scholarly journals Hydrological dynamics and fire history of the last 1300 years in western Siberia reconstructed from a high-resolution, ombrotrophic peat archive

2015 ◽  
Vol 84 (3) ◽  
pp. 312-325 ◽  
Author(s):  
Mariusz Lamentowicz ◽  
Michał Słowiński ◽  
Katarzyna Marcisz ◽  
Małgorzata Zielińska ◽  
Karolina Kaliszan ◽  
...  

Siberian peatlands provide records of past changes in the continental climate of Eurasia. We analyzed a core from Mukhrino mire in western Siberia to reconstruct environmental change in this region over the last 1300 years. The pollen analysis revealed little variation of local pine-birch forests. A testate amoebae transfer function was used to generate a quantitative water-table reconstruction; pollen, plant macrofossils, and charcoal were analyzed to reconstruct changes in vegetation and fire activity. The study revealed that Mukhrino mire was wet until the Little Ice Age (LIA), when drought was recorded. Dry conditions during the LIA are consistent with other studies from central and eastern Europe, and with the pattern of carbon accumulation across the Northern Hemisphere. A significant increase in fire activity between ca. AD 1975 and 1990 may be associated with the development of the nearby city of Khanty-Mansiysk, as well as with the prevailing positive Arctic Oscillation.

2013 ◽  
Vol 22 (2) ◽  
pp. 207 ◽  
Author(s):  
Vyacheslav I. Kharuk ◽  
Mariya L. Dvinskaya ◽  
K. Jon Ranson

A fire history of northern larch forests was studied. These larch forests are found near the northern limit of their range at ~71°N, where fires are predominantly caused by lightning strikes rather than human activity. Fire-return intervals (FRIs) were calculated based on fire scars and dates of tree natality. Tree natality was used as an approximation of the date of the last fire. The average FRI was found to be 295±57 years, which is the longest reported for larch-dominated stands. Prior studies reported 80–90-year FRIs at 64°N and ~200 years near the latitude of the Arctic Circle. Comparing data from fires that occurred in 1700–1849 (end of the Little Ice Age, LIA) and 1850–1999 (post-LIA warming) indicates approximately twice as many fires occurred during the latter period. This agrees with the hypothesis that observed climatic warming will result in an increase in fire frequency. Our results also indicate that fires that did not leave visible fire scars on the tree stem may be identified based on the date of growth release revealed from dendrochronology.


2020 ◽  
Vol 20 (4) ◽  
Author(s):  
Guilherme Alexandre Stecher Justini Pinto ◽  
Mats Niklasson ◽  
Nina Ryzhkova ◽  
Igor Drobyshev

AbstractThe Sala fire in the Västmanland County of central Sweden that burned about 14,000 ha in 2014 has been the largest fire recorded in the modern history of Sweden. To understand the long-term fire history of this area, we dendrochronologically dated fire scars on Scots pine (Pinus sylvestris L.) trees (live and deadwood) to reconstruct the fire cycle and fire occurrence in the area affected by the 2014 fire. We identified 64 fire years, using a total of 378 pine samples. The earliest reconstructed fire dated back to 1113 AD. The spatial reconstruction extended over the period of 1480–2018 AD. Lower levels of fire activity (fire cycle, FC = 43 years, with the central 90% of the distribution limited by 35 to 57 years) dominated in the earlier period (1480–1690 AD) that was followed by a strong decrease in fire activity since 1700 (FC = 403 years, with 90% of the distribution being within 149 to 7308 years), with a fire-free period between 1756 and 2014. Sala area, therefore, features the earliest known onset of fire suppression in Scandinavia. The high demand for timber during the peak in mining activities in the study area around the 1700–1800s, accompanied by passive fire suppression policies, were possibly the main drivers of the decline in fire activity. Superposed epoch analysis (SEA) did not show significant departures in the drought proxy during the ten years with the largest area burned between 1480 and1690. It is unclear whether the result is due to the relatively small area sampled or an indication that human controls of fires dominated during that period. However, significant departures during the following period with low fire activity (1700–1756), which just preceded the last fire-free period, suggested that the climate became an increasingly important driver of fire during the onset of the suppression period. We speculate that the lack of major firebreaks, the homogenization of forests, and the lack of burned areas with low fuel loads might contribute to the occurrence of the exceptionally large 2014 fire in Sala.


2008 ◽  
Vol 17 (1) ◽  
pp. 84 ◽  
Author(s):  
Jennifer Pierce ◽  
Grant Meyer

Alluvial fan deposits are widespread and preserve millennial-length records of fire. We used these records to examine changes in fire regimes over the last 2000 years in Yellowstone National Park mixed-conifer forests and drier central Idaho ponderosa pine forests. In Idaho, frequent, small, fire-related erosional events occurred within the Little Ice Age (~1450–1800 AD), when greater effective moisture probably promoted grass growth and low-severity fires. This regime is consistent with tree-ring records showing generally wetter conditions and frequent fires before European settlement. At higher elevations in Yellowstone, cool conditions limited overall fire activity. Conversely, both Idaho and Yellowstone experienced a peak in fire-related debris flows between ~950 and 1150 AD. During this generally warmer time, severe multidecadal droughts were interspersed with unusually wet intervals that probably increased forest densities, producing stand-replacing fires. Thus, severe fires are clearly within the natural range of variability in Idaho ponderosa pine forests over longer timescales. Historical records indicate that large burn areas in Idaho correspond with drought intervals within the past 100 years and that burn area has increased markedly since ~1985. Recent stand-replacing fires in ponderosa pine forests are likely related to both changes in management and increasing temperatures and drought severity during the 20th century.


2019 ◽  
Vol 91 (2) ◽  
pp. 861-880 ◽  
Author(s):  
Teresa R. Krause ◽  
James M. Russell ◽  
Rui Zhang ◽  
John W. Williams ◽  
Stephen T. Jackson

AbstractThe patterns and drivers of late Quaternary vegetation dynamics in the southeastern United States are poorly understood due to low site density, problematic chronologies, and a paucity of independent paleoclimate proxy records. We present a well-dated (15 accelerator mass spectrometry14C dates) 30,000-yr record from White Pond, South Carolina that consists of high-resolution analyses of fossil pollen, macroscopic charcoal, andSporormiellaspores, and an independent paleotemperature reconstruction based on branched glycerol dialkyl tetraethers. Between 30,000 and 20,000 cal yr BP, openPinus-Piceaforest grew under cold and dry conditions; elevatedQuercusbefore 26,000 cal yr BP, however, suggest warmer conditions in the Southeast before the last glacial maximum, possibly corresponding to regionally warmer conditions associated with Heinrich event H2. Warming between 19,700 and 10,400 cal yr BP was accompanied by a transition from conifer-dominated to mesic hardwood forest.Sporormiellaspores were not detected and charcoal was low during the late glacial period, suggesting megaherbivore grazers and fire were not locally important agents of vegetation change.Pinusreturned to dominance during the Holocene, with step-like increases inPinusat 10,400 and 6400 cal yr BP, while charcoal abundance increased tenfold, likely due to increased biomass burning associated with warmer conditions. Low-intensity surface fires increased after 1200 cal yr BP, possibly related to the establishment of the Mississippian culture in the Southeast.


2004 ◽  
Vol 61 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Robert K. Booth ◽  
Stephen T. Jackson ◽  
Catherine E.D. Gray

We investigated the developmental and hydrological history of a Sphagnum-dominated, kettle peatland in Upper Michigan using testate amoebae, plant macrofossils, and pollen. Our primary objective was to determine if the paleohydrological record of the peatland represents a record of past climate variability at subcentennial to millennial time scales. To assess the role of millennial-scale climate variability on peatland paleohydrology, we compared the timing of peatland and upland vegetation changes. To investigate the role of higher-frequency climate variability on peatland paleohydrology, we used testate amoebae to reconstruct a high-resolution, hydrologic history of the peatland for the past 5100 years, and compared this record to other regional records of paleoclimate and vegetation. Comparisons revealed coherent patterns of hydrological, vegetational, and climatic changes, suggesting that peatland paleohydrology responded to climate variability at millennial to sub-centennial time scales. Although ombrotrophic peatlands have been the focus of most high-resolution peatland paleoclimate research, paleohydrological records from Sphagnum-dominated, closed-basin peatlands record high-frequency and low-magnitude climatic changes and thus represent a significant source of unexplored paleoclimate data.


The Holocene ◽  
2016 ◽  
Vol 27 (1) ◽  
pp. 130-141 ◽  
Author(s):  
Mariusz Gałka ◽  
Kazimierz Tobolski ◽  
Aleksandra Górska ◽  
Mariusz Lamentowicz

This study explores the history of the development of Sphagnum communities in an ombrotrophic peatland – Bagno Kusowo – over the past 650 years, based on high-resolution plant macrofossil and testate amoebae analysis. Our research provided information related to the length of peatland existence and the characteristics of its natural/pristine state before the most recent human impacts. Changes in the Sphagnum communities before human impact could have resulted from climate cooling during the ‘Little Ice Age’ (LIA). In this cold and unstable hydrological period, among vascular plants, Eriophorum vaginatum and Baeothryon caespitosum dominated in the peatland vegetation. Peat-forming Sphagnum communities survived the drainage conducted during the 20th century at the Bagno Kusowo bog. We provide three important messages through this study: (1) testate amoebae reflect similar hydrological trends in two peat cores despite considerable microhabitat variability, (2) average long-term water level 10 cm below the surface should be a target for active bog conservation and (3) sites like Bagno Kusowo are extremely important to preserve the remains of pristine biodiversity (including genetic diversity of plants and protists) that was completely removed from most of the raised bogs in Europe due to human activities, for example, drainage.


2019 ◽  
Vol 91 (2) ◽  
pp. 705-713
Author(s):  
Colin J. Long ◽  
Jaqueline J. Shinker ◽  
Thomas A. Minckley ◽  
Mitchell J. Power ◽  
Patrick J. Bartlein

AbstractWe used pollen and high-resolution charcoal analysis of lake sediment to reconstruct a 7600 yr vegetation and fire history from Anthony Lake, located in the Blue Mountains of northeastern Oregon. From 7300 to 6300 cal yr BP, the forest was composed primarily of Populus, and fire was common, indicating warm, dry conditions. From 6300 to 3000 cal yr BP, Populus declined as Pinus and Picea increased in abundance and fire became less frequent, suggesting a shift to cooler, wetter conditions. From 3000 cal yr BP to present, modern-day forests composed of Pinus and Abies developed, and from 1650 cal yr BP to present, fires increased. We utilized the modern climate-analogue approach to explain the potential synoptic climatological processes associated with regional fire. The results indicate that years with high fire occurrence experience positive 500 mb height anomalies centered over the Great Basin, with anomalous southerly component of flow delivering dry air into the region and with associated sinking motions to further suppress precipitation. It is possible that such conditions became more common over the last 1650 cal yr BP, supporting an increase in fire despite the shift to more mesic conditions.


The Holocene ◽  
2020 ◽  
Vol 31 (1) ◽  
pp. 28-37
Author(s):  
Gina E Hannon ◽  
Karen Halsall ◽  
Chiara Molinari ◽  
Erin Stoll ◽  
Diana Lilley ◽  
...  

Palaeoecological studies can identify past trends in vegetation communities and processes over long time scales. Pollen, plant macrofossils and charcoal analyses are used to reconstruct vegetation over the last 6400 years and provide information about former human impact and disturbance regimes in Färnebofjärden National Park, Central Sweden. Three specific conservation planning topics were addressed: (1) the changing ratio of conifers to broadleaved trees; (2) the origin and history of the river meadows and the biodiverse Populus tremula meadows; (3) the role of fire in the maintenance of biological values. Early diverse mixed broadleaved forest assemblages with pine were followed by significant declines of the more thermophilic forest elements prior to the expansion of spruce in the Iron Age. The rise to dominance of spruce was a ‘natural’ process that has been exaggerated by anthropogenic disturbance to artificially high levels today. The initial river meadow communities were facilitated by fire and frequent flooding events, but subsequent dynamics have more definitely been supported by human activities. Rural abandonment during the last 100 years has led to woody successions. Fire has been a continual disturbance factor with an influence on conservation issues such as Picea abies dominance and the maintenance of diverse, non-forest communities. Present occurrence of fire is unusually low, but natural fire frequencies are increasing in the region.


The Holocene ◽  
2001 ◽  
Vol 11 (1) ◽  
pp. 65-80 ◽  
Author(s):  
E. A.D. Mitchell ◽  
W. O. van der Knaap ◽  
J. F.N. van Leeuwen ◽  
A. Buttler ◽  
B. G. Warner ◽  
...  

2022 ◽  
Vol 9 ◽  
Author(s):  
Thomas J. Rodengen ◽  
Marlow G. Pellatt ◽  
Karen E. Kohfeld

Paleoecological investigation of two montane lakes in the Kootenay region of southeast British Columbia, Canada, reveal changes in vegetation in response to climate and fire throughout the Holocene. Pollen, charcoal, and lake sediment carbon accumulation rate analyses show seven distinct zones at Marion Lake, presently in the subalpine Engelmann Spruce-Subalpine Fir (ESSF) biogeoclimatic (BEC) zone of Kootenay Valley, British Columbia. Comparison of these records to nearby Dog Lake of Kootenay National Park of Canada in the Montane Spruce (MS) BEC zone of Kootenay Valley, British Columbia reveals unique responses of ecosystems in topographically complex regions. The two most dramatic shifts in vegetation at Marion Lake occur firstly in the early Holocene/late Pleistocene in ML Zone 3 (11,010–10,180 cal. yr. B.P.) possibly reflecting Younger Dryas Chronozone cooling followed by early Holocene xerothermic warming noted by the increased presence of the dry adapted conifer, Douglas-fir (Pseudotsuga menziesii) and increasing fire frequency. The second most prominent change occurred at the transition from ML Zone 5 through 6a (∼2,500 cal. yr. B.P.). This zone transitions from a warmer to a cooler/wetter climate as indicated by the increase in western hemlock (Tsuga heterophylla) and subsequent drop in fire frequency. The overall cooling trend and reduction in fire frequency appears to have occurred ∼700 years later than at Dog Lake (∼43 km to the south and 80 m lower in elevation), resulting in a closed montane spruce forest, whereas Marion Lake developed into a subalpine ecosystem. The temporal and ecological differences between the two study sites likely reflects the particular climate threshold needed to move these ecosystems from developed forests to subalpine conditions, as well as local site climate and fire conditions. These paleoecological records indicate future warming may result in the MS transitioning into an Interior Douglas Fir (IDF) dominated landscape, while the ESSF may become more forested, similar to the modern MS, or develop into a grassland-like landscape dependent on fire frequency. These results indicate that climate and disturbance over a regional area can dictate very different localized vegetative states. Local management implications of these dynamic landscapes will need to understand how ecosystems respond to climate and disturbance at the local or ecosystem/habitat scale.


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