scholarly journals Terrestrial mountain islands and Pleistocene climate fluctuations as motors for speciation: A case study on the genus Pseudovelia (Hemiptera: Veliidae)

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Zhen Ye ◽  
Pingping Chen ◽  
Wenjun Bu
Keyword(s):  
Climate Fluctuations ◽  
Pleistocene Climate

Distributional and demographic consequences of Pleistocene climate fluctuations for a marine demersal fish in the north-eastern Atlantic

2009 ◽  
Vol 36 (6) ◽  
pp. 1138-1151 ◽  
Author(s):  
Maarten H. D. Larmuseau ◽  
Jeroen K. J. Van Houdt ◽  
Jef Guelinckx ◽  
Bart Hellemans ◽  
Filip A. M. Volckaert
Keyword(s):  
Demersal Fish ◽  
Climate Fluctuations ◽  
The North ◽  
Pleistocene Climate ◽  
North Eastern

Prehistoric Human Activities and its Environmental Background in Central China: A Case Study in Henan Province

2013 ◽  
Vol 357-360 ◽  
pp. 448-452
Author(s):  
Zhong Xuan Li ◽  
Guo Xi Wu
Keyword(s):  
Cultural Transmission ◽  
Distribution Density ◽  
Cultural Exchange ◽  
Henan Province ◽  
Central China ◽  
Growth Type ◽  
Climate Fluctuations ◽  
Environmental Background ◽  
Early And Middle Holocene

Based on amount change and distribution density of the Neolithic sites in Henan Province, these sites are divided into three types: (1)the Growth type. This type is mainly located in Luoyang Basin where the landform was convenient for millet-farming and settlement-clustering. (2) the Atrophy type. It mainly sits in the Nanyang Basin in which was a transition zone for cultural exchange. And (3) is the Oscillation type. This type distributes around the area of Yinghe-Ruhe River downstream with low land and frequent floods, which affected the amounts of sites in respond to series climate fluctuations in the early and middle Holocene. Comparatively, the unique terrain environment and water networks in the Luoyang Basin heralded the earliest civilized fruit in China and to be the cradle of early cultural transmission.

scholarly journals The flickering connectivity system of the north Andean páramos

2019 ◽  
Author(s):  
Suzette G.A. Flantua ◽  
Aaron O’Dea ◽  
Renske E. Onstein ◽  
Henry Hooghiemstra
Keyword(s):  
Lower Boundary ◽  
Habitat Connectivity ◽  
Pollen Record ◽  
Climate Conditions ◽  
Northern Andes ◽  
Climate Fluctuations ◽  
Mountain Ranges ◽  
Biogeographic Patterns ◽  
The North ◽  
Pleistocene Climate

ABSTRACT AND KEYWORDSAimTo quantify the effect of Pleistocene climate fluctuations on habitat connectivity across páramos in the Neotropics.LocationThe Northern AndesMethodsThe unique páramos habitat underwent dynamic shifts in elevation in response to changing climate conditions during the Pleistocene. The lower boundary of the páramos is defined by the upper forest line, which is known to be highly responsive to temperature. Here we reconstruct the extent and connectivity of páramos over the last 1 million years (Myr) by reconstructing the UFL from the long fossil pollen record of Funza09, Colombia, and applying it to spatial mapping on modern topographies across the Northern Andes for 752 time slices. Data provide an estimate of how often and for how long different elevations were occupied by páramos and estimates their connectivity to provide insights into the role of topography in biogeographic patterns of páramos.ResultsOur findings show that connectivity amongst páramos of the Northern Andes was highly dynamic, both within and across mountain ranges. Connectivity amongst páramos peaked during extreme glacial periods but intermediate cool stadials and mild interstadials dominated the climate system. These variable degrees of connectivity through time result in what we term the ‘flickering connectivity system’. We provide a visualization (video) to showcase this phenomenon. Patterns of connectivity in the Northern Andes contradict patterns observed in other mountain ranges of differing topographies.Main conclusionsPleistocene climate change was the driver of significant elevational and spatial shifts in páramos causing dynamic changes in habitat connectivity across and within all mountain ranges. Some generalities emerge, including the fact that connectivity was greatest during the most ephemeral of times. However, the timing, duration and degree of connectivity varied substantially among mountain ranges depending on their topographic configuration. The flickering connectivity system of the páramos uncovers the dynamic settings in which evolutionary radiations shaped the most diverse alpine biome on Earth.

A Numerical Approach for the Hygro-Thermal Monitoring of Timber Structures under Environmental Conditions

2013 ◽  
Vol 778 ◽  
pp. 786-793
Author(s):  
Alessandra Genoese ◽  
Andrea Genoese ◽  
Stefania Fortino ◽  
Petr Hradil
Keyword(s):  
Numerical Approach ◽  
Coupled Analysis ◽  
Timber Structures ◽  
Climate Variations ◽  
Thermal Monitoring ◽  
Climate Fluctuations ◽  
User Subroutine ◽  
Natural Climate ◽  
Numerical Case Study

The monitoring of timber structures exposed to natural climate fluctuations during their service life is an important topic for both their serviceability and safety. Numerical methods based on the recent advances in hygro-thermal modelling of wood can integrate the usual sensor-based monitoring techniques by reducing the maintenance costs for timber structures. In this paper, a 3D full coupled analysis based on the multi-Fickian theory with sorption hysteresis of wood is implemented in Abaqus FEM code by defining a new finite element in a user subroutine. To verify the method, the hygro-thermal behaviour of a glulam beam tested in laboratory under variable humidity within a previous research is analysed and the numerical values of moisture content are found to be in agreement with the experimental data. Furthermore, a numerical case-study of a glulam cross section under real climate variations is presented and the related results show the capability of the method to predict the moisture states in each points of the glulam member under continuously variable humidity and temperature.

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