A record of late-Holocene environmental change from southern New England, USA

2011 ◽  
Vol 76 (3) ◽  
pp. 314-318 ◽  
Author(s):  
W. Wyatt Oswald ◽  
David R. Foster
Keyword(s):  
New England ◽  
Late Holocene ◽  
Climatic Variability ◽  
Organic Content ◽  
Pollen Record ◽  
Southern New England ◽  
Ecological Changes ◽  
Dry Conditions ◽  
History Of ◽  
The Town

AbstractAnalyses of a sediment core from Little Pond, located in the town of Bolton, Massachusetts, provide new insights into the history of environmental and ecological changes in southern New England during the late Holocene. Declines in organic content and peaks in the abundance of Isoetes spores indicate reduced water depth at 2900–2600, 2200–1800, and 1200–800 calibrated years before present (cal yr BP), generally consistent with the timing of dry conditions in records from elsewhere in the northeastern United States. The Little Pond pollen record features little change over the last 3000 yr, indicating that the surrounding vegetation was relatively insensitive to these periods of drought. The 1200–800 cal yr BP dry interval, however, coincides with increased abundance of Castanea pollen, suggesting that the expansion of Castanea in southern New England may have been influenced by late-Holocene climatic variability.

Synergy between climate and human land-use maintained open vegetation in southwest Madagascar over the last millennium

The Holocene ◽  
2021 ◽  
pp. 095968362110417
Author(s):  
Estelle Razanatsoa ◽  
Lindsey Gillson ◽  
Malika Virah-Sawmy ◽  
Stephan Woodborne
Keyword(s):  
Late Holocene ◽  
Tropical Dry Forest ◽  
Dry Forest ◽  
Pollen Record ◽  
Last Millennium ◽  
Human Land Use ◽  
Dry Conditions ◽  
History Of ◽  
Southwest Region ◽  
Subsistence Activities

Madagascar experienced environmental change during the Late-Holocene, and the relative importance of climatic and anthropogenic drivers is still the subject of an ongoing debate. Using palaeoecological records from the southwest region at Lake Longiza, we provide additional records to elucidate the complex history of the island and to identify the changes that occurred in the tropical dry forest during the Late-Holocene. The data showed vegetation changes associated with climate variability until AD 900 as reflected by the variation in grass, dry-adapted taxa, deciduous trees, and isotope records. An increasing effect of human activities was recorded, indicated by increased coprophilous spore concentration, as a result of a shift from foraging to pastoralism leading to further opening of the ecosystem from AD 980. At the same time, the regional palaeoclimate record showed drier conditions from around AD 1000, which could have accentuated the changes in vegetation structure. More open vegetation was likely maintained by increased use of fire and herbivory around the area, as indicated by the multiple peaks in the charcoal and spore records. Since AD 1900, the pollen record from the southwest region showed that the ecosystem became increasingly open with an increased abundance of grass, pioneer taxa, and reduced diversity, which was linked to a simultaneous effect of climate and agropastoralism activities. Our study suggests that the dry conditions around AD 950 initiated the replacement of forest-dominant vegetation with grass-dominant communities over the last millennium, depicted as an open ecosystem at present. Subsequent changes in subsistence activities would have further maintained an open-structured ecosystem.

A late-Holocene pollen record from the western Qilian Mountains and its implications for climate change and human activity along the Silk Road, Northwestern China

The Holocene ◽  
2018 ◽  
Vol 28 (7) ◽  
pp. 1141-1150 ◽  
Author(s):  
Jun Zhang ◽  
Xiaozhong Huang ◽  
Zongli Wang ◽  
Tianlong Yan ◽  
En’yuan Zhang
Keyword(s):  
Late Holocene ◽  
Qilian Mountains ◽  
Archaeological Sites ◽  
Pollen Record ◽  
Human Environment ◽  
Plant Remains ◽  
Tree Ring Data ◽  
History Of ◽  
The Silk Road

The sparsity of long-term reliable climatic records hampers our understanding of human–environment interactions in the semi-arid Hexi Corridor, NW China. Here, we present a late-Holocene pollen record from a small alpine lake, Tian’E, in the western Qilian Mountains. The chronology is provided by nine accelerator mass spectrometry (AMS) 14C dates from terrestrial plant remains. The ratios of Artemisia and Amaranthaceae (A/C) are used to reconstruct the history of regional humidity: An unstable climate occurred during 1530–1270 BC; there were three relatively wet periods, at 1270 BC–AD 400, AD 1200–1350, and AD 1600–present; and there were two dry periods, from AD 400 to 1200 and from AD 1350 to 1600. Comparison with tree-ring data indicates that continuous droughts were responsible for the abandonment of several archaeological sites and ancient cities in the region, including the major city of Dunhuang, which was abandoned in AD 1372 and AD 1524 for nearly 200 years.

Radiocarbon-Dated Pollen and Sediment Records From Near the Boylston Street Fishweir Site in Boston, Massachusetts

1994 ◽  
Vol 41 (2) ◽  
pp. 214-224 ◽  
Author(s):  
Paige E. Newby ◽  
Thompson Webb
Keyword(s):  
New England ◽  
Tidal Flow ◽  
Vegetation Changes ◽  
Pollen Record ◽  
Marine Animals ◽  
Middle Holocene ◽  
Archaeological Data ◽  
Bay Area ◽  
Southern New England ◽  
Water Vegetation

AbstractA radiocarbon-dated pollen record near the Boylston Street Fishweir site in Boston; Massachusetts, provides a regional and local record of vegetation changes from the middle Holocene to present. The stratigraphy begins about 5630 ± 90 yr B.P. with a marine transgression and is continuous up to the historic backfilling of the Back Bay area about 100 yr B.P. When pollen began accumulating at the site, the immediate area resembled the swamp forests growing today in southern New England. Fresh- and brackish-water vegetation was present before the area near the site was submerged. While these vegetation changes occurred locally, oak forest grew in the region. Correlation of this stratigraphy with archaeological data collected from 500 Boylston Street indicates that between 4700 and 3700 yr B.P., a number of fence-like alignments ("weirs"), were probably placed within existing channels and/or along shorelines to capture fish and other marine animals as they moved with the tidal flow.

Evidence of a late glacial warming event and early Holocene cooling in the southern Brazilian coastal highlands

2017 ◽  
Vol 89 (1) ◽  
pp. 90-102 ◽  
Author(s):  
Hermann Behling ◽  
Marcelo Accioly Teixeira de Oliveira
Keyword(s):  
Late Glacial ◽  
Dry Season ◽  
Atlantic Rain Forest ◽  
Pollen Record ◽  
Grassland Vegetation ◽  
History Of Vegetation ◽  
Tree Ferns ◽  
Dry Conditions ◽  
History Of ◽  
Vegetation And Climate

AbstractA high-resolution pollen record of the Atlantic rain forest (ARF) biome from the coastal Serra do Tabuleiro mountains of southern Brazil documents an 11,960 yr history of vegetation and climate change. A marked expansion of Weinmannia into the grassland vegetation marks the latter part of the Younger Dryas, reflecting warm and relatively wet conditions. Between 11,490 and 9110 cal yr BP, grasslands became dominant again, indicating a long cold and dry phase, probably in response to the stronger influence of cold South Atlantic seawater and to Antarctic cold fronts. Between 9110 and 2640 cal yr BP, four distinct phases with strong or moderate expansions of different ARF biome taxa were recorded, reflecting warmer and relatively dry conditions with changes in rainfall and length of the annual dry season. After 2640 cal yr BP, the modern ARF biome became established with high amounts of ferns, reflecting somewhat cooler and wetter conditions with a reduced annual dry season. In particular, after 1000 cal yr BP tree ferns increased, reflecting wetter conditions with no dry season.

14,000 Years of Sediment, Vegetation, and Water-Level Changes at the Makepeace Cedar Swamp, Southeastern Massachusetts

2000 ◽  
Vol 53 (3) ◽  
pp. 352-368 ◽  
Author(s):  
Paige E. Newby ◽  
Peter Killoran ◽  
Mahlon R. Waldorf ◽  
Bryan N. Shuman ◽  
Robert S. Webb ◽  
...  
Keyword(s):  
New England ◽  
Water Level ◽  
Sediment Accumulation ◽  
Vegetation Development ◽  
Peat Accumulation ◽  
Southern New England ◽  
Hemlock Decline ◽  
Pine Trees ◽  
Dry Conditions ◽  
Cedar Swamp

AbstractData from a transect of four cores collected in the Makepeace Cedar Swamp, near Carver, Massachusetts, record past changes in deposition, vegetation, and water level. Time series of palynological data provide a 14,000-yr record of regional and local vegetation development, a means for biostratigraphic correlation and dating, and information about changes in water level. Differences in records among cores in the basin show that water level decreased at least 1.5 m between ∼10,800 and 9700 cal yr B.P., after which sediment accumulation was slow and intermittent across the basin for about 1700 yr. Between 8000 and 5600 cal yr B.P., water level rose ∼2.0 m, after which slow peat accumulation indicates a low stand about the time of the hemlock decline at 5300 ± 200 cal yr B.P. Dry conditions may have continued after this time, but by 3200 cal yr B.P., the onset of peat accumulation in shallow cores indicates that water level had risen to close to its highest postglacial level, where it is today. Peat has accumulated across the whole basin since 3200 cal yr B.P. Data from Makepeace and the Pequot Cedar Swamp, near Ledyard, Connecticut, indicate an early Holocene dry interval in southern New England that began 11,500 yr ago near the end of the Younger Dryas interval. The dry conditions prevailed between 10,800 and 8000 cal yr B.P. and coincide with the arrival and later rise to dominance of white pine trees (Pinus strobus) both regionally and near the basins. Our results indicate a climatic cause for the “pine period” in New England.

A late-glacial transition from Picea glauca to Picea mariana in southern New England

2007 ◽  
Vol 67 (3) ◽  
pp. 502-508 ◽  
Author(s):  
Matts Lindbladh ◽  
W. Wyatt Oswald ◽  
David R. Foster ◽  
Edward K. Faison ◽  
Juzhi Hou ◽  
...  
Keyword(s):  
North America ◽  
New England ◽  
Picea Mariana ◽  
Picea Glauca ◽  
Single Species ◽  
Late Glacial ◽  
Eastern North America ◽  
Southern New England ◽  
Edaphic Conditions ◽  
Ecological Changes

AbstractPicea is an important taxon in late-glacial pollen records from eastern North America, but little is known about which species of Picea were present. We apply a recently developed palynological method for discriminating the three Picea species in eastern North America to three records from New England. Picea glauca was dominant at ∼ 14,500–14,000 cal yr BP, followed by a transition to Picea mariana between ∼ 14,000 and 13,500 cal yr BP. Comparison of the pollen data with hydrogen isotope data shows clearly that this transition began before the beginning of the Younger Dryas Chronozone. The ecological changes of the late-glacial interval were not a simple oscillation in the position of a single species' range, but rather major changes in vegetation structure and composition occurring during an interval of variations in several environmental factors, including climate, edaphic conditions, and atmospheric CO2 levels.

The postglacial history of three Picea species in New England, USA

2003 ◽  
Vol 59 (1) ◽  
pp. 61-69 ◽  
Author(s):  
Matts Lindbladh ◽  
George L. Jacobson ◽  
Molly Schauffler
Keyword(s):  
New England ◽  
Late Holocene ◽  
Classification Tree ◽  
Population Expansion ◽  
Pollen Grains ◽  
Late Glacial ◽  
Early Holocene ◽  
Pollen Record ◽  
Recent Population Expansion ◽  
Picea Species

AbstractGiven the difficulty of separating the three Picea species—P. glauca, P. mariana, and P. rubens (white, black, and red spruce)—in the pollen record, little is known about their unique histories in eastern North America following deglaciation. Here we report the first use of a classification tree analysis (CART) to distinguish pollen grains of these species. It was successfully applied to fossil pollen from eight sites in Maine and one in Massachusetts. We focused on the late glacial/early Holocene (14,000 to 8000 cal yr B.P.) and the late Holocene (1400 cal yr B.P. to present)—the two key periods since deglaciation when Picea has been abundant in the region. The result shows a shift from a Picea forest of P. glauca and P. mariana in the late glacial to a forest of P. rubens and P. mariana in the late Holocene. The small number of P. rubens grains identified from the late glacial/early Holocene samples (<5%) suggests that that species was either absent or rare at most of the sites. The occurrence and distribution of the three species do not reveal any geographic or temporal trend during late glacial time, but the data suggest that they were distributed in local patches on the landscape. The results of this study indicate that the recent population expansion of Picea (1000 to 500 cal yr B.P.) was likely the first time since deglaciation that P. rubens was abundant in the region.

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