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Menicagli V, Balestri E, Vallerini F, Castelli A, Lardicci C. Combined effect of plastic litter and increased atmospheric nitrogen deposition on vegetative propagules of dune plants: A further threat to coastal ecosystems. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 266:115281. [PMID: 32841805 DOI: 10.1016/j.envpol.2020.115281] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/23/2020] [Accepted: 07/26/2020] [Indexed: 06/11/2023]
Abstract
Large amounts of non-biodegradable plastics are currently deposited on beach-dune systems, and biodegradable plastics could enter these already declining habitats in coming years. Yet, the impacts of plastics on vegetative recruitment, a plant strategy playing a key role in dune stabilization, are unknown. Whether these pollutants interact with increased atmospheric nitrogen (N) deposition, a major global driver of plant biodiversity loss, in affecting plant communities of such nutrient-poor habitats, and how plant-plant interactions mediate their effects need to be explored. In a one-year field experiments, we examined individual and combined effects of plastic (non-biodegradable, biodegradable), N deposition (ambient, elevated) and biotic condition (no interaction, interaction with a conspecific or with a hetero-specific) on the colonization success and growth of vegetative propagules of dune plants. Thinopyrum junceum and Sporobolus pumilus were chosen as models because they co-occur along Mediterranean dunes and differ in ecological role (dune- vs. non dune-building) and photosynthetic pathway (C3 vs. C4). For both species, survival probability was reduced by non-biodegradable plastic and elevated N by up to 100%. Thinopyrum junceum survival was also reduced by S. pumilus presence. Elevated N and biodegradable plastic reduced T. junceum shoot biomass when grown alone and with a conspecific, respectively; these factors in combination mitigated their negative individual effects on root biomass. Biodegradable plastic increased S. pumilus shoot and root biomass, and in combination with elevated N caused a greater biomass investment in belowground (root plus rhizome) than aboveground organs. Non-biodegradable plastic may be a further threat to dune habitats by reducing plant colonization. Biodegradable plastic and increased N deposition could favour the generalist S. pumilus and hinder the dune-building T. junceum. These findings highlight the urgency of implementing measures for preventing plastic deposition on beaches and reducing N input.
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Affiliation(s)
- Virginia Menicagli
- Department of Biology, University of Pisa, Via Derna 1, 56126, Pisa, Italy
| | - Elena Balestri
- Department of Biology, University of Pisa, Via Derna 1, 56126, Pisa, Italy.
| | - Flavia Vallerini
- Department of Biology, University of Pisa, Via Derna 1, 56126, Pisa, Italy
| | - Alberto Castelli
- Department of Biology, University of Pisa, Via Derna 1, 56126, Pisa, Italy; Centre for Climate Change Impact, University of Pisa, Via Del Borghetto 80, Pisa, 56124, Italy
| | - Claudio Lardicci
- Department of Earth Sciences, University of Pisa, Via S. Maria 53, 56126, Pisa, Italy; Centre for Climate Change Impact, University of Pisa, Via Del Borghetto 80, Pisa, 56124, Italy
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Hayes F, Lloyd B, Mills G, Jones L, Dore AJ, Carnell E, Vieno M, Dise N, Fenner N. Impact of long-term nitrogen deposition on the response of dune grassland ecosystems to elevated summer ozone. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 253:821-830. [PMID: 31344543 DOI: 10.1016/j.envpol.2019.07.088] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 07/04/2019] [Accepted: 07/17/2019] [Indexed: 06/10/2023]
Abstract
Nitrogen deposition and tropospheric ozone are important drivers of vegetation damage, but their interactive effects are poorly understood. This study assessed whether long-term nitrogen deposition altered sensitivity to ozone in a semi-natural vegetation community. Mesocosms were collected from sand dune grassland in the UK along a nitrogen gradient (5-25 kg N/ha/y, including two plots from a long-term experiment), and fumigated for 2.5 months to simulate medium and high ozone exposure. Ozone damage to leaves was quantified for 20 ozone-sensitive species. Soil solution dissolved organic carbon (DOC) and soil extracellular enzymes were measured to investigate secondary effects on soil processes. Mesocosms from sites receiving the highest N deposition showed the least ozone-related leaf damage, while those from the least N-polluted sites were the most damaged by ozone. This was due to differences in community-level sensitivity, rather than species-level impacts. The N-polluted sites contained fewer ozone-sensitive forbs and sedges, and a higher proportion of comparatively ozone-resistant grasses. This difference in the vegetation composition of mesocosms in relation to N deposition conveyed differential resilience to ozone. Mesocosms in the highest ozone treatment showed elevated soil solution DOC with increasing site N deposition. This suggests that, despite showing relatively little leaf damage, the 'ozone resilient' vegetation community may still sustain physiological damage through reduced capacity to assimilate photosynthate, with its subsequent loss as DOC through the roots into the soil. We conclude that for dune grassland habitats, the regions of highest risk to ozone exposure are those that have received the lowest level of long-term nitrogen deposition. This highlights the importance of considering community- and ecosystem-scale impacts of pollutants in addition to impacts on individual species. It also underscores the need for protection of 'clean' habitats from air pollution and other environmental stressors.
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Affiliation(s)
- Felicity Hayes
- Centre for Ecology & Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd, LL57 2UW, UK.
| | - Bethan Lloyd
- Centre for Ecology & Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd, LL57 2UW, UK; Centre for Ecology & Hydrology, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK
| | - Gina Mills
- Centre for Ecology & Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd, LL57 2UW, UK
| | - Laurence Jones
- Centre for Ecology & Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd, LL57 2UW, UK
| | - Anthony J Dore
- Centre for Ecology & Hydrology, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK
| | - Edward Carnell
- Centre for Ecology & Hydrology, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK
| | - Massimo Vieno
- Centre for Ecology & Hydrology, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK
| | - Nancy Dise
- Centre for Ecology & Hydrology, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK
| | - Nathalie Fenner
- Bangor University, School of Natural Sciences, Bangor University, Bangor, Gwynedd, LL57 2DG, UK
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Yang GJ, Lü XT, Stevens CJ, Zhang GM, Wang HY, Wang ZW, Zhang ZJ, Liu ZY, Han XG. Mowing mitigates the negative impacts of N addition on plant species diversity. Oecologia 2019; 189:769-779. [PMID: 30725373 DOI: 10.1007/s00442-019-04353-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Accepted: 02/01/2019] [Indexed: 10/27/2022]
Abstract
Increasing availability of reactive nitrogen (N) threatens plant diversity in diverse ecosystems. While there is mounting evidence for the negative impacts of N deposition on one component of diversity, species richness, we know little about its effects on another one, species evenness. It is suspected that ecosystem management practice that removes nitrogen from the ecosystem, such as hay-harvesting by mowing in grasslands, would mitigate the negative impacts of N deposition on plant diversity. However, empirical evidence is scarce. Here, we reported the main and interactive effects of N deposition and mowing on plant diversity in a temperate meadow steppe with 4-year data from a field experiment within which multi-level N addition rates and multiple N compounds are considered. Across all the types of N compounds, species richness and evenness significantly decreased with the increases of N addition rate, which was mainly caused by the growth of a tall rhizomatous grass, Leymus chinensis. Such negative impacts of N addition were accumulating with time. Mowing significantly reduced the dominance of L. chinensis, and mitigated the negative impacts of N deposition on species evenness. We present robust evidence that N deposition threatened biodiversity by reducing both species richness and evenness, a process which could be alleviated by mowing. Our results highlight the changes of species evenness in driving the negative impacts of N deposition on plant diversity and the role of mowing in mediating such negative impacts of N deposition.
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Affiliation(s)
- Guo-Jiao Yang
- Erguna Forest-Steppe Ecotone Research Station, CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiao-Tao Lü
- Erguna Forest-Steppe Ecotone Research Station, CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China.
| | - Carly J Stevens
- Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK
| | - Guang-Ming Zhang
- State Key Laboratory of Vegetation of Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Hong-Yi Wang
- Erguna Forest-Steppe Ecotone Research Station, CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China.,Heilongjiang Bayi Agricultural University, Daqing, 163319, China
| | - Zheng-Wen Wang
- Erguna Forest-Steppe Ecotone Research Station, CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Zi-Jia Zhang
- Erguna Forest-Steppe Ecotone Research Station, CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Zhuo-Yi Liu
- Erguna Forest-Steppe Ecotone Research Station, CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xing-Guo Han
- Erguna Forest-Steppe Ecotone Research Station, CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China.,University of Chinese Academy of Sciences, Beijing, 100049, China.,State Key Laboratory of Vegetation of Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
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Zhou X, Bowker MA, Tao Y, Wu L, Zhang Y. Chronic nitrogen addition induces a cascade of plant community responses with both seasonal and progressive dynamics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 626:99-108. [PMID: 29335179 DOI: 10.1016/j.scitotenv.2018.01.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 01/03/2018] [Accepted: 01/04/2018] [Indexed: 05/22/2023]
Abstract
Short-lived herbaceous plants provide a useful model to rapidly reveal how multiple generations of plants in natural plant communities of sensitive desert ecosystems will be affected by N deposition. We monitored dynamic responses of community structure, richness, evenness, density and biomass of herbaceous plants to experimental N addition (2:1 NH4+:NO3- added at 0, 0.5, 1, 3, 6 and 24gNm-2a-1) in three seasons in each of three years in the Gurbantunggut desert, a typical temperate desert of central Asia. We found clear rate-dependent and season-dependent effects of N deposition on each of these variables, in most cases becoming more obvious through time. N addition reduced plant richness, leading to a loss of about half of the species after three generations in the highest N application level. Evenness and density were relatively insensitive to all but the greatest levels of N addition for two generations, but negative effects emerged in the third generation. Biomass, both above and below ground, was non-linearly affected by N deposition. Low and intermediate levels of N deposition often increased biomass, whereas the highest level suppressed biomass. Stimulatory effects of intermediate N addition disappeared in the third generation. All of these responses are strongly interrelated in a cascade of changes. Notably, changes in biomass due to N deposition were mediated by declines in richness and evenness, and other changes in community structure, rather than solely being the direct outcome of release from limitation. The interrelationships between N deposition and the different plant community attributes change not only seasonally, but also progressively change through time. These temporal changes appear to be largely independent of interannual or seasonal climatic conditions.
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Affiliation(s)
- Xiaobing Zhou
- Xinjiang Institute of Ecology and Geography, Key Laboratory of Biogeography and Bioresources in Arid Land, Chinese Academy of Sciences, Urumqi 830011, China.
| | - Matthew A Bowker
- School of Forestry, Northern Arizona University, Flagstaff, AZ 86011, USA.
| | - Ye Tao
- Xinjiang Institute of Ecology and Geography, Key Laboratory of Biogeography and Bioresources in Arid Land, Chinese Academy of Sciences, Urumqi 830011, China
| | - Lin Wu
- Xinjiang Institute of Ecology and Geography, Key Laboratory of Biogeography and Bioresources in Arid Land, Chinese Academy of Sciences, Urumqi 830011, China
| | - Yuanming Zhang
- Xinjiang Institute of Ecology and Geography, Key Laboratory of Biogeography and Bioresources in Arid Land, Chinese Academy of Sciences, Urumqi 830011, China.
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Zhang Y, Zhou X, Yin B, Downing A. Sensitivity of the xerophytic moss Syntrichia caninervis to prolonged simulated nitrogen deposition. ANNALS OF BOTANY 2016; 117:1153-61. [PMID: 27085182 PMCID: PMC4904175 DOI: 10.1093/aob/mcw058] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 11/29/2015] [Accepted: 02/18/2016] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND AIMS Biological soil crusts, comprising assemblages of cyanobacteria, fungi, lichens and mosses, are common in dryland areas and are important elements in these ecosystems. Increasing N deposition has led to great changes in community structure and function in desert ecosystems worldwide. However, it is unclear how moss crusts respond to increased atmospheric N deposition, especially in terms of growth and physiological parameters. The aim of this study was to understand how Syntrichia caninervis, a dominant species in moss crusts in many northern hemisphere desert ecosystems, responds to added N. METHODS The population and shoot growth, and physiological responses of S. caninervis to six different doses of simulated N deposition (0, 0·3, 0·5, 1·0, 1·5 and 3·0 g N m(-2) year(-1)) were studied over a 3 year period. KEY RESULTS Low amounts of added N increased shoot length and leaf size, whereas high doses reduced almost all growth parameters. Moss shoot density increased, but population biomass decreased with high N. Low N augmented chlorophyll b, total chlorophyll content and soluble protein concentrations, but not chlorophyll a or chlorophyll fluorescence. High N was detrimental to all these indices. Soluble sugar concentration declined with increased N, but proline concentration was not affected significantly. Antioxidant enzyme activities generally decreased with low N additions and increased with high doses of simulated N deposition. CONCLUSIONS Low amounts of added N (0-0·5 g N m(-2) year(-1)) may enhance moss growth and vitality, while higher amounts have detrimental effects.
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Affiliation(s)
- Yuanming Zhang
- Xinjiang Institute of Ecology and Geography, Key Laboratory of Biogeography and Bioresource in Arid Land, Chinese Academy of Sciences, Urumqi 830011, China
| | - Xiaobing Zhou
- Xinjiang Institute of Ecology and Geography, Key Laboratory of Biogeography and Bioresource in Arid Land, Chinese Academy of Sciences, Urumqi 830011, China
| | - Benfeng Yin
- Xinjiang Institute of Ecology and Geography, Key Laboratory of Biogeography and Bioresource in Arid Land, Chinese Academy of Sciences, Urumqi 830011, China State Key Laboratory of Earth Surface Processes and Resource Ecology, College of life sciences of Beijing Normal University, Beijing 100875, China
| | - Alison Downing
- Department of Biological Sciences, Macquarie University, NSW 2109, Australia
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Pakeman RJ, Alexander J, Brooker R, Cummins R, Fielding D, Gore S, Hewison R, Mitchell R, Moore E, Orford K, Pemberton C, Trinder C, Lewis R. Long-term impacts of nitrogen deposition on coastal plant communities. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 212:337-347. [PMID: 26854704 DOI: 10.1016/j.envpol.2016.01.084] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 01/22/2016] [Accepted: 01/26/2016] [Indexed: 06/05/2023]
Abstract
Nitrogen deposition has been shown to have significant impacts on a range of vegetation types resulting in eutrophication and species compositional change. Data from a re-survey of 89 coastal sites in Scotland, UK, c. 34 years after the initial survey were examined to assess the degree of change in species composition that could be accounted for by nitrogen deposition. There was an overall increase in the Ellenberg Indicator Value for nitrogen (EIV-N) of 0.15 between the surveys, with a clear shift to species characteristic of more eutrophic situations. This was most evident for Acid grassland, Fixed dune, Heath, Slack and Tall grass mire communities and despite falls in EIV-N for Improved grass, Strand and Wet grassland. The increase in EIV-N was highly correlated to the cumulative deposition between the surveys, and for sites in south-east Scotland, eutrophication impacts appear severe. Unlike other studies, there appears to have been no decline in species richness associated with nitrogen deposition, though losses of species were observed on sites with the very highest levels of SOx deposition. It appears that dune vegetation (specifically Fixed dune) shows evidence of eutrophication above 4.1 kg N ha(-1) yr(-1), or 5.92 kg N ha(-1) yr(-1) if the lower 95% confidence interval is used. Coastal vegetation appears highly sensitive to nitrogen deposition, and it is suggested that major changes could have occurred prior to the first survey in 1976.
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Affiliation(s)
- Robin J Pakeman
- The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK.
| | - Jim Alexander
- The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
| | - Rob Brooker
- The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
| | - Roger Cummins
- The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
| | - Debbie Fielding
- The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
| | - Sarah Gore
- The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
| | - Richard Hewison
- The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
| | - Ruth Mitchell
- The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
| | - Emily Moore
- School of Biological Sciences, The University of Edinburgh, The King's Buildings, Ashworth Laboratories, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK
| | - Katy Orford
- School of Biological Sciences, University of Bristol, Bristol Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Clare Pemberton
- The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
| | - Clare Trinder
- School of Biological Science, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UL, UK
| | - Rob Lewis
- Department of Bioscience - Ecoinformatics and Biodiversity, Aarhus University, Ny Munkegade 116, 8000 Aarhus C, Denmark
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Ford H, Roberts A, Jones L. Nitrogen and phosphorus co-limitation and grazing moderate nitrogen impacts on plant growth and nutrient cycling in sand dune grassland. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 542:203-209. [PMID: 26519581 DOI: 10.1016/j.scitotenv.2015.10.089] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 10/07/2015] [Accepted: 10/19/2015] [Indexed: 06/05/2023]
Abstract
UNLABELLED Atmospheric nitrogen (N) deposition alters plant biodiversity and ecosystem function in grasslands worldwide. This study examines the impact of 6 years of nutrient addition and grazing management on a sand dune grassland. Results indicate that co-limitation of N and phosphorus (P) moderates the impact of realistic rates of N addition (7.5, 15 kg N ha(1) year(-1)). Combined NP addition (15 kg N + 10 kg P ha(-1) year(-1)) was the only nutrient treatment to differ significantly from the control, with greater above-ground biomass (mainly moss), and enhanced N and P mineralisation rates. Grazing management altered plant functional group composition, reduced above-ground biomass and meso-faunal feeding rates, and decoupled N and P mineralisation. There were no synergistic effects of grazing and N treatment. Although NP co-limitation apparently prevents adverse impacts of N deposition above the critical load, excess N is likely to be stored in moss biomass and soil, with unknown future consequences. CAPSULE This study shows that at realistic levels of N addition, NP co-limitation in a dune grassland appears to prevent adverse impacts of N on plant growth and nutrient cycling.
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Affiliation(s)
- Hilary Ford
- School of Ocean Sciences, Bangor University, Anglesey LL59 5AB, UK; Centre for Ecology and Hydrology, Environment Centre Wales, Bangor LL57 2UW, UK.
| | - Aled Roberts
- Centre for Ecology and Hydrology, Environment Centre Wales, Bangor LL57 2UW, UK
| | - Laurence Jones
- Centre for Ecology and Hydrology, Environment Centre Wales, Bangor LL57 2UW, UK.
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Rhymes J, Wallace H, Fenner N, Jones L. Evidence for sensitivity of dune wetlands to groundwater nutrients. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 490:106-113. [PMID: 24846404 DOI: 10.1016/j.scitotenv.2014.04.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 04/07/2014] [Accepted: 04/08/2014] [Indexed: 06/03/2023]
Abstract
Dune slacks are seasonal wetlands, high in biodiversity, which experience considerable within-year and between-year variations in water-table. They are subject to many pressures including climate change, land use change and eutrophication. Despite their biological importance and the threats facing them, the hydrological and nutrient parameters that influence their soil properties and biodiversity are poorly understood and there have been no empirical studies to date testing for biological effects in dune systems resulting from groundwater nutrients at low concentrations. In this study we examined the impact of groundwater nutrients on water chemistry, soil chemistry and vegetation composition of dune slacks at three distance classes (0-150 m, 150-300 m, 300-450 m) away from known (off-site) nutrient sources at Aberffraw dunes in North Wales, whilst accounting for differences in water-table regime. Groundwater nitrate and dissolved inorganic nitrogen (DIN) and soil nitrate and nitrite all had significantly higher concentrations closest to the nutrient source. Multivariate analysis showed that although plant species composition within this site was primarily controlled by water table depth and water table fluctuation, nitrogen from groundwater also influenced species composition, independently of water table and soil development. A model containing all hydrological parameters explained 17% of the total species variance; an additional 7% was explained following the addition of NO3 to this model. Areas exposed to elevated, but still relatively low, groundwater nutrient concentrations (mean 0.204 mg/L+/-0.091 of DIN) had greater abundance of nitrophilous species and fewer basipholous species than in areas with lower concentrations. This shows that clear biological impact occurs below previously suggested DIN thresholds of 0.20-0.40 (mg/L).
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Smith PH, Lockwood PA. Grazing is the key to the conservation ofGentianella campestris(L.) Börner (Gentianaceae): evidence from the north Merseyside sand-dunes. ACTA ACUST UNITED AC 2013. [DOI: 10.1179/204234811x13194453002904] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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10
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Jones L, Nizam MS, Reynolds B, Bareham S, Oxley ERB. Upwind impacts of ammonia from an intensive poultry unit. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2013; 180:221-8. [PMID: 23792381 DOI: 10.1016/j.envpol.2013.05.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 05/01/2013] [Accepted: 05/04/2013] [Indexed: 05/14/2023]
Abstract
This study investigated potential ammonia impacts on a sand dune nature reserve 600 m upwind of an intensive poultry unit. Ammonia concentrations and total nitrogen deposition were measured over a calendar year. A series of ammonia and nitrogen exposure experiments using dune grassland species were conducted in controlled manipulations and in the field. Ammonia emissions from the intensive poultry unit were detected up to 2.8 km upwind, contributing to exceedance of critical levels of ammonia 800 m upwind and exceedance of critical loads of nitrogen 2.8 km upwind. Emissions contributed 30% of the total N load in parts of the upwind conservation site. In the nitrogen exposure experiments, plants showed elevated tissue nitrogen contents, and responded to ammonia concentrations and nitrogen deposition loads observed in the conservation site by increasing biomass. Estimated long-term impacts suggest an increase in the soil carbon pool of 9% over a 50-year timescale.
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Affiliation(s)
- L Jones
- Centre for Ecology and Hydrology Bangor, Environment Centre Wales, Deiniol Road, Bangor LL57 2UW, UK.
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11
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Millett J, Edmondson S. The impact of 36 years of grazing management on vegetation dynamics in dune slacks. J Appl Ecol 2013. [DOI: 10.1111/1365-2664.12113] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jonathan Millett
- Centre for Hydrological and Ecosystem Sciences; Department of Geography; Loughborough University; Loughborough UK
| | - Sally Edmondson
- Centre for Hydrological and Ecosystem Sciences; Department of Geography; Loughborough University; Loughborough UK
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12
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Frosini S, Lardicci C, Balestri E. Global change and response of coastal dune plants to the combined effects of increased sand accretion (burial) and nutrient availability. PLoS One 2012; 7:e47561. [PMID: 23077636 PMCID: PMC3471884 DOI: 10.1371/journal.pone.0047561] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 09/18/2012] [Indexed: 11/23/2022] Open
Abstract
Coastal dune plants are subjected to natural multiple stresses and vulnerable to global change. Some changes associated with global change could interact in their effects on vegetation. As vegetation plays a fundamental role in building and stabilizing dune systems, effective coastal habitat management requires a better understanding of the combined effects of such changes on plant populations. A manipulative experiment was conducted along a Mediterranean dune system to examine the individual and combined effects of increased sediment accretion (burial) and nitrogen enrichment associated with predicted global change on the performance of young clones of Sporobolus virginicus, a widespread dune stabilizing species. Increased burial severity resulted in the production of taller but thinner shoots, while nutrient enrichment stimulated rhizome production. Nutrient enrichment increased total plant biomass up to moderate burial levels (50% of plant height), but it had not effect at the highest burial level (100% of plant height). The effects of such factors on total biomass, shoot biomass and branching were influenced by spatial variation in natural factors at the scale of hundreds of metres. These results indicate that the effects of burial and nutrient enrichment on plant performance were not independent. Their combined effects may not be predicted by knowing the individual effects, at least under the study conditions. Under global change scenarios, increased nutrient input could alleviate nutrient stress in S. virginicus, enhancing clonal expansion and productivity, but this benefit could be offset by increased sand accretion levels equal or exceeding 100% of plant height. Depletion of stored reserves for emerging from sand could increase plant vulnerability to other stresses in the long-term. The results emphasize the need to incorporate statistical designs for detecting non-independent effects of multiple changes and adequate spatial replication in future works to anticipate the impact of global change on dune ecosystem functioning.
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Affiliation(s)
| | | | - Elena Balestri
- Department of Biology, University of Pisa, Pisa, Italy
- * E-mail:
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Kooijman AM, Lubbers I, van Til M. Iron-rich dune grasslands: relations between soil organic matter and sorption of Fe and P. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2009; 157:3158-3165. [PMID: 19608316 DOI: 10.1016/j.envpol.2009.05.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 05/05/2009] [Accepted: 05/07/2009] [Indexed: 05/28/2023]
Abstract
Effects of high atmospheric nitrogen-deposition partly depend on availability of phosphate. Lime-poor, but iron-rich dune grasslands are supposedly protected from grass-encroachment, due to P-fixation in iron phosphate. However, in iron-rich Dutch hinterdunes, dunes have low, but dry former beach plains high grass-encroachment. To test whether these zones differ in nutrient availability, and whether this changed with duration of grass-encroachment, we measured net N-mineralization, microbial characteristics and different fractions of P and Fe from pioneer and shortgrass to tallgrass stages approximately 10, 20 and >25 years old. N-mineralization did not differ between zones, but increased in older tallgrass stages in the organic layer. P-availability was significantly lower in the low grass-encroachment zone, with SOM values below 3% and mineral Fe above 40% allowing for P-fixation in iron phosphates. In the high grass-encroachment zone, however, P-availability increased, because SOM increased and Fe became incorporated in organic matter complexes, with more reversible P-sorption.
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Affiliation(s)
- A M Kooijman
- Institute of Biodiversity and Ecosystem Dynamics, Paleoecology & Landscape Ecology, University of Amsterdam, Amsterdam, The Netherlands.
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