Seasonal transpiration dynamics of evergreen Ligustrum lucidum linked with water source and water-use strategy in a limestone karst area, southwest China

2021 ◽  
Vol 597 ◽  
pp. 126199
Author(s):  
Ze Wu ◽  
Hamid M. Behzad ◽  
Qiufang He ◽  
Chao Wu ◽  
Ying Bai ◽  
...  
Keyword(s):  
Water Use ◽  
Southwest China ◽  
Water Source ◽  
Karst Area ◽  
Ligustrum Lucidum ◽  
Water Use Strategy

Water use strategy of Ammopiptanthus mongolicus community in a drought year on the Mongolian Plateau

2020 ◽  
Vol 13 (6) ◽  
pp. 793-800
Author(s):  
Ya-Juan Zhu ◽  
Guo-Jie Wang ◽  
Zhi-Ming Xin
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Water Source ◽  
Water Sources ◽  
Desert Ecosystem ◽  
Total Water ◽  
Mongolian Plateau ◽  
Ammopiptanthus Mongolicus ◽  
Deep Soil ◽  
Water Use Strategy

Abstract Aims In desert ecosystems, water is a restricting factor for plant growth and vegetation dynamics. The relatively stable water source from deep soil profile or groundwater is important for plant survival during drought. Understanding water use strategy of endangered species, in desert ecosystem is essential for their conservation and restoration such as Ammopiptanthus mongolicus on the Mongolian Plateau. Methods The stable isotope method of δD and δ 18O was used to examine the main water sources of A. mongolicus and two companion shrubs, e.g. Artemisia ordosica and Artemisia xerophytica. The contribution of different water sources to each species was calculated by IsoSource model. Leaf δ 13C was used to compare long-term water use efficiency of three shrubs. Soil moisture and root distribution of three shrubs was measured to explain plant water use strategy. Important Findings The results showed that A. mongolicus relied on groundwater and 150–200 cm deep soil water, with the former contributing to almost half of its total water source. Artemisia ordosica mainly used 150–200 cm deep soil water, but also used shallow soil water within 100 cm in summer and autumn. Artemisia xerophytica mainly used 150–200 cm deep soil water and groundwater, with the latter contributing to about 30%–60% of its total water source. The three shrubs had dimorphic or deep root systems, which are in accord with their water sources. The WUE in the evergreen shrub A. mongolicus was higher than in two deciduous Artemisia shrubs, which may be an adaptive advantage in desert ecosystem. Therefore, groundwater is an important water source for the endangered shrub A. mongolicus in a drought year on Mongolian Plateau. Ammopiptanthus mongolicus and two Artemisia shrubs competed for deep soil water and groundwater.

Seasonal water use strategy of Cyclobalanopsis glauca in a karst area of southern China

2014 ◽  
Vol 74 (2) ◽  
pp. 1007-1014 ◽  
Author(s):  
Daxing Gu ◽  
Zhongfeng Zhang ◽  
Azim Mallik ◽  
Aiping Zhou ◽  
Ling Mo ◽  
...  
Keyword(s):  
Water Use ◽  
Southern China ◽  
Karst Area ◽  
Water Use Strategy ◽  
Seasonal Water Use ◽  
Cyclobalanopsis Glauca

scholarly journals Contrasting Water Use Strategies of Tamarix ramosissima in Different Habitats in the Northwest of Loess Plateau, China

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2791
Author(s):  
Pengyan Su ◽  
Mingjun Zhang ◽  
Deye Qu ◽  
Jiaxin Wang ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Loess Plateau ◽  
Meteoric Water ◽  
Water Source ◽  
Water Sources ◽  
Tamarix Ramosissima ◽  
Water Line ◽  
Meteoric Water Line ◽  
Utilization Ratio

As a species for ecological restoration in northern China, Tamarix ramosissima plays an important role in river protection, flood control, regional climate regulation, and landscape construction with vegetation. Two sampling sites were selected in the hillside and floodplain habitats along the Lanzhou City, and the xylems of T. ramosissima and potential water sources were collected, respectively. The Bayesian mixture model (MixSIAR) and soil water excess (SW-excess) were applied to analyze the relationship on different water pools and the utilization ratios of T. ramosissima to potential water sources in two habitats. The results showed that the slope and intercept of local meteoric water line (LMWL) in two habitats were smaller compared with the global meteoric water line (GMWL), which indicated the existence of drier climate and strong evaporation in the study area, especially in the hillside habitat. Except for the three months in hillside, the SW-excess of T. ramosissima were negative, which indicated that xylems of T. ramosissima are more depleted in δ2H than the soil water line. In growing seasons, the main water source in hillside habitat was deep soil water (80~150 cm) and the utilization ratio was 63 ± 17% for T. ramosissima, while the main water source in floodplain habitat was shallow soil water (0~30 cm), with a utilization ratio of 42.6 ± 19.2%, and the water sources were different in diverse months. T. ramosissima has a certain adaptation mechanism and water-use strategies in two habitats, and also an altered water uptake pattern in acquiring the more stable water. This study will provide a theoretical basis for plant water management in ecological environment protection in the Loess Plateau.

scholarly journals Reforestation Impacted Soil Heavy Metal Fractionation and Related Risk Assessment in the Karst Area, Southwest China

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 891
Author(s):  
Qian Zhang ◽  
Guilin Han ◽  
Xingliang Xu
Keyword(s):  
Heavy Metals ◽  
Risk Assessment ◽  
Ecological Risk ◽  
Southwest China ◽  
Risk Index ◽  
Contamination Factor ◽  
Karst Area ◽  
Risk Assessment Code ◽  
Bcr Sequential Extraction ◽  
Soil Heavy Metals

Human agricultural activities have resulted in widespread land degradation and soil contamination in the karst areas. However, the effects of reforestation after agricultural abandonment on the mobility risks and contamination of heavy metals have been rarely reported. In the present study, six soil profiles were selected from cropland and abandoned cropland with reforestation in the Puding karst regions of Southwest China. The Community Bureau of Reference (BCR) sequential extraction method was used to evaluate the compositions of different chemical fractions of soil heavy metals, including Fe, Mn, Cr, Zn, Ni, and Cd. The total contents of Cr, Ni, Zn, Cd, and Mn in the croplands were significantly higher than those in the abandoned croplands. For all soils, Cr, Ni, Zn, and Fe were mainly concentrated in the residual fractions (>85%), whereas Mn and Cd were mostly observed in the non-residual fractions (>65%). The non-residual fractions of Cd, Cr, Ni, and Zn in the croplands were higher than those in the abandoned croplands. These results indicated that the content and mobility of soil heavy metals decreased after reforestation. The individual contamination factor (ICF) and risk assessment code (RAC) showed that Cd contributed to considerable contamination of karst soils. The global contamination factor (GCF) and potential ecological risk index (RI) suggested low contamination and ecological risk of the investigated heavy metals in the croplands, moreover they can be further reduced after reforestation.

scholarly journals Intensified Interspecific Competition for Water after Afforestation with Robinia pseudoacacia into a Native Shrubland in the Taihang Mountains, Northern China

2021 ◽  
Vol 13 (2) ◽  
pp. 807
Author(s):  
Wanrui Zhu ◽  
Wenhua Li ◽  
Peili Shi ◽  
Jiansheng Cao ◽  
Ning Zong ◽  
...  
Keyword(s):  
Soil Water ◽  
Introduced Species ◽  
Water Use ◽  
Rainy Season ◽  
Robinia Pseudoacacia ◽  
Water Source ◽  
Total Water ◽  
Mountainous Areas ◽  
Water Competition ◽  
Seasonal Water Use

Understanding how soil water source is used spatiotemporally by tree species and if native species can successfully coexist with introduced species is crucial for selecting species for afforestation. In the rocky mountainous areas of the Taihang Mountains, alien Robinia pseudoacacia L. has been widely afforested into the native shrublands dominated by Ziziphus jujuba Mill var. spinosa and Vitex negundo L. var. heterophylla to improve forest coverage and soil nutrients. However, little is known about the water relation among species, especially seasonal water use sources in different microsites. We selected the soil and plant xylem samples of two opposite microtopographic sites (ridge and valley) monthly in the growth season to analyze isotope composition. The proportions of water sources were quantified by the MixSIAR model and compared pairwise between species, microsites and seasons. We found that deep subsoil water at a depth of 40–50 cm contributed up to 50% of the total water uptake for R. pseudoacacia and Z. jujuba in the growing season, indicating that they stably used deeper soil water and had intense water competition. However, V. negundo had a more flexible water use strategy, which derived more than 50% of the total water uptake from the soil layer of 0–10 cm in the rainy season, but majorly captured soil water at a depth of 30–50 cm in the dry season. Therefore, high niche overlaps were shown in V. negundo with the other two species in the dry season, but niche segregation was seen in the rainy season. The microtopographic sites did not shift the seasonal dynamic of the water source use patterns of the three studied species, but the water use niche overlap was higher in the valley than in the ridge. Taken together, the introduced species R. pseudoacacia intensified water competition with the native semi-arbor species Z. jujuba, but it could commonly coexist with the native shrub species V. negundo. Therefore, our study on seasonal water use sources in different microsites provides insight into species interaction and site selection for R. pseudoacacia afforestation in the native shrub community in rocky mountainous areas. It is better to plant R. pseudoacacia in the shrubland in the valley so as to avoid intense water competition and control soil erosion.

scholarly journals Determination of virtual water content of rice and spatial characteristics analysis in China

2014 ◽  
Vol 18 (6) ◽  
pp. 2103-2111 ◽  
Author(s):  
L. J. Zhang ◽  
X. A. Yin ◽  
Y. Zhi ◽  
Z. F. Yang
Keyword(s):  
Water Content ◽  
Water Use ◽  
Southwest China ◽  
Virtual Water ◽  
Northwest China ◽  
Green Water ◽  
Blue Water ◽  
Grey Water ◽  
Spatial Characteristics ◽  
Water Values

Abstract. China is a water-stressed country, and agriculture consumes the bulk of its water resources. Assessing the virtual water content (VWC) of crops is one important way to develop efficient water management measures to alleviate water resource conflicts among different sectors. In this research, the VWC of rice, a major crop in China, is taken as the research object. China covers a vast land area, and the VWC of rice varies widely between different regions. The VWC of rice in China is assessed and the spatial characteristics are also analysed. The total VWC is the total volume of freshwater both consumed and affected by pollution during the crop production process, including both direct and indirect water use. Prior calculation frameworks of the VWC of crops did not contain all of the virtual water content of crops. In addition to the calculation of green, blue and grey water – the direct water in VWC – the indirect water use of rice was also calculated, using an input–output model. The percentages of direct green, blue, grey and indirect water in the total VWC of rice in China were found to be 43.8, 28.2, 27.6, and 0.4%. The total VWC of rice generally showed a roughly three-tiered distribution, and decreased from southeast to northwest. The higher values of direct green water usage were mainly concentrated in Southeast and Southwest China, while the values were relatively low in Northwest China and Inner Mongolia. The higher direct blue water values were mainly concentrated in the eastern and southern coastal regions and Northwest China, and low values were mainly concentrated in Southwest China. Grey water values were relatively high in Shanxi and Guangxi provinces and low in Northeast and Northwest China. The regions with high values for indirect water were randomly distributed but the regions with low values were mainly concentrated in Northwest and Southwest China. For the regions with relatively high total VWC the high values of blue water made the largest contribution, although for the country as a whole the direct green water is the most important contributor.

scholarly journals Impact of different fertilizers on the carbonate weathering in a typical karst area, Southwest China: a field column experiment

2016 ◽  
Author(s):  
Chao Song ◽  
Changli Liu ◽  
Guilin Han
Keyword(s):  
Southwest China ◽  
Column Experiment ◽  
Phosphate Fertilizer ◽  
Global Scale ◽  
Karst Area ◽  
Carbonate Weathering ◽  
Nitrogenous Fertilizer ◽  
Co2 Consumption ◽  
Common Ion ◽  
Calcium Magnesium

Abstract. Carbonate weathering, as a significant vector for the movement of carbon both between and within ecosystems, are strongly influenced by anthropogenic perturbations such as agricultural fertilization. Different fertilizer may exert a different impact on carbonate weathering, but their differences are not still well-known so far. In this study, a field column experiment was employed to explore the responses of carbonate weathering to different fertilizer addition. The eleven different treatments with three replicates including control, NH4NO3, NH4HCO3, NaNO3, NH4Cl, (NH4)2CO3, Ca3(PO4)2, (NH4)3PO4, fused calcium-magnesium phosphate fertilizer (Ca-Mg-P), Urea and K2CO3 were established in this column experiment, where limestone and dolostone tablets were buried at the bottom of each to determine the weathering amount and ratio of carbonate in soil. The result showed that the addition of urea, NH4NO3, NH4HCO3, NH4Cl and (NH4)2CO3 distinctly increased carbonate weathering, which was attributed to the nitrification of NH4+, and the addition of Ca3(PO4)2, Ca-Mg-P and K2CO3 induced carbonate precipitation due to common ion effect. Whereas the (NH4)3PO4 and NaNO3 addition did not impact significantly on carbonate weathering. The results of NaNO3 treatment seem to be raising a new question: the little impact of nitrate on carbonate weathering may result in the overestimation of impact of N-fertilizer on CO2 consumption by carbonate weathering at the regional/global scale if the effect of NO3 and NH4 are not distinguished. Moreover, in order to avoid misunderstanding more or less, the statement that nitrogenous fertilizer can aid carbonate weathering should be replaced by ammonium fertilizer.

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