Early holocene tree growth at a high elevation site in the northernmost scandes of sweden (lapland): a palaeobiogeographical case study based on megafossil evidence

1999 ◽  
Vol 81 (1) ◽  
pp. 63-74 ◽  
Author(s):  
Leif Kullman
2012 ◽  
Vol 124 (2) ◽  
pp. 366-370 ◽  
Author(s):  
David F. Vogt ◽  
Mark E. Hopey ◽  
G. Rad Mayfield ◽  
Eric C. Soehren ◽  
Laura M. Lewis ◽  
...  

2017 ◽  
Vol 41 (4) ◽  
pp. 478-495 ◽  
Author(s):  
UK Thapa ◽  
S St. George ◽  
DK Kharal ◽  
NP Gaire

The climate of Nepal has changed rapidly over the recent decades, but most instrumental records of weather and hydrology only extend back to the 1980s. Tree rings can provide a longer perspective on recent environmental changes, and since the early 2000s, a new round of field initiatives by international researchers and Nepali scientists have more than doubled the size of the country’s tree-ring network. In this paper, we present a comprehensive analysis of the current tree-ring width network for Nepal, and use this network to estimate changes in forest growth nation-wide during the last four centuries. Ring-width chronologies in Nepal have been developed from 11 tree species, and half of the records span at least 290 years. The Nepal tree-ring width network provides a robust estimate of annual forest growth over roughly the last four centuries, but prior to this point, our mean ring-width composite fluctuates wildly due to low sample replication. Over the last four centuries, two major events are prominent in the all-Nepal composite: (i) a prolonged and widespread growth suppression during the early 1800s; and (ii) heightened growth during the most recent decade. The early 19th century decline in tree growth coincides with two major Indonesian eruptions, and suggests that short-term disturbances related to climate extremes can exert a lasting influence on the vigor of Nepal’s forests. Growth increases since AD 2000 are mainly apparent in high-elevation fir, which may be a consequence of the observed trend towards warmer temperatures, particularly during winter. This synthesis effort should be useful to establish baselines for tree-ring data in Nepal and provide a broader context to evaluate the sensitivity or behavior of this proxy in the central Himalayas.


2016 ◽  
Vol 12 (7) ◽  
pp. 1435-1444 ◽  
Author(s):  
James Shulmeister ◽  
Justine Kemp ◽  
Kathryn E. Fitzsimmons ◽  
Allen Gontz

Abstract. Here we present the results of a multi-proxy investigation – integrating geomorphology, ground-penetrating radar, and luminescence dating – of a high-elevation lunette and beach berm in northern New South Wales, eastern Australia. The lunette occurs on the eastern shore of Little Llangothlin Lagoon and provides evidence for a lake high stand combined with persistent westerly winds at the Last Glacial Maximum (LGM – centring on 21.5 ka) and during the early Holocene (ca. 9 and 6 ka). The reconstructed atmospheric circulation is similar to the present-day conditions, and we infer no significant changes in circulation at those times, as compared to the present day. Our results suggest that the Southern Hemisphere westerlies were minimally displaced in this sector of Australasia during the latter part of the last ice age. Our observations also support evidence for a more positive water balance at the LGM and early Holocene in this part of the Australian sub-tropics.


Agro Ekonomi ◽  
2021 ◽  
Vol 32 (2) ◽  
Author(s):  
Setia Sari Girsang ◽  
Agung B Santosa ◽  
Tommy Purba ◽  
Deddy R Siagian ◽  
Khadijah E Ramija

Accelerating the introduction of a new technological package is needed to increase the productivity of high elevation puddled rice in Humbang Hasundutan. The objectives of the study are to find out the perception of the existence of technological packages and farmers' preference for a new technological package. The study used a survey method with primary data gathered using questionnaires. The criteria of locations and respondents were used to obtain relevant respondents and data concerning their knowledge of high elevation puddled rice cultivation.  The collected data were processed by using Importance Performance Analysis in order to find out the level of Importance and Satisfaction of the indicators and the valued aspects in the technological package components. The results of the study showed that the socio-economic aspects had to be heeded in organizing the technological package. Indicators having a high level of importance and a low level of satisfaction consisted of production cost, quality of seeds, farmer groups empowerment, technology information institution, capital cost, agricultural tools and machines, pest control, sales price, irrigation canals, and farm roads. On the other hand, introducing new superior seeds, productivity attribute and planting age were important indicators for local farmers as to improve the quality of existing seeds. Farmers group expected that the technological package had a high level of productivity, better access to input, low cost, and good user-friendliness in its application.


2019 ◽  
Vol 85 ◽  
pp. 131-159
Author(s):  
Steven Mithen

In light of the enculturation of landscapes by ethnographically documented hunter-gatherers, we should expect Mesolithic hunter-gatherers to have endowed their early Holocene landscapes with meaning. Attempts to find evidence for this have focussed on the unusual and exotic – those aspects of the archaeological record that seem immediately unrelated to subsistence. In this contribution, I suggest that fireplaces, ubiquitous on Mesolithic sites and often swiftly passed over in site reports as evidence for cooking alone, had played a key role in the process of landscape enculturation. Although we cannot reconstruct the specific meanings once attached to early Holocene landscapes, by appreciating the social and cultural significance of fireplaces we gain a more holistic view of the Mesolithic than is currently the case, whether in those studies that focus on settlement and subsistence or those that cite examples of ritual. In the course of making this argument, I summarise the evidence for fireplaces from Mesolithic Britain, noting the need for more systematic reporting. Finally, I provide a case study from western Scotland that seeks to view a suite of fireplaces in the context of the landscape topography, early Holocene environments, subsistence economy, and by drawing on selected ethnographic analogies.


2010 ◽  
Vol 26 (5) ◽  
pp. 521-531 ◽  
Author(s):  
David Laurencio ◽  
Lee A. Fitzgerald

Abstract:Disentangling local and historical factors that determine species diversity patterns at multiple spatial scales is fundamental to elucidating processes that govern ecological communities. Here we investigated how environmental correlates may influence diversity at local and regional scales. Primarily utilizing published species lists, amphibian and reptile alpha and beta diversity were assessed at 17 well-surveyed sites distributed among ecoregions throughout Costa Rica. The degree to which regional species diversity patterns were related to environmental variables and geographic distance was determined using Canonical Correspondence Analysis and Mantel tests. Amphibian alpha diversity was highest in lowland Pacific sites (mean = 43.3 species) and lowest at the high elevation site (9 species). Reptile alpha diversity values were high for both lowland Atlantic (mean = 69.5 species) and lowland Pacific (mean = 67 species) sites and lowest for the high elevation site (8 species). We found high species turnover between local sites and ecoregions, demonstrating the importance of beta diversity in the determination of regional diversity. For both amphibians and reptiles, beta diversity was highest between the high-elevation site and all others, and lowest among lowland sites within the same ecoregion. The effect of geographic distance on beta diversity was minor. Ecologically significant climatic variables related to rain, temperature, sunshine and insolation were found to be important determinants of local and regional diversity for both amphibians and reptiles in Costa Rica.


2018 ◽  
Vol 17 ◽  
pp. 173-183 ◽  
Author(s):  
Tristan Carter ◽  
Thomas F. Strasser ◽  
Eleni Panagopoulou ◽  
Kathryn Campeau ◽  
Danica D. Mihailović
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