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In recent decades, the biodiversity of freshwater environments has decreased sharply due to anthropogenic disturbances that damaged ecosystem structures and functions. Habitat restoration has emerged as an important method to mitigate the degradation of river ecosystems. Although in many cases a post-project monitoring has been promoted to access the restoration progress, it is still unclear how aquatic community changes following river habitat restoration in China. Macroinvertebrate communities intermediately positioned within ecosystem food webs play a key role in ecosystem processes within river ecosystem, driving energy flow and nutrient cycling. Here, benthic macroinvertebrates are used as bio-indicators to assess the ecosystem health of degraded urban rivers, restored urban rivers, and undisturbed rivers. This study aims to determine (i) how habitat restoration influences macroinvertebrates diversity and how this compared to degraded and reference conditions; (ii) how did macroinvertebrate community compositions differ in restored, degraded, and reference sites; and (iii) the environmental factors shaping macroinvertebrate communities. Habitat restoration significantly increased the diversity and richness of macroinvertebrate community and intolerant species and shifted the community composition towards reference status. Habitat characteristics and water chemistry, including substrate diversity, water velocity, and both nutrients (TN) and organic pollutants (TOC), appeared to shape the turnover of these communities. Habitat characteristics contributed to most of the variation of the entire macroinvertebrate community. Our research indicates that habitat restoration is an efficient approach to restore the aquatic community and hence improve river ecosystem health for freshwater conservation and sustainable management in Zhejiang province. This study strengthens our understanding of the changes of macroinvertebrate community after habitat restoration and important controlling variables that attribute to these changes, which provides an important guidance for future freshwater management.
Qiaoyan Lin; Yixin Zhang; Rob Marrs; Raju Sekar; Naicheng Wu; Xin Luo. The effect of habitat restoration on macroinvertebrate communities in Shaoxi rivers, China. Environmental Science and Pollution Research 2021, 1 -13.
AMA StyleQiaoyan Lin, Yixin Zhang, Rob Marrs, Raju Sekar, Naicheng Wu, Xin Luo. The effect of habitat restoration on macroinvertebrate communities in Shaoxi rivers, China. Environmental Science and Pollution Research. 2021; ():1-13.
Chicago/Turabian StyleQiaoyan Lin; Yixin Zhang; Rob Marrs; Raju Sekar; Naicheng Wu; Xin Luo. 2021. "The effect of habitat restoration on macroinvertebrate communities in Shaoxi rivers, China." Environmental Science and Pollution Research , no. : 1-13.
Conventional centralized drainage systems are not only expensive, but their mono-function to discharge surface runoff also imposes a negative effect on the local environment while compounding regional watershed dysfunction. Sponge city initiative promoted by the Chinese government is a broader sustainable stormwater management concept that aims to use more nature-based solutions, reduce urban flooding and runoff pollution, and increase rainwater resource usage. As part of decentralized and cost-effective solutions, green infrastructure (GI) is considered in the Sponge City development across China. Although GI has been successfully implemented through a range of small-scale projects, the GI approach has not been adopted widely, which is because the GI approach is micro-scale techniques and the local government is skeptical about the efficiency of GI to mitigate stormwater on a large scale. Although some researchers have explored the effectiveness of GI to reduce stormwater in small catchments, only a limited number of studies have examined the efficacy of GI at the watershed scale. Moreover, there is lack of a system and cross-scale approach in sponge city practices. To understand the effect of GI on the watershed scale, this paper proposed a comprehensive approach using ArcGIS and SWMM platforms to study the spatial configuration and implementation of multi-scale stormwater management. The approach is to apply a three-step sequence of catchments, sub-catchments, and micro-catchments for the urban watershed through designing interconnected network of landscape infrastructure (LI) systems. The design scenarios and performance of LI system-based approach with different combinations and sizes of the sponge facilities were analyzed based on the Old Town district of Hefei City, China. This study demonstrated that the inherent capacity of the landscape can act as the conduit for multifunctional, flexible, localized, and synergistic infrastructural systems, in which cross watershed holds promise to decrease both runoff volumes and peak flows while providing ecosystem services, such as enhancing neighborhood aesthetics and cultural/health benefits through shared public green spaces. Thus, Sponge City Development here as green concepts and techniques for nature-based solutions enhances the function and value of green infrastructure with benefits of ecological, economic and social significances, which presents a new approach for sustainable city making.
Jun Zhai; Jing Ren; Miao Xi; Xiaonan Tang; Yixin Zhang. Multiscale watershed landscape infrastructure: Integrated system design for sponge city development. Urban Forestry & Urban Greening 2021, 60, 127060 .
AMA StyleJun Zhai, Jing Ren, Miao Xi, Xiaonan Tang, Yixin Zhang. Multiscale watershed landscape infrastructure: Integrated system design for sponge city development. Urban Forestry & Urban Greening. 2021; 60 ():127060.
Chicago/Turabian StyleJun Zhai; Jing Ren; Miao Xi; Xiaonan Tang; Yixin Zhang. 2021. "Multiscale watershed landscape infrastructure: Integrated system design for sponge city development." Urban Forestry & Urban Greening 60, no. : 127060.
Stormwater management is a key issue in line with global problems of urbanization and climate change. Assessing the effectiveness in managing stormwater is crucial to maintain urban resilience to flooding risk. A method based on a stormwater management model (SWMM) was developed for assessing the control of stormwater runoff volume and the percentage removal of suspended solids by implementing a Sponge City strategy. An interdisciplinary approach was adopted incorporating Low Impact Development (LID) with urban green infrastructure and grey infrastructure paradigms in a typical old residential community in Suzhou, China. Sponge facilities for reducing stormwater runoff included bio-retention cells, permeable pavements, grassed pitches, and stormwater gardens. The simulation results of SWMM show that the stormwater pipe system can meet the management standard for storms with a five-year recurrence interval. The volume capture ratio of annual runoff was 91%, which is higher than control target of 80%. The suspended solids reduction rate was 56%, which meets the requirement of planning indicators. Thus, the proposed method of spongy facilities can be used for renovation planning in old residential areas in China. Implementing spongy facilities with a LID strategy for stormwater management can significantly enhance urban water resilience and improve ecosystem services.
Yixin Zhang; Weihan Zhao; Xue Chen; Changhyun Jun; Jianli Hao; Xiaonan Tang; Jun Zhai. Assessment on the Effectiveness of Urban Stormwater Management. Water 2020, 13, 4 .
AMA StyleYixin Zhang, Weihan Zhao, Xue Chen, Changhyun Jun, Jianli Hao, Xiaonan Tang, Jun Zhai. Assessment on the Effectiveness of Urban Stormwater Management. Water. 2020; 13 (1):4.
Chicago/Turabian StyleYixin Zhang; Weihan Zhao; Xue Chen; Changhyun Jun; Jianli Hao; Xiaonan Tang; Jun Zhai. 2020. "Assessment on the Effectiveness of Urban Stormwater Management." Water 13, no. 1: 4.
Ensuring the provision of essential ecosystem services in systems affected by multiple stressors is a key challenge for theoretical and applied ecology. Trait‐based approaches have increasingly been used in multiple‐stressor research in freshwaters because they potentially provide a powerful method to explore the mechanisms underlying changes in populations and communities. Individual benthic macroinvertebrate traits associated with mobility, life history, morphology, and feeding habits are often used to determine how environmental drivers structure stream communities. However, to date multiple‐stressor research on stream invertebrates has focused more on taxonomic than on functional metrics. We conducted a fully crossed, 4‐factor experiment in 64 stream mesocosms fed by a pristine montane stream (21 days of colonization, 21 days of manipulations) and investigated the effects of nutrient enrichment, flow velocity reduction and sedimentation on invertebrate community, taxon, functional diversity and trait variables after 2 and 3 weeks of stressor exposure. 89% of the community structure metrics, 59% of the common taxa, 50% of functional diversity metrics, and 79% of functional traits responded to at least one stressor each. Deposited fine sediment and flow velocity reduction had the strongest impacts, affecting invertebrate abundances and diversity, and their effects translated into a reduction of functional redundancy. Stressor effects often varied between sampling occasions, further complicating the prediction of multiple‐stressor effects on communities. Overall, our study suggests that future research combining community, trait, and functional diversity assessments can improve our understanding of multiple‐stressor effects and their interactions in running waters.
Noel P. D. Juvigny‐Khenafou; Jeremy J. Piggott; David Atkinson; Yixin Zhang; Samuel J. Macaulay; Naicheng Wu; Christoph D. Matthaei. Impacts of multiple anthropogenic stressors on stream macroinvertebrate community composition and functional diversity. Ecology and Evolution 2020, 11, 133 -152.
AMA StyleNoel P. D. Juvigny‐Khenafou, Jeremy J. Piggott, David Atkinson, Yixin Zhang, Samuel J. Macaulay, Naicheng Wu, Christoph D. Matthaei. Impacts of multiple anthropogenic stressors on stream macroinvertebrate community composition and functional diversity. Ecology and Evolution. 2020; 11 (1):133-152.
Chicago/Turabian StyleNoel P. D. Juvigny‐Khenafou; Jeremy J. Piggott; David Atkinson; Yixin Zhang; Samuel J. Macaulay; Naicheng Wu; Christoph D. Matthaei. 2020. "Impacts of multiple anthropogenic stressors on stream macroinvertebrate community composition and functional diversity." Ecology and Evolution 11, no. 1: 133-152.
Stormwater management is a key urban issue in the world, in line with the global issues of urban sprawl and climate change. It is urgent to investigate the effectiveness in managing stormwater with different strategies for maintain urban resilience. A method based on a storm water management model (SWMM) was developed for assessing the control of stormwater runoff volume and the percentage removal of suspended solids by implementing a Sponge City strategy. An interdisciplinary approach was adopted incorporating Low Impact Development (LID) with urban Green Infrastructure and Gray Infrastructure paradigms in a typical old residential community in Suzhou, China. Four types of sponge facilities for reducing stormwater runoff were bio-retention cells, permeable pavements, grassed pitches, and stormwater gardens. The simulation results indicate that the stormwater pipe system can meet the management standard for storms with a five-year recurrence interval. The volume capture ratio of annual runoff is 91% and the reduction rate of suspended solids is 56%. This study demonstrates that Sponge City strategy is an effective approach for managing stormwater, particularly in old and densely populated urban areas. Implementing spongy facilities with a LID strategy for stormwater management can significantly enhance urban water resilience and increase ecosystem services.
Yixin Zhang; Weihan Zhao; Xue Chen; Changhyun Jun; Jianli Hao; Xiaonan Tang; Jun Zhai. Assessment on the Effectiveness of Urban Stormwater Management. 2020, 1 .
AMA StyleYixin Zhang, Weihan Zhao, Xue Chen, Changhyun Jun, Jianli Hao, Xiaonan Tang, Jun Zhai. Assessment on the Effectiveness of Urban Stormwater Management. . 2020; ():1.
Chicago/Turabian StyleYixin Zhang; Weihan Zhao; Xue Chen; Changhyun Jun; Jianli Hao; Xiaonan Tang; Jun Zhai. 2020. "Assessment on the Effectiveness of Urban Stormwater Management." , no. : 1.
Freshwater ecosystems face many simultaneous pressures due to human activities. Consequently, there has been a rapid loss of freshwater biodiversity and an increase in biomonitoring programs. Our study assessed the potential of benthic stream bacterial communities as indicators of multiple‐stressor impacts associated with urbanisation and agricultural intensification. We conducted a fully crossed 4‐factor experiment in 64 flow‐through mesocosms fed by a pristine montane stream (21 days of colonisation, 21 days of manipulations) and investigated the effects of nutrient enrichment, flow velocity reduction and added fine sediment after 2 and 3 weeks of stressor exposure. We used high‐throughput sequencing and metabarcoding techniques (16S rRNA genes), as well as curated biological databases (METAGENassit, MetaCyc), to identify changes in bacterial relative abundances and predicted metabolic functional profile. Sediment addition and flow velocity reduction were the most pervasive stressors. Both increased α‐diversity and had strong, taxon‐specific effects on community composition and predicted functions. Sediment and flow velocity also interacted frequently, with 88% of all bacterial response variables showing 2‐way interactions and 33% showing 3‐way interactions including nutrient enrichment. Changes in relative abundances of common taxa were associated with shifts in dominant predicted functions, which can be extrapolated to underlaying stream‐wide mechanisms such as carbon use and bacterial energy production pathways. Observed changes were largely stable over time and occurred after just 2 weeks of exposure, demonstrating that bacterial communities can be well‐suited for early detection of multiple stressors. Overall, added sediment and reduced flow velocity impacted both bacterial community structure and predicted function more than nutrient enrichment. In future research and stream management, a holistic approach to studying multiple‐stressor impacts should include multiple trophic levels with their functional responses, to enhance our mechanistic understanding of complex stressor effects and promote establishment of more efficient biomonitoring programs.
Noël P. D. Juvigny‐Khenafou; Jeremy J. Piggott; David Atkinson; Yixin Zhang; Naicheng Wu; Christoph D. Matthaei. Fine sediment and flow velocity impact bacterial community and functional profile more than nutrient enrichment. Ecological Applications 2020, 31, e2212 .
AMA StyleNoël P. D. Juvigny‐Khenafou, Jeremy J. Piggott, David Atkinson, Yixin Zhang, Naicheng Wu, Christoph D. Matthaei. Fine sediment and flow velocity impact bacterial community and functional profile more than nutrient enrichment. Ecological Applications. 2020; 31 (1):e2212.
Chicago/Turabian StyleNoël P. D. Juvigny‐Khenafou; Jeremy J. Piggott; David Atkinson; Yixin Zhang; Naicheng Wu; Christoph D. Matthaei. 2020. "Fine sediment and flow velocity impact bacterial community and functional profile more than nutrient enrichment." Ecological Applications 31, no. 1: e2212.
Fungi are an important, yet often, neglected component of the aquatic microflora, and is responsible for primary decomposition and further processing of organic matter. By comparison, the ecological roles of terrestrial fungi have been well-studied, but the diversity and function of fungi that populate aquatic environments remain poorly understood. Here, the impact of urbanization on fungal diversity and community composition in the canal system of Suzhou was assessed by sequencing the internal transcribed spacer 1 (ITS1) region of the rRNA operon. It was amplified from environmental DNA that has been extracted from water samples and pre-deployed decomposing leaves collected from nine sampling locations (high, medium and low urbanization) over two seasons. The fungal diversity and community composition were determined by bioinformatic analysis of the large DNA sequence datasets generated to identify operational taxonomic units (OTUs) for phylogenetic assignment; over 1 million amplicons were sequenced from 36 samples. The alpha-diversity estimates showed high differences in fungal diversity between water and leaf samples, and winter versus summer. Higher numbers of fungal OTUs were identified in both water and leaf samples collected in the summer, and fungal diversity was also generally higher in water than on colonized leaves in both seasons. The fungal community on leaves was usually dominated by Ascomycetes, especially in winter, while water samples contained more diversity at phylum level with Chytridiomycetes often prominent, particularly in summer. At a genus level, a very high relative abundance of Alternaria on leaves was observed in winter at all locations, in contrast to very low abundance of this genus across all water samples. Fungal community composition also varied between sampling locations (i.e., urbanization); in cluster analysis, samples from high urbanization locations formed a distinct cluster, with medium and low urbanization samples clustering together or in some instances, separately. Redundancy analysis shed further light on the relationships between variation in fungal community composition and water physico-chemical properties. Fungal community diversity variation and correlation with different parameters is discussed in detail, but overall, the influence of season outweighed that of urbanization. This study is significant in cataloguing the impact of urbanization on fungal diversity to inform future restoration of urban canal systems on the importance of protecting the natural aquatic fungal flora.
Tianma Yuan; Haihan Zhang; Qiaoli Feng; Xiangyu Wu; Yixin Zhang; Alan McCarthy; Raju Sekar. Changes in Fungal Community Structure in Freshwater Canals across a Gradient of Urbanization. Water 2020, 12, 1917 .
AMA StyleTianma Yuan, Haihan Zhang, Qiaoli Feng, Xiangyu Wu, Yixin Zhang, Alan McCarthy, Raju Sekar. Changes in Fungal Community Structure in Freshwater Canals across a Gradient of Urbanization. Water. 2020; 12 (7):1917.
Chicago/Turabian StyleTianma Yuan; Haihan Zhang; Qiaoli Feng; Xiangyu Wu; Yixin Zhang; Alan McCarthy; Raju Sekar. 2020. "Changes in Fungal Community Structure in Freshwater Canals across a Gradient of Urbanization." Water 12, no. 7: 1917.
Ecological restoration of freshwater ecosystems is now being implemented to mitigate anthropogenic disruption. Most emphasis is placed on assessing physico-chemical and hydromorphological properties to monitor restoration progress. However, less is known about the structural integrity and ecosystem health of aquatic ecosystems. In particular, little is known about how ecosystem function changes following river habitat restoration, especially in China. Leaf litter decomposition can be used as an indicator of stream ecosystem integrity. Therefore, the leaf breakdown rate was measured to assess the ecosystem function of restored rivers. By comparing leaf breakdown rates in urban rivers undergoing habitat restoration with that in degraded urban rivers and rivers in forested areas (i.e., reference conditions), we aimed to determine: (i) how habitat restoration affected leaf litter decomposition? (ii) the relationship between leaf litter decomposition to both environmental (habitat and physico-chemical variables) and biological factors (benthic communities), and (iii) identify the factors that contribute most to the variance in leaf litter breakdown rates. The results demonstrated a significant increase in leaf breakdown rate (120% in summer and 28% in winter) in the restored rivers compared to the degraded rivers. All environmental and biotic factors evaluated contributed synergistically to the differences in leaf litter decomposition among the three river types. The role of macroinvertebrates, mainly shredders, appeared to be particularly important, contributing 52% (summer) and 33% (winter) to the variance in decomposition, followed by habitat characteristics (e.g. substrate diversity, water velocity; 17% in summer, 29% in winter), physico-chemical variables (e.g. nutrient and organic pollutants; 11% in summer, 1% in winter) and biofilm bacteria (0% in summer, 15% in winter). Habitat restoration positively affected the structure and function of the previously degraded streams. Knowledge on controlling variables and their attribution to changes of ecosystem functioning provides guidance to assist the future planning of ecological restoration strategies.
Qiaoyan Lin; Yixin Zhang; Rob Marrs; Raju Sekar; Xin Luo; Naicheng Wu. Evaluating ecosystem functioning following river restoration: the role of hydromorphology, bacteria, and macroinvertebrates. Science of The Total Environment 2020, 743, 140583 .
AMA StyleQiaoyan Lin, Yixin Zhang, Rob Marrs, Raju Sekar, Xin Luo, Naicheng Wu. Evaluating ecosystem functioning following river restoration: the role of hydromorphology, bacteria, and macroinvertebrates. Science of The Total Environment. 2020; 743 ():140583.
Chicago/Turabian StyleQiaoyan Lin; Yixin Zhang; Rob Marrs; Raju Sekar; Xin Luo; Naicheng Wu. 2020. "Evaluating ecosystem functioning following river restoration: the role of hydromorphology, bacteria, and macroinvertebrates." Science of The Total Environment 743, no. : 140583.
Streams and surrounding terrestrial ecosystems are closely linked by numerous resource subsidies including anthropogenic subsidies which are increasingly entering streams due to intensive human activities. Also, streams are threatened by stressors such as glyphosate—the most widely used herbicide worldwide. However, the ecological consequences of anthropogenic subsidies and glyphosate on freshwaters are not fully understood. Here, we deployed leaf litter (Cinnamomum camphora) bags containing neither, either, or both treatments of anthropogenic carrion subsidy (chicken meat) and glyphosate (coated in agar) in four streams, which had different land use (i.e., forest, village, and suburban) in Huangshan, Anhui Province, China. We aimed to investigate the individual and combined effects of anthropogenic carrion subsidy and glyphosate on macroinvertebrates in streams and whether these effects differ with land use change. Macroinvertebrate communities significantly differed among streams: biodiversity index and total taxon richness were highest in village streams and lowest in suburban stream. Overall effects of carrion subsidy and glyphosate on macroinvertebrates were not significant. However, several taxa were affected in one or more streams by the individual or combined effects of carrion subsidy and glyphosate, indicating the importance of local community structure and physical habitats in driving the response of macroinvertebrates to carrion subsidy and glyphosate. Collectively, these results imply that the effects of carrion subsidy and glyphosate on macroinvertebrates are site-specific, and future studies should cover more streams and last longer time to better understand the ecological mechanisms driving such pattern.
Hongyong Xiang; Yixin Zhang; David Atkinson; Raju Sekar. Effects of anthropogenic subsidy and glyphosate on macroinvertebrates in streams. Environmental Science and Pollution Research 2020, 27, 21939 -21952.
AMA StyleHongyong Xiang, Yixin Zhang, David Atkinson, Raju Sekar. Effects of anthropogenic subsidy and glyphosate on macroinvertebrates in streams. Environmental Science and Pollution Research. 2020; 27 (17):21939-21952.
Chicago/Turabian StyleHongyong Xiang; Yixin Zhang; David Atkinson; Raju Sekar. 2020. "Effects of anthropogenic subsidy and glyphosate on macroinvertebrates in streams." Environmental Science and Pollution Research 27, no. 17: 21939-21952.
Microplastic particles are widely distributed in a variety of ecosystems and can be transferred to predators along a food chain after being ingested by prey. However, how microplastic particles affect prey and predator populations is not fully understood. In this study, using the Lotka-Volterra model, we theoretically investigated predator-prey population dynamics in terms of toxicological response intensity (strength to population growth rate) to microplastic particles, and examined the negative effects on prey feeding ability and predator performance due to microplastic particles. Results of numerical simulations indicate the critical properties of the predator-prey system in response to microplastic particles: (i) predators are more vulnerable than prey under exposure to microplastic particles; (ii) the effect of microplastic particles on prey and predator population growths can be negligible when toxicological response intensities of prey and predator are small; (iii) this system is prey dependent for predator functional response, whose stability highly relies on the density of prey; (iv) the reduced feeding capacity of prey and predator induced by microplastic particles does not significantly affect the population dynamics of the predator-prey system. Moreover, our analysis suggests that dynamic Lotka-Volterra models can play a vital role in predicting ecological impacts of microplastic particles on predator-prey population dynamics.
Qi Huang; Yuyang Lin; Qiyin Zhong; Fei Ma; Yixin Zhang. The Impact of Microplastic Particles on Population Dynamics of Predator and Prey: Implication of the Lotka-Volterra Model. Scientific Reports 2020, 10, 1 -10.
AMA StyleQi Huang, Yuyang Lin, Qiyin Zhong, Fei Ma, Yixin Zhang. The Impact of Microplastic Particles on Population Dynamics of Predator and Prey: Implication of the Lotka-Volterra Model. Scientific Reports. 2020; 10 (1):1-10.
Chicago/Turabian StyleQi Huang; Yuyang Lin; Qiyin Zhong; Fei Ma; Yixin Zhang. 2020. "The Impact of Microplastic Particles on Population Dynamics of Predator and Prey: Implication of the Lotka-Volterra Model." Scientific Reports 10, no. 1: 1-10.
Despite the progress made in environmental microbiology techniques and knowledge, the succession and functional changes of the microbial community under multiple stressors are still poorly understood. This is a substantial knowledge gap as microbial communities regulate the biogeochemistry of stream ecosystems. Our study assessed the structural and temporal changes in stream fungal and bacterial communities associated with decomposing leaf litter under a multiple-stressor scenario. We conducted a fully crossed 4-factor experiment in 64 flow-through mesocosms fed by a pristine montane stream (21 days of colonisation, 21 days of manipulations) and investigated the effects of nutrient enrichment, flow velocity reduction and sedimentation after 2 and 3 weeks of stressor exposure. We used high-throughput sequencing and metabarcoding techniques (16S and 18S rRNA genes) to identify changes in microbial community composition. Our results indicate that (1) shifts in relative abundances of the pre-existing terrestrial microbial community, rather than changes in community identity, drove the observed responses to stressors; (2) changes in relative abundances within the microbial community paralleled decomposition rate patterns with time; (3) both fungal and bacterial communities had a certain resistance to stressors, as indicated by relatively minor changes in alpha diversity or multivariate community structure; (4) overall, stressor interactions were more common than stressor main effects when affecting microbial diversity metrics or abundant individual genera; and (5) stressor effects on microbes often changed from 2 weeks to 3 weeks of stressor exposure, with several response patterns being reversed. Our study suggests that future research should focus more on understanding the temporal dynamics of fungal and bacterial communities and how they relate to ecosystem processes to advance our understanding of the mechanisms associated with multiple-stressor interactions.
Noël P.D. Juvigny-Khenafou; Yixin Zhang; Jeremy Piggott; David Atkinson; Christoph D. Matthaei; Sunshine A. Van Bael; Naicheng Wu. Anthropogenic stressors affect fungal more than bacterial communities in decaying leaf litter: A stream mesocosm experiment. Science of The Total Environment 2019, 716, 135053 .
AMA StyleNoël P.D. Juvigny-Khenafou, Yixin Zhang, Jeremy Piggott, David Atkinson, Christoph D. Matthaei, Sunshine A. Van Bael, Naicheng Wu. Anthropogenic stressors affect fungal more than bacterial communities in decaying leaf litter: A stream mesocosm experiment. Science of The Total Environment. 2019; 716 ():135053.
Chicago/Turabian StyleNoël P.D. Juvigny-Khenafou; Yixin Zhang; Jeremy Piggott; David Atkinson; Christoph D. Matthaei; Sunshine A. Van Bael; Naicheng Wu. 2019. "Anthropogenic stressors affect fungal more than bacterial communities in decaying leaf litter: A stream mesocosm experiment." Science of The Total Environment 716, no. : 135053.
The decomposition of organic matter in freshwaters, such as leaf litter, can affect global nutrient (e.g., carbon) cycling. This process can be influenced by fast urbanization through increased water temperature, reduced aquatic diversity and changed leaf litter quality traits. In this study, we performed a mesocosm experiment to explore the individual and combined effects of warming (8°C higher and ambient), the presence versus absence of grazing snails (Parafossarulus striatulus), and intraspecific difference of leaf litter quality (intact versus > 40% area of Liriodendron chinense leaves grazed by terrestrial insects) on litter decomposition in urban streams. Litter decomposition rates ranged from 0.019 d-1 to 0.058 d-1 with an average decomposition rate of 0.032 ± 0.002 d-1. All the three factors had significant effects on litter decomposition rate. Warming and the presence of snails accelerated litter decomposition rates by 60% and 35% respectively. Litter decomposition rates of leaves damaged by terrestrial insects were 5% slower than that of intact leaves, because litter quality of terrestrial insect-damaged leaves was lower (i.e., higher specific leaf weight) than intact leaves. For treatments with snails, warming stimulated microbial and snail mediated litter decomposition rates by 35% and 167%, respectively. All combinations of treatments showed additive effects on litter decomposition except for the interaction between warming and snails which showed positive synergistic effects. In addition, neither temperature nor litter quality affected snail growth rate. These results imply that higher water temperature and the presence of abundant snails in urban streams greatly enhanced litter decomposition. Moreover, the effect of pest outbreaks, which resulted in lower litter quality, can cascade to aquatic ecosystems by retarding microbe-mediated litter decomposition. When these factors co-occurred, warming could synergistically interact with snails to speed up the depletion of organic matter, while the effect of leaf quality on litter decomposition may be diminished at high water temperature. These effects could further influence stream food webs and nutrient cycling.
Hongyong Xiang; Yixin Zhang; David Atkinson; Raju Sekar. Combined effects of water temperature, grazing snails and terrestrial herbivores on leaf decomposition in urban streams. PeerJ 2019, 7, e7580 .
AMA StyleHongyong Xiang, Yixin Zhang, David Atkinson, Raju Sekar. Combined effects of water temperature, grazing snails and terrestrial herbivores on leaf decomposition in urban streams. PeerJ. 2019; 7 ():e7580.
Chicago/Turabian StyleHongyong Xiang; Yixin Zhang; David Atkinson; Raju Sekar. 2019. "Combined effects of water temperature, grazing snails and terrestrial herbivores on leaf decomposition in urban streams." PeerJ 7, no. : e7580.
Across the world, there have been increasing attempts to restore good ecological condition to degraded rivers through habitat restoration. Microbial communities developing as biofilms play an important role in river ecosystem functioning by driving organic matter decomposition and ecosystem respiration. However, little is known about the structure and function of microbial communities in riverine systems and how these change when habitat restoration is implemented. Here, we compared the biofilm bacterial community composition using 16S rRNA genes targeted high-throughput Illumina Miseq sequencing in three river types, degraded urban rivers, urban rivers undergoing habitat restoration and forested rivers (our reference conditions). We aimed to determine: (i) the biofilm bacterial community composition affected by habitat restoration (ii) the difference in bacterial diversity in restored rivers, and (iii) correlations between environmental variables and bacterial community composition. The results showed that both water quality and biofilm bacterial community structure were changed by habitat restoration. In rivers where habitat had been restored, there was an increase in dissolved oxygen, a reduction in organic pollutants, a reduction in bacterial diversity and a related developing pattern of microbial communities, which is moving towards that of the reference conditions (forested rivers). River habitat management stimulated the processing of organic pollutants through the variation in microbial community composition, however, a big difference in bacterial structure still existed between the restored rivers and the reference forest rivers. Thus, habitat restoration is an efficient way of modifying the biofilm microbial community composition for sustainable freshwater management. It will, however, take a much longer time for degraded rivers to attain a similar ecosystem quality as the “pristine” forest sites than the seven years of restoration studied here.
Qiaoyan Lin; Raju Sekar; Rob Marrs; Yixin Zhang. Effect of River Ecological Restoration on Biofilm Microbial Community Composition. Water 2019, 11, 1244 .
AMA StyleQiaoyan Lin, Raju Sekar, Rob Marrs, Yixin Zhang. Effect of River Ecological Restoration on Biofilm Microbial Community Composition. Water. 2019; 11 (6):1244.
Chicago/Turabian StyleQiaoyan Lin; Raju Sekar; Rob Marrs; Yixin Zhang. 2019. "Effect of River Ecological Restoration on Biofilm Microbial Community Composition." Water 11, no. 6: 1244.
Urbanization is increasing worldwide and is happening at a rapid rate in China in line with economic development. Urbanization can lead to major changes in freshwater environments through multiple chemical and microbial contaminants. We assessed the impact of urbanization on physicochemical characteristics and microbial loading in canals in Suzhou, a city that has experienced rapid urbanization in recent decades. Nine sampling locations covering three urban intensity classes (high, medium and low) in Suzhou were selected for field studies and three locations in Huangshan (natural reserve) were included as pristine control locations. Water samples were collected for physicochemical, microbiological and molecular analyses. Compared to medium and low urbanization sites, there were statistically significant higher levels of nutrients and total and thermotolerant coliforms (or fecal coliforms) in highly urbanized locations. The effect of urbanization was also apparent in the abundances of human-associated fecal markers and bacterial pathogens in water samples from highly urbanized locations. These results correlated well with land use types and anthropogenic activities at the sampling sites. The overall results indicate that urbanization negatively impacts water quality, providing high levels of nutrients and a microbial load that includes fecal markers and pathogens.
Tianma Yuan; Kiran Kumar Vadde; Jonathan D. Tonkin; Jianjun Wang; Jing Lu; Zimeng Zhang; Yixin Zhang; Alan J. McCarthy; Raju Sekar. Urbanization Impacts the Physicochemical Characteristics and Abundance of Fecal Markers and Bacterial Pathogens in Surface Water. International Journal of Environmental Research and Public Health 2019, 16, 1739 .
AMA StyleTianma Yuan, Kiran Kumar Vadde, Jonathan D. Tonkin, Jianjun Wang, Jing Lu, Zimeng Zhang, Yixin Zhang, Alan J. McCarthy, Raju Sekar. Urbanization Impacts the Physicochemical Characteristics and Abundance of Fecal Markers and Bacterial Pathogens in Surface Water. International Journal of Environmental Research and Public Health. 2019; 16 (10):1739.
Chicago/Turabian StyleTianma Yuan; Kiran Kumar Vadde; Jonathan D. Tonkin; Jianjun Wang; Jing Lu; Zimeng Zhang; Yixin Zhang; Alan J. McCarthy; Raju Sekar. 2019. "Urbanization Impacts the Physicochemical Characteristics and Abundance of Fecal Markers and Bacterial Pathogens in Surface Water." International Journal of Environmental Research and Public Health 16, no. 10: 1739.
The optimized design of water quality monitoring networks can not only minimize the pollution detection time and maximize the detection probability for river systems but also reduce redundant monitoring locations. In addition, it can save investments and costs for building and operating monitoring systems as well as satisfy management requirements. This paper aims to use the beneficial features of multi-objective discrete particle swarm optimization (MODPSO) to optimize the design of water quality monitoring networks. Four optimization objectives: minimum pollution detection time, maximum pollution detection probability, maximum centrality of monitoring locations and reservation of particular monitoring locations, are proposed. To guide the convergence process and keep reserved monitoring locations in the Pareto frontier, we use a binary matrix to denote reserved monitoring locations and develop a new particle initialization procedure as well as discrete functions for updating particle’s velocity and position. The storm water management model (SWMM) is used to model a hypothetical river network which was studied in the literature for comparative analysis of our work. We define three pollution detection thresholds and simulate pollution events respectively to obtain all the pollution detection time for all the potential monitoring locations when a pollution event occurs randomly at any potential monitoring locations. Compared to the results of an enumeration search method, we confirm that our algorithm could obtain the Pareto frontier of optimized monitoring network design, and the reserved monitoring locations are included to satisfy the management requirements. This paper makes fundamental advancements of MODPSO and enables it to optimize the design of water quality monitoring networks with reserved monitoring locations.
Xiaohui Zhu; Yong Yue; Prudence W.H. Wong; Yixin Zhang; Hao Ding. Designing an Optimized Water Quality Monitoring Network with Reserved Monitoring Locations. Water 2019, 11, 713 .
AMA StyleXiaohui Zhu, Yong Yue, Prudence W.H. Wong, Yixin Zhang, Hao Ding. Designing an Optimized Water Quality Monitoring Network with Reserved Monitoring Locations. Water. 2019; 11 (4):713.
Chicago/Turabian StyleXiaohui Zhu; Yong Yue; Prudence W.H. Wong; Yixin Zhang; Hao Ding. 2019. "Designing an Optimized Water Quality Monitoring Network with Reserved Monitoring Locations." Water 11, no. 4: 713.
The urban heat island (UHI) effect caused by urbanization is a major environmental concern. Utilizing cooling effects of water bodies as one type of ecosystem service is an important way to mitigate UHI in urban areas during the daytime. This study aims to examine the influence of water bodies’ cooling effects on the urban land surface temperature (LST). The potential influence on the relationship between urban land cover and the LST are also discussed. The daytime LST in April was retrieved from Landsat-8 thermal infrared band and the grid-based method was adopted to analyze the potential influence. The results indicated that Suzhou Bay is broadly capable of lowering daytime temperatures. The cooling distance can reach 800 m in horizontal space, and the maximum cooling effect was 3.02 °C. Furthermore, the distance to the Suzhou Bay is a great factor for the relationship between land cover and the LST. We found that the cooling effects have weakened the correct quantitative correlation between land cover (e.g., green space and impervious surface) and the LST, particularly green space in the range of 200 m. In addition, the cooling effects have strengthened the “cool edge” phenomenon when analyzing the relationship between the normal difference vegetation index (NDVI) and the LST. We suggest that the distance to the water bodies should be effectively utilized in the microclimate regulation provided by ecosystem services of water bodies. When investigating the thermal effects of urban land, urban planners and designers should consider water bodies’ effects on surrounding areas. These findings have implications for understanding the role of water bodies with ecosystem services of temperature mitigation, which must be fully appreciated for sustainable urban and landscape planning.
Zhijie Wu; Yixin Zhang. Water Bodies’ Cooling Effects on Urban Land Daytime Surface Temperature: Ecosystem Service Reducing Heat Island Effect. Sustainability 2019, 11, 787 .
AMA StyleZhijie Wu, Yixin Zhang. Water Bodies’ Cooling Effects on Urban Land Daytime Surface Temperature: Ecosystem Service Reducing Heat Island Effect. Sustainability. 2019; 11 (3):787.
Chicago/Turabian StyleZhijie Wu; Yixin Zhang. 2019. "Water Bodies’ Cooling Effects on Urban Land Daytime Surface Temperature: Ecosystem Service Reducing Heat Island Effect." Sustainability 11, no. 3: 787.
Riparian zone provides a variety of resources to organisms, including availability of water and subsidies. Water availability in riparian areas influences species distribution and trophic interaction of terrestrial food webs. Cross-ecosystem subsidies as resource flux of additional energy, nutrients, and materials benefit riparian populations and communities (e.g. plants, spiders, lizards, birds and mammals). However, aquatic ecosystems and riparian zones are prone to anthropogenic disturbances, which change water availability and affect the flux dynamics of cross-system subsidies. Yet, we still lack sufficient empirical studies assessing impacts of disturbances of land use, climate change and invasive species individually and interactively on aquatic and riparian ecosystems through influencing subsidy resource availability. In filling this knowledge gap, we can make more effective efforts to protect and conserve riparian habitats and biodiversity, and maintain riparian ecosystem functioning and services.
Hongyong Xiang; Yixin Zhang; John. S. Richardson. Importance of Riparian Zone: Effects of Resource Availability at Land-water Interface. ENERGYO 2019, 1 .
AMA StyleHongyong Xiang, Yixin Zhang, John. S. Richardson. Importance of Riparian Zone: Effects of Resource Availability at Land-water Interface. ENERGYO. 2019; ():1.
Chicago/Turabian StyleHongyong Xiang; Yixin Zhang; John. S. Richardson. 2019. "Importance of Riparian Zone: Effects of Resource Availability at Land-water Interface." ENERGYO , no. : 1.
Particulate matter (PM2.5 with the diameter ≤ 2.5 μm) as one of the most harmful and complex pollutants can reduce environment quality and affect human health. Through acidification by wet deposition, PM2.5 can cause acid rain to impact aquatic ecosystems. However, our understanding of PM2.5 effect on ecosystem functioning is highly limited. This study investigated the relationship between PM2.5 concentration, associated acidity, and leaf litter breakdown of three tree species in laboratory experimental mesocosms, which are weeping willow (Salix babylonica), camphor tree(Cinnamomum camphora), and the south magnolia (Magnolia grandiflora). We found that leaf litter breakdown was significant affected by PM2.5 and associated acidity. With the increase of acidity, the leaf breakdown rate of all three tree species decreased. With the increase of PM2.5 concentration, the leaf breakdown rates of those leaves slowed down. When considering the influence of leaf toughness, willow leaves with lower toughness had a higher breakdown rate than that of camphor tree and the south magnolia. Our study suggests that PM2.5 has significant impact on the aquatic ecosystem functioning through increasing acidification in aquatic environment. Hence, along with ecological restoration of local aquatic habitats, further freshwater ecosystem management should include reducing air pollution through regional efforts of best ecosystem management.
Wenting Wu; Yixin Zhang. Effects of particulate matter (PM2.5) and associated acidity on ecosystem functioning: response of leaf litter breakdown. Environmental Science and Pollution Research 2018, 25, 30720 -30727.
AMA StyleWenting Wu, Yixin Zhang. Effects of particulate matter (PM2.5) and associated acidity on ecosystem functioning: response of leaf litter breakdown. Environmental Science and Pollution Research. 2018; 25 (30):30720-30727.
Chicago/Turabian StyleWenting Wu; Yixin Zhang. 2018. "Effects of particulate matter (PM2.5) and associated acidity on ecosystem functioning: response of leaf litter breakdown." Environmental Science and Pollution Research 25, no. 30: 30720-30727.
The rapid changes of land covers in urban areas are one of major environmental concerns because of their environmental impacts. Such land cover changes include the transformation of green space to impervious surface, and the increase of land surface temperature (LST). The objective of this study was to examine the spatial variation of urban landscape composition and configuration, as well as their influences on LST in Suzhou City, China. Landsat-8 image was processed to extract land covers and retrieve LSTs that were used to study relationship between spatial variation of LST and land covers. The results indicated that there was a significantly negative correlation between mean LST and green space coverage along the urban–rural gradients. With every 10% increased green space coverage, the mean LST drop was about 1.41 °C. A grid-base analysis performed at various grid sizes indicated that an increase in the percentage of surface water body area has a greater cooling effect of the mean LST than a vegetation increase. The mean LST had a significantly negative correlation with both the shape and aggregation indexes of the green space patches. Our results suggest that the sustainable landscape planning of green space in a typical city with a large water area should include both the vegetation and the surface water covers. The increased percentage of vegetation and surface water covers had the greatest cooling effect on an urban thermal environment, which is one of the ecosystem services that green space provides. A dense distribution of green space patches with complex shapes should be considered in urban sustainable landscape planning for increasing ecosystem services.
Zhijie Wu; Yixin Zhang. Spatial Variation of Urban Thermal Environment and Its Relation to Green Space Patterns: Implication to Sustainable Landscape Planning. Sustainability 2018, 10, 2249 .
AMA StyleZhijie Wu, Yixin Zhang. Spatial Variation of Urban Thermal Environment and Its Relation to Green Space Patterns: Implication to Sustainable Landscape Planning. Sustainability. 2018; 10 (7):2249.
Chicago/Turabian StyleZhijie Wu; Yixin Zhang. 2018. "Spatial Variation of Urban Thermal Environment and Its Relation to Green Space Patterns: Implication to Sustainable Landscape Planning." Sustainability 10, no. 7: 2249.
Affected by regular tides, bidirectional water flows play a crucial role in surface river systems. Using optimization theory to design a water quality monitoring network can reduce the redundant monitoring nodes as well as save the costs for building and running a monitoring network. A novel algorithm is proposed to design an optimum water quality monitoring network for tidal rivers with bidirectional water flows. Two optimization objectives of minimum pollution detection time and maximum pollution detection probability are used in our optimization algorithm. We modify the Multi-Objective Particle Swarm Optimization (MOPSO) algorithm and develop new fitness functions to calculate pollution detection time and pollution detection probability in a discrete manner. In addition, the Storm Water Management Model (SWMM) is used to simulate hydraulic characteristics and pollution events based on a hypothetical river system studied in the literature. Experimental results show that our algorithm can obtain a better Pareto frontier. The influence of bidirectional water flows to the network design is also identified, which has not been studied in the literature. Besides that, we also find that the probability of bidirectional water flows has no effect on the optimum monitoring network design but slightly changes the mean pollution detection time.
Xiaohui Zhu; Yong Yue; Prudence W. H. Wong; Yixin Zhang; Jianhong Tan. Optimum Water Quality Monitoring Network Design for Bidirectional River Systems. International Journal of Environmental Research and Public Health 2018, 15, 195 .
AMA StyleXiaohui Zhu, Yong Yue, Prudence W. H. Wong, Yixin Zhang, Jianhong Tan. Optimum Water Quality Monitoring Network Design for Bidirectional River Systems. International Journal of Environmental Research and Public Health. 2018; 15 (2):195.
Chicago/Turabian StyleXiaohui Zhu; Yong Yue; Prudence W. H. Wong; Yixin Zhang; Jianhong Tan. 2018. "Optimum Water Quality Monitoring Network Design for Bidirectional River Systems." International Journal of Environmental Research and Public Health 15, no. 2: 195.