Holocene regional climate change and formation of southern Ontario's largest swamp inferred from a kettle-lake pollen record

2021 ◽  
pp. 1-19
Author(s):  
Eunji Byun ◽  
Sharon A. Cowling ◽  
Sarah A. Finkelstein
Keyword(s):  
Vegetation History ◽  
Regional Climate ◽  
Regional Climate Change ◽  
High Water ◽  
Carbon Accumulation ◽  
Pollen Record ◽  
Thuja Occidentalis ◽  
Peat Core ◽  
Northern High Latitude ◽  
Wetland Complex

Abstract Greenock Swamp wetland complex is one of few remaining natural wetlands in the Great Lakes region and, at 89 km2 in areal extent, is currently the largest hardwood swamp in southern Ontario, Canada. We present here pollen and sediment records from a kettle hole (Schmidt Lake) and adjacent Thuja occidentalis swamp to reconstruct regional paleoclimate and vegetation history, and to assess the timing and development of the swamp ecosystem and associated carbon stocks. Pollen-inferred paleoclimate reconstructions show the expected warming in the Early Holocene, and indicate the Mid-Holocene initiation of lake-effect snow. This enhanced snowfall may have maintained high water tables in the adjacent wetland since ca. 8300 years ago, promoting the establishment of a swamp dominated by Thuja occidentalis. Carbon accumulation rates in a >2-m-long peat core collected from a Thuja occidentalis stand adjacent to Schmidt Lake are 30–40 g C/m2/yr, which is higher than the average of northern high-latitude peatlands. Using topographic and hydrological parameters, we estimated that mean swamp peat thicknesses could exceed 2 m. Thus, this study encourages future investigations on temperate swamps from the perspective of hitherto underestimated Holocene carbon sinks and shows the importance of regional hydroclimate in supporting swamp ecosystems.

A 10,300 14C yr Record of Climate and Vegetation Change from Haiti

1999 ◽  
Vol 52 (2) ◽  
pp. 159-170 ◽  
Author(s):  
Antonia Higuera-Gundy ◽  
Mark Brenner ◽  
David A. Hodell ◽  
Jason H. Curtis ◽  
Barbara W. Leyden ◽  
...  
Keyword(s):  
Vegetation Change ◽  
Human Impacts ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Early Holocene ◽  
Pollen Record ◽  
Caribbean Islands ◽  
Moist Forest ◽  
Dry Conditions ◽  
American Tropics

Pleistocene and Holocene vegetation dynamics in the American tropics are inferred largely from pollen in continental lake sediments. Maritime influences may have moderated climate and vegetation changes on Caribbean islands. Stable isotope (δ18O) study of a 7.6-m core from Lake Miragoane, Haiti, provided a high-resolution record of changing evaporation/precipitation (E/P) since ∼10,300 14C yr B.P. The Miragoane pollen record documents climate influences and human impacts on vegetation in Hispaniola. The δ18O and pollen data near the base of the core indicate cool, dry conditions before ∼10,000 14C yr B.P. Lake Miragoane filled with water in the early Holocene as E/P declined and the freshwater aquifer rose. Despite increasing early Holocene moisture, shrubby, xeric vegetation persisted. Forest expanded ∼7000 14C yr B.P. in response to greater effective moisture and warming. The middle Holocene (∼7000–3200 14C yr B.P.) was characterized by high lake levels and greatest relative abundance of pollen from moist forest taxa. Climatic drying that began ∼3200 14C yr B.P. may have driven some mesophilic animal species to extinction. The pollen record of the last millennium reflects pre-Columbian (Taino) and European deforestation. Long-term, Holocene vegetation trends in southern Haiti are comparable to trends from continental, lowland circum-Caribbean sites, suggesting a common response to regional climate change.

scholarly journals First evidence of a lake at Ancient Phaistos (Messara Plain, South-Central Crete, Greece): Reconstructing paleoenvironments and differentiating the roles of human land-use and paleoclimate from Minoan to Roman times

The Holocene ◽  
2018 ◽  
Vol 28 (8) ◽  
pp. 1225-1244 ◽  
Author(s):  
Matthieu Ghilardi ◽  
David Psomiadis ◽  
Valérie Andrieu-Ponel ◽  
Maxime Colleu ◽  
Pavlos Sotiropoulos ◽  
...  
Keyword(s):  
Climate Change ◽  
Vegetation History ◽  
Eastern Mediterranean ◽  
Regional Climate ◽  
Pollen Grains ◽  
Regional Climate Change ◽  
Tectonic Activity ◽  
Radiocarbon Dates ◽  
South Central ◽  
The Impact

Phaistos was one of the most important Minoan palaces in Crete and previous studies have addressed its relationship with the paleo-seashore position during historical times. Here, we reconstruct the environmental evolution of Phaistos from Early Minoan to Roman times. Study of two stratigraphic sections and nine boreholes drilled in the westernmost part of the Messara Plain has revealed the stratigraphy of the Mid- to Late-Holocene sediments. Laboratory analyses comprise granulometry, magnetic susceptibility measurements and identification of mollusks, diatoms and pollen grains. Eighteen radiocarbon dates provide a robust chronostratigraphy. In addition, a geophysical survey (electric resistivity tomography (ERT) method) was conducted to reveal the sub-surface morphology in the coring area. The results reveal that a freshwater lake existed from ca. 2100–2000 BC to ca. 1200–1100 BC, which subsequently became swampland until ca. 700 BC. A lake retreat is identified at ca. 1200–1000 BC and can be interpreted as resulting from the 3.2 cal kyr BP rapid climate change (RCC) dry event, observed elsewhere in the Eastern Mediterranean. Subsequently, from the 7th to the 5th century BC, there was the input of detrital material and fluvial dynamics prevailed until at least Roman times. The origin of the lake and its disappearance are discussed in the context of regional climate change and local tectonic activity, without excluding possible human influences. We also reconstruct the vegetation history for the period from the Late Minoan to the Early Archaic period. Pollen analysis reveals a Mediterranean maquis landscape dominated by Olea, together with hygrophilous vegetation, and highlights a clear transition from limnic to swampy environmental conditions around 1100 BC. The pollen sequence is also important for assessing the impact of the 3.2 cal. kyr BP RCC event and for assessing the possibility of an abrupt discontinuity in human activity around Phaistos after the demise of the Minoan Civilization.

Postglacial vegetation history of Mitkof Island, Alexander Archipelago, southeastern Alaska

2010 ◽  
Vol 73 (2) ◽  
pp. 259-268 ◽  
Author(s):  
Thomas A. Ager ◽  
Paul E. Carrara ◽  
Jane L. Smith ◽  
Victoria Anne ◽  
Joni Johnson
Keyword(s):  
Pinus Contorta ◽  
Vegetation History ◽  
Regional Climate ◽  
Sitka Spruce ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Thuja Plicata ◽  
Pollen Record ◽  
Coastal Forests ◽  
History Of

An AMS radiocarbon-dated pollen record from a peat deposit on Mitkof Island, southeastern Alaska provides a vegetation history spanning ∼12,900 cal yr BP to the present. Late Wisconsin glaciers covered the entire island; deglaciation occurred > 15,400 cal yr BP. The earliest known vegetation to develop on the island (∼12,900 cal yr BP) was pine woodland (Pinus contorta) with alder (Alnus), sedges (Cyperaceae) and ferns (Polypodiaceae type). By ∼12,240 cal yr BP, Sitka spruce (Picea sitchensis) began to colonize the island while pine woodland declined. By ∼11,200 cal yr BP, mountain hemlock (Tsuga mertensiana) began to spread across the island. Sitka spruce-mountain hemlock forests dominated the lowland landscapes of the island until ∼10,180 cal yr BP, when western hemlock (Tsuga heterophylla) began to colonize, and soon became the dominant tree species. Rising percentages of pine, sedge, and sphagnum after ∼7100 cal yr BP may reflect an expansion of peat bog habitats as regional climate began to shift to cooler, wetter conditions. A decline in alders at that time suggests that coastal forests had spread into the island's uplands, replacing large areas of alder thickets. Cedars (Chamaecyparis nootkatensis, Thuja plicata) appeared on Mitkof Island during the late Holocene.

Holocene hydro-climatic change and effects on carbon accumulation inferred from a peat bog in the Attawapiskat River watershed, Hudson Bay Lowlands, Canada

2012 ◽  
Vol 78 (2) ◽  
pp. 275-284 ◽  
Author(s):  
Joan Bunbury ◽  
Sarah A. Finkelstein ◽  
Jörg Bollmann
Keyword(s):  
Carbon Accumulation ◽  
Testate Amoeba ◽  
Hudson Bay ◽  
Pollen Record ◽  
Medieval Climate Anomaly ◽  
Northern Ontario ◽  
Peat Core ◽  
Hudson Bay Lowlands ◽  
Isostatic Rebound

AbstractMultiple proxies from a 319-cm peat core collected from the Hudson Bay Lowlands, northern Ontario, Canada were analyzed to determine how carbon accumulation has varied as a function of paleohydrology and paleoclimate. Testate amoeba assemblages, analysis of peat composition and humification, and a pollen record from a nearby lake suggest that isostatic rebound and climate may have influenced peatland growth and carbon dynamics over the past 6700 cal yr BP. Long-term apparent rates of carbon accumulation ranged between 8.1 and 36.7 g C m− 2 yr− 1 (average = 18.9 g C m− 2 yr− 1). The highest carbon accumulation estimates were recorded prior to 5400 cal yr BP when a fen existed at this site, however following the fen-to-bog transition carbon accumulation stabilized. Carbon accumulation remained relatively constant through the Neoglacial period after 2400 cal yr BP when pollen-based paleoclimate reconstructions from a nearby lake (McAndrews et al., 1982) and reconstructions of the depth to the water table derived from testate amoeba data suggest a wetter climate. More carbon accumulated per unit time between 1000 and 600 cal yr BP, coinciding in part with the Medieval Climate Anomaly.

scholarly journals The study of the periodicity of catastrophic spring floods on the territory of Ukraine

2019 ◽  
Keyword(s):  
Climate Change ◽  
Regional Climate ◽  
Regional Climate Change ◽  
High Water ◽  
Current Data ◽  
Practical Significance ◽  
Donets Basin ◽  
Left Bank ◽  
Almost All ◽  
Maximum Runoff

Introduction. In the period of global and regional climate change in almost all the regions of our planet there is an increase in cases of extreme natural phenomena, which definitely include floods of various origin. Over the past decades, according to the Centre for Research on the Epidemiology of Disasters (CRED), in many countries of the world there has been a record high number of natural disasters which affected about 2.7 billion people, that is more than one third of the world's population. The purpose of article is to analyze historical data and study the current state and trends in the frequency of catastrophic floods. Methods. To estimate the trends in the chronological series of the maximum runoff of rivers the methods of statistical analysis and spatial generalization have been used. Results. On the basis of literature sources and taking into account current data, frequency of flooding in the period from 900 to 2010 in the territory of Kyivan Rus and modern Ukraine has been estimated. Analyzing the results obtained, it can be noted that the largest number of floods was observed in the period from 1501 to 1600 years (11 cases), from 1601 to 1700 years (13 cases), and in the modern period from 1901 to 2000 (10 cases); 900-1000 and 1701-1800 years can be considered as the periods with the smallest number of cases. Since the beginning of the new millennium catastrophic and high floods have been observed in Europe almost every year. In order to estimate the repeatability of catastrophic floods at the rivers in Ukraine, the chronological series of the maximum runoff of spring water have been made up in accordance with the data of hydrological stations, which have the largest and preferably continuous periods of observations from their beginning until 2015 inclusive. The analysis has shown that in Ukraine the spring floods in 1932 and 1970 are classified as catastrophic. The analysis of trends in the chronological series of annual maxima in conditions of climate change showed their heterogeneity across the territory of Ukraine: on the left bank of the Dnieper and in the Siverskyi Donets basin there is a tendency towards earlier periods of snowmelt and the occurrence of the spring floods, and on the other territory, on the contrary, there is a tendency of increase in cases of winter floods instead of the spring high water. The scientific novelty of the study is determined by the use of observational data up to 2015 inclusive, and its practical significance is determined by the opportunity to use the results when justifying hydrotechnical projects in order to minimize the consequences of catastrophic floods on rivers.

scholarly journals Incorrect Asian aerosols affecting the attribution and projection of regional climate change in CMIP6 models

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Zhili Wang ◽  
Lei Lin ◽  
Yangyang Xu ◽  
Huizheng Che ◽  
Xiaoye Zhang ◽  
...  
Keyword(s):  
Climate Change ◽  
Radiative Forcing ◽  
Impact Analysis ◽  
Climate Model ◽  
Regional Climate ◽  
Eastern China ◽  
Coupled Model ◽  
Regional Climate Change ◽  
Anthropogenic Aerosol ◽  
Wide Range

AbstractAnthropogenic aerosol (AA) forcing has been shown as a critical driver of climate change over Asia since the mid-20th century. Here we show that almost all Coupled Model Intercomparison Project Phase 6 (CMIP6) models fail to capture the observed dipole pattern of aerosol optical depth (AOD) trends over Asia during 2006–2014, last decade of CMIP6 historical simulation, due to an opposite trend over eastern China compared with observations. The incorrect AOD trend over China is attributed to problematic AA emissions adopted by CMIP6. There are obvious differences in simulated regional aerosol radiative forcing and temperature responses over Asia when using two different emissions inventories (one adopted by CMIP6; the other from Peking university, a more trustworthy inventory) to driving a global aerosol-climate model separately. We further show that some widely adopted CMIP6 pathways (after 2015) also significantly underestimate the more recent decline in AA emissions over China. These flaws may bring about errors to the CMIP6-based regional climate attribution over Asia for the last two decades and projection for the next few decades, previously anticipated to inform a wide range of impact analysis.

scholarly journals Regional Climate Change Competitiveness—Modelling Approach

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3704
Author(s):  
Agnieszka Karman ◽  
Andrzej Miszczuk ◽  
Urszula Bronisz
Keyword(s):  
Climate Change ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Measurement Scale ◽  
Practical Application ◽  
Adaptation To Climate Change ◽  
Regional Competitiveness ◽  
The Face ◽  
Competitiveness Index ◽  
Modelling Approach

The article deals with the competitiveness of regions in the face of climate change. The aim was to present the concept of measuring the Regional Climate Change Competitiveness Index. We used a comparative and logical analysis of the concept of regional competitiveness and heuristic conceptual methods to construct the index and measurement scale. The structure of the index includes six broad sub-indexes: Basic, Natural, Efficiency, Innovation, Sectoral, Social, and 89 indicators. A practical application of the model was presented for the Mazowieckie province in Poland. This allowed the region’s performance in the context of climate change to be presented, and regional weaknesses in the process of adaptation to climate change to be identified. The conclusions of the research confirm the possibility of applying the Regional Climate Change Competitiveness Index in the economic analysis and strategic planning. The presented model constitutes one of the earliest tools for the evaluation of climate change competitiveness at a regional level.

scholarly journals Tropical cyclones cumulatively control regional carbon fluxes in Everglades mangrove wetlands (Florida, USA)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaochen Zhao ◽  
Victor H. Rivera-Monroy ◽  
Luis M. Farfán ◽  
Henry Briceño ◽  
Edward Castañeda-Moya ◽  
...  
Keyword(s):  
Tropical Cyclones ◽  
Functional Role ◽  
Net Primary Productivity ◽  
Dissolved Inorganic Carbon ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Neotropical Region ◽  
Limited Information ◽  
Organic C ◽  
Wide Range

AbstractMangroves are the most blue-carbon rich coastal wetlands contributing to the reduction of atmospheric CO2 through photosynthesis (sequestration) and high soil organic carbon (C) storage. Globally, mangroves are increasingly impacted by human and natural disturbances under climate warming, including pervasive pulsing tropical cyclones. However, there is limited information assessing cyclone’s functional role in regulating wetlands carbon cycling from annual to decadal scales. Here we show how cyclones with a wide range of integrated kinetic energy (IKE) impact C fluxes in the Everglades, a neotropical region with high cyclone landing frequency. Using long-term mangrove Net Primary Productivity (Litterfall, NPPL) data (2001–2018), we estimated cyclone-induced litterfall particulate organic C (litter-POC) export from mangroves to estuarine waters. Our analysis revealed that this lateral litter-POC flux (71–205 g C m−2 year−1)—currently unaccounted in global C budgets—is similar to C burial rates (69–157 g C m−2 year−1) and dissolved inorganic carbon (DIC, 61–229 g C m−2 year−1) export. We proposed a statistical model (PULITER) between IKE-based pulse index and NPPL to determine cyclone’s impact on mangrove role as C sink or source. Including the cyclone’s functional role in regulating mangrove C fluxes is critical to developing local and regional climate change mitigation plans.

scholarly journals On the Suitability of Current Atmospheric Reanalyses for Regional Warming Studies over China

2017 ◽  
Author(s):  
Chunlüe Zhou ◽  
Yanyi He ◽  
Kaicun Wang
Keyword(s):  
Regional Climate ◽  
Surface Air Temperature ◽  
Longwave Radiation ◽  
Regional Climate Change ◽  
Precipitation Frequency ◽  
Regional Warming ◽  
Downward Longwave Radiation ◽  
In Situ Observations ◽  
Mean Differences

Abstract. Reanalyses have been widely used because they add value to the routine observations by generating physically/dynamically consistent and spatiotemporally complete atmospheric fields. Existing studies have extensively discussed their temporal suitability in global change study. This study moves forward on their suitability for regional climate change study where land–atmosphere interactions play a more important role. Here, surface air temperature (Ta) from 12 current reanalysis products were investigated, focusing on spatial patterns of Ta trends, using homogenized Ta from 1979 to 2010 at ~ 2200 meteorological stations in China. Results show that ~ 80 % of the Ta mean differences between reanalyses and in-situ observations are attributed to station and model-grid elevation differences, denoting good skill in Ta climatology and rebutting the previously reported Ta biases. However, the Ta trend biases in reanalyses display spatial divergence (standard deviation = 0.15–0.30 °C/decade at 1° × 1° grids). The simulated Ta trend biases correlate well with those of precipitation frequency, surface incident solar radiation (Rs), and atmospheric downward longwave radiation (Ld) among the reanalyses (r = −0.83, 0.80 and 0.77, p 

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