided sufficient soil water. The vegetation communities only used the water in the 0-20 cm soil layer during the early successional stage. This range increased to 0-100 cm as the succession developed, with strong seasonal variation; water was accessed from deeper soil during the dry season, and water was accessed from shallower soil during the wet season. Discussion. Antecedent rainfall, soil-water content and root distribution strongly influenced the use of water in all four vegetation communities. In the process of restoration and succession of vegetation communities, the behavior characteristics and water absorption strategies of the root system are the important theoretical basis for optimizing the selection of species and accelerating the speed of ecological restoration in Chinese Loess Plateau.

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