期刊,Ecological engineering 2022年181卷期_国家学术搜索

期刊信息/Journal information

Ecological engineering

Elsevier Science B.V.

主办单位：Elsevier Science B.V.

国际刊号：0925-8574

Ecological engineering/Journal Ecological engineeringSCIISTPEI

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Erosion resistance of vegetation-covered soils: Impact of different grazing conditions in salt marshes and analysis of soil-vegetation interactions by the novel DiCoastar method

Kosmalla, ViktoriaKeimer, KaraSchuerenkamp, DavidLojek, Oliver...

14页

查看更多>>摘要：The analysis of soil-vegetation interactions in erosion processes along coastlines requires accurate information about various factors influencing the upper soil layer. Yet, some of these parameters were previously determined by simplified, often hand held devices, and these were often biased by the skill and experience of the operator. This study thus investigates the erosion resistance of salt marsh soils influenced by grazing conditions for providing crucial findings for policy making and land management decisions; to that end, we present and use a novel shear resistance measuring device. This measuring device, called DiCoastar, was developed with a controllable step-motor and now allows us for the first time the determination of time histories of shear resistance by repeatable in-situ measurements, gaining information about the interaction between soil and root systems. A field study was conducted in salt marshes at Ca center dot ciliengroden and at So center dot nke-Nissen-Koog, both foreland salt marshes at the German North Sea coast. The two sites had been chosen due to their difference in grazing intensities, featuring semi-natural/ungrazed, moderately grazed and intensively grazed salt marshes. This was to enable the investigation of influences on soil shear strength and vegetation cover. Measurements of shear resistance were conducted with the DiCoastar in the chosen sites in the vicinity of the dike toes; it is found that the new device now provides consistent and repeatable measurements, irrespective of the operator, and only based on the pre-set control parameters. Results of the field study demonstrate that a marked increase of shear strength is only found in sites with high intensity grazing, but this is accompanied by a strong reduction in the vegetation cover and plant diversity, especially with regard to the vertical density distribution of the vegetation cover. As the reduction in vegetation cover leads to reduced wave attenuation over salt marshes and increased flow velocities, an increased shear stress on the soil surface, which potentially exceeds the increased shear strength, is expected. Based on this, the results obtained lead to the assumption that an increase in the erosion potential of these foreland marshes by high grazing pressure is more likely as well as a reduction in dike stability.

原文链接:

NSTL
Elsevier

The corrosiveness of artificial soil may lead to the collapse of eco-engineering projects on rock slopes in mining areas

Li, WenyaQiao, OumengChen, ZhangHan, Ying...

13页

查看更多>>摘要：Large-scale highways, railways and mining infrastructures have created a large amount of denuded steep rocky slopes, causing ecological and environmental problems. Artificial soil and metal mesh are the key components for eco-engineering on rocky slopes to restore slope ecosystems. However, artificial soil significantly differs from natural soil in composition and electrochemistry, which may accelerate the corrosion of metal mesh. In this study, three eco-engineering projects for rocky slope protection in an abandoned opencast quarry were chosen to conduct our experiments, in which ecological restoration measures have been conducted for 3 years, 6 years, and 10 years and corresponding soil samples of artificial soil and metal mesh were collected, and the electrochemical properties of artificial soil and the life span of metal mesh at different slope conditions were examined. The results showed that the electrochemistry of artificial soil was significantly different from that of natural soil since their soil compositions were extremely different. The corrosion of metal mesh at the lower slope position was the strongest and the soil corrosivity of artificial soil was stronger than that of natural soil. Moreover, artificial soil had low resistivity and a moderate degree of stray current, with the oxidation-reduction potential being oxidative. The results from PCA analysis further confirmed the above-mentioned results. The results in this study suggested that metal mesh rocky slopes should be closely monitored around the 10-year mark after its application, especially at the lower slope position, to prevent soil collapse and ecosystem degradation. Overall, our study has provided new insights into the eco-engineering of rocky slopes and implications on how to avoid environmental risks induced by metal mesh failures.

原文链接:

NSTL
Elsevier

Assessment of carbon sequestration potential of tropical tree species for urban forestry in India

Mishra, ShrutiBehera, Soumit K.Sahu, NayanManika, N....

8页

查看更多>>摘要：Urban, peri urban and patch forests play a critical role in climate change mitigation through increased carbon storage and for that, it is imperative to assess the species response in an eco-region to recommend a potentially higher carbon sequestering species. In urban settings, green spaces, in particular, trees play a vital role in pre-serving biodiversity, reducing the impact of urban heat islands, enhancing the hydrological cycle, as well as sequestering carbon. When introduced in urban greening projects, native species provide better ecosystem ser-vices, conserve and maintain biodiversity more sustainably than exotic species. However, fewer efforts are being made to evaluate the carbon sequestration potential of native tropical tree species in urban greening initiatives. The present study aims to assess the biomass production and carboxylation efficiency of three native tropical tree species to identify the high carbon sequestering species, which will enhance the carbon stocks under urban green spaces. Above ground biomass, carbon stock and physiological performance of three native tropical tree species (Tectona grandis, Mallotus nudiflorus and Syzygium cumini) were measured in Botanical Garden of CSIR-National Botanical Research Institute, Lucknow for eight years old tree stands. Above ground biomass (AGB, Mg/ha) was measured using a non-destructive method by applying allometric equations. Tree height, diameter at breast height (DBH) and leaf area index (LAI) was maximum in T. grandis stand (10.43 m, 29.21 cm, 1.95, respectively). Maximum AGB (71.94 Mg/ha) and carbon stock (25.54 Mg/ha) was observed in T. grandis plantations among the three tree stands. T. grandis stand also had maximum litter fall (5.82 Mg/ha). Highest diurnal photosynthesis rate, water use efficiency and stomatal conductance were also observed in T. grandis stand. However, maximum photosynthetic rate was observed in Mallotus nudiflorus. One way ANOVA revealed significant differences (p < 0.001) in AGB, carbon stock and physiological parameters among the three species. Pearson's Correlation matrix established the positive relationship between growth performance and physiological traits of species with their capacity to sequester carbon. T. grandis can be promoted for urban greening projects for achieving carbon sequestration targets with short time span, however plantation of mixed native species will provide better de-livery of all ecosystem services in sustainable mode. Results from the present study shed light on the patterns of carbon sequestration by these species, which in turn will help in the decision-making process for sustainable urban greening. Further, more tropical species can be assessed for their biomass and carbon capture capacities to determine the best species matrix for plantations to enhance carbon storage and develop climate resilient greenbelt under urban landscape forestry programs.

原文链接:

NSTL
Elsevier

Effect identification and analysis of tailwater on sediment denitrifier abundances and denitrification in an urban wetland

Xu, KeWu, HaopingCai, YanpengLi, Bo...

11页

查看更多>>摘要：Excessive anthropogenic nitrogen discharges have led to increasing nitrogen in aquatic systems, resulting in eutrophication problems. To address this problem, urban wetlands are used to remove nitrogen from wastewater treatment plant tailwater because of their efficient nitrogen removal capabilities. At the same time, high-nitrogen tailwater can exert numerous impacts on the sediment denitrifier communities and denitrification of urban wetlands, and it is necessary to clarify this impact. In this research, we investigated denitrifier (nirK-, nirS- and nosZ-denitrifier) abundances and potential denitrification rate of 30 sediment samples from two urban wetland rivers in Haizhu National Wetland Park (China). One river called experimental river (ER) receives tailwater from a wastewater treatment plant, and the other called control river (CR) is unaffected by the tailwater. Moreover, we also determined the environmental variables to distinguish their relative effects on the variance of denitrifier abundances and denitrification rate in the two rivers. The results showed that the water quality was significantly different between ER and CR, while sediment property was not significant (p < 0.05). And it is unable to distinguish which has the greater denitrification rate between ER and CR. The redundancy analysis and path analysis indicated that riverine nutrient concentrations (e.g., ambient carbon and nitrogen) and physicochemical parameters (e.g., ambient temperature, dissolved oxygen and pH) were important determinants for denitrifier abundances and denitrification in ER and in CR, respectively. Furthermore, denitrifier abundances had an insignificant impact on denitrification in ER, but a considerable impact on denitrification in CR. The findings of this research can help to further understand how the tailwater affects sediment denitrifier communities and denitrification in urban wetland rivers, and to make better use of urban wetlands as a natural purification method.

原文链接:

NSTL
Elsevier