scholarly journals Cladoceran (Crustacea) Niches, Sex, and Sun Bathing—A Long-Term Record of Tundra Lake (Lapland) Functioning and Paleo-Optics

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2008 ◽  
Author(s):  
Liisa Nevalainen ◽  
E. Henriikka Kivilä ◽  
Marttiina V. Rantala ◽  
Tomi P. Luoto
Keyword(s):  
Major Change ◽  
Open Water ◽  
Ice Age ◽  
Benthic Habitat ◽  
Aquatic Communities ◽  
Benthic Production ◽  
Finnish Lapland ◽  
Environmental Controls ◽  
Holistic Understanding

Under fundamental ecosystem changes in high latitude lakes, a functional paleolimnological approach may increase holistic understanding of lake responses and resilience to climate warming. A ~2000-year sediment record from Lake Loažžejávri in the tundra of northern Finnish Lapland was examined for fossil Cladocera assemblages to examine long-term environmental controls on aquatic communities. In addition, cladoceran functional attributes, including functional diversity (FD), UV absorbance (ABSUV) of Alona carapaces, and sexual reproduction (ephippia) in Bosmina and Chydoridae were analyzed. Cladoceran communities responded to a major change in benthic habitat quality, reflected as elevated (increasingly benthic) sediment organic matter δ13C signal since the 17th century. FD fluctuations showed association with climate oscillation, FD being generally higher during warm climate periods. These ecological changes were likely attributable to diversification of littoral-benthic consumer habitat space. ABSUV, irrespective of increases during the Little Ice Age (LIA) due to higher UV transparency of lake water, was lower under increasing autochthony (benthic production) suggesting establishment of physical UV refugia by the benthic vegetative substrata. Bosmina ephippia exhibited a decreasing trend associated with increasing benthic production, indicating favorable environmental regime, and, together with chydorid ephippia, transient increases during the climate cooling of the LIA driven by shorter open-water season.

Temperature patterns over the past eight centuries in Northern Fennoscandia inferred from sedimentary diatoms

2006 ◽  
Vol 66 (1) ◽  
pp. 78-86 ◽  
Author(s):  
Jan Weckström ◽  
Atte Korhola ◽  
Panu Erästö ◽  
Lasse Holmström
Keyword(s):  
Temperature Variability ◽  
Ice Age ◽  
Terminal Phase ◽  
Polar Regions ◽  
The Past ◽  
Northern Fennoscandia ◽  
Finnish Lapland ◽  
Sedimentary Diatoms ◽  
Natural Climate

AbstractEstablishing natural climate variability becomes particularly important in remote polar regions, especially when considering questions regarding higher than average warming. We present a high-resolution record of temperature variability for the past 800 yr based on sedimentary diatoms from a treeline lake in Finnish Lapland. The BSiZer multiscale smoothing technique is applied to the data to identify significant features in the record at different temporal levels. The overall reconstruction shows relatively large multi-centennial temperature variability with a total range of about 0.6–0.8°C. At millennial scales, the temperatures exhibit a statistically significant long-term cooling trend prior to industrialization (ΔT = −0.03°C/century). At the centennial timescale, three warm time intervals were identified around AD 1200–1300 (terminal phase of the Medieval Warm Period, MWP), 1380–1550 and from 1920 until the present. Pronounced coolness occurred between AD 1600 and 1920, indicative of the Little Ice Age (LIA). At the decadal level, certain shorter-term climate excursions were revealed. The warmest ∼10–30 yr, non-overlapping periods occurred in AD 1220–1250, 1470–1500 and 1970–2000, respectively. The classic events of MWP and LIA are evident in our record, as is also the 20th century warming.

Monitoring Effects of Catchment Management Practices on Phosphorus Loads into the Eutrophic Peel-Harvey Estuary, Western Australia

1986 ◽  
Vol 18 (4-5) ◽  
pp. 53-61 ◽  
Author(s):  
P. B. Birch ◽  
G. G. Forbes ◽  
N. J. Schofield
Keyword(s):  
Management Practices ◽  
Major Change ◽  
High Flow ◽  
Catchment Management ◽  
Flow Rates ◽  
Early Results ◽  
Phosphorus Loads ◽  
Time Of Year ◽  
High Runoff

Early results from monitoring runoff suggest that the programme to reduce application of superphosphate to farmlands in surrounding catchments has been successful in reducing input of phosphorus to the eutrophic Peel-Harvey estuary. In the estuary this phosphorus fertilizes algae which grow in abundance and accumulate and pollute once clean beaches. The success of the programme has been judged from application of an empirical statistical model, which was derived from 6 years of data from the Harvey Estuary catchment prior to a major change in fertilizer practices in 1984. The model relates concentration of phosphorus with rate of flow and time of year. High phosphorus concentrations were associated with high flow rates and with flows early in the high runoff season (May-July). The model predicted that the distribution of flows in 1984 should have resulted in a flow-weighted concentration of phosphorus near the long-term average; the observed concentration was 25% below the long-term average. This means that the amount of phosphorus discharged into the Harvey Estuary could have been about 2 5% less than expected from the volume of runoff which occurred. However several more years of data are required to confirm this trend.

scholarly journals Content analysis for <i>Agricultural Records</i> of the United Kingdom, AD 200 to 1977: a study of frequency in human records concerning climate phenomenon

2011 ◽  
Vol 7 (4) ◽  
pp. 2555-2577
Author(s):  
D. H. Holt
Keyword(s):  
Content Analysis ◽  
Ice Age ◽  
Climate Data ◽  
The United Kingdom ◽  
Weather Phenomenon ◽  
Continuous Record ◽  
Frequency Occurrence ◽  
The Uk ◽  
Climate Events

Abstract. A content analysis has been completed on a text from the UK that has gathered agricultural and climate data from the years AD 220 to 1977 from 100s of sources. The content analysis coded all references to climate and agriculture to ascertain which climate events were recorded and which were not. This study addressed the question: is there bias in human records of climate? This evaluated the continuous record (AD 1654–1977), discontinous record (AD 220–1653), the whole record (AD 220–1977), the Little Climate Optimum (AD 850–1250) and the Little Ice Age (AD 1450–1880). This study shows that there is no significant variation in any of these periods in frequency occurrence of "good" or "bad" climate suggesting humans are not recording long-term changes in climate, but they are recording weather phenomenon as it occurs.

scholarly journals Ice genesis and its long-term dynamics in Scărişoara Ice Cave, Romania

2010 ◽  
Vol 4 (4) ◽  
pp. 1909-1929
Author(s):  
A. Perşoiu ◽  
A. Pazdur
Keyword(s):  
Radiocarbon Dating ◽  
Ice Age ◽  
Clear Understanding ◽  
Lake Ice ◽  
Ice Flow ◽  
Paleoclimatic Significance ◽  
Basal Melting ◽  
Perennial Ice ◽  
Level Monitoring

Abstract. The paleoclimatic significance of the perennial ice deposit in Scărişoara Ice Cave has been remarked since the early 20th century, but a clear understanding of the processes involved in the genesis, age and long-term dynamics of ice hampered all attempts to extract valuable data on past climate and vegetation changes. In this paper, we present a model of ice genesis and dynamics, based on stable isotopes, ice level monitoring (modern and archived) and radiocarbon dating of organic matter found in the ice. Ice in Scărişoara Ice Cave mostly consists of layers of lake ice, produced as liquid water freezes from top to bottom in mid-autumn, a mechanism that was also acting in the past, during the Medieval Warm Period and the Little Ice Age. The ice block is not stable in shape and volume, being continuously modified by ablation on top, basal melting and lateral flow. Radiocarbon dating shows that the ice block is older than 1200 years, the rate of ice flow and basal melting suggesting that the ice could be much older.

scholarly journals Effects of reindeer grazing and recovery after cessation of grazing on the ground-dwelling spider assemblage in Finnish Lapland

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7330
Author(s):  
Teemu Saikkonen ◽  
Varpu Vahtera ◽  
Seppo Koponen ◽  
Otso Suominen
Keyword(s):  
Species Richness ◽  
Rangifer Tarandus ◽  
Forest Ecosystems ◽  
Grazing Pressure ◽  
Ground Vegetation ◽  
Total Abundance ◽  
Finnish Lapland ◽  
Species Specific ◽  
The Impact

The effect of reindeer Rangifer tarandus L. grazing on the ground-dwelling spider assemblage in Northern Finland was studied. Changes in species richness, abundance and evenness of spider assemblages were analyzed in relation to changes in vegetation and environmental factors in long term grazed and ungrazed sites as well as sites that had recently switched from grazed to ungrazed and vice versa. Grazing was found to have a significant impact on height and biomass of lichens and other ground vegetation. However, it seemed not to have an impact on the total abundance of spiders. This is likely caused by opposing family and species level responses of spiders to the grazing regime. Lycosid numbers were highest in grazed and linyphiid numbers in ungrazed areas. Lycosidae species richness was highest in ungrazed areas whereas Linyphiidae richness showed no response to grazing. Four Linyphiidae, one Thomisidae and one Lycosidae species showed strong preference for specific treatments. Sites that had recovered from grazing for nine years and the sites that were grazed for the last nine years but were previously ungrazed resembled the long term grazed sites. The results emphasize the importance of reindeer as a modifier of boreal forest ecosystems but the impact of reindeer grazing on spiders seems to be family and species specific. The sites with reversed grazing treatment demonstrate that recovery from strong grazing pressure at these high latitudes is a slow process whereas reindeer can rapidly change the conditions in previously ungrazed sites similar to long term heavily grazed conditions.

Transitions in Technology Mediated Cardiac Rehabilitation and Self-management: A Qualitative Study using the Theoretical Domains Framework (Preprint)

2021 ◽  
Author(s):  
Shreya Tadas ◽  
Claudette Pretorius ◽  
Emma J. Foster ◽  
Trish Gorely ◽  
Stephen J. Leslie ◽  
...  
Keyword(s):  
Cardiac Rehabilitation ◽  
Behaviour Change ◽  
Theoretical Domains Framework ◽  
Self Management ◽  
Normal Life ◽  
Use Of Technology ◽  
Holistic Understanding ◽  
The Impact ◽  
Over Time

BACKGROUND An acute cardiac incident is a life changing event, often necessitating surgery. While surgery has high success rates, rehabilitation, behaviour change, and self-care are critical to long-term health. Recent systematic reviews highlight the potential of technology in this area, but significant shortcomings are also identified, particularly in regard to patient experience. OBJECTIVE To improve future systems this paper explores the experiences of cardiac patients during key phases post-hospitalisation: recuperation, initial rehabilitation and long term self-management. The key objective is to provide a holistic understanding of behavioural factors that impact people across these phases, understand how experiences evolve over time, and provide user-centred recommendations to improve the design of cardiac rehabilitation and self-management technologies. METHODS Semi-structured interviews were conducted with people who attended rehabilitation programs following hospitalisation for an acute cardiac event. Interviews were developed and data is analysed via the Theoretical Domains Framework (TDF), a pragmatic framework that synthesizes prior theories of behaviour change. RESULTS Three phases that arise post-hospitalisation are examined: recuperation, rehabilitation, and long-term self-management. Through these phases we describe the impact of key factors and important changes that occur in patients’ experiences over time, including: a desire for and redefinition of normal life; the need for different types of formal and informal knowledge; the benefits of safe-zoning and connectedness; and the need to recognise capability. The use of the TDF allows us to show how factors that influence behaviour evolve over time and identify potential sources of tension. CONCLUSIONS The paper provides empirically grounded recommendations for the design of technology-mediated cardiac rehabilitation and self-management systems. Key recommendations include the use of technology to support a normal life; leveraging social influences to extend participants’ sense of normality; the use of technology to provide a safe zone; the need to support both emotional and physical wellbeing; and a focus on recognizing capability and providing recommendations that are positive and reinforce this capability.

Effect of soil physical properties on the long-term performance of planted Scots pine in Finnish Lapland

2010 ◽  
Vol 90 (3) ◽  
pp. 451-465 ◽  
Author(s):  
K. Mäkitalo ◽  
V. Alenius ◽  
J. Heiskanen ◽  
K. Mikkola
Keyword(s):  
Physical Properties ◽  
Water Content ◽  
Scots Pine ◽  
Soil Physical Properties ◽  
Height Growth ◽  
Site Preparation ◽  
Preparation Methods ◽  
Finnish Lapland

Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies L. Karst.) forests dominate in Finnish Lapland. This study examined the long-term effects of soil physical properties and conditions measured in intact intermediate areas, as well as site preparation, on the survival and height growth of planted pine on eight experimental sites, 25-27 yr after reforestation. On the four originally spruce-dominated sites, pine survival was the highest on sites with a high soil air-filled porosity (AFP) near saturation (at -1 kPa), a high van Genuchten parameter, and a low soil water content (SWC) in situ, and height growth was the fastest on sites with a high soil AFP in situ and a high van Genuchten parameter n, and on sites reaching a soil AFP of ca. 0.20 m3 m-3 at a high matric potential after saturation. Survival, but not mean height, was enhanced on the spruce sites by intensive site preparation methods such as ploughing instead of lighter site preparation methods. On the four originally pine-dominated sites, site preparation affected the mean height but not survival. The use of SWC as a sole criterion for sites suitable for pine reforestation was tested and found to be uncertain. Key words: Boreal forest soils, soil water content, air-filled porosity, van Genuchten function, site preparation, reforestation, Scots pine

A 1000-year record of Adélie penguin diets in the southern Ross Sea

2002 ◽  
Vol 14 (4) ◽  
pp. 327-332 ◽  
Author(s):  
MICHAEL POLITO ◽  
STEVEN D. EMSLIE ◽  
WILLIAM WALKER
Keyword(s):  
Ross Sea ◽  
Prey Selection ◽  
Ice Age ◽  
Adélie Penguin ◽  
Pleuragramma Antarcticum ◽  
Adelie Penguin ◽  
Radiocarbon Dates ◽  
Antarctic Silverfish ◽  
The Antarctic

Non-krill prey remains were recovered from ornithogenic sediments at three active Adélie penguin colonies on Ross Island, to assess long-term dietary trends in this species. Radiocarbon dates place the age of these deposits from a maximum of 947 years ago to the present. We identified 12 taxa of fish and two of squid with the Antarctic silverfish (Pleuragramma antarcticum) as the most abundant prey species represented at all sites. In addition, silverfish have decreased in importance in Adélie penguin diet over the past 600 years, perhaps in response to climate change since the onset of the Little Ice Age, though it remains much more abundant in current penguin diet in the Ross Sea than in the Antarctic Peninsula. Other prey taxa reflect the diversity of prey selection by Adélie penguins in Antarctica.

A first-order global model of late Cenozoic climatic change

1990 ◽  
Vol 81 (4) ◽  
pp. 315-325 ◽  
Author(s):  
Barry Saltzman ◽  
Kirk A. Maasch
Keyword(s):  
Deep Ocean ◽  
Ice Age ◽  
Global Ocean ◽  
Late Cenozoic ◽  
Glacial Ice ◽  
Quaternary Climate ◽  
Comprehensive Theory ◽  
Climatic System ◽  
Additional Influence

ABSTRACTThe theory of the Quaternary climate will be incomplete unless it is embedded in a more general theory for the fuller Cenozoic that can accommodate the onset of the ice-age fluctuations. Here we construct a simple mathematical model for the late Cenozoic climatic changes based on the hypothesis that forced and free variations of the concentration of atmospheric greenhouse gases (notably CO2) coupled with changes in the global ocean state and ice mass, under the additional influence or earth-orbital forcing, are primary determinants of the climatic state over this long period. Our goal is to illustrate how a single model governing both very long-term variations and higher frequency oscillatory variations in the Pleistocene can be formulated with relatively few adjustable parameters. Although the details of this model are speculative, and other factors neglected here are undoubtedly of importance, it is hoped that the formalism described can provide a basis for developing a comprehensive theory and systematically extending and improving it. According to our model the major near-100 ka period ice-age oscillations of the Pleistocene were caused by the downdraw of atmospheric CO2 (possibly a result of weathering of rapidly uplifted topography) to low enough levels for the ‘slow climatic system’, including glacial ice and the deep ocean state, to become unstable.

Patterns of long-term dynamics of aquatic communities and water quality parameters in the Great Lakes: Are they synchronized?

2018 ◽  
Vol 44 (4) ◽  
pp. 660-669 ◽  
Author(s):  
Katya E. Kovalenko ◽  
Euan D. Reavie ◽  
Richard P. Barbiero ◽  
Lyubov E. Burlakova ◽  
Alexander Y. Karatayev ◽  
...  
Keyword(s):  
Water Quality ◽  
Great Lakes ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Aquatic Communities
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