scholarly journals Temperature, Wind, Cloud, and the Postglacial Tree Line History of Sub-Antarctic Campbell Island

Forests ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 998 ◽  
Author(s):  
Matt S. McGlone ◽  
Janet M. Wilmshurst ◽  
Sarah J. Richardson ◽  
Chris S.M. Turney ◽  
Jamie R. Wood
Keyword(s):  
Vegetation Change ◽  
Tree Line ◽  
Subsequent Increase ◽  
Temperature Trends ◽  
History Of Vegetation ◽  
Future Global Warming ◽  
History Of ◽  
Change Temperature ◽  
Ocean Sector ◽  
Campbell Island

Campbell Island, which is 600 km south of New Zealand, has the southernmost tree line in this ocean sector. Directly under the maximum of the westerlies, the island is sensitive to changes in wind strength and direction. Pollen records from three peat cores spanning the tree line ecotone provide a 17,000-year history of vegetation change, temperature, and site moisture. With postglacial warming, tundra was replaced by tussock grassland 12,500 years ago. A subsequent increase of shrubland was reversed at 10,500 years ago and wetland-grassland communities became dominant. Around 9000 years ago, trees spread, with maximum tree line elevation reached around 6500 to 3000 years ago. This sequence is out of step with Southern Ocean sea surface temperatures, which were warmer than 12,500 to 9000 years ago, and, subsequently, cooled. Campbell Island tree lines were decoupled from temperature trends in the adjacent ocean by weaker westerlies from 12,500 to 9000 years ago, which leads to the intrusion of warmer, cloudier northern airmasses. This reduced solar radiation and evapotranspiration while increasing atmospheric humidity and substrate wetness, which suppressed tree growth. Cooler, stronger westerlies in the Holocene brought clearer skies, drier air, increased evapotranspiration, and rising tree lines. Future global warming will not necessarily lead to rising tree lines in oceanic regions.

Climate and local controls of long-term vegetation dynamics in northern Patagonia (Lat 41°S)

2012 ◽  
Vol 78 (3) ◽  
pp. 502-512 ◽  
Author(s):  
Virginia Iglesias ◽  
Cathy Whitlock ◽  
María Martha Bianchi ◽  
Gustavo Villarosa ◽  
Valeria Outes
Keyword(s):  
Late Holocene ◽  
Vegetation Change ◽  
Late Glacial ◽  
Fire Frequency ◽  
Forest Steppe ◽  
Ecological Change ◽  
Postglacial History ◽  
New Information ◽  
History Of Vegetation ◽  
History Of

AbstractPatagonian vegetation has dramatically changed in composition and distribution over the last 16,000 yr. Although patterns of vegetation change are relatively clear, our understanding of the processes that produce them is limited. High-resolution pollen and charcoal records from two lakes located at lat 41°S provide new information on the postglacial history of vegetation and fire activity at the forest–steppe ecotone, and help clarify the relative importance of local and regional drivers of late-Holocene ecological change. Our results suggest that late-glacial parkland was colonized by shrubs at ca. 11,200 cal yr BP and this vegetation persisted until 4900 cal yr BP, when increased humidity allowed for the establishment of Nothofagus forest. The late Holocene is characterized by oscillations in forest dominance largely driven by changes in humidity, possibly associated with the onset or strengthening of ENSO. In the last 4900 yr, humid periods (4900–3800 and 2850–1350 cal yr BP) have promoted Nothofagus forest, whereas drier times (3800–2850 and 1350–450 cal yr BP) have favored Austrocedrus expansion. At intermediate moisture levels, however, the lower forest supported both taxa, and fire became an important control of community composition, with severe, infrequent fires facilitating Nothofagus regeneration and high fire frequency and intensity supporting Austrocedrus.

scholarly journals The history of vegetation and landscapes of the lake Ilchir basin for understanding the modern vegetation structure in the Okinsky plateau

2021 ◽  
Vol 629 ◽  
pp. 012046
Author(s):  
E V Volchatova ◽  
E V Bezrukova ◽  
N V Kulagina ◽  
O V Levina ◽  
A A Shchetnikov ◽  
...  
Keyword(s):  
Vegetation Structure ◽  
History Of Vegetation ◽  
History Of

The History of Vegetation in Ulyanovsk and Its Environs

2021 ◽  
Vol 48 (10) ◽  
pp. 1733-1739
Author(s):  
N. V. Blagoveshchenskaya ◽  
Ch. T. Zamaldinova ◽  
G. V. Funk
Keyword(s):  
History Of Vegetation ◽  
History Of

scholarly journals Neoglacial history of Robson Glacier, British Columbia

2017 ◽  
Vol 54 (11) ◽  
pp. 1153-1164 ◽  
Author(s):  
B.H. Luckman ◽  
M.H. Masiokas ◽  
K. Nicolussi
Keyword(s):  
British Columbia ◽  
Little Ice Age ◽  
Ice Age ◽  
Tree Line ◽  
Canadian Rockies ◽  
The Holocene ◽  
Forest Sites ◽  
History Of ◽  
Subfossil Wood ◽  
Glacier Advance

As glaciers in the Canadian Rockies recede, glacier forefields continue to yield subfossil wood from sites overridden by these glaciers during the Holocene. Robson Glacier in British Columbia formerly extended below tree line, and recession over the last century has progressively revealed a number of buried forest sites that are providing one of the more complete records of glacier history in the Canadian Rockies during the latter half of the Holocene. The glacier was advancing ca. 5.5 km upvalley of the Little Ice Age terminus ca. 5.26 cal ka BP, at sites ca. 2 km upvalley ca. 4.02 cal ka BP and ca. 3.55 cal ka BP, and 0.5–1 km upvalley between 1140 and 1350 A.D. There is also limited evidence based on detrital wood of an additional period of glacier advance ca. 3.24 cal ka BP. This record is more similar to glacier histories further west in British Columbia than elsewhere in the Rockies and provides the first evidence for a post-Hypsithermal glacier advance at ca. 5.26 cal ka BP in the Rockies. The utilization of the wiggle-matching approach using multiple 14C dates from sample locations determined by dendrochronological analyses enabled the recognition of 14C outliers and an increase in the precision and accuracy of the dating of glacier advances.

Palynology and Paleoecology of Postglacial Sediments from the Lower Fraser River Canyon of British Columbia

1975 ◽  
Vol 12 (5) ◽  
pp. 745-756 ◽  
Author(s):  
R. W. Mathewes ◽  
G. E. Rouse
Keyword(s):  
Tsuga Heterophylla ◽  
Climatic Conditions ◽  
Douglas Fir ◽  
Fraser River ◽  
Pollen Assemblage ◽  
Glacial Ice ◽  
Transitional Area ◽  
Postglacial History ◽  
History Of Vegetation ◽  
History Of

The postglacial history of vegetation in the Yale area of the lower Fraser River Canyon is described from sediments of two lakes using percentage pollen analysis supplemented with macrofossil evidence and radiocarbon dating. Deposition of postglacial sediments, ranging from basal clays to gyttjas, began about 11 500 y B.P. Three distinct pollen assemblage zones are distinguished, reflecting in part the main climatic conditions for the intervals. The oldest zone, with high percentages of pine (Pinus) and alder (Alnus) pollen, suggests cool and moist conditions following withdrawal of glacial ice. This is followed by marked increases in Douglas-fir (Pseudotsuga), grasses and other nonarboreal pollen, suggesting in part, warmer and drier conditions. The third zone, ranging from about the Mt. Mazama ash at 6600 y B.P. to the present, is marked by high alder and Douglas-fir, and increasing cedar (Thuja-Chamaecyparis type), western hemlock (Tsuga heterophylla), fir (Abies) and birch; an assemblage indicating a return to wetter conditions. This sequence contrasts with previously described successions that recognized the classical Hypsithermal in adjacent areas. The sequence of inferred vegetational changes, although similar to those described for the Haney area to the west, suggests that the Yale area has been a biogeoclimatically transitional area for much of postglacial time.

Household Economy, Long-Term Change, and Social Transformation: The Bronze Age Political Economy of Northwestern Europe

2007 ◽  
Vol 2 (2) ◽  
pp. 161-175 ◽  
Author(s):  
Kristian Kristiansen
Keyword(s):  
Bronze Age ◽  
Iron Age ◽  
Social Transformation ◽  
Environmental Changes ◽  
Term Change ◽  
History Of Vegetation ◽  
History Of ◽  
Triggering Factor ◽  
The Bronze Age

In this article I examine how long-term economic strategies in the Bronze Age of northern Europe between 2300 and 500 BCE transformed the environment and thus created and imposed new ecological constraints that finally led to a major social transformation and a "dark age" that became the start of the new long-term cycle of the Iron Age. During the last 30 years hundreds of well-excavated farmsteads and houses from south Scandinavia have made it possible to reconstruct the size and the structure of settlement and individual households through time. During the same period numerous pollen diagrams have established the history of vegetation and environmental changes. I will therefore use the size of individual households or farmsteads as a parameter of economic strength, and to this I add the role of metal as a triggering factor in the economy, especially after 1700 BCE when a full-scale bronze technology was adopted and after 500 BCE when it was replaced by iron as the dominant metal. A major theoretical concern is the relationships between micro- and macroeconomic changes and how they articulated in economic practices. Finally the nature of the "dark age" during the beginning of the Iron Age will be discussed, referring to Sing Chew's use of the concept (Chew 2006).

scholarly journals Humboldt’sTableau Physiquerevisited

2019 ◽  
Vol 116 (26) ◽  
pp. 12889-12894 ◽  
Author(s):  
Pierre Moret ◽  
Priscilla Muriel ◽  
Ricardo Jaramillo ◽  
Olivier Dangles
Keyword(s):  
Environmental Changes ◽  
Original Data ◽  
Range Shift ◽  
Tree Line ◽  
Tropical Andes ◽  
Altitudinal Distribution ◽  
Climate Change Effects ◽  
Altitudinal Shift ◽  
History Of ◽  
Vegetation Belt

Alexander von Humboldt’sTableau Physique(1807) has been one of the most influential diagrams in the history of environmental sciences. In particular, detailed observations of the altitudinal distribution of plant species in the equatorial Andes, depicted on a cross-section of Mt. Chimborazo, allowed Humboldt to establish the concept of vegetation belt, thereby laying the foundations of biogeography. Surprisingly, Humboldt’s original data have never been critically revisited, probably due to the difficulty of gathering and interpreting dispersed archives. By unearthing and analyzing overlooked historical documents, we show that the top section of theTableau Physique, above the tree line, is an intuitive construct based on unverified and therefore partly false field data that Humboldt constantly tried to revise in subsequent publications. This finding has implications for the documentation of climate change effects in the tropical Andes. We found that Humboldt’s primary plant data above tree line were mostly collected on Mt. Antisana, not Chimborazo, which allows a comparison with current records. Our resurvey at Mt. Antisana revealed a 215- to 266-m altitudinal shift over 215 y. This estimate is about twice lower than previous estimates for the region but is consistent with the 10- to 12-m/decade upslope range shift observed worldwide. Our results show the cautious approach needed to interpret historical data and to use them as a resource for documenting environmental changes. They also profoundly renew our understanding of Humboldt’s scientific thinking, methods, and modern relevance.

HISTORY OF VEGETATION

2011 ◽  
pp. 243-275
Author(s):  
Jane Haldimand Marcet
Keyword(s):  
History Of Vegetation ◽  
History Of

scholarly journals History of vegetation and habitat change in the Austral-Asian region

2004 ◽  
Vol 118-119 ◽  
pp. 103-126 ◽  
Author(s):  
Geoffrey Hope ◽  
A.Peter Kershaw ◽  
Sander van der Kaars ◽  
Sun Xiangjun ◽  
Ping-Mei Liew ◽  
...  
Keyword(s):  
Habitat Change ◽  
Asian Region ◽  
History Of Vegetation ◽  
History Of
Sign in / Sign up

Export Citation Format

Share Document