A 12,000-Year History of Vegetation and Climate for Cape Cod, Massachusetts

1985 ◽  
Vol 23 (3) ◽  
pp. 301-312 ◽  
Author(s):  
Marjorie Green Winkler

Pollen and charcoal analysis of radiocarbon-dated sediment cores from Duck Pond in the Cape Cod National Seashore provide a continuous 12,000-yr vegetation and climate history of outer Cape Cod. A Picea-Hudsonia parkland and then a Picea-Pinus banksiana-Alnus crispa boreal forest association grew near the site between 12,000 and 10,000 yr B.P. This vegetation was replaced by a northern conifer forest of Pinus strobus-P. banksiana, and, subsequently, by a more mesophytic forest (Pinus strobus, Tsuga, Quercus, Fagus, Acer, Ulmus, Fraxinus, Ostrya) as the climate became warmer and wetter by 9500 yr B.P. By 9000 yr B.P. a Pinus rigida-Quercus association dominated the landscape. High charcoal frequencies from this and subsequent levels suggest that the pine barrens association developed during a warmer and drier climate that lasted from 9000 to about 5000 yr B.P. Increased percentages of Pinus strobus pollen indicate a return to moister and cooler conditions by about 3500 yr B.P. A doubled sedimentation rate, increased charcoal, and increased herb pollen suggest land disturbance near the pond before European settlement. These results suggest a rapid warming in the northeast in the early Holocene and support a hypothesis of a rapid sea level rise at that time. Comparison of the pollen results from Duck Pond with those from Rogers Lake, Connecticut, illustrates the importance of edaphic factors in determining the disturbance frequency and vegetation history of an area.

2019 ◽  
Vol 59 (1) ◽  
pp. 145-163
Author(s):  
Farooq Jan ◽  
Lisa Schüler ◽  
Fayaz Asad ◽  
Hermann Behling

Abstract We present a pollen-based palaeoenvironmental reconstruction of the past 3300 years in the Kabal Valley of Swat District in the Hindu Kush mountains of Khyber Pakhtunkhwa Province, north-western Pakistan. We studied the pollen record from 38 samples taken from a 150 cm long radiocarbon-dated sediment core in order to analyse the vegetation history of the area. Only the upper 76 cm of the core, with 20 samples recording the last 3300 years, had sufficiently preserved pollen. Conifers such as Pinus, Picea, Abies, Cedrus and Taxus, and herbs belonging to Poaceae, Cyperaceae and Amaranthaceae were found consistently throughout the period, at varying abundance. The vegetation reconstruction revealed that Cyperaceae and Poaceae dominated the conifers from 3300 to 300 cal yr BP. The decrease in herbaceous vegetation (mainly Poaceae) from 2400 to 1500 cal yr BP, and its increase from 1500 to 1200 cal yr BP, indicate contraction followed by expansion of grassland in the Kabal Valley of Swat, pointing to corresponding dry-cool and wet-warm periods. Herbs were abundant in most samples from 900 to 300 cal yr BP. This change from conifer forest to open grassland can be attributed to the more pronounced impact of widespread deforestation, agricultural activity and a drier summer climate. Evergreen trees and shrubs such as Oleaceae, Myrtaceae, Moraceae species, Juglans and Dodonaea dominated and were constant from 2400 cal yr BP to the present. Conifers such as Pinus, Taxus, Picea, Abies and Cedrus were frequent in the study area from 300 cal yr BP to the present. Today these conifers occur mostly in mixed coniferous forests at higher elevation in the alpine area.


1991 ◽  
Vol 69 (7) ◽  
pp. 1507-1519 ◽  
Author(s):  
J. M. Szeicz ◽  
G. M. MacDonald

Sizable areas of oak savanna were present in southern Ontario when the region was first settled by Europeans. The objective of this study was to reconstruct the vegetation history of oak savanna at a site in Ontario and to test the hypothesis that the savanna was created by Indian burning. The fossil pollen, plant macrofossil, and fossil charcoal records of the sediments of a small lake were used to reconstruct postglacial vegetation development in an area formerly occupied by oak savanna. The fossil record from the site extends from approximately 11 800 BP to the present. The initial vegetation around the lake was an open Picea woodland similar to that reported from other late glacial sites in southern Ontario. Pinus banksiana forest dominated the vegetation of the site between about 10 000 and 9000 BP. Pinus strobus replaced Pinus banksiana and remained the dominant tree species in the area until approximately 6000 BP. The persistence of Pinus strobus as the dominant tree species until 6000 BP is unique in southern Ontario. Between 6000 and 4000 BP the Pinus strobus forest was replaced by oak savanna. Oak savanna occupied the area until land clearance by Europeans at approximately A.D. 1850. The early date at which oak savanna developed makes it unlikely that Indian burning was the cause of savanna formation. Determining the cause of the late persistence of Pinus strobus-dominated vegetation and its replacement by oak savanna is difficult. It is possible that the late persistence of Pinus strobus in the study area is related to dry climatic conditions during the mid-Holocene (~8000 to 6000 BP). The establishment of oak savanna may have been caused by the transition to moister climatic conditions in the later half of the Holocene. The particularly dry and well-drained substrates associated with oak savanna may have restricted occupation of these regions by more mesic tree species and maintained herb and graminoid dominated openings by promoting natural fires. Key words: Palaeoecology, fossil pollen, Holocene, oak savanna, southern Ontario.


2002 ◽  
Vol 58 (2) ◽  
pp. 171-181 ◽  
Author(s):  
Mark E. Lyford ◽  
Julio L. Betancourt ◽  
Stephen T. Jackson

AbstractRecords of Holocene vegetation and climate change at low elevations (<2000 m) are rare in the central Rocky Mountain region. We developed a record of Holocene vegetation and climate change from 55 14C-dated woodrat middens at two low-elevation sites (1275 to 1590 m), currently vegetated by Juniperus osteosperma woodlands, in the northern Bighorn Basin. Macrofossil and pollen analyses show that the early Holocene was cooler than today, with warming and drying in the middle Holocene. During the Holocene, boreal (Juniperus communis, J. horizontalis) and montane species (J. scopulorum) were replaced by a Great Basin species (J. osteosperma). J. osteosperma colonized the east side of the Pryor Mountains 4700 14C yr B.P. Downward movement of lower treeline indicates wetter conditions between 4400 and 2700 14C yr B.P. Increased aridity after 2700 14C yr B.P. initiated expansion of J. osteosperma from the east to west side of the Pryor Mountains.


1973 ◽  
Vol 51 (11) ◽  
pp. 2085-2103 ◽  
Author(s):  
Rolf W. Mathewes

The postglacial vegetation history of the University of British Columbia Research Forest was investigated using percentage and absolute pollen analysis, macrofossil analysis, and radiocarbon dating. A marine silty clay deposit records the oldest (12 690 ± 190 years before present (B.P.)) assemblage of terrestrial plant remains so far recovered from the postglacial of south-coastal British Columbia. Lodge-pole pine (Pinus contorta) dominated this early vegetation, although some Abies, Picea, Alnus, and herbs were also present. Sediment cores from two lakes were also studied. The older is Marion Lake, where five pollen assemblage zones are recognized, beginning with a previously undescribed assemblage of Pinus contorta, Salix, and Shepherdia in clay older than 12 350 ± 190 B.P. The pollen diagram from Surprise Lake (11 230 ± 230 B.P.) is divided into three pollen zones which show the same major trends of vegetation change as the Marion Lake diagram.The first report of the postglacial vegetation history of cedar (Thuja and perhaps Chamaecyparis) in southwestern British Columbia is presented from pollen and macrofossil analyses.At about 10 500 B.P. in both lakes, pollen of Douglas fir (Pseudotsuga menziesii) began a rapid increase, probably in response to climatic amelioration. The palynological evidence, supported by well-preserved bryophyte subfossils, suggests that humid coastal conditions have prevailed in the study area since about 10 500 B.P., with virtually no evidence for a classical Hypsithermal interval between 8500 B.P. and 3000 B.P.


2013 ◽  
Vol 293 ◽  
pp. 157-169 ◽  
Author(s):  
Konstantinos Panagiotopoulos ◽  
Anne Aufgebauer ◽  
Frank Schäbitz ◽  
Bernd Wagner

Boreas ◽  
2008 ◽  
Vol 27 (2) ◽  
pp. 115-126 ◽  
Author(s):  
DOROTHY PETEET ◽  
ANDREI ANDREEV ◽  
WILLIAM BARDEEN ◽  
FRANCESCA MISTRETTA

1987 ◽  
Vol 65 (9) ◽  
pp. 1792-1801 ◽  
Author(s):  
K. D. Bennett

Three new Holocene pollen percentage and accumulation rate diagrams for southern Ontario are presented. They greatly increase the available information on the history of the area's forest trees and permit a discussion of the competitive interactions that have brought about the forest pattern seen today. In the earliest Holocene, the forests were dominated by Picea, which was replaced by first Pinus banksiana–resinosa and then Pinus strobus. In extreme southern Ontario, Pinus strobus was replaced by Acer saccharum and Fagus grandifolia, but in the area east of Georgian Bay, Tsuga canadensis became the dominant, and near Mattawa, Betula (probably lutea). Late Holocene stability of forests is considered to be a function of the lack of taxa better able to compete than those already present.


Sign in / Sign up

Export Citation Format

Share Document