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

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

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

Global dataset of soil organic carbon in tidal marshes

Tidal marshes store large amounts of organic carbon in their soils. Field data quantifying soil organic carbon (SOC) stocks provide an important resource for researchers, natural resource managers, and policy-makers working towards the protection, restoration, and valuation of these ecosystems. We collated a global dataset of tidal marsh soil organic carbon (MarSOC) from 99 studies that includes location, soil depth, site name, dry bulk density, SOC, and/or soil organic matter (SOM). The MarSOC dataset includes 17,454 data points from 2,329 unique locations, and 29 countries. We generated a general transfer function for the conversion of SOM to SOC. Using this data we estimated a median (± median absolute deviation) value of 79.2 ± 38.1 Mg SOC ha−¹ in the top 30 cm and 231 ± 134 Mg SOC ha−¹ in the top 1 m of tidal marsh soils globally. This data can serve as a basis for future work, and may contribute to incorporation of tidal marsh ecosystems into climate change mitigation and adaptation strategies and policies.ISSN:2052-446

‘Everyone has a secret they keep close to their hearts’: challenges faced by adolescents living with HIV infection at the Kenyan coast

Abstract: Background: The upsurge in the uptake of antiretroviral therapy (ART) has led to a significant increase in the survival of vertically acquired HIV infected children, many of whom are currently living into adolescence and early adulthood. However little if anything is known of the lived experiences and the challenges faced by HIV positive adolescents in the African context. We set out to investigate psychosocial challenges faced by HIV infected adolescents on the Kenyan coast. Methods: A total of 44 participants (12 HIV-infected adolescents, 7 HIV uninfected adolescents, and 25 key informants) took part in this qualitative study, using individually administered in-depth interviews. A framework approach was used to analyze the data using NVIVO software. Results: We observed that the challenges faced by adolescents in rural Kenya could be placed into six major themes: poverty, poor mental and physical health, the lack of a school system that is responsive to their needs, challenges in how to disclose to peers and family members, high levels of stigma in its various forms, and challenges of medical adherence leading to the need for close monitoring. Conclusion: In this African community, vertically acquired HIV-infected adolescents face a complex set of social, economic and medical challenges. Our study points to the urgent need to develop multisectorial intervention support programmes to fully address these challenges

‘There’s so much to it’: the ways physiotherapy students and recent graduates experience practice

Health science courses aim to prepare students for the demands of their chosen profession by learning ways appropriate to that profession and the contexts they will work and live in. Expectations of what students should learn become re-contextualised and translated into entry-level curriculum, with students operating as a connection between what is intended and enacted in curriculum, and required in the real world. Drawing on phenomenology, this paper explores how students understand practice—the collective, purposeful knowing, doing and being of a community—in entry-level physiotherapy programs. Ways of thinking and practising (WTP)—a framework attentive to the distinctive nature of a discipline, its values, philosophies and world-view (McCune and Hounsell in High Educ 49(3):255–289, 2005)—provides the conceptual lens. Six themes describing how students see the WTP of physiotherapy practice emerged from the analysis: discovery of new knowledge; problem solving client related contexts; adopting a systems based approach to the body; contributing to a positive therapeutic alliance; developing a sense of self and the profession; and the organisation of the workforce. The study produces knowledge about practice by focusing on physiotherapy students’ experiences of disciplinary learning. Including students in educational research in this way is an approach that can help students realise their potential as part of a community of practice