Blue Carbon and Marine Carbon Sequestration in Irish Waters and Coastal Habitats

Atmospheric CO2 is rising globally. Opportunities for reducing this trend include energy sector adjustments and management of both land and ocean resources. Improved management of coastal and oceanic ecosystems is therefore poised to contribute to, and enhance, climate mitigation and adaptation. This report outlines the emergence of blue carbon as a concept for the integration of coastal carbon dynamics into policy and management frameworks and defines blue carbon ecosystems. It also emphasises the importance of marine carbon sequestration and highlights its potential role in climate adaptation. Ireland is estimated to store at least 9.2 Mt of carbon in its saltmarsh and seagrass habitats, which cover an estimated minimum area of 162 km2. Estimates of carbon stocks in potential blue carbon ecosystems such as macroalgae beds are hampered by lack of data on extent, productivity and actual contribution. Irish coastal blue carbon ecosystems and their carbon sequestration capacity are currently threatened by anthropogenic factors such as land reclamation and poor water quality. The possibility of including saltmarsh and seagrass habitats in Ireland’s National Inventory Report on GHG emissions to the United Nations Framework Convention on Climate Change (UNFCCC) and including Ireland’s potential blue carbon ecosystems in Ireland’s Nationally Determined Contributions is highlighted. The critical knowledge gaps and future research priorities are outlined, so that Ireland can advance the pace of scientific discovery whilst harnessing the climate change potential of its coastal and marine environment.Marine Institut

Saltmarshes on peat substrate on the southwest coast of Ireland: edaphic parameters and plant species distribution

Abstract. Saltmarshes on peat substrate are common along the western Atlantic coast of Ireland. The peat which underlies these marshes was formed under freshwater conditions in post glacial times, after which these systems were subjected to a marine transgression. The aim of this study was to determine the relationship between edaphic factors, substrate type and saltmarsh vegetation, specifically investigating the role of edaphic factors in determining the distribution of saltmarsh species Atriplex portulacoides in Ireland. Edaphic parameters measured for each substrate included pH, moisture content, ammonium and nitrate. The peat was found to differ markedly from other substrates. Using canonical correspondence analysis it was found that pH and ammonium were the major drivers in influencing saltmarsh vegetation on peat substrate. Under both in situ and ex situ conditions Atriplex portulacoides showed an affinity for drier substrate and its absence from fringe marshes in Ireland is likely due to a combination of both biotic and abiotic factors, including intolerance to high soil moisture levels

Deforestation in Ireland 2000 – 2012

Although Ireland’s national forest area continues to expand, recent evidence has suggested that the gross annual rate of deforestation is also increasing. Heretofore, no spatially explicit characterisation of contemporary deforestation areas in Ireland exists. Given uncertainties associated with current deforestation estimates, investigation of new methodologies is required to inform future land-use change accounting approaches. This paper presents a summary of the DEFORMAP project, which investigated the extent and nature of deforestation in Ireland for the 2000 – 2012 period. A combination of high resolution aerial photography, satellite imagery and ancillary datasets was used to quantify forest loss in the Republic of Ireland. In total, 5,457 ha of deforested land was identified which, following accuracy assessment, was error-adjusted to 7,465 ±785 ha. The error-adjusted gross annual national deforestation rate for the period of study was 0.103%. The deforestation rate increased from the first time interval investigated (2000-2005) to the second (2005-2010), followed by a reduction during the 2010 – 2012 period. High inter-county variation in gross annual deforestation was identified, with the highest level of deforestation occurring in Co. Monaghan (0.25% yr-1) and the lowest in Co. Limerick (0.02% yr-1). Principal post-deforestation land-use transitions were to agricultural grassland, built-land and wetland. Patterns of post-deforestation land-use transitions varied widely between counties indicating changing regional pressures on forest land. This paper presents an important development in our understanding of contemporary land-use change in Ireland by developing the first national deforestation map. The Deforestation Map presented here will provide a valuable record of forest loss, which can be used to validate any future earth observation based deforestation monitoring approaches, such as automated radar remote sensing techniques

Differential effects of biological invasions on coastal blue carbon: A global review and meta‐analysis

Human‐caused shifts in carbon (C) cycling and biotic exchange are defining characteristics of the Anthropocene. In marine systems, saltmarsh, seagrass, and mangrove habitats—collectively known as “blue carbon” and coastal vegetated habitats (CVHs) —are a leading sequester of global C and increasingly impacted by exotic species invasions. There is growing interest in the effect of invasion by a diverse pool of exotic species on C storage and the implications for ecosystem‐based management of these systems. In a global meta‐analysis, we synthesized data from 104 papers that provided 345 comparisons of habitat‐level response (plant and soil C storage) from paired invaded and uninvaded sites. We found an overall net effect of significantly higher C pools in invaded CVHs amounting to 40% (±16%) higher C storage than uninvaded habitat, but effects differed among types of invaders. Elevated C storage was driven by blue C‐forming plant invaders (saltmarsh grasses, seagrasses, and mangrove trees) that intensify biomass per unit area, extend and elevate coastal wetlands, and convert coastal mudflats into C‐rich vegetated habitat. Introduced animal and structurally distinct primary producers had significant negative effects on C pools, driven by herbivory, trampling, and native species displacement. The role of invasion manifested differently among habitat types, with significant C storage increases in saltmarshes, decreases in seagrass, and no significant effect in mangroves. There were also counter‐directional effects by the same species in different systems or locations, which underscores the importance of combining data mining with analyses of mean effect sizes in meta‐analyses. Our study provides a quantitative basis for understanding differential effects of invasion on blue C habitats and will inform conservation strategies that need to balance management decisions involving invasion, C storage, and a range of other marine biodiversity and habitat functions in these coastal systems

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Nitrogen uptake kinetics and saltmarsh plant responses to global change

Abstract Coastal wetlands are important carbon sinks globally, but their ability to store carbon hinges on their nitrogen (N) supply and N uptake dynamics of dominant plant species. In terrestrial ecosystems, uptake of nitrate (NO3 −) and ammonium (NH4 +) through roots can strongly influence N acquisition rates and their responses to environmental factors such as rising atmospheric CO2 and eutrophication. We examined the 15N uptake kinetics of three dominant plant species in North American coastal wetlands (Spartina patens, C4 grass; Phragmites australis, C3 grass; Schoenoplectus americanus, C3 sedge) under ambient and elevated CO2 conditions. We further related our results to the productivity response of these species in two long-term field experiments. S. patens had the greatest uptake rates for NO3 − and NH4 + under ambient conditions, suggesting that N uptake kinetics may underlie its strong productivity response to N in the field. Elevated CO2 increased NH4 + and NO3 − uptake rates for S. patens, but had negative effects on NO3 − uptake rates in P. australis and no effects on S. americanus. We suggest that N uptake kinetics may explain differences in plant community composition in coastal wetlands and that CO2-induced shifts, in combination with N proliferation, could alter ecosystem-scale productivity patterns of saltmarshes globally

21st Century Deforestation in Ireland

No abstract available

Deforestation in Ireland 2000 – 2012

Although Ireland’s national forest area continues to expand, recent evidence has suggested that the gross annual rate of deforestation is also increasing. Heretofore, no spatially explicit characterisation of contemporary deforestation areas in Ireland exists. Given uncertainties associated with current deforestation estimates, investigation of new methodologies is required to inform future land-use change accounting approaches. This paper presents a summary of the DEFORMAP project, which investigated the extent and nature of deforestation in Ireland for the 2000 – 2012 period. A combination of high resolution aerial photography, satellite imagery and ancillary datasets was used to quantify forest loss in the Republic of Ireland. In total, 5,457 ha of deforested land was identified which, following accuracy assessment, was error-adjusted to 7,465 ±785 ha. The error-adjusted gross annual national deforestation rate for the period of study was 0.103%. The deforestation rate increased from the first time interval investigated (2000-2005) to the second (2005-2010), followed by a reduction during the 2010 – 2012 period. High inter-county variation in gross annual deforestation was identified, with the highest level of deforestation occurring in Co. Monaghan (0.25% yr-1) and the lowest in Co. Limerick (0.02% yr-1). Principal post-deforestation land-use transitions were to agricultural grassland, built-land and wetland. Patterns of post-deforestation land-use transitions varied widely between counties indicating changing regional pressures on forest land. This paper presents an important development in our understanding of contemporary land-use change in Ireland by developing the first national deforestation map. The Deforestation Map presented here will provide a valuable record of forest loss, which can be used to validate any future earth observation based deforestation monitoring approaches, such as automated radar remote sensing techniques

21st Century Deforestation in Ireland

No abstract available