Climate change and human disturbance of fynbos vegetation during the late Holocene at Princess Vlei, Western Cape, South Africa

The Holocene ◽  
2011 ◽  
Vol 21 (7) ◽  
pp. 1137-1149 ◽  
Author(s):  
F.H. Neumann ◽  
L. Scott ◽  
M.K. Bamford
Keyword(s):  
Anthropogenic Disturbance ◽  
Late Holocene ◽  
Climate Changes ◽  
Western Cape ◽  
Radiocarbon Dates ◽  
The Core ◽  
Pollen Types ◽  
Hydrological System ◽  
Vegetation And Climate ◽  
Floating Mat

Pollen analysis of a core in Princess Vlei in the Fynbos Biome near Cape Town gives a 4150 year record of vegetation and climate changes followed by disturbance by colonial settlers since c. 300 years ago. Their impact replaced climate as a major factor in changing the vegetation. The chronology is based on eight radiocarbon dates. Pollen types such as Restionaceae, Ericaceae, and Proteaceae reflect changes in fynbos. Pollen indicators at the bottom of the core suggest drier conditions followed by an increase in Morella, Cyperaceae and Carpacoce pollen, which might indicate moist conditions c. 3400–2600 cal. yr BP. Drier conditions prevail c. 2600–1900 cal. yr BP. Apparent light disturbance after c. 2000 cal. yr BP might be attributed to Khoi herders. Deeper water and damp surroundings are indicated c. 1900–1000 cal. yr BP. The top of the core shows an increase of Poaceae while Restionaceae decrease with anthropogenic disturbance, including the introduction of neophytes such as Pinus ( c. 300 years ago) and Zea mays. Charcoal percentages point to intense fires after the arrival of the Europeans. Water between 105 and 75 cm indicates the development of a floating mat resulting from changes in the hydrological system possibly connected to disturbances by settlers.

Holocene Vegetation and Paleoclimatic and Paleomagnetic History from Lake Johnston, Tasmania

2001 ◽  
Vol 56 (2) ◽  
pp. 264-274 ◽  
Author(s):  
Sharon A. Anker ◽  
Eric A. Colhoun ◽  
Charles E. Barton ◽  
Mike Peterson ◽  
Mike Barbetti
Keyword(s):  
Magnetic Susceptibility ◽  
Master Curve ◽  
Late Holocene ◽  
Climate Changes ◽  
Holocene Climate ◽  
Radiocarbon Dates ◽  
Southeastern Australia ◽  
Lagarostrobos Franklinii ◽  
Glacial Relict ◽  
Vegetation And Climate

AbstractLake Johnston cirque contains some of the best subalpine rainforest in Tasmania. Pollen from the sediments shows Lagarostrobos franklinii, which presently reaches 1040 m, may be a glacial relict. Nothofagus cunninghamii–Nothofagus gunnii subalpine rainforest developed between 9000 and 6000 14C yr B.P., with a maximum at 8700 14C yr B.P. After 6000 14C yr B.P. Nothofagus gunnii became more important, and from 3600 14C yr B.P. sclerophyll and heath components increased. Partial burning of the catchment occurred periodically. Early Holocene climate was warmer and wetter than late Holocene climate. The vegetation and climate changes are similar to those recorded from western South Island New Zealand and Chile. Radiocarbon dates give a sedimentation rate of 0.43 mm/yr. Cores are correlated by magnetic susceptibility. Magnetic ages are assigned by matching with the 14C-dated secular variation master curve for southeastern Australia. Magnetic ages are consistent with the 14C chronology when the former are adjusted by 350 years.

First high-resolution dated records of vegetation and climate changes on the Lake Baikal northern shore in the middle-late Holocene

2006 ◽  
Vol 411 (1) ◽  
pp. 1331-1335 ◽  
Author(s):  
E. V. Bezrukova ◽  
A. V. Belov ◽  
A. A. Abzaeva ◽  
P. P. Letunova ◽  
L. A. Orlova ◽  
...  
Keyword(s):  
High Resolution ◽  
Lake Baikal ◽  
Late Holocene ◽  
Climate Changes ◽  
Northern Shore ◽  
Vegetation And Climate

Holocene sedimentary architecture and paleoclimate variability at Mono Lake, California

2019 ◽  
Author(s):  
S.R.H. Zimmerman ◽  
S.R. Hemming ◽  
S.W. Starratt
Keyword(s):  
Sierra Nevada ◽  
Lake Level ◽  
Late Holocene ◽  
Mono Lake ◽  
Ice Age ◽  
Historical Period ◽  
Radiocarbon Dates ◽  
The Core ◽  
Sedimentary Architecture ◽  
Lake Floor

ABSTRACT Mono Lake occupies an internally drained basin on the eastern flank of the Sierra Nevada, and it is sensitive to climatic changes affecting precipitation in the mountains (largely delivered in the form of snowpack). Efforts to recover cores from the lake have been impeded by coarse tephra erupted from the Mono Craters, and by disruption of the lake floor due to the uplift of Paoha Island ~300 yr ago. In this study, we describe the stratigraphy of cores from three recent campaigns, in 2007, 2009, and 2010, and the extents and depths of the tephras and disturbed sediments. In the most successful of these cores, BINGO-MONO10-4A-1N (BINGO/10-4A, 2.8 m water depth), we used core stratigraphy, geochemistry, radiocarbon dates, and tephrostratigraphy to show that the core records nearly all of the Holocene in varying proportions of detrital, volcanic, and authigenic sediment. Both the South Mono tephra of ca. 1350 cal yr B.P. (calibrated years before A.D. 1950) and the 600-yr-old North Mono–Inyo tephra are present in the BINGO/10-4A core, as are several older, as-yet-unidentified tephras. Laminated muds are inferred to indicate a relatively deep lake (³10 m over the core site) during the Early Holocene, similar to many records across the region during that period. The Middle and Late Holocene units are more coarsely bedded, and coarser grain size and greater and more variable amounts of authigenic carbonate detritus in this interval are taken to suggest lower lake levels, possibly due to lower effective wetness. A very low lake level, likely related to extreme drought, is inferred to have occurred sometime between 3500 and 2100 cal yr B.P. This interval likely corresponds to the previously documented Marina Low Stand and the regional Late Holocene Dry Period. The BINGO/10-4A core does not preserve a complete record of the period encompassing the Medieval Climate Anomaly, the Little Ice Age, and the historical period, probably due to erosion because of its nearshore position.

scholarly journals Multi-proxy approach to reconstruct Middle and Late Holocene paleoenvironment and climate in the eastern Carpathians.

2020 ◽  
Author(s):  
Maria J. Ramos-Roman ◽  
Heikki Seppä ◽  
Eniko Magyari ◽  
Cindy De Jonge ◽  
Daniel Veres ◽  
...  
Keyword(s):  
Late Holocene ◽  
Climate Changes ◽  
Organic Geochemistry ◽  
Lipid Biomarkers ◽  
The Black Sea ◽  
Radiocarbon Dates ◽  
Past Climate ◽  
Eastern Carpathians ◽  
Complementary Techniques ◽  
Middle And Late Holocene

<p>Sediments from lakes are a useful climate archive that provides information about past climate changes and human impact. It is well-known that abrupt climate change can be the trigger of the collapse or migrations of past civilizations. To have a better understanding of the migration of the Yamnaya civilization, located west of the Black Sea at ~5.5-5 cal kyr BP, we hypothesize that past climate changes acts as a driver of this migration. To test this we focus on a sedimentary record retrieved from the Mocearu lake that is located at 780 m a.s.l. in the Buzau mountains (eastern Carpathians, Romania). The record has a length of 7 m and covers the last ~6.5 cal kyr BP based on AMS radiocarbon dates. To reconstruct vegetation, environment and climate during the Middle and Late Holocene, we use complementary techniques: pollen, inorganic (XRF-analysis) and organic geochemistry based on lipid biomarkers (brGDGTs). The reconstruction has been carried out with higher resolution during the Middle Holocene, with the objective of finding evidence of the climatic changes that may have occurred around 5 cal kyr BP. Based on preliminary radiocarbon dating, the climatic reconstruction (based on brGDGTs) shows an increase in temperature from ~6 to 5.5 cal kyr BP, followed by a prominent decrease ~5.3-5 cal kyr BP.</p>

Late Holocene vegetation and climate changes in the Great Hinggan Mountains, northeast China

2019 ◽  
Vol 532 ◽  
pp. 138-145 ◽  
Author(s):  
Dongxue Han ◽  
Chuanyu Gao ◽  
Zicheng Yu ◽  
Xiaofei Yu ◽  
Yunhui Li ◽  
...  
Keyword(s):  
Northeast China ◽  
Late Holocene ◽  
Climate Changes ◽  
Vegetation And Climate

Pollen-based reconstructions of vegetation and climate changes during the late Holocene in the southern Altai Mountains

The Holocene ◽  
2019 ◽  
Vol 29 (9) ◽  
pp. 1450-1458 ◽  
Author(s):  
Yunpeng Yang ◽  
Dongliang Zhang ◽  
Aizhi Sun ◽  
Wei Wang ◽  
Bo Lan ◽  
...  
Keyword(s):  
Late Holocene ◽  
Climate Changes ◽  
Altai Mountains ◽  
Pollen Data ◽  
Raised Bog ◽  
Increasing Trend ◽  
Surrounding Areas ◽  
Vegetation And Climate ◽  
Peat Area

We here preset a result of high-resolution pollen data of a lacustrine-peat sediment core from Yushenkule (YSKL) Peat, southern Altai Mountains, northwestern China. We aim to reconstruct the palaeovegetation and palaeoclimate variations in the southern Altai Mountains and further evaluate the role of autogenic process of the raised bog itself in driving the local vegetation dynamics. The pollen data of YSKL core-2 show two major vegetation stages in YSKL Peat area and the surrounding areas during the data-covering period. During the stage lasting from ~4870 to ~2550 cal. yr BP, regional vegetation was dominated by desert steppe and local vegetation in YSKL Peat was characterized by Artemisia-dominated mountain steppe. During the stage lasting from ~2550 to ~700 cal. yr BP, regional vegetation was characterized by Artemisia-dominated steppe and local vegetation in YSKL Peat was characterized by Cyperaceae-dominated wetland herbs. The Ar/Am ( Artemisia/Amaranthaceae) ratio-indicated moisture increasing trend of southern Altai Mountains can attribute to the combined effects of decreased temperature and increased precipitation. The lithologic transition from lake to peat of YSKL core-2 can be explained by invoking the variations in the areal extent of ice covers in the Altai Mountains.

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