Coastal evolution in a Mediterranean microtidal zone: mid to late Holocene natural dynamics and human management of the Castelló lagoon, NE Spain

© 2016 Ejarque et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. We present a palaeoenvironmental study of the Castelló lagoon (NE Spain), an important archive for understanding long-term interactions between dynamic littoral ecosystems and human management. Combining geochemistry, mineralogy, ostracods, diatoms, pollen, non-pollen palynomorphs, charcoal and archaeo-historical datasets we reconstruct: 1) the transition of the lagoon from a marine to a marginal environment between ∼ 3150 cal BC to the 17 th century AD; 2) fluctuations in salinity; and 3) natural and anthropogenic forces contributing to these changes. From the Late Neolithic to the Medieval period the lagoon ecosystem was driven by changing marine influence and the land was mainly exploited for grazing, with little evidence for impact on the natural woodland. Land-use exploitation adapted to natural coastal dynamics, with maximum marine flooding hampering agropastoral activities between ∼ 1550 and ∼ 150 cal BC. In contrast, societies actively controlled the lagoon dynamics and become a major agent of landscape transformation after the Medieval period. The removal of littoral woodlands after the 8 th century was followed by the expansion of agrarian and industrial activities. Regional mining and smelting activities polluted the lagoon with heavy metals from the ∼ 11 th century onwards. The expansion of the milling industry and of agricultural lands led to the channelization of the river Muga into the lagoon after ∼ 1250 cal AD. This caused its transformation into a freshwater lake, increased nutrient load, and the infilling and drainage of a great part of the lagoon. By tracking the shift towards an anthropogenically-controlled system around∼ 750 yr ago, this study points out Mediterranean lagoons as ancient and heavily-modified systems, with anthropogenic impacts and controls covering multi-centennial and even millennial timescales. Finally, we contributed to the future construction of reliable seashell-based chronologies in NE Spain by calibrating the Banyuls-sur-Mer ▵ R offset with ceramic imports from the Emporiae archaeological site

Reconciling diverse lacustrine and terrestrial system response to penultimate deglacial warming in southern Europe

Unlike the most recent deglaciation, the regional expression of climate changes during the penultimate deglaciation remains understudied, even though it led into a period of excess warmth with estimates of global average temperature 1–2 °C, and sea level ∼6 m, above pre-industrial values. We present the first complete high-resolution southern European diatom record capturing the penultimate glacial-interglacial transition, from Lake Ioannina (northwest Greece). It forms part of a suite of proxies selected to assess the character and phase relationships of terrestrial and aquatic ecosystem response to rapid climate warming, and to resolve apparent conflicts in proxy evidence for regional paleohydrology. The diatom data suggest a complex penultimate deglaciation driven primarily by multiple oscillations in lake level, and provide firm evidence for the regional influence of abrupt changes in North Atlantic conditions. There is diachroneity in lake and terrestrial ecosystem response to warming at the onset of the last interglacial, with an abrupt increase in lake level occurring ∼2.7 k.y. prior to sustained forest expansion with peak precipitation. We identify the potentially important role of direct input of snow melt and glacial meltwater transfer to the subterranean karst system in response to warming, which would cause rising regional groundwater levels. This explanation, and the greater sensitivity of diatoms to subtle changes in temperature, reconciles the divergent lacustrine and terrestrial proxy evidence and highlights the sensitivity of lakes situated in mountainous karstic environments to past climate warming

Cyclotella paleo-ocellata, a new centric diatom (Bacillariophyta) from Lake Kinneret (Israel)

© Czech Phycological Society (2015). Large, subfossil populations of an unknown centric, planktonic diatom were observed in a lake sediment core from Lake Kinneret (Israel), which is here described as Cyclotella paleo–ocellata sp. nov. The new taxon, which belongs to the Cyclotella ocellata species complex, is described and separated from other similar taxa (e.g., Cyclotella ocellata, Cyclotella kuetzingiana, Cyclotella polymorpha, Cyclotella paraocellata) based on a combination of the following morphological characters: valve diameter, number of orbiculi depressi (circular depressions), number of striae/10 μm, stria length, number and position of rimoportulae and the number of central and marginal fultoportulae. Cyclotella paleo–ocellata can be distinguished mainly by two prominent characteristics: (1) the number and the arrangement of the orbiculi depressi (4–8) which increase with the valve diameter and (2) the marginal fultoportulae, situated on each, every second or third costa. Since Cyclotella paleo–ocellata is at present only known from the subfossil bottom sediments of Lake Kinneret, its ecological preferences are inferred simply from the associated diatom flora

Multi-indicator conductivity transfer functions for Quaternary palaeoclimate reconstruction

Diatoms (Bacillariophyceae; single-celled algae) and ostracods (Ostracoda; shelled microcrustacea) are known for their sensitivity to salinity. In palaeolimnology, the potential has yet to be tested for quantifying past salinity, lake level, and by inference, climate change, by application of multiple-indicator transfer functions. We used weighted averaging techniques to derive diatom (n=91; r 2 =0.92) and ostracod (n=53; r 2 =0.83) conductivity transfer functions from modern diatom, ostracod and water chemistry data collected in lakes of central, western and northern Turkey. Diatoms were better represented across the full gradient than ostracods, at intermediate levels of conductivity in particular, but both transfer functions were statistically robust. Because transfer functions are not infallible, we further tested the strength and simplicity of salinity response and the potential for identifying characteristic associations of diatom and ostracod taxa in different parts of the salinity gradient, to improve palaeoclimate reconstruction. We identified a subset of 51 samples that contained both diatoms and ostracods, collected at the same time from the same habitat. We used Two-Way Indicator Species Analysis of a combined diatom-ostracod data set, transformed to achieve numerical equivalence, to explore distributions in more detail. A clear ecological threshold was apparent at ~3gl-1 salinity, rather than at 5gl-1, the boundary used by some workers, equating to the oligosaline-mesosaline boundary. Other salinity boundaries were poorly defined, indicating lack of a simple, well-defined salinity response. We did, however, define characteristic associations of taxa, to facilitate the distinction to be drawn between a hydrologically open, fresh lake and an oligosaline lake, in palaeoenvironmental reconstruction. Over the rest of the salinity gradient, we highlighted the potential for the multi-proxy approach to strengthen ostracod-based reconstruction in particular, to overcome the problem of broad apparent tolerance ranges in common halophilic taxa such as Limnocythere inopinata, which often dominate in low-diversity fossil assemblages. The combination of multi-proxy quantitative reconstruction, complemented by qualitative understanding of ecological responses generated by the analysis, remains a powerful tool in Quaternary palaeoclimate research

Late Glacial to Holocene climate change and human impact in the Mediterranean: The last ca. 17ka diatom record of Lake Prespa (Macedonia/Albania/Greece)

Lake Prespa (Macedonia/Albania/Greece) occupies an important location between Mediterranean and central European climate zones. Although previous multi-proxy research on the Late Glacial to Holocene sequence, core Co1215 (320 cm; ca. 17 cal ka BP to present), has demonstrated its great value as an archive of Quaternary palaeoclimate data, some uncertainty remains in the interpretation of climate change. With the exception of oxygen stable isotope data, previous palaeolimnological interpretation has relied largely on proxies for productivity. Here, existing interpretation is strengthened by the addition of diatom data. Results demonstrate that shifts in diatom assemblage composition are driven primarily by lake-level changes and thus permit more confident interpretation of shifts in moisture availability over time, while corroborating previous interpretation of catchment- and climate-induced productivity shifts. An inferred cold, arid shallow lake phase between ca. 17.1 and 15.7 cal ka BP is not only followed by a high-productivity phase from ca. 15.7 cal ka BP with Late Glacial warming, but also is the first evidence for a gradual increase in lake level, in line with other regional records. Clear evidence for a Younger Dryas climate reversal between ca. 13.1 and 12.3 cal ka BP is followed by an unusually gradual transition to the Holocene and deeper, oligotrophic–mesotrophic lake conditions are reached by ca. 11.0 cal ka BP. In contrast to the arid episode from ca. 10.0 to 8.0 ka inferred from positive 18δOcalcite values, rapid diatom-inferred lake-level increase after the start of the Holocene suggests high moisture availability, in line with palynological evidence, but with only very subtle evidence for the impact of an 8.2 ka cold event. The maintenance of high lake levels until 1.9 cal ka BP, and the peak of inferred humidity from ca. 7.9 to 6.0 cal ka BP, matches the oxygen stable isotope profile and confirms that the latter is driven primarily by evaporative concentration rather than reflecting regional shifts in precipitation sources over time. During the Late Holocene progressive eutrophication is inferred between 1.9 and present. Two shallow phases at ca. 1.0 cal ka BP and at ca. 100 years ago probably represent an aridity response which is added to increase human impact in the catchment. Overall, the study is important in confirming previous tentative inferences that Late Glacial to Holocene moisture availability has strong affinity with other sites in the Eastern Mediterranean. It also tracks the pattern of North Atlantic forcing

Complexity of diatom response to Lateglacial and Holocene climate and environmental change in ancient, deep and oligotrophic Lake Ohrid (Macedonia and Albania)

© Author(s) 2016. Lake Ohrid (Macedonia and Albania) is a rare example of a deep, ancient Mediterranean lake and is a key site for palaeoclimate research in the northeastern Mediterranean region. This study conducts the analysis of diatoms as a proxy for Lateglacial and Holocene climate and environmental change in Lake Ohrid at a higher resolution than in previous studies. While Lake Ohrid has the potential to be sensitive to water temperature change, the data demonstrate a highly complex diatom response, probably comprising a direct response to temperature-induced lake productivity in some phases and an indirect response to temperaturerelated lake stratification or mixing and epilimnetic nutrient availability in others. The data also demonstrate the possible influence of physical limnological (e.g. the influence of wind stress on stratification or mixing) and chemical processes (e.g. the influence of catchment dynamics on nutrient input) in mediating the complex response of diatoms. During the Lateglacial (ca. 12 300-11 800 cal yr BP), the low-diversity dominance of hypolimnetic Cyclotella fottii indicates low lake productivity, linked to low water temperature. Although the subsequent slight increase in small, epilimnetic C. minuscula during the earliest Holocene (ca. 11 800-10 600 cal yr BP) suggests climate warming and enhanced stratification, diatom concentration remains as low as during the Lateglacial, suggesting that water temperature increase was muted across this major transition. The early Holocene (ca. 10 600-8200 cal yr BP) is characterised by a sustained increase in epilimnetic taxa, with mesotrophic C. ocellata indicating high water-temperature-induced productivity between ca. 10 600-10 200 cal yr BP and between ca. 9500-8200 cal yr BP and with C. minuscula in response to low nutrient availability in the epilimnion between ca. 10 200-9500 cal yr BP. During the middle Holocene (ca. 8200-2600 cal yr BP), when sedimentological and geochemical proxies provide evidence for maximum Holocene water temperature, anomalously low C. ocellata abundance is probably a response to epilimnetic nutrient limitation, almost mimicking the Lateglacial flora apart from the occurrence of mesotrophic Stephanodiscus transylvanicus in the hypolimnion. During the late Holocene (ca. 2600 cal yr BP-present), high abundance and fluctuating composition of epilimnetic taxa are probably a response more to enhanced anthropogenic nutrient input, particularly nitrogen enrichment, than to climate. Overall, the data indicate that previous assumptions concerning the linearity of diatom response in this deep, ancient lake are invalid, and multi-proxy analysis is essential to improve understanding of palaeolimnological dynamics in future research on the long, Quaternary sequence

Lake Kinneret (Israel): New insights into Holocene regional palaeoclimate variability based on high-resolution multi-proxy analysis

The southern Levant is a Mediterranean climate zone of complex variability in which uncertainty remains in regional palaeoclimate reconstruction. In spite of the proven value of diatoms in circum-Mediterranean palaeoenvironmental research, their potential remains largely unexplored in the southern Levant region. In this study, we generate a new, high-resolution multi-proxy record for the last ca. 9000 cal. yr BP, supported by diatom data and key biological, mineralogical and geochemical indicators preserved in a 17.8-m-long sediment sequence recovered from Lake Kinneret (the Sea of Galilee), Israel. During the Holocene, well-correlated shifts in the diatom, minero-geochemical and palynological data indicate marked lake-level variation over time as well as changes in the trophic state of Lake Kinneret. Our results are particularly important in improving the reconstruction of Holocene lake-level variation, and thus past moisture availability. Diatom-inferred lake-level oscillations correlate well with the output from climatic models from the Levantine region and clarify previous uncertainty concerning regional variation in moisture availability. The Early Holocene (from ca. 9000 to 7400 cal. yr BP) was characterized by lake-level shifts due to fluctuating dry-wet climate conditions. During the mid-Holocene (from 7400 to 2200 cal. yr BP), a stable, deep lake-level phase persisted due to high humidity. The lake level of modern Lake Kinneret not only fluctuates seasonally with available moisture, but has also been influenced for ca. 2000 years by the impacts of water abstraction for human consumption and agriculture. Over the last 9000 cal. yr BP, the trophic state of Lake Kinneret has changed from an oligotrophic to a meso- to eutrophic environment, mainly triggered by increased human impact from around 2200 cal. yr BP onwards. The lake’s ecosystem status was not strongly affected by the documented major changes in human occupation patterns during the mid-Holocene, when a relatively stable environment persisted

Western Mediterranean climate and environment since Marine Isotope Stage 3: a 50,000-year record from Lake Banyoles, Spain

We present new stable isotope (δ¹⁸Ocalcite and δ¹³ Ccalcite) and diatom data from a 67-m sediment core (BAN II) from Lake Banyoles, northeastern Spain. We reassessed the chronology of the sequence by correlating stable isotope data with a shorter U-series-dated record from the lake, confirming a sedimentological offset between the two cores and demonstrating that BAN II spans Marine Isotope Stages (MIS) 3–1. Through comparison with previous records, the multi-proxy data are used to improve understanding of palaeolimnological dynamics and, by inference, western Mediterranean climate and environmental change during the past ca. 50,000 years. Three main zones, defined by isotope and diatom data, correspond to the MIS. The basal zone (MIS 3) is characterised by fluctuating δ¹⁸Ocalcite and benthic diatom abundance, indicating a high degree of environmental and climate variability, concomitant with large lake-level changes. During the full glacial (MIS 2), relatively constant δ¹⁸Ocalcite and a poorly preserved planktonic-dominated diatom assemblage suggest stability, and intermittently, unusually high lake level. In MIS 1, δ¹⁸Ocalcite and δ¹³Ccalcite initially transition to lower values, recording a pattern of Late Glacial to Holocene change that is similar to other Mediterranean records. This study suggests that Lake Banyoles responds limnologically to changes in the North Atlantic ocean–atmosphere system and provides an important dataset from the Iberian Peninsula, a region in need of longer-term records that can be used to correlate between marine and terrestrial archives, and between the western and eastern Mediterranean

Validation of a new measure of concept of a good death

BACKGROUND: The concept of a good death is central to end-of-life care research. Despite its importance and the high interest in the topic, there are few measures currently available for use in clinical research. PURPOSE: The present work describes the development and testing of a set of items intended to measure the importance of several components posited to be critical to the concept of a good death. It is intended for use with health care providers and lay people in the context of end-of-life care research and education. POPULATION: Four cohorts (n = 596) were recruited to participate, representing two helping profession disciplines, nonhelping professionals, and a range of ages, specifically: (1) undergraduate medical students; (2) master\u27s degree students in nursing; (3) graduate students from the life sciences; and (4) practicing hospice nurses. METHODS: Participants completed self-report questionnaires at baseline and retest. Psychometric analyses included item frequency distributions, factor analysis, alpha reliability, intraclass correlation, and measures of association. RESULTS: The new Concept of a Good Death measure demonstrated good item frequency distributions, acceptable internal consistency reliability, and test-retest stability. Its factor structure revealed that three distinct domains are measured, reflecting the psychosocial/spiritual, physical, and clinical aspects of a good death. An examination of patterns of correlations showed differential associations with death anxiety, spiritual beliefs and practices, anxious mood, and sociodemographic characteristics. CONCLUSIONS: The new Concept of a Good Death instrument appears to measure three distinct factors which people consider important to a Good Death. Ratings of the importance of these factors are reliable and valid. The instrument has the advantage of being a brief, self-report index for use in end-of-life care research

A scoping review of determinants of performance in dressage

As a first step in achieving an evidence-based classification system for the sport of Para Dressage, there is a clear need to define elite dressage performance. Previous studies have attempted to quantify performance with able-bodied riders using scientific methods; however, definitive measures have yet to be established for the horse and/or the rider. This may be, in part, due to the variety of movements and gaits that are found within a dressage test and also due to the complexity of the horse-rider partnership. The aim of this review is therefore to identify objective measurements of horse performance in dressage and the functional abilities of the rider that may influence them to achieve higher scores. Five databases (SportDiscuss, CINAHL, MEDLINE, EMBASE, VetMed) were systematically searched from 1980 to May 2018. Studies were included if they fulfilled the following criteria: (1) English language; (2) employ objective, quantitative outcome measures for describing equine and human performance in dressage; (3) describe objective measures of superior horse performance using between-subject comparisons and/or relating outcome measures to competitive scoring methods; (4) describe demands of dressage using objective physiological and/or biomechanical measures from human athletes and/or how these demands are translated into superior performance. In total, 773 articles were identified. Title and abstract screening resulted in 155 articles that met the eligibility criteria, 97 were excluded during the full screening of articles, leaving 58 included articles (14 horse, 44 rider) involving 311 equine and 584 able-bodied human participants. Mean ± sd (%) quality scores were 63.5 ± 15.3 and 72.7 ± 14.7 for the equine and human articles respectively. Significant objective measures of horse performance (n = 12 articles) were grouped into themes and separated by gait/movement. A range of temporal variables that indicated superior performance were found in all gaits/movements. For the rider, n = 5 articles reported variables that identified significant differences in skill level, which included the postural position and ROM of the rider’s pelvis, trunk, knee and head. The timing of rider pelvic and trunk motion in relation to the movement of the horse emerged as an important indicator of rider influence. As temporal variables in the horse are consistently linked to superior performance it could be surmised that better overall dressage performance requires minimal disruption from the rider whilst the horse maintains a specific gait/movement. Achieving the gait/movement in the first place depends upon the intrinsic characteristics of the horse, the level of training achieved and the ability of the rider to apply the correct aid. The information from this model will be used to develop an empirical study to test the relative strength of association between impairment and performance in able-bodied and Para Dressage riders