scholarly journals Legacy Effects of Nitrogen Deposition and Increased Precipitation on Plant Productivity in a Semi-Arid Grassland

Author(s):  
Ya-ni Meng ◽  
Tianpeng Li ◽  
Heyong Liu ◽  
Shao-peng Li ◽  
Zhuwen Xu ◽  
...  

Abstract Nitrogen (N) deposition and increased precipitation induced by anthropogenic activities were widely reported to promote plant productivity in terrestrial ecosystems. However, few studies have explored the effects of historical resource supplement on plant communities although N deposition was predicted to decrease in the near future and the directional change of precipitation would shift among years. Here, we examined the legacy effects of N deposition and increased precipitation on plant productivity in a semi-arid steppe after cessation of a 13-year N and water addition experiment. We found historical N and water addition generally had positive effects on plant productivity even after the treatments were ceased. However, such legacy effects showed strong inter-annual variation, and the positive effect of N and water addition on productivity were stronger in a wet year (i.e., 2019) than an extremely drought year (i.e., 2018). Although N and water availability decreased rapidly, the independently positive effects of historical N and water input persisted after 2 years of cessation largely due to the stable community composition. The increased plant stature of dominant functional groups largely contributed to the increased current productivity after the historical N and water addition. Together, these findings will facilitate the projection of the primary productivity and carbon cycling under the scenarios of predicted reduce in N deposition and changeable precipitation.

2017 ◽  
Vol 106 (3) ◽  
pp. 991-1000 ◽  
Author(s):  
Xian Yang ◽  
Zhongling Yang ◽  
Jiaqi Tan ◽  
Guoyong Li ◽  
Shiqiang Wan ◽  
...  

2016 ◽  
Vol 24 (2) ◽  
pp. 132-143 ◽  
Author(s):  
Zhenzhu Xu ◽  
Yanling Jiang ◽  
Guangsheng Zhou

The nitrogen (N) cycle and N balance have primarily been modified by anthropogenic activities and environmental changes at various scales, including biological individual, ecosystem, local landscape, continental region, and global. These modifications have drastically affected the structures and functions of natural and agricultural ecosystems in terrestrial and aquatic areas. In this manuscript, we first present a modified view of the global N cycle that includes N transport, conversion, and exchange processes. Second, several crucial issues concerning N balance, including N deposition and excessive addition and the dynamics of N and other nutrients, are reviewed. Third, the effects of climate change factors, including water status, warming, and elevated CO2 concentrations, on N balance and the N cycle and their interactions within and with other environmental factors are outlined. Finally, intervention strategies for improving N balance and N cycling to address rapid continual climatic change and socio-economic development are presented and discussed. It is highlighted that the altered N balance and N cycle between the geosphere, biosphere, and atmosphere have produced the profoundly critical challenge of maintaining N levels within an appropriate range, which should be considered by relevant people and sectors, including researchers, managers, and policy makers from ecological, environmental, and sustainable development sectors.


2018 ◽  
Vol 21 (2) ◽  
pp. 229-239 ◽  
Author(s):  
Qing Chen ◽  
Zhong-Liang Wang ◽  
Chris B. Zou ◽  
Yonghui Fan ◽  
Klaus Dittert ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abdur Rahman ◽  
N. C. Mondal ◽  
K. K. Tiwari

AbstractAn increased nitrate (NO3−) concentration in groundwater has been a rising issue on a global scale in recent years. Different consumption mechanisms clearly illustrate the adverse effects on human health. The goal of this present study is to assess the natural and anthropogenic NO3− concentrations in groundwater in a semi arid area of Rajasthan and its related risks to human health in the different groups of ages such as children, males, and females. We have found that most of the samples (n = 90) were influenced by anthropogenic activities. The background level of NO3− had been estimated as 7.2 mg/L using a probabilistic approach. About 93% of nitrate samples exceeded the background limit, while 28% of the samples were beyond the permissible limit of 45 mg/L as per the BIS limits. The results show that the oral exposure of nitrate was very high as compare to dermal contact. With regard to the non-carcinogenic health risk, the total Hazard Index (HITotal) values of groundwater nitrate were an average of 0.895 for males, 1.058 for females, and 1.214 for children. The nitrate health risk assessment shows that about 38%, 46%, and 49% of the samples constitute the non-carcinogenic health risk to males, females, and children, respectively. Children were found to be more prone to health risks due to the potential exposure to groundwater nitrate.


2020 ◽  
Author(s):  
Tongrui Zhang ◽  
Frank Yonghong Li ◽  
Hao Wang ◽  
Lin Wu ◽  
Chunjun Shi ◽  
...  

Abstract Aims Nutrient resorption is a key plant nutrient conservation strategy, and its response to environmental and management changes is linked to nutrient cycling and production of ecosystems. Defoliation is a major pathway of mowing affecting plant nutrient resorption and production in grasslands, while the effect of defoliation timing has not been unexplored. The aim of this study was to examine the effect of defoliation timing on plant nutrient resorption and production in a steppe ecosystem. Methods We conducted a field experiment in a semi-arid steppe of Inner Mongolia including four treatments: early defoliation, peak defoliation, late defoliation and non-defoliation. We measured plant nitrogen (N) and phosphorus (P) resorption at species and community levels, and quantified plant N and P fluxes in resorption, litter return and hay output. Plant production in the mowing system was assessed by hay production and quality. Important Findings Peak and late defoliation, but not early defoliation, reduced plant community N and P resorption proficiency (RP); and late defoliation reduced N resorption efficiency (RE) but not P resorption efficiency. Peak and late defoliation, but not early defoliation, reduced plant nutrient resorption flux and litter nutrient return flux. Defoliation timing did not alter root nutrient accumulation as nutrient uptake from soil likely compensated the deficit of nutrient resorption. Peak defoliation had the highest hay production and quality, while early defoliation had the lowest. Our results provide new insights into the nutrient cycling in mowing grassland, and imply that the mowing timing can be used as a tool to mediate the balance between conservation and production of steppes, and the early mowing before plant peak biomass period is recommended for conservation of the steppes while keeping sustainable pastoral production.


2021 ◽  
Vol 304-305 ◽  
pp. 108434
Author(s):  
Yujie Shi ◽  
Junfeng Wang ◽  
Ya'nan Li ◽  
Jinwei Zhang ◽  
Yunna Ao ◽  
...  
Keyword(s):  

Pedobiologia ◽  
2021 ◽  
Vol 85-86 ◽  
pp. 150711
Author(s):  
Jianwei Cheng ◽  
Frank Yonghong Li ◽  
Xinmin Liu ◽  
Xinyu Wang ◽  
Dong Zhao ◽  
...  

2010 ◽  
Vol 24 (18) ◽  
pp. 2507-2519 ◽  
Author(s):  
Y. Zhao ◽  
S. Peth ◽  
X. Y. Wang ◽  
H. Lin ◽  
R. Horn

2021 ◽  
Author(s):  
Abdur Rahman ◽  
N.C. Mondal ◽  
K.K. Tiwari

Abstract An increased nitrate (NO3-) concentration in groundwater has been a rising issue on a global scale in recent years. Through different consumption mechanisms, it clearly illustrates the adverse effects on human health. The goal of this present study is to assess the natural and anthropogenic NO3- concentration in groundwater and its related risks to human health in the different groups of ages such as children, males, and females. Groundwater samples (n=101) were obtained and analysed for their physicochemical components, along with the nitrate concentration in a semi-arid area of Rajasthan. The results show that most of the samples were influenced by anthropogenic activities. The background and anthropogenic levels had been estimated and marked as 7.2 mg/L and 13.3 mg/L for the background and anthropogenic concentrations, respectively. About 83% of nitrate samples were exceeded the background limit, while 28% of the samples were beyond the permissible limit of 45 mg/L as stated by the Bureau of Indian Standards (BIS). Nitrate health risks were also measured by oral intake and dermal contact sources for the residents in this area. The oral exposure of nitrate was very high as compare to dermal contact. With regards to the non-carcinogenic health risk, the total Heath Index (HITotal) values of groundwater nitrate in the study area varied from 0.045 to 3.153 with an average of 0.964 for males, 0.053 to 3.726 with an average of 1.139 for females, and 0.061 to 4.278 with an average of 1.308 for children. The nitrate health risk assessment shows that about 38%, 46%, and 49% of groundwater samples constitute the non-carcinogenic health risk to males, females, and children, respectively.


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