SwePub - search: WFRF:(Norström Elin)

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1.	Daniau, A. -L, et al. (author) predictability of biomass burning in response to climate changes 2012 In: Global Biogeochemical Cycles. - 0886-6236 .- 1944-9224. ; 26, s. GB4007- Journal article (peer-reviewed)abstract Climate is an important control on biomass burning, but the sensitivity of fire to changes in temperature and moisture balance has not been quantified. We analyze sedimentary charcoal records to show that the changes in fire regime over the past 21,000 yrs are predictable from changes in regional climates. Analyses of paleo-fire data show that fire increases monotonically with changes in temperature and peaks at intermediate moisture levels, and that temperature is quantitatively the most important driver of changes in biomass burning over the past 21,000 yrs. Given that a similar relationship between climate drivers and fire emerges from analyses of the interannual variability in biomass burning shown by remote-sensing observations of month-by-month burnt area between 1996 and 2008, our results signal a serious cause for concern in the face of continuing global warming.
2.	Elinor, Breman, et al. (author) Phytolith-based environmental reconstruction from an altitudinal gradient in Mpumalanga, South Africa, 10,600 BP-present 2019 In: Review of Palaeobotany and Palynology. - : Elsevier BV. - 0034-6667 .- 1879-0615. ; 263, s. 104-116 Journal article (peer-reviewed)abstract Studying vegetation change across biome boundaries provides insight into vegetation resilience. In this study, shifts in grassland composition are reconstructed from sediments in three wetland sites across altitudinal gradient from 2128 to 897 m.a.s.l., representing a gradient from the grassland biome to the grassland/savanna boundary in the Mpumalanga region, north-eastern South Africa. Phytolith records from Verloren Valei (dated from 10,600 BP), Graskop (dated from 6500 BP) and Versailles (dated from 4500 BP) are used to reconstruct shifts in grassland composition and vegetation change. Phytolith morphotypes are used to construct environmental indices that are correlated with pollen main ecological groups, charcoal and delta 13C and C/N ratio. The results are compared to available regional paleoclimate data. Both Verloren Valei and Graskop have been dominated by grassland, but Versailles show a stronger influence of bushveld/savanna pollen. Phytolith data suggest that grassland composition was stable at Versailles and Graskop, but grassland at Verloren Valei has changed significantly over time. The early Holocene was dominated by a Pooideae/Chloridoideae C3 and C4 grassland, probably a remnant of the earlier Pleistocene cool-dry conditions. After 8500 BP grassland composition changed gradually to a Chloridoideae and Panicoidea dominated C4 grassland BP, and finally a moist Cyperaceae and Panicoidea dominated C3/C4 grassland after 4000 BP. This shift possibly occurs as a delayed response to the warmer and wetter conditions of the mid Holocene optimum at this high altitude site. The results suggest that the grassland/savanna boundary has remained stable over time, indicating considerable resilience of grasslands to climate change. This resilience may be related to the turnover of species within the grassland biome, as indicated by shifts between 8500 and 4000 BP at Verloren Valei.
3.	Emmanouilidis, Alexandros, et al. (author) Middle to late Holocene palaeoenvironmental study of Gialova Lagoon, SW Peloponnese, Greece 2018 In: Quaternary International. - : Elsevier BV. - 1040-6182 .- 1873-4553. ; 476, s. 46-62 Journal article (peer-reviewed)abstract The coastal areas of Eastern Mediterranean have long been the subject of research, due to their rapid geomorphological changes, but also because of their archaeological interest. Our study is focused on a shallow coastal lagoon of Peloponnese, Gialova Lagoon, which for several years has attracted the scientific interest of archaeologists, geomorphologists as well as sedimentologists. Gialova lagoon is located near the ancient city of Pylos, the kingdom of king Nestor during the Mycenaean period (1600-1100 BC). The objectives of this study are: (a) to reconstruct the middle to late Holocene depositional environments of the lagoon and (b) to correlate our data to already existing publications, in order to shed new light on the Holocene evolution of the lagoon and the associated coastal palaeoenvironmental changes. An 8m deep vibracore was drilled and a multi proxy analysis was carried out on the sediment sequence, including sedimentological (grain size analysis and moment measures, total organic carbon - TOC, total nitrogen e TN and total phosphorus - TP), high resolution geochemical (XRF-scanning) and palaeontological (micro-and macro faunal) analysis. The chronological framework is based on five C-14 datings forming the basis for an age depth model, calculated using the OxCal software. The radiocarbon dates from previous studies (6 cores, similar to 20 dates) were also taken into account. The data synthesis and interpretation provided robust and coherent indications regarding the palaeoenvironment, shoreline changes and the rate of geomorphological changes of the coastal area of Gialova Lagoon, as well as useful information about the palaeonvironmental and palaeoclimatic conditions that prevailed during the Mycenaean period. The interpretation, reveal a transition from a shallow marine environment (65005800 yr B.P.) to a brackish/lagoonal (5800-3300 yr B.P.), followed by a shift towards a freshwater/marsh environment (3300 yr B.P. to present).
4.	Finné, Martin, et al. (author) Siliceous microfossils as Late Quaternary paleo-environmental indicators at Braamhoek wetland, South Africa 2010 In: The Holocene. - : SAGE Publications. - 0959-6836 .- 1477-0911. ; 20:5, s. 747-760 Journal article (peer-reviewed)abstract A peat-sequence covering the last 16 ka (16 000 cal. yr BP) from Braamhoek wetland, eastern South Africa, was analysed in terms of phytolith and diatom composition. The fossil peat was rich in phytoliths, while diatoms were less prominent, probably as a result of degradation during wetland plant growth associated with silica uptake. With this study we present the first continuous phytolith and diatom record from South Africa covering the Late Pleistocene and Holocene period. The phytolith assemblages indicate a clear dominance of C 3-grasses within the wetland throughout the sequence. The fossil diatom record infer changes in past moisture conditions. Unlike the modern wetland, which is dominated by benthic and aerophilic diatoms, the Late Pleistocene– early Holocene wetland favoured growth of planktonic species. Abundance of planktonic diatoms suggests three main phases when water depth was deeper than today; at c.13.6 ka, 11.3 ka and 10.4–10.0 ka. These indications of past fluctuations in humidity mostly provide confirmation of previously published indications of pollen, charcoal fragments and isotopes in the same core, but the siliceous microfossil data also help to refine the paleo-environmental interpretation of the sequence.
5.	Hellqvist, Magnus, et al. (author) Environment and climate change during the late Holocene in Hjaltadalur, Skagafjorour, northern Iceland 2020 In: Geografiska Annaler Series a-Physical Geography. - : Informa UK Limited. - 0435-3676 .- 1468-0459. ; 102:1, s. 68-82 Journal article (peer-reviewed)abstract We present an overview of the local environmental development of the valley of Hjaltadalur, situated in Skagafjorour, northern Iceland. The aim of this study is to increase the knowledge about the valley region before and during human settlement in the ninth century. Four mires were investigated after which the Viovik peat bog was selected as the main site for evaluating changes in climate and landscape. The master core from Viovik (V-325) was dated and studied further through sediment analysis, loss-on-ignition (LOI), and pollen analysis. According to the age-depth model, based on three radiocarbon dates and analysis of two tephra layers, the 325 cm long Viovik core comprises approximately 5500 years. In the pollen percentage record, there is a decrease in birch (Betula) and an increase in grass (Poaceae) in the central part of the core, between Hekla 3 horizon at c. 2800 BP and the next dated level at c. 2000 BP. This change corresponds well with previously outlined environmental fluctuations, showing a transition from warm and dry climate to cool and humid climate at this time. Human activity is mainly reflected by a distinct peak in Lactucae pollen in the uppermost part of the core. This change in vegetation corresponds with earlier studies, showing that the vegetation changed dramatically after the colonization of Iceland in the ninth century (during Landnam period, 870-930 AD). The present study shows that a decline in birch started well before human settlement, although the subsequent Viking Age and later settlements continued the deforestation trend.
6.	Holmgren, Karin, et al. (author) The vulnerable continent (PLATINA) : Historical perspectives on Africa´s climate, environment and societies 2009 In: Meeting global challenges in research cooperation. - Uppsala : Uppsala University. - 9789197574198 ; , s. 585-596 Conference paper (peer-reviewed)abstract Our research, based on studies of different climate archives from Tanzania, Mozambique and South Africa, contributes information on changes in climate and vegetation over the past 24000 years. This time perspective, reaching beyond the information available from instrumental records is needed for a better understanding of regional global climate dynamics and issues surrounding environmental change, throughout Africa, and is a prerequisite for increasing climate forecasting capabilities for the region. We argue that African people have vast experience from living in a variable climate and research on past interactions between climate and societies demonstrate the significance of lessons learnt for present situations. Our findings, underline the complex interactions between climate/environment and societies that may lead to different developments in time and space. Considering the so called vulnerable continent, extended investigations of how African communities cope with and adapt to climatically driven changes is needed to increase the capability to realise the potential as well as the limitations, of modern African communities to adapt to future climate change.
7.	Holmgren, Karin, et al. (author) Water-level variations in Lake Nhauhache, Mozambique, during the last 2,300 years 2012 In: Journal of Paleolimnology. - : Springer Science and Business Media LLC. - 0921-2728 .- 1573-0417. ; 48:2, s. 311-322 Journal article (peer-reviewed)abstract Stratigraphic variations in diatom composition and phytolith abundance in a sediment core from a small, hydrologically isolated waterbody, Lake Nhauhache, Mozambique, provide evidence of water-level fluctuations over the past 2,300 years. Ten AMS radiocarbon dates on bulk sediment samples show that the lake came into existence about 2,300 years ago and that it has dried out since then, but only for brief time periods. Changes in the diatom assemblage composition indicate that lake level fluctuated in response to shifting humidity conditions. The changes reflect wetter conditions ca. 300 BC-AD 800, more variable conditions between AD 800 and 1150, a distinct dry phase within the time span AD 1150-1700 and a return thereafter to more humid conditions until present. There is general agreement between the Lake Nhauhache record and other records from the Southern Hemisphere summer rainfall region. This suggests that sediments from small interdunal lakes, which are abundant along the coast of southern Africa, provide reliable, regional paleoenvironmental information about an area from which more such data are needed.
8.	Katrantsiotis, Christos, et al. (author) Climate changes in the Eastern Mediterranean over the last 5000 years and their links to the high-latitude atmospheric patterns and Asian monsoons 2019 In: Global and Planetary Change. - : Elsevier BV. - 0921-8181 .- 1872-6364. ; 175, s. 36-51 Journal article (peer-reviewed)abstract This research aims to improve the knowledge of the mid to late Holocene climate changes and the underlying drivers in the eastern Mediterranean. We focus on the Peloponnese peninsula, SW Greece, characterized by a W-E rainfall/temperature gradient and a strong climate-sensitivity to shifts in the large-scale atmospheric patterns. A radiocarbon-dated sediment core, taken from the ancient Lake Lerna, a former lake in NE Peloponnese, was analyzed for distribution and hydrogen isotope (δD) composition of n-alkanes and bulk organic geochemistry (δ13C, TOC). The predominantly macrophyte (submerged/floating)-derived δD23 profile exhibits the largest long-term fluctuation in the record and co-varies with δD of long-chain n-alkanes providing evidence for precipitation and temperature changes over the last 5000 years. The Lerna δD23 signal is sometimes in agreement with other n-alkane δD records from SW Peloponnese indicating wetter conditions in the peninsula at ca 5000–4600, ca 4500–4100, ca 3000–2600 (more unstable in SW) and after ca 700 cal BP with drier periods at ca 4100–3900 and ca 1000–700 cal BP. Conversely, a NE-SW climate see-saw is revealed at ca 4600–4500, ca 3200, ca 2600–1800, and ca 1200–1000 cal BP when the δD23 Lerna exhibits more positive trends (drier in NE) with a reversal at ca 3900–3300, ca 3200–3000 and ca 1800–1300 cal BP. These opposing and sometimes similar signals between NE and SW Peloponnese can be explained by the relative dominance of high-latitude atmospheric patterns over the peninsula. A similar signal would be expected when the North Atlantic Oscillation (NAO) exerts the main control with NAO (+) creating conditions of reduced moisture. The dipole pattern is likely driven by shifts in North Sea–Caspian Atmospheric pattern (NCP), which account for the present-day regional climate variability with NCP (+) leading to wetter and colder conditions in NE Peloponnese. The Asian monsoonal system likely has an additional impact on the δD variabilities through influencing the summer temperatures. There is a consistency between the Peloponnesian δD signals and monsoonal records after ca 4000 cal BP confirming the actualistic models. Strong monsoonal periods coincide with cooler summers (lower δD values) in Lerna, due to the northerly winds, the Etesians. On the contrary, SW Peloponnese is dominated by warmer conditions during the same periods as the area is located on the lee side of the mountain and highly influenced by the adiabatic warming associated with the subsidence over the Eastern Mediterranean.
9.	Katrantsiotis, Christos, et al. (author) Eastern Mediterranean hydroclimate reconstruction over the last 3600 years based on sedimentary n-alkanes, their carbon and hydrogen isotope composition and XRF data from the Gialova Lagoon, SW Greece 2018 In: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791 .- 1873-457X. ; 194, s. 77-93 Journal article (peer-reviewed)abstract Understanding past hydroclimate variability and related drivers is essential to improve climate forecasting capabilities especially in areas with high climatic sensitivity, such as the Mediterranean. This can be achieved by using a broad spectrum of high resolution, multiple proxy records which can also allow us to assess linkages between regional hydroclimate variability and shifts in the large-scale atmospheric patterns. Here, we present a multiproxy reconstruction of the central-eastern Mediterranean hydro climate changes over the last 3600 years based on a sediment core from the Gialova Lagoon, a shallow coastal ecosystem in SW Peloponnese, Greece. Our combined dataset consists of the distribution and compound-specific carbon and hydrogen isotope (delta C-13 and 8D) composition of n-alkanes, bulk organic matter properties and X-ray fluorescence (XRF) core scanning data. This approach was complemented with a semi-quantitative analysis of plant remains in the core. The results indicate a high contribution of local aquatic vegetation to organic matter. Large delta C-13 variations in predominantly aquatic plant-derived mid-chain alkanes (C23-23) mainly reflect changes in the aquatic plant abundance and their carbon source. Our data suggest that higher delta C-13(23-25) values (up to 19 parts per thousand) largely correspond to expansion of aquatic vegetation during wet and/or cold periods causing carbon-limiting conditions in the water and assimilation of isotopically-enriched bicarbonate by the plants. The 8D records of the individual n-alkanes (C-17 to C-31) exhibit a nearly identical pattern to each other, which implies that they all reflect changes in the source water isotope composition, driven by hydroclimate variability. In addition, the 8D profiles are consistent with the XRF data with both proxies being driven by a common hydroclimate signal. We observe two major shifts from dry and/or warm periods at ca 3600-3000 cal BP and ca 17001300 cal BP to wet and/or cold episodes at ca 3000-2700 cal BP and ca 1300-900 cal BP. The period ca 700-200 cal BP is the wettest and/or coldest in our record and coeval with the Little Ice Age. The climatic fluctuation reported in this study can be explained by the relative dominance of high-latitude (e.g. North Atlantic Oscillation during winters) and the low-latitude atmospheric patterns (Intertropical convergence zone, Subtropical High and the effects of Asian monsoons during summers) which suggests an Atlantic-Mediterranean-Monsoon climate link in this area for the late Holocene.
10.	Katrantsiotis, Christos, et al. (author) High-resolution environmental reconstruction in SW Peloponnese, Greece, covering the last c. 6000years : Evidence from Agios Floros fen, Messenian plain 2016 In: The Holocene. - : SAGE Publications. - 0959-6836 .- 1477-0911. ; 26:2, s. 188-204 Journal article (peer-reviewed)abstract A paleolimnological record from the central Messenian plain (southwestern Peloponnese, southern Greece) indicates rapid changes in the water level and chemistry of a transient lake on the flanks of the Taygetos Mountains during the last c. 6000years. The analyses are based on diatoms as well as carbon and nitrogen isotopes from bulk sediments in a 7.5-m-long sediment core retrieved from the drained fen of Agios Floros, at the northern banks of the ancient River Pamisos. The sequence consists of fen peat in the uppermost section underlain by lacustrine sediments, which are punctuated by two layers of clay with diatomaceous silt bands. High accumulation rate is recorded in the oldest part of the section (up to 23mm/yr), particularly during two decadal-long periods centered at c. 5700 and c. 5300 cal. BP. The diatom record reveals pronounced peaks in the planktonic taxon Cyclotella distinguenda, which correspond to the laminated sequences, reflecting the rapid development of a deep lake with an open water environment during these two time periods. Another two events with intermediate water levels are inferred at c. 5200 and c. 4600 cal. BP. These short-lived phases were probably, to a large extent, caused by local tectonic processes and the consequent hydrological anomalies of the nearby karst springs, although abrupt climatic changes with enhanced precipitation might have also played a role. At c. 4500 cal. BP, our data suggest the development of terrestrial conditions in this area, which can be attributed to the decreasing activity/dry up of springs, probably associated with more arid climate. After c. 2500 cal. BP, the diatom record infers a return to wetter conditions, probably as a response to more humid climate with marked seasonality and human activities, developing the present-day environment with cultivated and seasonally semi-flooded fields.
11.	Katrantsiotis, Christos, 1982- (author) Holocene environmental changes and climate variability in the Eastern Mediterranean : Multiproxy sediment records from the Peloponnese peninsula, SW Greece 2019 Doctoral thesis (other academic/artistic)abstract This thesis presents multiproxy reconstructions of the mid to late Holocene climate and environmental changes in the Peloponnese peninsula, SW Greece. The combined dataset consists of diatom, biomarker and X-ray fluorescence spectrometry (XRF) elemental data in radiocarbon-dated sediment cores taken from the Agios Floros fen and the Gialova Lagoon in SW Peloponnese and the Ancient Lake Lerna in NE Peloponnese. Overall, the results highlight the complex interaction between climate, tectonics and human activities in the landscape development and further reveal changes in the W-E precipitation/temperature gradient over the peninsula connected to shifts in the large-scale atmospheric circulation patterns.The Agios Floros study provides a 6000-year hydrological record based on diatoms and hydrogen isotopic (δD) analysis of aquatic plant-derived n-C23 alkanes. The records indicate two decadal-long periods of deep water conditions at ca 5700 and 5300 cal BP, largely attributed to local tectonic processes and the hydrological anomalies of the nearby karst springs. A period of intermediate water level at ca 4600 cal BP is dominated by the new fossil species Cyclotella paradistinguenda described in this thesis. The gradual development of a fen at ca 4500 cal BP is attributed to a combination of human activities and drier conditions, the latter culminating in SW Peloponnese mainly after ca 4100 cal BP. From ca 2800 cal BP and onwards, there is evidence for flooding events probably related to marked rainfall seasonality.The n-alkane δD profiles and XRF data analyzed in the Gialova core co-vary with each other indicating a common climate signal during the last 3600 years, which resembles the Agios Floros record. The n-alkane δ13C values show high contribution of aquatic vegetation to sedimentary organic matter during wet/cold periods. The n-alkane δD signals from the Lake Lerna also exhibit a similar pattern to each other providing further evidence for precipitation/temperature changes over the last 5000 years.Comparison of the δD records reveals sometimes similar and sometimes opposing signals between NE and SW Peloponnese, which can be attributed to the relative dominance of high latitude and low latitude atmospheric patterns over the peninsula. The records show wet conditions at ca 5000-4600 cal BP likely associated with the weakening of the Hadley circulation. High humidity is also evident at ca 4500-4100, ca 3000-2600 (more unstable in SW) and after ca 700 cal BP with drier conditions at ca 4100-3900 and ca 1000-700 cal BP. These periods correspond to regional climate changes, when the North Atlantic Oscillation (NAO) likely exerted the main control with NAO (+) creating conditions of reduced moisture. A NE-SW climate see-saw with drier conditions in NE Peloponnese is evident at ca 4600-4500, ca 3200, ca 2600-1800 and ca 1200-1000 cal BP and a reversal at ca 3900-3300 ca 3200-3000 and ca 1800-1300 cal BP. The dipole pattern is likely driven by shifts in the North Sea–Caspian Atmospheric pattern (NCP), with NCP (+) leading to wetter and colder conditions in NE Peloponnese. The opposing signal can also be explained by changes in summer temperatures driven by the Asian monsoon intensity. Strong monsoonal periods coincide with cool summers in Lerna, due to the northerly winds (Etesians), in contrast to SW Peloponnese, located on the lee side of the mountain and most affected by the large-scale air subsidence.
12.	Katrantsiotis, Christos, et al. (author) Late quaternary hydroclimate variability in Madagascar and its connection to atmospheric circulation patterns 2024 In: Palaeogeography, Palaeoclimatology, Palaeoecology. - : Elsevier. - 0031-0182 .- 1872-616X. ; 649 Journal article (peer-reviewed)abstract Large uncertainties still exist about the long-term mechanisms influencing the hydroclimate variability of southeast Africa where proxy data and model simulations indicate rainfall dipoles between subtropical and tropical areas. The topography of Madagascar, located off the southeastern coast of Africa, modulates these dipoles while its climate is influenced by the position of the Intertropical Convergence Zone (ITCZ) and the Subtropical High as well as the sea surface temperature (SST) of SW Indian Ocean. The island can thus be considered a key location for the understanding of the tropical SE African climatic variability and the interplay between atmospheric patterns. However, the scarcity of continuous records from Madagascar has made the evolution of regional late Quaternary climate and its driving mechanisms difficult to assess. Here, we present a 26-kyr record of the deuterium/hydrogen isotope ratio (δD) of biomarkers (n-alkanes) from the central eastern part of the island at Antananarivo at around 1250 m a.s.l. Preliminary summary pollen data are also presented as a comparison. The δD profiles of aquatic plant and terrestrial plant-derived n-alkanes generally exhibit similar trends implying that they all record changes in the isotope composition of source water, namely meteoric water that recharges soil and lake waters. In this tropical region, the δD variability of precipitation is mainly influenced by the amount effect reflecting the intensity of precipitation associated with the monsoon. We observe: (i) stable and wet conditions during the Last Glacial Maximum, (ii) drier conditions from 18.5 to 15 ka (ka before present) during the Heinrich Stadial 1 (iii) high humidity after 15 ka culminating at the Younger Dryas (YD), (iv) drier conditions from 11.7 ka to 8.2 ka, (v) a return to humid climate until 2.8 ka, and (vi) an arid phase followed by increased wetness after 0.9 ka, although the record is likely influenced by human-induced vegetation changes the last 1.2 ka. This climate signal is similar to other records from the Mozambique Channel but opposite to records from the East African mainland and the subtropical southern Africa, especially between 20 and 25°S. Although there is a good correspondence of our record with insolation- driven migrations of ITCZ during the LGM and the early Holocene, the dipoles are largely consistent with the modern rainfall anomaly and are best explained by the interlinked effects of the SST changes and the variability of the Mozambique Channel Trough.
13.	Katrantsiotis, Christos, et al. (author) Morphological study of Cyclotella distinguenda with a description of a new fossil species Cyclotella paradistinguenda sp nov from the Agios Floros fen, SW Peloponnese, Greece in relation to other Cyclotella species 2016 In: Diatom Research. - 0269-249X .- 2159-8347. ; 31:3, s. 243-267 Journal article (peer-reviewed)abstract In a previous palaeoenvironmental study based on a high-resolution diatom record from a core sampled at the Agios Floros fen, SW Peloponnese, Greece, Cyclotella distinguenda was reported as exhibiting two morphs with distinct central area and stria arrangement, as well as a specific distribution throughout the sequence. In the present paper, we examine this morphological variability through detailed observations using light and scanning electron microscope combined with a simple statistical approach. Our new data suggest that the two morphs present substantial and constant differences in the structure and size of their central areas, the structure and number of their striae, the arrangement of their marginal fultoportulae/density of costae between fultoportulae, the shape of their rimoportulae and their alveolar chambers. On the basis of these morphological and stratigraphic variations one morph is described as a new species, Cyclotella paradistinguenda sp. nov., while the other is assigned to C. distinguenda and is also consistent with the original description of this taxon. The two species share well-defined central areas without fultoportulae, almost equal length striae and one rimoportula situated on a costa within the ring of marginal fultoportulae. Cyclotella paradistinguenda sp. nov. can be distinguished by a combination of the following characteristics: (1) large central area (1/3 of valve diameter), smooth or decorated with puncta and depressions, flat or concentrically undulated, (2) distinct, narrow striae (12-15/10 mu m) consisting of one or two short rows of areolae of the same size expanding into three rows at the mantle, (3) marginal fultoportulae on each first to third costae (4) poorly developed alveolar chambers and rimoportula. Based on the stratigraphic distribution and the associated flora in the Agios Floros sequence, it can be inferred that C. paradistinguenda sp. nov. is tolerant of shallower water conditions with lower nutrient availability and/or higher pH than C. distinguenda.
14.	Katrantsiotis, Christos, et al. (author) Seasonal variability in temperature trends and atmospheric circulation systems during the Eemian (Last Interglacial) based on n-alkanes hydrogen isotopes from Northern Finland 2021 In: Quaternary Science Reviews. - Amsterdam : Elsevier. - 0277-3791 .- 1873-457X. ; 273, s. 107250-107250 Journal article (peer-reviewed)abstract The Last Interglacial warm period, the Eemian (ca. 130-116 thousand years ago), serves as a reference for projected future climate in a warmer world. However, there is a limited understanding of the seasonal characteristics of interglacial climate dynamics, especially in high latitude regions. In this study, we aimto provide new insights into seasonal trends in temperature and moisture source location, linked to shifts in atmospheric circulation patterns, for northern Fennoscandia during the Eemian. Our study is based on the distribution and stable hydrogen isotope composition (dD) of n-alkanes in a lake sediment sequence from the Sokli paleolake in NE Finland, placed in a multi-proxy framework. The dD values of predominantly macrophyte-derived mid-chain n-alkanes are interpreted to reflect lake water dD variability influenced by winter precipitation dD (dDprec), ice cover duration and deuterium (D)-depleted meltwater. The dD values of terrestrial plant-derived long-chain n-alkanes primarily reflect soil water dD variability modulated by summer dDprec and by the evaporative enrichment of soil and leaf water. The dDprec variability in our study area is mostly attributed to the temperature effect and the moisture source location linked to the relative dominance between D-depleted continental and polar air masses and Denriched North Atlantic air masses. The biomarker signal further corroborates earlier diatom-based studies and pollen-inferred January and July temperature reconstructions from the same sediment sequence. Three phases of climatic changes can be identified that generally follow the secular variationsin seasonal insolation: (i) an early warming trend succeeded by a period of strong seasonality (ii) a midoptimum phase with gradually decreased seasonality and cooler summers, and (iii) a late climatic instability with a cooling trend. Superimposed on this trend, two abrupt cooling events occur in the early and late Eemian. The Sokli dD variability is generally in good agreement with other North Atlantic and Siberian records, reflecting major changes in the atmospheric circulation patterns during the Eemian as a response to orbital and oceanic forcings.
15.	Kylander, Malin E., et al. (author) Late glacial (17,060-13,400 cal yr BP) sedimentary and paleoenvironmental evolution of the Sekhokong Range (Drakensberg), southern Africa 2021 In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 16:3 Journal article (peer-reviewed)abstract Southern Africa sits at the junction of tropical and temperate systems, leading to the formation of seasonal precipitation zones. Understanding late Quaternary paleoclimatic change in this vulnerable region is hampered by a lack of available, reliably-dated records. Here we present a sequence from a well-stratified sedimentary infill occupying a lower slope basin which covers 17,060 to 13,400 cal yr BP with the aim to reconstruct paleoclimatic variability in the high Drakensberg during the Late Glacial. We use a combination of pollen, total organic carbon and nitrogen, delta C-13, Fourier transform infrared spectroscopy attenuated total reflectance (FTIR-ATR) spectral and elemental data on contiguous samples with high temporal resolution (10 to 80 years per sample). Our data support a relatively humid environment with considerable cold season precipitation during what might have been the final stage of niche-glaciation on the adjoining southern aspects around 17,000 cal yr BP. Then, after an initial warmer and drier period starting similar to 15,600 cal yr BP, we identify a return to colder and drier conditions with more winter precipitation starting similar to 14,380 cal yr BP, which represents the first local evidence for the Antarctic Cold Reversal (ACR) in this region. On decadal to centennial timescales, the Late Glacial period was one marked by considerable climatic fluctuation and bi-directional environmental change, which has not been identified in previous studies for this region. Our study shows complex changes in both moisture and thermal conditions providing a more nuanced picture of the Late Glacial for the high Drakensburg.
16.	Malmborg, Katja, et al. (author) Embracing complexity in landscape management : Learning and impacts of a participatory resilience assessment Other publication (other academic/artistic)
17.	Malmborg, Katja, 1988-, et al. (author) Embracing complexity in landscape management : Learning and impacts of a participatory resilience assessment 2022 In: Ecosystems and People. - : Informa UK Limited. - 2639-5908 .- 2639-5916. ; 18:1, s. 241-257 Journal article (peer-reviewed)abstract Landscapes and their management are at the center of many of the sustainability challenges that we face. Landscapes can be described as social-ecological systems shaped by a myriad of human activities and biophysical processes, interacting across space and time. Managing them sustainably requires considering this complexity. Resilience thinking offers ways to address complexity in decision-making. In this paper, we analyse the learning and impact on a diverse group of local actors from participating in a participatory resilience assessment. The assessment, focused on sustainable landscape management in the Helge a catchment, Sweden, produced concrete knowledge outputs, describing ecosystem service bundles, a future vision, conceptual system models, and a strategic action plan. Follow-up interviews indicate that the process and its outputs supported the participants' learning process and helped them to articulate complexity thinking in practice. The outputs, and the exercises to produce them, emerged as complementary in supporting this articulation. Furthermore, they helped build participants' capacity to communicate the diverse values of the landscape to others and to target leverage points more strategically. Thus, it supported the application of resilience thinking in landscape management, especially by generating learning and fostering complex adaptive systems thinking.
18.	Malmborg, Katja, 1988- (author) How on Earth : Operationalizing the ecosystem service concept for local sustainability 2019 Licentiate thesis (other academic/artistic)abstract Ecosystem services are co-produced in social-ecological systems. Due to their social-ecological framing, ecosystem services hold the potential to be a concept around which different stakeholders with vested interests in different aspects of landscape management can meet. However, how this potential is to be realized and the ecosystem services concept operationalized for local decision-making needs to be explored further.In this licentiate thesis, focusing on the Helge å catchment, Sweden, I investigate the social-ecological system dynamics underlying current ecosystem services generation in the area. Together with a group of local to regional stakeholders I performed an iterative, participatory ecosystem service assessment, producing three distinct ecosystem service bundles in the study area. The process to produce the ecosystem service bundles helped in creating a common picture of the landscape among the participants. Ecosystem services also emerged as abridging concept around which the diverse set of participants could meet (paper 1). The ecosystem service bundles were then used as the starting point to co-produce a shared system understanding among the participants and though the formulation of a positive vision for the landscape, start a conversation about sustainability transformations. Based on the outputs from the participatory process and two rounds of interviews with the participants, we assessed to what extent these exercises promoted learning about complexity among the participants, fostered resilience thinking and produced usable knowledge for decision-making (paper 2).Throughout this participatory process of exploring system dynamics and positive futures, I believe that I have kept the rich social-ecological nature of the ecosystem service concept intact while at the same time co-developed concrete, usable results to support local decision-making for sustainability. In addition to being a bridging concept in the participatory process, the ecosystem service concept emerged as a valuable pedagogical tool and as a means for the participants to communicate their system understanding to other actors within and outside their own organizations.
19.	Malmborg, Katja, et al. (author) Operationalizing ecosystem service bundles for strategic sustainability planning : A participatory approach 2021 In: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 50, s. 314-331 Journal article (peer-reviewed)abstract The ecosystem service concept is recognized as a useful tool to support sustainability in decision-making. In this study, we collaborated with actors in the Helge a catchment, southern Sweden, in an iterative participatory ecosystem service assessment. Through workshops and interviews, we jointly decided which ecosystem services to assess and indicators to use in order to achieve a sense of ownership and a higher legitimacy of the assessment. Subsequently, we explored the landscape-level interactions between the 15 assessed services, and found that the area can be described using three distinct ecosystem service bundles. The iterative, participatory process strengthened our analysis and created a shared understanding and overview of the multifunctional landscape around Helge a among participants. Importantly, this allowed for the generated knowledge to impact local strategic sustainability planning. With this study, we illustrate how similar processes can support local decision-making for a more sustainable future.
20.	Meacham, Megan, 1986-, et al. (author) Advancing research on ecosystem service bundles for comparative assessments and synthesis 2022 In: Ecosystems and People. - : Informa UK Limited. - 2639-5908 .- 2639-5916. ; 18:1, s. 99-111 Journal article (peer-reviewed)abstract Social-ecological interactions have been shown to generate interrelated and reoccurring sets of ecosystem services, also known as ecosystem service bundles. Given the potential utility of the bundles concept, along with the recent surge in interest it is timely to reflect on the concept, its current use and potential for the future. Based on our ecosystem service bundle experience, expertise, and ecosystem service bundle analyses, we have found critical elements for advancing the utility of ecosystem service bundle concept and deepening its impact in the future. In this paper we 1) examine the different conceptualizations of the ecosystem service bundle concept; 2) show the range of benefits of using a bundles approach; 3) explore key issues for improving research on ecosystem service bundles, including indicators, scale, and drivers and relationships between ecosystem services; and 4) outline priorities for the future by facilitating comparisons of ecosystem service bundle research.
21.	Meacham, Megan, et al. (author) Ecosystem service bundles : insights for assessments and comparisons Other publication (other academic/artistic)
22.	Moore, Michele-Lee, et al. (author) Studying the complexity of change : toward an analytical framework for understanding deliberate social-ecological transformations 2014 In: Ecology and Society. - 1708-3087. ; 19:4, s. 54- Journal article (peer-reviewed)abstract Faced with numerous seemingly intractable social and environmental challenges, many scholars and practitioners are increasingly interested in understanding how to actively engage and transform the existing systems holding such problems in place. Although a variety of analytical models have emerged in recent years, most emphasize either the social or ecological elements of such transformations rather than their coupled nature. To address this, first we have presented a definition of the core elements of a social-ecological system (SES) that could potentially be altered in a transformation. Second, we drew on insights about transformation from three branches of literature focused on radical change, i.e., social movements, socio-technical transitions, and social innovation, and gave consideration to the similarities and differences with the current studies by resilience scholars. Drawing on these findings, we have proposed a framework that outlines the process and phases of transformative change in an SES. Future research will be able to utilize the framework as a tool for analyzing the alteration of social-ecological feedbacks, identifying critical barriers and leverage points and assessing the outcome of social-ecological transformations.
23.	Norström, Elin, et al. (author) A 600 year long δ18O-record from cellulose of Breonadia salicina trees, South Africa 2008 In: Dendrochronologia. ; :26, s. 21-33 Journal article (peer-reviewed)abstract The oxygen isotope composition in cellulose was analysed along the growth axis of two 600-year-old Breonadia salicina trees (Matumi) from subtropical South Africa, with the aim of testing the isotope variations as a regional climate proxy. The visible tree rings in B. salicina are not annual and therefore radiocarbon analysis was applied to produce an age model for the isotope record, covering the time period between 1375 and 1995 AD. Before _1600 AD, a co-variation is evident between the variations in d18Ocellulose and previously published d13Ccellulose, indicating that a common factor is responsible for both the carbon and the oxygen isotope signals in the tree cellulose. Between _1600 and _1900 AD, the correlation between the isotope series weakens, concurrently with drastic changes in growth rates and average ring production rates. Possibly, this phase was a result of extreme changes in the growth environment, affecting the cellulose production rate, the source water d18O signal and the proportion of different types of oxygen isotope fractionation processes affecting the final isotope composition in the tree cellulose. We suggest that during the lifetime of the two B. salicina trees, different factors have governed the oxygen isotope signal in the cellulose. Both regional climate conditions and site-specific factors associated with the riparian growth environment have had an impact on the oxygen isotope variations in the two trees, clearly complicating the possibilities to utilise a d18Ocellulose record from this tree species for paleoclimatic reconstruction.
24.	Norström, Elin, et al. (author) Biomarker hydrogen isotope composition (D) as proxy for Holocene hydroclimatic change and seismic activity in SW Peloponnese, Greece 2018 In: Journal of Quaternary Science. - : Wiley. - 0267-8179 .- 1099-1417. ; 33:5, s. 563-574 Journal article (peer-reviewed)abstract We present a 6000-year-long record tracing hydroclimate changes in SW Greece, based on hydrogen isotope composition of aquatic plant-derived n-C-23 alkanes (D-C23) in a sediment core from the Messenian plain, Peloponnese. The D-C23 record co-varies with other eastern Mediterranean records, suggesting relatively wetter conditions c. 6-4.5ka, followed by progressively drier conditions leading up to maximum aridity c. 2.8 ka. This arid phase was interrupted by a shift in D-C23 between 3.3 and 3.1ka inferring wetter conditions and/or tentative responses to anthropogenic water regulating activities during the Late Bronze Age. After 2.7ka, a return to more humid conditions was followed by increased dryness and stronger seasonality contrasts from c. 2.0ka. The D-C23 record shows three short-lived excursions (5.7, 5.3, 2.8ka), where isotope values dropped by >20 parts per thousand and immediately stabilized again. The events were paralleled by abrupt increases in sedimentation rates. We hypothesize that the isotopic shifts represent a response to mixing of ground water systems during tectonic events, followed by sealing of seismically derived cracks in the active fault. The outcome of the study is promising for future expansion of isotope-based proxies on sediments in the region, to reconstruct both hydroclimate and past seismic activity.
25.	Norström, Elin, et al. (author) Chemotaxonomy in some Mediterranean plants and implications for fossil biomarker records 2017 In: Geochimica et Cosmochimica Acta. - : Elsevier BV. - 0016-7037 .- 1872-9533. ; 219, s. 96-110 Journal article (peer-reviewed)abstract The increasing utilization of n-alkanes as plant-derived paleo-environmental proxies calls for improved chemotaxonomic control of the modern flora in order to calibrate fossil sediment records to modern analogues. Several recent studies have investigated long-chain n-alkane concentrations and chain-length distributions in species from various vegetation biomes, but up to date, the Mediterranean flora is relatively unexplored in this respect. Here, we analyse the n-alkane concentrations and chain-length distributions in some of the most common species of the modern macchia and phrygana vegetation in south western Peloponnese, Greece. We show that the drought adapted phrygana herbs and shrubs, as well as some of the sclerophyll and gymnosperm macchia components, produce high concentrations of n-alkanes, on average more than double n-alkane production in local wetland reed vegetation. Furthermore, the chain-length distribution in the analysed plants is related to plant functionality, with longer chain lengths associated with higher drought adaptive capacities, probably as a response to long-term evolutionary processes in a moisture limited environment. Furthermore, species with relatively higher average chain lengths (ACL) showed more enriched carbon isotope composition in their tissues (delta C-13(plant)), suggesting a dual imprint from both physiological and biochemical drought adaptation. The findings have bearings on interpretation of fossil sedimentary biomarker records in the Mediterranean region, which is discussed in relation to a case study from Agios Floros fen, Messenian plain, Peloponnese. The 6000 year long n-alkane record from Agios Floros (ACL, delta C-13(wax)) is linked to the modern analogue and then evaluated through a comparison with other regional-wide as well as local climate and vegetation proxy-data. The high concentration of long chain n-alkanes in phrygana vegetation suggests a dominating imprint from this vegetation type in sedimentary archives from this ecotone.

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