scholarly journals Vegetation Response to Climate Change and Human Impacts in the Usambara Mountains

ISRN Forestry ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
C. T. Mumbi ◽  
R. Marchant ◽  
P. Lane
Keyword(s):  
Forest Fires ◽  
Human Impacts ◽  
Sediment Cores ◽  
Peat Bogs ◽  
Coprophilous Fungi ◽  
Close Proximity ◽  
Lowland Forests ◽  
The Indian Ocean ◽  
Usambara Mountain ◽  
Depth Curve

East and West Usambara Mountain blocks are unique based on three characteristics. Firstly, they are connected blocks; secondly, they have an oceanic-influenced climate; and thirdly, the rain seasons are not easily discernible due to their close proximity to the Indian Ocean and Equator. Sediment cores were collected from peat bogs in Derema (DRM) and Mbomole (MBML) in East Usambara and from Madumu (DUMU) in West Usambara. The multiproxy record provides an understanding on climate and vegetation changes during the last 5000 years. DRM and MBML cores result in radiocarbon ages and age-depth curve which showed hiatus at 20 cm and 61 cm and huge inversion for DUMU core at 57 cm. Period 5000–4000 14C yr BP for DUMU core revealed increased Montane forest indicative of relatively moist conditions. Periods 3000–2000 and 2000–1000 14C yr BP, DUMU core demonstrated increased submontane and lowland forests. Period 1000–200 14C yr BP, DUMU core signified increased coprophilous fungi while DRM and MBML cores signified fluctuating herbaceous pollen spectra (wet-dry episodes). Period 200 14C yr BP to present, all cores demonstrated stable recovery of forest types especially dominance of submontane forests. Abundant coprophilous fungi indicated increased human impacts including forest fires, cultivation, and grazing.

At Nature's Edge

2018 ◽  
Keyword(s):  
Human Impacts ◽  
Military Bases ◽  
East African ◽  
African Countries ◽  
The Road ◽  
European Experience ◽  
The Everyday ◽  
Long Time ◽  
The Indian Ocean ◽  
The Many

In an epoch when environmental issues make the headlines, this is a work that goes beyond the everyday. Ecologies as diverse as the Himalayas and the Indian Ocean coast, the Negev desert and the former military bases of Vietnam, or the Namib desert and the east African savannah all have in common a long-time human presence and the many ways people have modified nature. With research in six Asian and African countries, the authors come together to ask how and why human impacts on nature have grown in scale and pace from a long pre-history. The chapters in this volume illumine specific patterns and responses across time, going beyond an overt centring of the European experience. The tapestry of life and the human reshaping of environments evoke both concern and hope, making it vital to understand when, why, and how we came to this particular turn in the road. Eschewing easy labels and questioning eurocentrism in today’s climate vocabulary, this is a volume that will stimulate rethinking among scholars and citizens alike.

The History of Human Impacts in the Clear Lake Watershed ( California) as Deduced from Lake Sediment Cores*

1999 ◽  
Author(s):  
Douglas Nelson ◽  
Alan Heyvaert ◽  
Laurent Meillier ◽  
Jae Kim ◽  
Xiaoping Li ◽  
...  
Keyword(s):  
Lake Sediment ◽  
Human Impacts ◽  
Sediment Cores ◽  
Clear Lake ◽  
History Of

scholarly journals Changes in C<sub>3</sub>/C<sub>4</sub> vegetation in the continental interior of the Central Himalayas associated with monsoonal paleoclimatic changes during the last 600 kyr

2007 ◽  
Vol 3 (4) ◽  
pp. 871-898
Author(s):  
M. Mampuku ◽  
T. Yamanaka ◽  
M. Uchida ◽  
R. Fujii ◽  
T. Maki ◽  
...  
Keyword(s):  
Sediment Cores ◽  
Central Himalayas ◽  
Vegetation Shifts ◽  
Paleoenvironmental Changes ◽  
Paleoclimatic Changes ◽  
Continuous Record ◽  
The Indian Ocean ◽  
Glacial Periods ◽  
Continental Interior ◽  
Sw Monsoon

Abstract. A continuous lacustrine sediment core obtained from the Kathmandu Valley in the Central Himalayas revealed that cyclical changes in C3/C4 vegetation corresponded to global glacial-interglacial cycles from marine isotope stages (MIS) 15 to MIS 4. The C3/C4 vegetation shifts were reconstructed from significant changes in the δ13C values of bulk organic carbon. Glacial ages were characterized by significant 13C enrichment, due to the expansion of C4 plants, attributed to an intensification of aridity. Thus, the southwest (SW) summer monsoon, which brings the majority of rainfall to the Central Himalayan southern slopes, would have been weaker. Marine sediment cores from the Indian Ocean and Arabian Sea have demonstrated a weaker SW monsoon during glacial periods, and our results confirm that arid conditions and a weak SW monsoon prevailed in the continental interior of the Central Himalayas during glacial ages. This study provides the first continuous record for the continental interior of paleoenvironmental changes directly influenced by the Indian monsoon.

scholarly journals Changes in C<sub>3</sub>/C<sub>4</sub> vegetation in the continental interior of the Central Himalayas associated with monsoonal paleoclimatic changes during the last 600 kyr

2008 ◽  
Vol 4 (1) ◽  
pp. 1-9 ◽  
Author(s):  
M. Mampuku ◽  
T. Yamanaka ◽  
M. Uchida ◽  
R. Fujii ◽  
T. Maki ◽  
...  
Keyword(s):  
Sediment Cores ◽  
Central Himalayas ◽  
Vegetation Shifts ◽  
Paleoenvironmental Changes ◽  
Paleoclimatic Changes ◽  
Continuous Record ◽  
The Indian Ocean ◽  
Glacial Periods ◽  
Continental Interior ◽  
Sw Monsoon

Abstract. A continuous lacustrine sediment core obtained from the Kathmandu Valley in the Central Himalayas revealed that cyclical changes in C3/C4 vegetation corresponded to global glacial-interglacial cycles from marine isotope stages (MIS) 15 to MIS 4. The C3/C4 vegetation shifts were reconstructed from significant changes in the δ13C values of bulk organic carbon. Glacial ages were characterized by significant 13C enrichment, due to the expansion of C4 plants, attributed to an intensification of aridity. Thus, the southwest (SW) summer monsoon, which brings the majority of rainfall to the Central Himalayan southern slopes, would have been weaker. Marine sediment cores from the Indian Ocean and Arabian Sea have demonstrated a weaker SW monsoon during glacial periods, and our results confirm that arid conditions and a weak SW monsoon prevailed in the continental interior of the Central Himalayas during glacial ages. This study provides the first continuous record for the continental interior of paleoenvironmental changes directly influenced by the Indian monsoon.

A 12,000 Kyr Paleohydroclimate Record in the Southeastern, U.S.A based on Deuterium from Bat Guano

2021 ◽  
Author(s):  
Alexandra Tsalickis ◽  
Matthew Neal Waters ◽  
Joshua William Campbell
Keyword(s):  
United States ◽  
Human Impacts ◽  
Southeastern United States ◽  
Sediment Cores ◽  
Population Increase ◽  
Time Interval ◽  
Moisture Regimes ◽  
Climate Proxies ◽  
Bat Guano

Abstract The southeastern United States endures environmental change from human population increase, climate change, and land use alterations creating the need to understand baseline conditions and environmental patterns prior to human impacts. While paleoenvironmental data can be reconstructed from a variety of archives (e.g. lake sediments, tree rings, speleothems), some geographic areas contain fewer of such records. One archive capable of recording moisture regimes and other paleoenvironmental changes over millennia but has received little attention relative to other climate proxies, are bat guano deposits in cave systems. Bat guano deposits are found in many cave environments in the southeastern United States and can be used as an archive of paleoenvironmental data including precipitation, vegetation, and aspects associated with the ecology of bats. Here, we present a 12,000-year record of paleoenvironmental change based on δ2H stable isotopes in a guano core collected from Cave Springs Cave in Alabama, USA. Results suggest distinct shifts in moisture during the lower Holocene/upper Pleistocene (9,551 – 12,131 cal yr BP) (δ2H values -86.82 – -77.70) and during the middle Holocene (3,886 – 9,351 cal yr BP) (δ2H values -125.74 – -80.63), roughly coinciding with the Holocene Climatic Optimum (HCO) time interval (5,000 – 9,000 cal yr BP). During the last 4,000 years, conditions in the region shifted once again in the southeastern United States region. Climate inferences based on guano δ2H are consistent with the role of atmospheric moisture on regional vegetation changes suggested by previous pollen records obtained from lake sediment cores. This study suggests bat guano δ2H may be a reliable method to provide a long-term paleoclimate record.

NATURAL RADIOISOTOPES AND 137CS IN THE SECTION OF THE SHERSTOBITOVO PEAT BOG OF THE BARABA FOREST-STEPPE (WESTERN SIBERIA)

2021 ◽  
pp. 96-109
Author(s):  
G. A. Leonova ◽  
◽  
M. S. Melgunov ◽  
K. A. Mezina ◽  
A. E. Maltsev ◽  
...  
Keyword(s):  
Forest Fires ◽  
Suspended Matter ◽  
Western Siberia ◽  
Coarse Grained ◽  
Dust Particles ◽  
Winter Period ◽  
Peat Bogs ◽  
Forest Steppe ◽  
Peat Bog ◽  
Additional Contribution

Specific activities of natural (7Be, 210Pb) and technogenic (137Cs) radioisotopes in the suspended matter of snow melted water have been determined and the density of their fallout on the surface of the Sherstobitovo and Ubinskoye peat bogs of the Baraba forest-steppe at the points of snow flow in winter period is estimated. It has been established that the main concentrator of the 7Be radioisotope is a finely dispersed fraction of suspended matter (<0.45 μm), consisting of colloids and dissolved component, 210Pbatm is a coarse-grained fraction (> 3 μm), consisting of dust particles. On the example of vertical profile of the Sherstobitovo peat bog, the first data on the distribution of natural (238U, 210Pb, 226Ra, 40K) and technogenic (137Cs) isotopes were obtained for peat bogs of forest –steppe zone of the Western Siberia. Both 226Ra and 238U show the same pattern of vertical distribution that is also usual for 137Cs and 40K. The increase of activity of these radionuclides is observed in the horizon of 6-12 cm as well as in the lower section part (25-35 cm). According to our assumption it is due to the same processes. Migration of 37Cs deep into peat accumulation is significantly determined by moor water fluctuations in the seasonal and long-term cycle, and it is closely related to the microrelief of bog surface. Besides, 137Cs, being a geochemical analogue of the 40K biophile, is pulled up from the underlying peat horizons by plant roots during the dry season. An additional contribution to the high activity of 137Cs in upper horizons is probably due to the input of 137Cs to the surface of the Sherstobitovo peat bog as a result of peat and forest fires.

Sampling of Data Derived from Historical Documents in Anthropological Research

2010 ◽  
Vol 75 (4) ◽  
pp. 973-977 ◽  
Author(s):  
Thomas H. Foster ◽  
Arthur Cohen
Keyword(s):  
Eighteenth Century ◽  
Forest Fires ◽  
Sediment Cores ◽  
Data Sources ◽  
Historical Documents ◽  
Creek Indians ◽  
Anthropological Research ◽  
Deerskin Trade

In response to Joshua Piker's (this issue) comment on our article (Foster and Cohen 2007), we point out that our article was a description of a test of a hypothesis. Piker's (this issue) criticism of our paper is grounded in the differences between historians and anthropological archaeologists. The historic literature that Piker (this issue) cited does not inform about whether or not Creek Indians hunted where we performed the sediment cores. It merely points out that Creek hunters may have hunted with greater frequency elsewhere. But that is irrelevant to our study, which tested whether the eighteenth-century deerskin trade increased the frequency of forest fires in a particular region. Archaeologists will benefit from using historical documents but archaeologists still have to be clear about the potential biases of those interdisciplinary data sources.

Remains of non-pollen-palynomorphs – tardigrades from Spitsbergen found during pollen analyses

Polar Record ◽  
2016 ◽  
Vol 52 (4) ◽  
pp. 450-463 ◽  
Author(s):  
Vlasta Jankovská ◽  
Milena Roszkowska ◽  
Łukasz Kaczmarek
Keyword(s):  
Environmental Conditions ◽  
Sediment Cores ◽  
Peat Bogs ◽  
Northwestern Part ◽  
Polar Regions ◽  
Native Flora ◽  
The Past ◽  
Analytical Studies ◽  
Pollen Analyses

ABSTRACTPollen- and non-pollen-palynomorphs (NPP) analytical studies of the northwestern part of Spitsbergen were conducted between 1988 and 1991. As well as pollen from local native flora and more dispersed species, some well preserved remains of tardigrada exuvia, buccal tubes and eggs were found. This study reviewed the remains of at least six tardigrade taxa reported:Dactylobiotus ambiguous, Paramacrobiotus richtersigroup,Richtersius coronifer, Macrobiotus hufelandigroup,Macrobiotus peterseniandMinibiotuscf.intermedius, which are reassessed and determined more accurately. These findings provide some new insights into the past environmental conditions and changes for Spitsbergen. Based on the present research it can be concluded that tardigrade remains are frequent NPP elements of pollen analyses from lake, peat bogs and detritus sub-fossil sediment cores, at least in polar regions. It can also be stated that tardigrades can be considered indicators in further palaeontological studies helping to reconstruct past environmental conditions (for example humidity) for some regions. However, the knowledge of tardigrades in these types of analyses is still rather poor.

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