Holocene Environmental Changes Research Articles

Recent environmental changes inferred from sediments in a shallow lake of the Argentinian pampas

Fil: Plastani, Maria Sofia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina

Flexible pollination system in an unpalatable shrub Daphne miyabeana (Thymelaeaceae)

AbstractThe stability of plant reproductive success is dependent on the reproductive system of the plant and the surrounding pollinator assemblages. Here we documented the pollination ecology of a shrub, Daphne miyabeana (Thymelaeaceae), that is unpalatable to deer in two different habitats (open and closed canopy) at a site with severe deer browsing. We found that 31.22 ± 3.07% (mean ± SE) and 9.01 ± 1.71% of the total number of D. miyabeana flowers become fruits in open and closed habitats, respectively. Although spontaneous selfing was possible, the fruit set of that was much lower than the fruit set of an artificial outcrossing treatment. In the closed habitat, the fruit set of the natural pollination was lower than that of artificial outcrossing, whereas in the open habitat the fruit set of those two were similar. In the open habitat, small bees were the major flower visitors, whereas in the closed habitat, ants were the major flower visitors, which did not contribute to pollination. Our findings suggest that D. miyabeana is pollinated by occasional visits of small bees, but it is also self‐compatible and spontaneous selfing is possible. Although its pollination is shaped by abiotic environmental factors, D. miyabeana can reproduce in different habitat conditions. These flexible reproductive systems may be an advantage in coping with the recent environmental change in forest habitats.

Geochemistry of Marmara Lake sediments - Implications for Holocene environmental changes in Western Turkey

Beginning from the Early Holocene marked environmental changes have been revealed by a multi-proxy study of two radiocarbon-dated sediment cores from Lake Marmara. Both cores are composed of fine clastic sediments deposited over the last 1845 years. The core taken from the western depocentre supplementary consists of a 20 cm thick interval which represents a time period of 10.28 to 8.28ka yrBP. A desiccation event caused 6435 year hiatus in the sedimentary record. The lake was established again at 1.85ka yrBP. After a transitional humid phase at the beginning of the Late Holocene, overall arid conditions were continuously effective.Especially the difference between the geochemical composition of Early and Late Holocene sediments indicates distinctive environmental conditions. Respective humid phases took place in between 10.28 and 8.28ka yrBP (Early Holocene) and 1.85 to 1.72ka yrBP (Late Holocene). The Early Holocene phase is characterized by higher fluvial activity controlled by the humid climate and active tectonics. Right after the Middle Holocene droughts, a short-termed tendency to relatively fresh and oxic conditions prevailed. However, the small surface area of the lake and its shallow conditions caused fast variations of hydrology, oxidation level, salinity and organic productivity during the last 1850 years. We suggest that a combination of the instability of the Eastern Mediterranean climate and local conditions is the main control on the changing paleo-environment during the study period.

Ice and Concrete

Recent environmental changes have sparked off unprecedented dialogues between practitioners of the earth sciences and the humanities, which defy some of the basic assumptions underpinning western science. However, a gap still persists between natural scientists and scholars in the humanities in their tendency to concentrate respectively on the solid matter and fluid meaning. This article seeks to close this gap by paying attention to glacial ice and concrete, materials that often mark the onset and culmination of human history and have been historically regarded as solid fluids. We suggest that ice and concrete are caught in a punctuated understanding of change that turns fluidity and solidity into mutually exclusive properties. The article concludes by comparing this oxymoronic syndrome with the ways the Inuit of West Greenland experience their cryogenic landscapes as nurturing environments in constant becoming.

On the sediment age estimated by 210Pb dating: probably misleading “prolonging” and multiple-factor-caused “loss”

The radionuclide 210Pb is suitable for century-scale dating and has been used to calculate the sedimentation rate in a variety of environments. However, two common ways to apply 210Pb dating techniques may give misleading results. One is “prolonging of age”, i.e., using the calculated sedimentation rate to date back to 200 or 300 years. This practice must be treated with caution because the 210Pb dating techniques do not guarantee direct dating for ages much older than 100 years. Another is “loss of age”, i.e., the calculated time span between the topmost layer and the 210Pb background layer in cores is less than 100 years when an apparent sedimentation rate is used in the calculation. Here, we propose that based on the principle of 210Pb dating, the upper limit of age suitable for direct 210Pb dating is between 110 and 155 years. The “prolonging” application is acceptable only if the sedimentary environment in the past several hundred years was stable and the sedimentation rate was generally constant, and verification with independent evidence (such as historical records or biomarker methodology) is needed. Furthermore, after analyzing many published and collected data, we found four possible reasons for the “loss of age”. First, the compaction effect of sediment should be corrected in laboratory analysis or else the calculated age will be underestimated. Second, the accuracy and uncertainty of 210Pb activity measurement affect the judgment of the background. To be cautious, researchers are apt to choose a background activity with a younger age. Third, use of a slightly smaller value of supported 210Pb activity in a calculation will lead to considerable underestimation of the time span. Finally, later-stage erosion and migration are common for sedimentation, which lead to loss of sedimentary records and are often reflected as a “loss of age” in cores. We believe that proper use of 210Pb dating data may provide helpful information on our understanding of sediment records and recent environmental changes.

Within-lake spatio-temporal dynamics of cladoceran and diatom communities in a deep subtropical mountain lake (Lugu Lake) in southwest China

Within-lake spatio-temporal variability of remains of cladocerans and diatoms were examined, using trap and surficial sediment sampling approaches in Lugu Lake, one of the deep mountain lakes in the subtropical region of southwest China, to understand the response to recent environmental change. Seasonality played a strong role in the distribution patterns of both cladocerans and diatoms, but their responses to seasonal change varied. The rich resources of food supported a cladoceran population peak during summer, while increased mixing and higher nutrient triggered diatom blooms in spring. The summer also witnessed increased grazing effects of primary consumers on diatoms when the water column was nutrient-enriched. In particular, Ceriodaphnia intensified grazing on small diatoms (Cyclotella ocellata), consequently affecting community patterns during summer, while increased wind activity during spring induced turbulence, remixing, transportation and depositional processes of remains of littoral Alona guttata and benthic diatoms. The distribution pattern of cladocerans in surface sediments was similar to that of diatoms. Seasonal community patterns and trophic interactions between cladocerans and diatoms in trap and surface sediments of differential depth gradients provide evidence that high-resolution sampling of multi-proxy biological remains in deep mountain lakes of southwest China can help reduce biases in paleoenvironmental reconstructions.

Disentangling the effects of acidic air pollution, atmospheric CO2 , and climate change on recent growth of red spruce trees in the Central Appalachian Mountains.

In the 45years after legislation of the Clean Air Act, there has been tremendous progress in reducing acidic air pollutants in the eastern United States, yet limited evidence exists that cleaner air has improved forest health. Here, we investigate the influence of recent environmental changes on the growth and physiology of red spruce (Picea rubens Sarg.) trees, a key indicator species of forest health, spanning three locations along a 100km transect in the Central Appalachian Mountains. We incorporated a multiproxy approach using 75-year tree ring chronologies of basal tree growth, carbon isotope discrimination (∆13 C, a proxy for leaf gas exchange), and δ15 N (a proxy for ecosystem N status) to examine tree and ecosystem level responses to environmental change. Results reveal the two most important factors driving increased tree growth since ca. 1989 are reductions in acidic sulfur pollution and increases in atmospheric CO2 , while reductions in pollutant emissions of NOx and warmer springs played smaller, but significant roles. Tree ring ∆13 C signatures increased significantly since 1989, concurrently with significant declines in tree ring δ15 N signatures. These isotope chronologies provide strong evidence that simultaneous changes in C and N cycling, including greater photosynthesis and stomatal conductance of trees and increases in ecosystem N retention, were related to recent increases in red spruce tree growth and are consequential to ecosystem recovery from acidic pollution. Intrinsic water use efficiency (iWUE) of the red spruce trees increased by ~51% across the 75-year chronology, and was driven by changes in atmospheric CO2 and acid pollution, but iWUE was not linked to recent increases in tree growth. This study documents the complex environmental interactions that have contributed to the recovery of red spruce forest ecosystems from pervasive acidic air pollution beginning in 1989, about 15years after acidic pollutants started to decline in the United States.

Hybrid Electric Powertrain with Fuel Cells for a Series Vehicle

Recent environmental and climate change issues make it imperative to persistently approach research into the development of technologies designed to ensure the sustainability of global mobility. At the European Union level, the transport sector is responsible for approximately 28% of greenhouse gas emissions, and 84% of them are associated with road transport. One of the most effective ways to enhance the de-carbonization process of the transport sector is through the promotion of electric propulsion, which involves overcoming barriers related to reduced driving autonomy and the long time required to recharge the batteries. This paper develops and implements a method meant to increase the autonomy and reduce the battery charging time of an electric car to comparable levels of an internal combustion engine vehicle. By doing so, the cost of such vehicles is the only remaining significant barrier in the way of a mass spread of electric propulsion. The chosen method is to hybridize the electric powertrain by using an additional source of fuel; hydrogen gas stored in pressurized cylinders is converted, in situ, into electrical energy by means of a proton exchange membrane fuel cell. The power generated on board can then be used, under the command of a dedicated management system, for battery charging, leading to an increase in the vehicle’s autonomy. Modeling and simulation results served to easily adjust the size of the fuel cell hybrid electric powertrain. After optimization, an actual fuel cell was built and implemented on a vehicle that used the body of a Jeep Wrangler, from which the thermal engine, associated subassemblies, and gearbox were removed. Once completed, the vehicle was tested in traffic conditions and its functional performance was established.

Late Pleistocene–Holocene environmental change in eastern Turkey: multi‐proxy palaeoecological data of vegetation and lake‐catchment changes

ABSTRACTThis study presents the first pollen record from Lake Hazar, eastern Turkey, together with previously published multi‐proxy records from core Hz11‐P03. The data provide insight into multi‐centennial‐scale climatic changes during the late Pleistocene–Holocene period. The onset of the Younger Dryas was marked by an increase in the number of herbaceous plants (such as those in the families Poaceae and Asteraceae and the genus Centaurea) and lake level lowering with a −73 m erosional terrace on the lake margin. At the beginning of the early Holocene, the expansion of deciduous Quercus was attributed to significant afforestation due to high humidity that was presumably sufficient for the establishment of the oak forest. An increase in deciduous Quercus was maintained until the middle Holocene. An increase in herbaceous plants, and lower lake levels occurred during the late Holocene as a result of cold and dry climatic conditions. Moreover, a deciduous Quercus delay was not detected in Lake Hazar, indicating that the presence of a warm and humid climate created favourable conditions for oaks to expand at the onset of the early Holocene.

Holocene hydrologic and vegetation developments in the Orange River catchment (South Africa) and their controls

The summer rainfall zone (SRZ) in the South African interior experienced pronounced hydrological and vegetation changes during the Holocene inferred to be driven mainly by shifts in atmospheric and oceanic circulations systems. The exact mechanisms controlling these changes are still debated. To gain better insights into the Holocene environmental changes in the South African SRZ and their driving factors, we analysed compound-specific carbon and hydrogen isotopes of plant wax n-alkanes (δ13Cwax and δDwax) from a marine sediment core covering the last 9900 years. The core has been recovered offshore the mouth of the Orange River, predominantly draining the South African summer rainfall region. Our data indicate a dry early Holocene and a gradual increase of wetter conditions with a higher abundance of C4 vegetation towards the middle Holocene. Wettest conditions occurred around 3900 cal. yr BP. The last 3900 years were characterised by a gradual aridification overlain by variable wetter conditions. During the ‘Little Ice Age’ (LIA: ca. 640–310 cal. yr BP), relatively dry conditions with elevated C4 plant contributions occurred. This opposite behaviour, that is, more C4 plant contribution during drier conditions compared to the remainder of the Holocene, points towards an influence of winter rainfall in the lower Orange River catchment during the late-Holocene and a decline in summer rainfall. We emphasise the importance of changes in the latitudinal insolation gradient (LIG) as a potentially important controlling mechanism for hydrologic and vegetation changes in the SRZ.

Sedimentary architecture of the southern basin of Lake of the Woods, Minnesota and its relation to Lake Agassiz history and Holocene environmental change

AbstractLake of the Woods (LOTW) is a large, complex lake basin once occupied by glacial Lake Agassiz. High-resolution seismic-reflection profiles and cores in the shallow, open southern basin of LOTW reveal a sedimentary architecture comprising four lacustrine units separated by three low-stand unconformities. These units represent several phases of Lake Agassiz and its changing configuration. One unconformity marks the Moorhead low phase and another marks the separation of LOTW from Lake Agassiz, perhaps ~10 cal ka BP, as the level of the latter fell, but before final drainage of Agassiz. Initially, the separate Holocene lake in the southern basin was broad and shallow, sometimes marshy or dry. Shortly after 8 cal ka BP, the southern basin dried up completely, despite the progressive rise of the northern outlet of the lake due to differential isostatic uplift. The resulting hiatus is related to the well-documented mid-Holocene arid interval in central North America. A return to wetter conditions in the late Holocene caused the southern basin of LOTW to refill since about 3800 cal yr BP. Late Holocene sediments have accumulated slightly asymmetrically in the basin, possible due to continued southward transgression of the lake as a result of isostatic tilting.

Late Holocene environmental change in Lake Boquete and its watershed: human or natural causes?

espanolEste trabajo consiste en una reconstruccion paleolimnologica y ambiental de la Laguna Boquete, ubicada en las tierras altas del Norte de Panama, dicha reconstruccion se hizo mediante analisis de diatomeas, sedimento y carbon. El proposito de este estudio es contribuir al entendimiento del efecto antropogenico en la laguna Boquete y su cuenca, un lugar unico (region del desarrollo de La Gran Chiriqui) donde la naturaleza y los humanos han interactuado desde ~7000 anos A.P. (Antes del Presente). Nuestros resultados indican dos principales periodos de cambio ambiental. En el primer periodo comprendido del ~2840 al 1740 anos cal AP la laguna estuvo bajo la influencia de altos niveles de energia de transporte de sedimentos, tasas de erosion elevadas, y el pH en la columna de agua fue cambiando gradualmente de neutro a alcalino. Los incendios fueron constantes durante todo el periodo, con 4 eventos significativos, algunos provocados por causas naturales y otros por acciones antropogenicas, estos ultimos relacionados con periodos intensos de agricultura. Un evento de fuego fue registrado ~2607 anos cal A.P. Durante este primer periodo, se infiere que la laguna y su cuenca estuvieron siendo impactadas por actividades humanas. En el segundo periodo de ~1740 al 197 anos cal A.P., la laguna se mantuvo en condiciones calmadas con un flujo de energia bajo (comparado al primer periodo), la vegetacion fue mas abundante y el pH tendio a ser mas acido; los eventos de fuego fueron menos frecuentes. Se infirio que estas condiciones fueron el resultado del abandonamiento de algunas tierras a causa de migraciones humanas hacia las tierras bajas. A pesar de los intensos y frecuentes episodios de clima seco durante el segundo periodo, los niveles de agua en la laguna Boquete no fueron afectados y por lo tanto, este registro sugiere que la principal causa del cambio ambiental y limnologico en el lago Boquete y su cuenca han sido las actividades antropogenicas. EnglishA paleolimnological and environmental reconstruction of the volcanic Lake Boquete, in the northern highlands of Panama, was produced based on diatom, sediment, and charcoal analyses. The main aim of this study is to contribute to the understanding of the long-term anthropogenic effect in Lake Boquete and its watershed, a unique space (Gran Chiriqui region) where human occupation and nature have interacted since ~7000 yr BP (years Before Present). Our results indicate two main periods of environmental change. In the first period, from ~2840 to 1740 cal yr BP (calibrated years Before Present), the lake was under the influence of high-energy flow regimes and high erosion rates. Water pH was gradually changing from neutral to alkaline. There’s evidence of fires with four main events, some appear to be natural as indicated by the proxies, while others seem to be associated with anthropic causes most likely related to intense periods of cultivation; a particularly intense fire event is identified at ~2607 cal yr BP. We infer that during this period the lake and its watershed were under intense human impact. In the second period, from ~1740 to 197 cal yr BP, the lake was under a steady low-energy flow regime, submerged vegetation was more abundant, and pH became more acidic, fire events were less frequent. We infer that these conditions were the result of land abandonment due to human migration to the lowlands. Notwithstanding intense and frequent dry climate spells during the second period, Lake Boquete water levels were not affected, and thus, this record suggest that the main cause of environmental and limnological change in Lake Boquete and its watershed has been anthropogenic activities.

Late Pleistocene and Holocene environmental changes recorded in deposits of the Bukovynka Cave (the East-Carpathian foreland, Ukraine)

A study of pollen, fossil mammals and lithology (including grain-size analysis) of the terrigenous deposits in the Bukovynka Cave enables the reconstruction of the environments of several geochronologic subdivisions of the Middle Pleniglacial, Late Glacial and Holocene. A comparison of pollen assemblages in surface samples from the cave deposits and from the soils prove the importance of cave palynology for palaeovegetation reconstruction. The same patterns were shown by a comparison of pollen from hyaena coprolites in the cave and their enclosing sediments. In the Trapeznyi Chamber record, the two interstadials and one stadial identified are correlated with those of the Moershoofd interval, and the following stadial (after 41,000 yrs BP) is compared with the Hosselo stadial of Western Europe. In the Sukhyi Chamber record, Late Glacial times (around 10,700 yrs BP) differed from the Holocene in having a much harsher climate (with the spread of boreal forest). During the Holocene, a relatively wet phase, transitional from Atlantic to Early Subboreal, was separated from the similar phase of the Late Subboreal (2800 yrs BP) by a drier Middle Subboreal (with the disappearance of water-loving trees and the existence of steppe rodents). The Subatlantic was the wettest time, with culmination of a broad-leaved flora in the Roman (2300–1800 yrs BP) and Medieval (1000 yrs BP) Warm Periods. The cultivation of Cerealia started from 2800 yrs BP, and forest clearances increased after the Medieval Warm Period.

Holocene environmental changes and human activity at the Jijitan site in the Nihewan Basin, China

Knowledge of the relationship between human activities and environmental changes during the Holocene is important for understanding the survival and development of prehistoric humans. Using AMS14C dating and pollen and charcoal analysis, we reconstructed the history of environmental changes and human activity during the Holocene at the Jijitan site in the Nihewan Basin. During 13,000–7500 cal. yr BP, the East Asian Summer Monsoon (EASM) gradually intensified and precipitation increased, the vegetation changed from temperate grassland to wooded grassland and human activity remained at a low intensity. During 7500–5500 cal. yr BP, the EASM reached peak level, and the climate was warm and humid interval, and human activity intensified substantially. Within this interval, from 6600 to 6000 cal. yr BP, the forests were burned to increase the area of farmland. After 5500 cal. yr BP, the forest cover continued to gradually decrease due to the combined influences of the weakening EASM and increasing human activity. Comparison with regional climate records shows that the optimum period of forest development in northern China was approximately 8000–5000 cal. yr BP, indicating that the EASM reached a peak level in the mid-Holocene, which we suggest may have been due to the reduced influence of the high northern-latitude ice sheets and rising global sea level, rather than in the early Holocene.

Profiling a possible rapid extinction event in a long-lived species

Infectious disease is a contributing factor to species extinction or endangerment. Extinction is most likely to occur when a pathogen is evolutionarily novel, or when it utilizes an alternate reservoir, or when hosts have small pre-epidemic populations. Here we focus on such a case where a mystery disease almost drove the range restricted, Bellinger River Snapping Turtle (Myuchelys georgesi), in north-eastern NSW, Australia, to extinction in less than a month. The disease did not affect other turtle species, and the juvenile population of M. georgesi appears unaffected. The cause of the disease remains unknown, but may be a novel virus and whether the species can recover with or without human intervention is currently unknown. Here, we review the biology of M. georgesi and explore the epidemiology of the disease. We highlight circumstantial evidence of the potential role of recent environmental change in the susceptibility of M. georgesi. We show that long-term regional warming and localised drying reduced both water levels in the river and the number of flooding events that occurred prior to the disease outbreak. We also provide evidence that the food web may have been disrupted, possibly causing malnutrition and reduced immunocompetence of sub-adult and adult turtles. We hypothesize that these factors may have exacerbated the virulence and contagiousness of a novel, but as-yet unidentified pathogen, and must be also mitigated in any future recovery actions. The identity of the pathogen is necessary for managing the recovery of the species, however, understanding the processes that rendered the species susceptible to infection is of equal importance for planning the recovery of the species from the brink of extinction.

Holocene environmental changes as recorded in the geochemistry of glacial lake sediments from Retezat Mountains, South Carpathians

Sediment cores obtained from two deep (>15 m) glacial lakes were analyzed in context of terrestrial vegetation development and in-lake processes from the Retezat Mountains (Southern Carpathians, Romania). Only the Holocene parts were chosen for study for testing what is the connection between geochemical changes and biotas around and in the lakes. The lakes are situated at slightly different altitudes on the northern (Lake Gales, 1990 m a.s.l.) and southern slope (Lake Bucura, 2040 m a.s.l.), respectively. Changes in geochemical composition were relatively low amplitude during the studied period (10,300–1790 and 10,300–695 cal yr BP) in both lakes, but the applicability of enrichment factor (EF) for geochemical elements and diatom ecological traits (guilds) in paleoecological reconstruction were demonstrated in this paper. The main changes have been observed at ca. 10,670–9000, 6500 and 3100 cal yr BP in geochemistry, vegetation and siliceous algal assemblages. Catchment soil stabilization was apparent from ∼9000 cal yr BP onwards, in-lake and terrestrial productivity was the highest between 9000 and 6500 cal yr BP and human impact became the dominant driver in both terrestrial vegetation and sediment geochemical changes and in-lake processes over the last ∼3400 years in both lakes. The geochemical record displayed frequent erosional events within the Holocene. The strongest soil erosions clustered around 6500–7400 and 3200-900 cal yr BP.

Impacts of Climate Change on Tibetan Lakes: Patterns and Processes

High-altitude inland-drainage lakes on the Tibetan Plateau (TP), the earth’s third pole, are very sensitive to climate change. Tibetan lakes are important natural resources with important religious, historical, and cultural significance. However, the spatial patterns and processes controlling the impacts of climate and associated changes on Tibetan lakes are largely unknown. This study used long time series and multi-temporal Landsat imagery to map the patterns of Tibetan lakes and glaciers in 1977, 1990, 2000, and 2014, and further to assess the spatiotemporal changes of lakes and glaciers in 17 TP watersheds between 1977 and 2014. Spatially variable changes in lake and glacier area as well as climatic factors were analyzed. We identified four modes of lake change in response to climate and associated changes. Lake expansion was predominantly attributed to increased precipitation and glacier melting, whereas lake shrinkage was a main consequence of a drier climate or permafrost degradation. These findings shed new light on the impacts of recent environmental changes on Tibetan lakes. They suggest that protecting these high-altitude lakes in the face of further environmental change will require spatially variable policies and management measures.

Late Holocene environmental changes in the vicinity of Kültepe (Kayseri), Central Anatolia, Turkey

The Central Anatolian Region (CAR), being a high orogenic plateau (1000–1500 masl) is located between the Pontides in the north and the Taurides in the south, has a semi-arid climate. Significant changes occurred in vegetation and human activities within the CAR due to climate changes during the Holocene. On the other hand, the anthropogenic effect on vegetation in the region which has experienced intensive settlements since the beginning of the Neolithic period, has become the destiny of the region. In this study, the pollen data obtained from Lake Engir are presented to show the effect of the late Holocene vegetation, climate changes and anthropogenic effect on vegetation around the archaeological settlement of Kültepe. The archaeological settlement of Kültepe which is an important Assyrian trade colony, dated between 3000 BC and 1000 BP, is located in the north of Kayseri in the CAR. Within the scope of this study, aiming to shed light on the paleo-environmental conditions during this settlement period, the pollen data characterizing the period between 2300 and 300 BP were obtained from core samples collected from Lake Engir near Kültepe. A total of 71 taxa were identified from palynological analysis of core samples. Significant changes in paleoclimatic conditions and vegetation were determined from these analysis. Significant changes were experienced between the years 1930-1820, 1850-1760, 1760-1650 and 1650-1470 BP in vegetation. The climate changes indicated by vegetation changes were determined as wet and dry periods. Wet periods took place between the years 2300-1850, 1760-1650, 1400-1150 and 920-300 BP, and dry periods took place in the years 1850-1760 and 1650-1400 and 1150-920 BP. The Beyşehir Occupation Phase representing an intensive agricultural period occurred between the years 1850-1400 BP, and this period suddenly ended at 1400 BP. This situation is related to the abandonment of the land with regard to the Arab raids on Anatolia between the years 1400-1150 BP. The pine forests developed again in this period. Agriculture and animal husbandry activities in which cereal farming was dominant started since 1050 BP.

Holocene environmental change along the southern Cape coast of South Africa – Insights from the Eilandvlei sediment record spanning the last 8.9 kyr

Abstract This study investigates Holocene sediments from Eilandvlei, a coastal lake located within the Wilderness embayment at the southern Cape coast of South Africa. The evolution of the present estuarine/coastal lake system is reconstructed based on seismic data as well as a multi-proxy approach on a 30.5 m sediment core spanning the last ~8.9 kyr. Geochemical (Ca, TOC/S, Br/TOC) and micropalaeontological data (diatoms, foraminifera) reflect changes in the degree of marine influence at the core site. The embayment likely developed via distinct phases of connectivity to the Indian Ocean caused by sea level changes and dune progradation. Marine conditions prevailed at the core site from ~8900 to 4700 cal BP. The rapid sea level rise during the early Holocene caused the inundation of a palaeovalley that most likely had formed at lower sea levels during the Pleistocene. Towards the mid-Holocene the sea level exceeded its present height around ~7500 cal BP creating a marine embayment. At ~4700 cal BP, the embayment became distinctly more disconnected from the ocean turning into a lagoon system that persisted until ~1200 cal BP. Subsequently, the marine influence further decreased and the present estuarine/coastal lake system was established. Grain size and geochemical data (Fe, Si/Al, chemical index of alteration (CIA)) further reflect changes in the deposition of terrigenous sediments at the core site. While the sedimentation of fine-grained (

Five Steps to Build an Effective Payer-Provider Partnership for Innovative Palliative Care Models (TH306)

•Describe the value of Palliative Care from the payer and provider perspective to achieve quadruple aim.•Discuss how palliative care can help achieve the Quadruple Aim.•Describe actions payers are taking to integrate palliative care into payment models, care management programs, and benefits.•List five steps to build effective payer-provider partnerships to support those with serious illness. Recent changes in the health care environment with shifting and shared risk have created unique opportunities for payers and palliative care providers to partner in the care of the most medically complex individuals. There is an increasing focus on the quadruple aim: better care, better health, lower costs and improving the work-life of those who deliver care. Considering the added value of palliative care and challenges in adequate volume-based reimbursement for palliative care, such payer-provider partnerships are essential for creating sustainable models of palliative care across settings. Through success stories, data, case examples, and group discussion, this session will focus on five steps palliative care can take to build effective payer-provider partners ship to support the quadruple aim. Our speakers will describe how effective palliative care provider-payer partnerships can be created in variety of settings including home, hospital, and a provider group–led Accountable Care Organization. The first step is to compare mutual priorities and needs from the provider and payer perspective, so the presenters will share strategies to align priorities to create innovative partnerships. The second step is to consider a pilot for payer-provider partnership that can help support palliative care across the continuum. Presenters will provide details of different types of models across the care continuum, including chronic care of the medically complex and palliative care and hospice models. The third step is to implement the program and measure outcomes. The forth step is to identify barriers in building effective payer-provider partnerships and practical strategies to overcome those barriers. The final step is to scale the program and consider next steps including alignment of incentives and leadership. The materials presented will be brainstormed in small and large group discussions facilitated by the session's faculty. Participants will have time to develop and work on plans for their own organizations.