Publicaciones

Found(s) 14 result(s)
Found(s) 2 page(s)

Impacts of urbanization around Mediterranean cities, changes in ecosystem service supply

Dipòsit Digital de Documents de la UAB
  • García-Nieto, Ana Paula
  • Geijzendorffer, Ilse R.|||0000-0002-8471-7695
  • Baró Porras, Francesc|||0000-0002-0145-6320
  • Roche, Philip K.|||0000-0003-4443-7434
  • Bondeau, Alberte
  • Cramer, Wolfgang|||0000-0002-9205-5812
Urbanization is an important driver of changes in land cover in the Mediterranean Basin and it is likely to impact the supply and demand of ecosystem services (ES). The most significant land cover changes occur in the peri-urban zone, but little is known about how these changes affect the ES supply. For eight European and four North African cities, we have quantified changes in peri-urban land cover, for periods of sixteen years (1990-2006) in the Northern African, and twenty-two years (1990-2012) in the European cities, respectively. Using an expert-based method, we derived quantitative estimates of the dynamics in the supply of twenty-seven ES. The nature of land cover changes slightly differed between European and North African Mediterranean cities, but overall it increased in urban areas and decreased in agricultural land. The capacity of the peri-urban areas of Mediterranean cities to supply ES generally reduced over the last 20-30 years. For nine ES the potential supply actually increased for all four North African cities and three out of the eight European cities. Across all cities, the ES timber, wood fuel and religious and spiritual experience increased. Given the expected increase of urban population in the Mediterranean Basin and the current knowledge of ES deficits in urban areas, the overall decrease in ES supply capacity of peri-urban areas is a risk for human well-being in the Mediterranean and poses a serious challenge for the Sustainable Development Goals in the Mediterranean basin.




Expanding Greenland seagrass meadows contribute new sediment carbon sinks

Dipòsit Digital de Documents de la UAB
  • Marbà, Núria|||0000-0002-8048-6789
  • Krause-Jensen, Dorte|||0000-0001-9792-256X
  • Masqué Barri, Pere|||0000-0002-1789-320X
  • Duarte, Carlos M..|||0000-0002-1213-1361
The loss of natural carbon sinks, such as seagrass meadows, contributes to grenhouse gas emissions and, thus, global warming. Whereas seagrass meadows are declining in temperate and tropical regions, they are expected to expand into the Arctic with future warming. Using paleoreconstruction of carbon burial and sources of organic carbon to shallow coastal sediments of three Greenland seagrass (Zostera marina) meadows of contrasting density and age, we test the hypothesis that Arctic seagrass meadows are expanding along with the associated sediment carbon sinks. We show that sediments accreted before 1900 were highly 13C depleted, indicative of low inputs of seagrass carbon, whereas from 1940's to present carbon burial rates increased greatly and sediment carbon stocks were largely enriched with seagrass material. Currently, the increase of seagrass carbon inputs to sediments of lush and dense meadows (Kapisillit and Ameralik) was 2.6 fold larger than that of sparse meadows with low biomass (Kobbefjord). Our results demonstrate an increasing important role of Arctic seagrass meadows in supporting sediment carbon sinks, likely to be enhanced with future Arctic warming.




Ecosystem services flows: Why stakeholders' power relationships matter

Biblos-e Archivo. Repositorio Institucional de la UAM
  • Felipe-Lucia, María R.
  • Martín-López, Berta
  • Lavorel, Sandra
  • Berraquero-Díaz, Luis
  • Escalera-Reyes, Javier
  • Comín, Francisco A.
The ecosystem services framework has enabled the broader public to acknowledge the benefits nature provides to different stakeholders. However, not all stakeholders benefit equally from these services. Rather, power relationships are a key factor influencing the access of individuals or groups to ecosystem services. In this paper, we propose an adaptation of the "cascade" framework for ecosystem services to integrate the analysis of ecological interactions among ecosystem services and stakeholders' interactions, reflecting power relationships that mediate ecosystem services flows. We illustrate its application using the floodplain of the River Piedra (Spain) as a case study. First, we used structural equation modelling (SEM) to model the dependence relationships among ecosystem services. Second, we performed semi-structured interviews to identify formal power relationships among stakeholders. Third, we depicted ecosystem services according to stakeholders' ability to use, manage or impair ecosystem services in order to expose how power relationships mediate access to ecosystem services. Our results revealed that the strongest power was held by those stakeholders who managed (although did not use) those keystone ecosystem properties and services that determine the provision of other services (i.e., intermediate regulating and final services). In contrast, non-empowered stakeholders were only able to access the remaining non-excludable and non-rival ecosystem services (i.e., some of the cultural services, freshwater supply, water quality, and biological control). In addition, land stewardship, access rights, and governance appeared as critical factors determining the status of ecosystem services. Finally, we stress the need to analyse the role of stakeholders and their relationships to foster equal access to ecosystem services, MFL was awarded a grant by the CSIC (Spanish National Research Council, www.csic.es)
under the JAE‐predoc program (JAE-Pre-2010-044), co-financed by the European Social Fund (http://ec.europa.eu/esf/home.jsp). This work contributes to the OPERAs FP7-ENV-2012-two-stage-308393 and OpenNESS FP7-EC-308428 European Union’s Seventh Program projects. The authors declare that no competing interests exist and that the funding sources had any involvement in study design, in data collection, analyses, and interpretation, and in the decision to submit the article




Posidonia oceanica changes in the Mediterranean sea

Digital.CSIC. Repositorio Institucional del CSIC
  • Marbà, Núria
  • Díaz-Almela, Elena
  • Duarte, Carlos M.
Methodology: We compiled available data published in peer-review articles and grey literature reports until year 2009 as well as our own unpublished data. We searched for data with the engine ISI web of Knowledge, using the keywords Posidonia oceanica AND (regression OR decline OR progression OR recovery OR status OR cartography OR limits OR cover OR density OR biomass OR dynamics), and conducting a back search of cited papers.
More information about the methodology to be found at: Calleja, M.L., N. Marbà, C.M. Duarte (2007). The relationship between seagrass (Posidonia oceanica) decline and sulfide porewater concentration in carbonate sediments. Estuarine coastal and shelf science 73: 583-588; Waycott M, CM. Duarte, T.J. B. Carruthers, R.J. Orth, W.C. Dennison, S. Olyarnik, A. Calladine, J.W. Fourqurean, K.L. Heck, Jr, A.R.ll Hughes, G A. Kendrick, W. J Kenworthy, F T. Short, S L. Williams (2009). Accelerating loss of seagrasses across the globe threatens coastal ecosystems. Proceedings of the National Academy of Science USA 106: 12377–12381; Moreno, D., P. A. Aguilera, H. Castro (2001). Assessment of the conservation status of seagrass (Posidonia oceanica) meadows: implications for monitoring strategy and the decision-making process. Biological Conservation 102: 325-332., Content and values displayed: The data set includes general information of the study conducted: the year or period of years of the study, site, country, water depth; and of the seagrass meadow investigated: extent, depth of deep and shallow limit, cover, shoot density, meadow status -decline, expansion, steady-state-, rate of change, Index of Conservation, Moreno et al. 2001) and types of coastal pressures present. The data set includes qualitative and quantitative data, since it contains studies where changes in seagrass meadow extension, cover and /or density are identified from expert judgement as well as studies that quantified the magnitude and rates of the changes reported.
The absolute and relative rates of change of seagrass extent, meadow depth limits, cover and shoot density are calculated as described in Marbà et al (submitted).
The meadows are categorized as declining (final area < 90% of initial area, net % cover abosolute change < -10, or µ density < -5% yr-1), increasing (final area >110% of initial area, net cover change > 10 % yr-1, or µ density > 5% yr-1) or without detectable change (final area within <90 % of initial area, -10 % yr-1 < net cover change < 10 % yr-1, or -5 % yr-1 < µ density < 5 % yr-1) following Waycott et al (2009) for area and Calleja et al (2007) for density criteria., Access and reuse: This dataset is subject to a Creative Commons Reconocimiento-NoComercial-CompartirIgual 4.0 Internacional License., This dataset compiles qualitative and quantitative information on the stability (i.e. decline, steady state, expansion) of the seagrass (Posidonia oceanica) in the Mediterranean Sea between years 1842 and 2009. Data on meadow extent, shallow and depth limits, cover and shoot density as well as rates of change for the study period are provided. A ReadMe file, the full list of references and explanation of dataset values are attached., SESAME Southern European Seas: Assessing and Modelling Ecosystem changes(EU, Project no: 036949, Integrated Project of the Thematic Priority: 6.3 Global Change and Ecosystems). Lenght: November 1, 2006-December 1, 2011., OPERAS (EU, Project no: 308393, Collaborative Project of Theme ENV.2012.6.2-1)., EstresX, Sinergia y antagonismo entre múltiples estreses en ecosistemas marinos Mediterráneos (Ministerio de Economía y Competividad, ref. CTM2012-32603). Lenght: January 1, 2013-December 31, 2015., Peer reviewed




Carbon stocks and sources in Oyster Harbor (W Australia) seagrass sediments

Digital.CSIC. Repositorio Institucional del CSIC
  • Marbà, Núria
  • Arias-Ortiz, Ariane
  • Masqué, Pere
  • Kendrick, Gary A.
  • Mazarrasa, Inés
  • Bastyan, Geoff R.
  • García-Orellana, Jordi
  • Duarte, Carlos M.
In March 2012 we collected 3-replicated sediment cores (9 cm diameter and 12-15 cm long) per restored site along the planting chronosequence (i.e. years 1994, 1997, 2003, 2004, 2006). Similarly, we collected 3 sediment cores in two bare sites, previously colonized by seagrasses, and in a large seagrass patch that survived the disturbances in the second half of the 20th Century that we considered a mature and thus reference meadow. We measured sediment bulk density and organic matter content and carbon stocks along all sediment cores sliced at 1 cm interval. Organic carbon content (% Corg) was estimated from loss of ignition (% LOI) at 550ºC for 5 h using the empirically fitted equation for Oyster Harbour sediments,Log % Corg = -0.62 + (1.33 * Log % LOI)
SEintercept = 0.01, SEslope =0.10, N = 55, R2 = 0.77, P<0.0001
We analyzed the ƌ3C of the organic carbon in the top 3 cm sediment layer (ƌ13Csediment) along the chronosequence to estimate the fraction of seagrass (X) and sestonic (1-X) deposition as
ƌ13Csediment = [X . Log % Corg = -0.62 + (1.33 * Log % LOI)
SEintercept = 0.01, SEslope =0.10, N = 55, R2 = 0.77, P<0.0001
We analyzed the ƌ3C of the organic carbon in the top 3 cm sediment layer (ƌ13Csediment) along the chronosequence to estimate the fraction of seagrass (X) and sestonic (1-X) deposition as
ƌ13Csediment = [X . ƌ13Cseagrass] + [(1-X) . ƌ13Cseston]
being ƌ13Cseagrass -9.65 ‰ and ƌ13Cseston -22 ‰ (Dauby 1989)., Access and reuse: This dataset is subject to a Creative Commons Reconocimiento-NoComercial-CompartirIgual 4.0 Internacional License., This dataset contains the values of ƌ13C, concentration and density of organic carbon measured along sediment cores collected where seagrasses (Posidonia australis) where lost, in re-vegetated plots and the continuously vegetated meadow at Oyster Harbor., Financial acknowledgements: CSIRO-Carbon Cluster (Australia);
Australian ARC Linkage projects (LP100200429, LP1301000155); Opera (EU FP7, Project No. 308393);
MEDEICG (CTM2009-07013); EstresX (CTM2012-32603).
Mobility grant of CSIC (PA1003258) to Núria Marbà;
Gledden Visiting Fellowship of the Institute of Advanced Studies (UWA) to Núria Marbà;
Gledden Visiting Fellowship of the Institute of Advanced Studies (UWA) to Pere Masqué;
IM by a PhD fellowship by the Government of the Balearic Islands; PM by ICREA Academia
Generalitat de Catalunya (2014 SGR – 1356);
PhD grant by the Govern of the Balearic Islands;
PhD grant by Obra Social “la Caixa”., Peer reviewed
Proyecto: EC/FP7/308393




Seagrass meadows as a globally significant carbonate reservoir

Digital.CSIC. Repositorio Institucional del CSIC
  • Mazarrasa, Inés
  • Marbà, Núria
  • Lovelock, Catherine E.
  • Serrano, Oscar
  • Lavery, Paul S.
  • Fourqurean, James W.
  • Kennedy, Hilary
  • Mateo, Miguel Ángel
  • Krause-Jensen, Dorte
  • Steven, Andy D. L.
  • Duarte, Carlos M.
11 páginas, 3 tablas, 6 figuras, There has been growing interest in quantifying
the capacity of seagrass ecosystems to act as carbon sinks
as a natural way of offsetting anthropogenic carbon emissions
to the atmosphere. However, most of the efforts have
focused on the particulate organic carbon (POC) stocks and
accumulation rates and ignored the particulate inorganic carbon
(PIC) fraction, despite important carbonate pools associated
with calcifying organisms inhabiting the meadows, such
as epiphytes and benthic invertebrates, and despite the relevance
that carbonate precipitation and dissolution processes
have in the global carbon cycle. This study offers the first
assessment of the global PIC stocks in seagrass sediments
using a synthesis of published and unpublished data on sediment
carbonate concentration from 403 vegetated and 34 adjacent
un-vegetated sites. PIC stocks in the top 1m of sediment
ranged between 3 and 1660MgPIC ha1, with an average
of 654 24MgPIC ha1, exceeding those of POC reported
in previous studies by about a factor of 5. Sedimentary
carbonate stocks varied across seagrass communities,
with meadows dominated by Halodule, Thalassia or Cymodocea
supporting the highest PIC stocks, and tended to decrease
polewards at a rate of 8 2MgPIC ha1 per degree
of latitude (general linear model, GLM; p < 0:0003). Using
PIC concentrations and estimates of sediment accretion in
seagrass meadows, the mean PIC accumulation rate in seagrass
sediments is found to be 126.3 31.05 g PICm2 yr1.
Based on the global extent of seagrass meadows (177 000 to
600 000 km2), these ecosystems globally store between 11
and 39 Pg of PIC in the top metre of sediment and accumulate
between 22 and 75 Tg PIC yr1, representing a significant
contribution to the carbonate dynamics of coastal areas.
Despite the fact that these high rates of carbonate accumulation
imply CO2 emissions from precipitation, seagrass meadows
are still strong CO2 sinks as demonstrated by the comparison
of carbon (PIC and POC) stocks between vegetated
and adjacent un-vegetated sediments., This study was funded by the EU FP7 project Opera (contract no. 308393), the project EstresX funded by the Spanish Ministry of Economy and Competitiveness (contract no. CTM2012-32603), the CSIRO Marine and Coastal Carbon Biogeochemistry Cluster and the Danish Environmental Protection Agency within the Danish Cooperation for Environment in the Arctic (DANCEA). I. Mazarrasa was supported by a PhD scholarship of the Government of the Balearic Islands (Spain) and The European Social Founding (ESF), and N. Marbà was partially supported by a Gledden visiting fellowship of The Institute of Advanced Studies UWA, Peer reviewed
Proyecto: EC/FP7/308393




Impact of seagrass loss and subsequent revegetation on carbon sequestration and stocks

Digital.CSIC. Repositorio Institucional del CSIC
  • Marbà, Núria
  • Arias-Ortiz, Ariane
  • Masqué, Pere
  • Kendrick, Gary A.
  • Mazarrasa, Inés
  • Bastyan, Geoff R.
  • García-Orellana, Jordi
  • Duarte, Carlos M.
© 2015 British Ecological Society. Seagrass meadows are sites of high rates of carbon sequestration and they potentially support 'blue carbon' strategies to mitigate anthropogenic CO2 emissions. Current uncertainties on the fate of carbon stocks following the loss or revegetation of seagrass meadows prevent the deployment of 'blue carbon' strategies. Here, we reconstruct the trajectories of carbon stocks associated with one of the longest monitored seagrass restoration projects globally. We demonstrate that sediment carbon stocks erode following seagrass loss and that revegetation projects effectively restore seagrass carbon sequestration capacity. We combine carbon chronosequences with 210Pb dating of seagrass sediments in a meadow that experienced losses until the end of 1980s and subsequent serial revegetation efforts. Inventories of excess 210Pb in seagrass sediments revealed that its accumulation, and thus sediments, coincided with the presence of seagrass vegetation. They also showed that the upper sediments eroded in areas that remained devoid of vegetation after seagrass loss. Seagrass revegetation enhanced autochthonous and allochthonous carbon deposition and burial. Carbon burial rates increased with the age of the restored sites, and 18 years after planting, they were similar to that in continuously vegetated meadows (26.4 ± 0.8 gCorg m-2 year-1). Synthesis. The results presented here demonstrate that loss of seagrass triggers the erosion of historic carbon deposits and that revegetation effectively restores seagrass carbon sequestration capacity. Thus, conservation and restoration of seagrass meadows are effective strategies for climate change mitigation., This work has been funded by the projects CSIRO Marine and Coastal Carbon Biogeochemistry Cluster, Opera (EU FP7, Project No. 308393), MEDEICG (CTM2009-07013) and EstresX (CTM2012-32603). NM was supported by a mobility grant of CSIC (PA1003258) and a Gledden Visiting Fellowship of the Institute of Advanced Studies (UWA), IM by a PhD fellowship by the Government of the Balearic Islands, PM by ICREA Academia and a Gledden Visiting Fellowship of the Institute of Advanced Studies (UWA), PM and JGO by Generalitat de Catalunya to MERS (2014 SGR–1356), AAO by a PhD grant of Obra Social ‘la Caixa’ and GAK by two concurrent Australian ARC Linkage projects (LP100200429, LP1301000155)., Peer Reviewed
Proyecto: EC/FP7/308393




Mediterranean seagrass (Posidonia oceanica) loss between 1842 and 2009

Digital.CSIC. Repositorio Institucional del CSIC
  • Marbà, Núria
  • Díaz-Almela, Elena
  • Duarte, Carlos M.
We compiled published data in peer-review articles and grey literature reports, which we appended with our own data, to assess the changes in areal extent, cover and shoot density that P. oceanica meadows have experienced between years 1842 and 2009 in the Mediterranean basin. Our results demonstrate an overall tendency towards decline of the areal extent, cover and shoot density of P. oceanica meadows during the last 50. years, the period with the largest availability of records. Available estimates indicated that between 13% and 50% of seagrass areal extent of P. oceanica in the Mediterranean basin appear to be lost, and that the remaining meadows of the Mediterranean may have thinned shoot density by 50% for the last 20. years and have became more fragmented. Considering the changes quantified in P. oceanica areal extent, cover and density, about 6.9% of the potential P. oceanica vegetation would have been lost annually over the last 50. years. The loss of P. oceanica meadows in the Mediterranean may have lead to a substantial (between 11% and 52%) reduction of the capacity of this key coastal ecosystem to sequester carbon in the last 50. years, hence reducing the carbon sink capacity of the entire Mediterranean Sea. The major causes of P. oceanica loss were widespread local disturbances, but recently, global disturbances, such as climate change and the spread of invasive exotic species, were also seriously threatening Posidonia meadows in the Mediterranean. These findings urgently call for implementation of management measures aiming at mitigating coastal deterioration by combining local and global actions. © 2014 Elsevier Ltd., This study was funded by the projects SESAME (EU, Project no: 036949, Integrated Project of the Thematic Priority: 6.3 Global Change and Ecosystems), OPERA (EU, Project no: 308393, Collaborative Project of Theme ENV.2012.6.2-1), EstresX (Spanish Ministry of Economy and Competitivness, Ref. CTM2012-32603) and GAEM (Government of the Balearic Islands). A Gledden Visiting Senior Fellowship from the Institute of Advanced Studies, University of Western Australia, partially supported NM., Peer Reviewed
Proyecto: EC/FP7/308393




Global analysis of seagrass restoration: The importance of large-scale planting

Digital.CSIC. Repositorio Institucional del CSIC
  • van Katwijk, M. M.
  • Marbà, Núria
  • Duarte, Carlos M.
  • Verduin, J.J.
M.M. van Katwijk et al., In coastal and estuarine systems, foundation species like seagrasses, mangroves, saltmarshes or corals provide important ecosystem services. Seagrasses are globally declining and their reintroduction has been shown to restore ecosystem functions. However, seagrass restoration is often challenging, given the dynamic and stressful environment that seagrasses often grow in. From our world-wide meta-analysis of seagrass restoration trials (1786 trials), we describe general features and best practice for seagrass restoration. We confirm that removal of threats is important prior to replanting. Reduced water quality (mainly eutrophication), and construction activities led to poorer restoration success than, for instance, dredging, local direct impact and natural causes. Proximity to and recovery of donor beds were positively correlated with trial performance. Planting techniques can influence restoration success. The meta-analysis shows that both trial survival and seagrass population growth rate in trials that survived are positively affected by the number of plants or seeds initially transplanted. This relationship between restoration scale and restoration success was not related to trial characteristics of the initial restoration. The majority of the seagrass restoration trials have been very small, which may explain the low overall trial survival rate (i.e. estimated 37%). Successful regrowth of the foundation seagrass species appears to require crossing a minimum threshold of reintroduced individuals. Our study provides the first global field evidence for the requirement of a critical mass for recovery, which may also hold for other foundation species showing strong positive feedback to a dynamic environment. Synthesis and applications. For effective restoration of seagrass foundation species in its typically dynamic, stressful environment, introduction of large numbers is seen to be beneficial and probably serves two purposes. First, a large-scale planting increases trial survival - large numbers ensure the spread of risks, which is needed to overcome high natural variability. Secondly, a large-scale trial increases population growth rate by enhancing self-sustaining feedback, which is generally found in foundation species in stressful environments such as seagrass beds. Thus, by careful site selection and applying appropriate techniques, spreading of risks and enhancing self-sustaining feedback in concert increase success of seagrass restoration. For effective restoration of seagrass foundation species in its typically dynamic, stressful environment, introduction of large numbers is seen to be beneficial and probably serves two purposes. First, a large-scale planting increases trial survival - large numbers ensure the spread of risks, which is needed to overcome high natural variability. Secondly, a large-scale trial increases population growth rate by enhancing self-sustaining feedback, which is generally found in foundation species in stressful environments such as seagrass beds. Thus, by careful site selection and applying appropriate techniques, spreading of risks and enhancing self-sustaining feedback in concert increase success of seagrass restoration. Journal of Applied Ecology, A.T. was funded by Greater Caribbean Energy and Environment Foundation grants. N.M. was supported by a Gledden Fellowship from the Institute of Advanced Studies of the University of Western Australia. N.M. C.M.D and A.C. were supported by Biomares contract number LIFE06 NAT/PT/000192. N.M. and C.M.D. were supported by Opera (FP7, contract number 308393). C.P. and the Cornell Cooperative Extension Marine Program are funded in part by County Executive Steve Bellone and the Suffolk County Legislature, Hauppauge, New York. E.B. and C.L. were funded by University of Pisa (Lardicci 308/ex60%2010). M.L.C and G.A.K were supported by ARC Linkage Grants (LP130100155, LP0454138), Peer Reviewed
Proyecto: EC/FP7/308393




Sediment carbon stores in Greenland seagrass meadows

Digital.CSIC. Repositorio Institucional del CSIC
  • Marbà, Núria
  • Krause-Jensen, Dorte
  • Masqué, Pere
  • Duarte, Carlos M.
The dataset contains data on profiles of bulk density, concentrations of organic matter, carbonate, organic carbon and inorganic carbon, density of organic and inorganic carbon, δ13C and abundance of 210Pb along sediment cores. The sediment cores were collected inside three Zostera marina meadows growing in Western Greenland: Ameralik (64°15’N, 51°35’W), Kapisillit (64°28’N, 50°13’W) and Kobbefjord (64°09’N, 51°33’W) (Marbà et al 2018). The sediment cores were sliced every 1 or 2 cm depending on the core. Dry bulk density was measured by dividing the weight after oven-drying them at 60 oC for 48 h by the wet volume of the sediment sample. Concentration of total 210Pb was determined by alpha spectrometry following Sanchez-Cabeza et al. (1998) . The concentration of excess 210Pb was calculated as total 210Pb minus supported 210Pb, estimated as the average of total 210Pb concentration at the base of each sediment core profile. Supported 210Pb values were comparable to the 226Ra concentrations obtained at selected depths in each core. The depth of the sediment horizon accreted since year 1900 was identified by applying constant flux: constant sedimentation (CF:CS) model (Krishnaswamy et al 1971) and the year of sediment accretion at the top of each slice by applying the constant rate of supply (CRS) model (Appleby and Oldfield 1978) . Organic matter concentration (OM, % DW) was measured using the loss of ignition technique. Sediment organic carbon concentrations (Corg, % DW) were estimated from measured organic matter concentrations (OM, % DW) using the relationship described by Fourqurean et al. (2012). Concentration of inorganic carbon (Cinorg, %DW) was measured by conducting a second combustion of the sediment samples at 1000 oC for 2 h and multiplying the amount of CO2 released from the carbonate by 0.27 (i.e. the ratio of the atomic weight of carbon (12 g) to the molecular weight of CO2 (44 g)). Densities of Corg (g Corg cm-3) and Cinorg (g Cinorg cm-3) were calculated by multiplying, respectively, Corg and Cinorg concentrations by the sediment dry bulk density of each sediment sample. We analyzed the 13C of the sediment organic carbon in acidified samples by an isotope ratio mass spectrometer (Thermo fisher scientific) and report it in the δ notation as the ratio of the 13C to the 12C isotope in the sample (Rsample) relative to that of a standard (Standard) i.e., δ sample = 1000 [(Rsample/ Rstandard) − 1]. The primary standard is Vienna Pee Dee Bellemnite (VPDB) and secondary standards are Acetanilide (Schimmelmann) and sucrose. The seagrass contribution in the sediment organic carbon pool after year 1900 was estimated by applying a two source-mixing model,
δ13Csed after 1900 = δ13Cseagr * f + [δ13Csed before 1900 * (1-f)],
that considered Z. marina (δ13Cseagr Ameralik = -7.31 ± 0.02 ‰, δ13Cseagr Kapisillit = -6.58 ± 0.33 ‰, δ13Cseagr Kobbefjord = -7.83 ± 0.15 ‰) and a business as usual carbon source scenario, represented by the average δ13Csed observed in sediments accreted before year 1900 (δ13Csed after 1900 = -30.44 ± 0.38 ‰), as end members. We corrected for the historical change in the δ13C source signatures due to 13C depletion in the atmospheric CO2 and oceanic DIC δ13C signature towards present derived from the burning of fossil fuels (i.e. Suess effect, Keeling 1979). This was done by applying the model described by Schelske and Hodell (1995) and modified by Verburg (2007):
δ13Catm = 4577.8 – 7.343 *Y + 3.9213 * 10-3 * Y2 – 6.9812 * 10-7 * Y3
to estimate the δ13C of atmospheric CO2 (δ13Catm) over time (years, Y) since year 1840. These values were subsequently normalized to δ13Catm in year 1840, and the resulting time-dependent depletion in δ13C since1840 was subtracted from the measured δ13Csed for each dated sediment section., The dataset provides data on organic matter (OM), carbonate (CaCO3), organic carbon (Corg), inorganic carbon (Cinorg), 13C in organic carbon and 210Pb in sediment cores collected at three Zostera marina meadows from Western Greenland., EU FP7 (project Opera’s, contract number 308393) and King Abdullah University of Science and Technology (KAUST). DKJ received support from the COCOA project under the BONUS program funded by the EU 7th framework program and the Danish Research Council and from the NOVAGRASS (0603-00003DSF) project funded by the Danish Council for Strategic Research. P.M. was supported by the Generalitat de Catalunya through its grant 2017 SGR-1588., Peer reviewed
Proyecto: EC/FP7/308393