scholarly journals How Important Are Resistance, Dispersal Ability, Population Density and Mortality in Temporally Dynamic Simulations of Population Connectivity? A Case Study of Tigers in Southeast Asia

Land ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 415
Author(s):  
Eric Ash ◽  
Samuel A. Cushman ◽  
David W. Macdonald ◽  
Tim Redford ◽  
Żaneta Kaszta
Keyword(s):  
Population Density ◽  
Southeast Asia ◽  
Population Distribution ◽  
Landscape Connectivity ◽  
Relative Effect ◽  
Relative Strength ◽  
Population Connectivity ◽  
Dispersal Ability ◽  
Landscape Resistance ◽  
Kernel Approach

Development of landscape connectivity and spatial population models is challenging, given the uncertainty of parameters and the sensitivity of models to factors and their interactions over time. Using spatially and temporally explicit simulations, we evaluate the sensitivity of population distribution, abundance and connectivity of tigers in Southeast Asia to variations of resistance surface, dispersal ability, population density and mortality. Utilizing a temporally dynamic cumulative resistant kernel approach, we tested (1) effects and interactions of parameters on predicted population size, distribution and connectivity, and (2) displacement and divergence in scenarios across timesteps. We evaluated the effect of varying levels of factors on simulated population, cumulative resistance kernel extent, and kernel sum across nine timesteps, producing 24,300 simulations. We demonstrate that predicted population, range shifts, and landscape connectivity are highly sensitive to parameter values with significant interactions and relative strength of effects varying by timestep. Dispersal ability, mortality risk and their interaction dominated predictions. Further, population density had intermediate effects, landscape resistance had relatively low impacts, and mitigation of linear barriers (highways) via lowered resistance had little relative effect. Results are relevant to regional, long-term tiger population management, providing insight into potential population growth and range expansion across a landscape of global conservation priority.

Convergence of regional population density in Russia over 120 years

2020 ◽  
pp. 133-158
Author(s):  
K. A. Kholodilin ◽  
Y. I. Yanzhimaeva
Keyword(s):  
Population Density ◽  
Spatial Dependence ◽  
Population Distribution ◽  
Regional Level ◽  
Capital City ◽  
County Level ◽  
Spatial Effects ◽  
Russian Regions ◽  
Regional Population ◽  
Regional Population Density

A relative uniformity of population distribution on the territory of the country is of importance from socio-economic and strategic perspectives. It is especially important in the case of Russia with its densely populated West and underpopulated East. This paper considers changes in population density in Russian regions, which occurred between 1897 and 2017. It explores whether there was convergence in population density and what factors influenced it. For this purpose, it uses the data both at county and regional levels, which are brought to common borders for comparability purposes. Further, the models of unconditional and conditional β-convergence are estimated, taking into account the spatial dependence. The paper concludes that the population density equalization took place in 1897-2017 at the county level and in 1926—1970 at the regional level. In addition, the population density increase is shown to be influenced not only by spatial effects, but also by political and geographical factors such as climate, number of GULAG camps, and the distance from the capital city.

scholarly journals Spatial capture–recapture models for jointly estimating population density and landscape connectivity

Ecology ◽  
2013 ◽  
Vol 94 (2) ◽  
pp. 287-294 ◽  
Author(s):  
J. Andrew Royle ◽  
Richard B. Chandler ◽  
Kimberly D. Gazenski ◽  
Tabitha A. Graves
Keyword(s):  
Population Density ◽  
Landscape Connectivity ◽  
Capture Recapture

The Worst of All Worlds

2005 ◽  
Vol 1902 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Eric Eidlin
Keyword(s):  
Los Angeles ◽  
Population Density ◽  
Travel Behavior ◽  
Traffic Congestion ◽  
Population Distribution ◽  
Housing Prices ◽  
The United States ◽  
Urban Life ◽  
Apparent Paradox ◽  
Gini Coefficients

Los Angeles, California, is generally considered the archetypal sprawling metropolis. Yet traditional measures equate sprawl with low population density, and Los Angeles is among the densest and thereby the least sprawling cities in the United States. How can this apparent paradox be explained? This paper argues that the answer lies in the fact that Los Angeles exhibits a comparatively even distribution of population throughout its urbanized area. As a result, the city suffers from many consequences of high population density, including extreme traffic congestion, poor air quality, and high housing prices, while offering its residents few benefits that typically accompany this density, including fast and effective public transit, vibrant street life, and tightly knit urban neighborhoods. The city's unique combination of high average population density with little differentiation in the distribution of population might best be characterized as dense sprawl, a condition that embodies the worst of urban and suburban worlds. This paper uses Gini coefficients to illustrate variation in population density and then considers a number of indicators–-most relating either to the provision of transportation infrastructure or to travel behavior–-that demonstrate the effects of low-variation population distribution on the quality of urban life in Los Angeles. This approach offers researchers, practitioners, and policy makers in Los Angeles and in smaller cities that are evolving in similar ways a useful and user-friendly tool for identifying, explaining, measuring, and addressing the most problematic aspects of sprawl.

scholarly journals Supporting Adaptive Connectivity in Dynamic Landscapes

Land ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 295 ◽  
Author(s):  
Megan K. Jennings ◽  
Katherine A. Zeller ◽  
Rebecca L. Lewison
Keyword(s):  
Protected Area ◽  
Landscape Connectivity ◽  
Management Strategies ◽  
Structural Connectivity ◽  
Area Network ◽  
Landscape Conservation ◽  
Landscape Resistance ◽  
Adaptive Planning ◽  
Dynamic Landscapes ◽  
Over Time

A central tenet of landscape conservation planning is that natural communities can be supported by a connected landscape network that supports many species and habitat types. However, as the planning environment, ecological conditions, and risks and stressors change over time, the areas needed to support landscape connectivity may also shift. We demonstrate an approach designed to assess functional and structural connectivity of an established protected area network that has experienced landscape and planning changes over time. Here we present an approach designed to inform adaptive planning for connectivity with a complementary suite of analytical techniques. Using existing occurrence, movement, and genetic data for six focal species, we create a spatially explicit connectivity assessment based on landscape resistance, paired with a landscape feature geodiversity analysis. Although factors such as cost, conservation goals, and land management strategies must be taken into account, this approach provides a template for leveraging available empirical data and robust analyses to evaluate and adapt planning for protected area networks that can preserve and promote both functional and structural connectivity in dynamic landscapes.

scholarly journals Population Distribution in the Wake of a Sphere

Symmetry ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1498 ◽  
Author(s):  
Taraprasad Bhowmick ◽  
Yong Wang ◽  
Michele Iovieno ◽  
Gholamhossein Bagheri ◽  
Eberhard Bodenschatz
Keyword(s):  
Reynolds Number ◽  
Spatial Distribution ◽  
Population Density ◽  
Density Distribution ◽  
Population Distribution ◽  
Fluid Velocity ◽  
Three Dimensional ◽  
Wake Flow ◽  
Sample Number ◽  
Scalar Fluxes

The physics of heat and mass transfer from an object in its wake has significant importance in natural phenomena as well as across many engineering applications. Here, we report numerical results on the population density of the spatial distribution of fluid velocity, pressure, scalar concentration, and scalar fluxes of a wake flow past a sphere in the steady wake regime (Reynolds number 25 to 285). Our findings show that the spatial population distributions of the fluid and the transported scalar quantities in the wake follow a Cauchy-Lorentz or Lorentzian trend, indicating a variation in its sample number density inversely proportional to the squared of its magnitude. We observe this universal form of population distribution both in the symmetric wake regime and in the more complex three dimensional wake structure of the steady oblique regime with Reynolds number larger than 225. The population density distribution identifies the increase in dimensionless kinetic energy and scalar fluxes with the increase in Reynolds number, whereas the dimensionless scalar population density shows negligible variation with the Reynolds number. Descriptive statistics in the form of population density distribution of the spatial distribution of the fluid velocity and the transported scalar quantities is important for understanding the transport and local reaction processes in specific regions of the wake, which can be used e.g., for understanding the microphysics of cloud droplets and aerosol interactions, or in the technical flows where droplets interact physically or chemically with the environment.

scholarly journals First assessment of habitat suitability and connectivity for the golden jackal in north-eastern Italy

2020 ◽  
Vol 100 (6) ◽  
pp. 631-643
Author(s):  
Elisa Torretta ◽  
Olivia Dondina ◽  
Claudio Delfoco ◽  
Luca Riboldi ◽  
Valerio Orioli ◽  
...  
Keyword(s):  
Habitat Selection ◽  
Habitat Suitability ◽  
Negative Impact ◽  
Rapid Expansion ◽  
Golden Jackal ◽  
Landscape Resistance ◽  
Least Cost Path ◽  
Study Region ◽  
North Eastern ◽  
Kernel Approach

AbstractCompared with the rapid expansion across Europe, the golden jackal colonization of Italy is still limited and slow. No study focused on the habitat selection or landscape connectivity for this species was performed in Italy; thus, the potential distribution and dispersal patterns in the country remain unknown. Our objectives were to evaluate the suitability of the Friuli-Venezia Giulia region (north-eastern Italy) for the golden jackal, as well as to identify the ecological corridors connecting the areas currently occupied by the species. Corridors modelling allowed us both to hypothesize the dispersal dynamics occurring in the study region and to identify possible obstacles to future range expansion. We surveyed golden jackal presence in two study areas, covering an area of 500 km2, from March 2017 to February 2018. Using collected data, we modelled the species home-range scale habitat suitability based on an ensemble modelling approach. Subsequently, a habitat suitability prediction at a finer scale was used to estimate landscape resistance, starting from which, we modelled dispersal corridors among areas currently occupied by the species using a factorial least cost path and a cumulative resistant kernel approach. Our results indicated a moderate potential for large parts of the study region to support the occurrence of golden jackal family groups, whose presence seems to be mainly driven by the presence of wide areas covered by broadleaved forests and shrublands and by the absence of wide intensive agricultural areas. The predicted connectivity networks showed that three main permeable corridors are likely to connect golden jackal occurrence areas within the study region, while all the other corridors are characterized by a very low path density. Both the habitat selection and connectivity analyses showed a strong negative impact of the intensive cultivated plain on species stable presence and movement providing critical information for the conservation of the golden jackal in Italy.

scholarly journals Mapping Changing Population Distribution on the Qinghai–Tibet Plateau since 2000 with Multi-Temporal Remote Sensing and Point-of-Interest Data

2020 ◽  
Vol 12 (24) ◽  
pp. 4059
Author(s):  
Lanhui Li ◽  
Yili Zhang ◽  
Linshan Liu ◽  
Zhaofeng Wang ◽  
Huamin Zhang ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Population Density ◽  
Rural Areas ◽  
Population Distribution ◽  
Local Population ◽  
Tibet Plateau ◽  
Point Of Interest ◽  
Tibet Autonomous Region ◽  
Multi Temporal ◽  
Qinghai Tibet Plateau

Advanced developments have been achieved in urban human population estimation, however, there is still a considerable research gap for the mapping of remote rural populations. In this study, based on demographic data at the town-level, multi-temporal high-resolution remote sensing data, and local population-sensitive point-of-interest (POI) data, we tailored a random forest-based dasymetric approach to map population distribution on the Qinghai–Tibet Plateau (QTP) for 2000, 2010, and 2016 with a spatial resolution of 1000 m. We then analyzed the temporal and spatial change of this distribution. The results showed that the QTP has a sparse population distribution overall; in large areas of the northern QTP, the population density is zero, accounting for about 14% of the total area of the QTP. About half of the QTP showed a rapid increase in population density between 2000 and 2016, mainly located in the eastern and southern parts of Qinghai Province and the central-eastern parts of the Tibet Autonomous Region. Regarding the relative importance of variables in explaining population density, the variables “Distance to Temples” is the most important, followed by “Density of Villages” and “Elevation”. Furthermore, our new products exhibited higher accuracy compared with five recently released gridded population density datasets, namely WorldPop, Gridded Population of the World version 4, and three national gridded population datasets for China. Both the root-mean-square error (RMSE) and mean absolute error (MAE) for our products were about half of those of the compared products except for WorldPop. This study provides a reference for using fine-scale demographic count and local population-sensitive POIs to model changing population distribution in remote rural areas.

GIS Based Spatialization of Population Data in Meijiang River Basin

2013 ◽  
Vol 295-298 ◽  
pp. 2378-2383 ◽  
Author(s):  
Xiang Gui Zeng ◽  
Ge Ying Lai ◽  
Fa Zhao Yi ◽  
Ling Ling Zhang
Keyword(s):  
Land Use ◽  
Population Density ◽  
River Basin ◽  
Population Distribution ◽  
Population Data ◽  
Fusion Technology ◽  
Processing Technologies ◽  
Source Data ◽  
Density Map ◽  
Main Factors

This paper used GIS spatial analysis and data processing technologies and multi-source data fusion technology to spatialize the population data of Meijiang river basin. Land use was selected as the index factor and the settlements as the indicative factor. Selected terrain, roads and rivers were the main influencing factors and were further classified into several sub-factors. During the simulation, we first calculated the weight indexes of sub-factors on the settlements distribution and then fused the indexes to calculate the weight indexes of the main factors. Second we calculated the weight indexes of settlements on the population distribution. Last we fused the weight indexes of the main factors and the weight indexes of settlements to obtain the population density indexes of whole region and then generated the 100m×100m resolution raster population density map.

scholarly journals Dispersal of the introduced red king crab (Paralithodes camtschaticus) in Norwegian waters: a tag-recapture study

2014 ◽  
Vol 71 (7) ◽  
pp. 1966-1976 ◽  
Author(s):  
Kristin Windsland ◽  
Carsten Hvingel ◽  
Einar M. Nilssen ◽  
Jan H. Sundet
Keyword(s):  
Logistic Regression ◽  
Population Density ◽  
Fishing Effort ◽  
Dispersal Ability ◽  
Large Individual ◽  
Red King Crab ◽  
Paralithodes Camtschaticus ◽  
Dispersal Rate ◽  
Long Distance ◽  
King Crab

Abstract The aim of this study was to explore the effect of sex, size, region, and density on dispersal rate of the introduced red king crab (Paralithodes camtschaticus) in Norwegian waters. We examined the effect of these factors using logistic regression analysis. Tag-recapture data corrected for fishing effort enabled us to estimate dispersal rates from four main regions along the Norwegian coast: Varangerfjorden, Tanafjorden, Laksefjorden, and Porsangerfjorden. The probability of dispersal was independent of sex and size, but both the logistic regression and the evaluation of corrected tag-recapture data revealed differences in dispersal between region and with increasing duration. The recapture data indicated a relationship between population density and dispersal within research regions but not between population density and dispersal between research regions. Our main conclusion is that there are large individual differences in dispersal ability and the range expansion of red king crab is a result of (i) the presence of long-distance dispersers and (ii) time-dependent slow migration by short distance dispersers. We also conclude that there appears less dispersal in Norwegian waters than in native waters, which might be caused by differences in geographical complexity.

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