scholarly journals Population Dynamics in Southern Europe: A Local-Scale Analysis, 1961–2011

2018 ◽  
Vol 11 (1) ◽  
pp. 109 ◽  
Author(s):  
Ilaria Zambon ◽  
Kostas Rontos ◽  
Pere Serra ◽  
Andrea Colantoni ◽  
Luca Salvati
Keyword(s):  
Population Dynamics ◽  
Settlement Patterns ◽  
Population Distribution ◽  
Regional Scale ◽  
Local Scale ◽  
Spatially Explicit ◽  
Southern Europe ◽  
Scale Analysis ◽  
Demographic Trends ◽  
Explicit Analysis

Different socioeconomic, historical, political, and cultural factors have influenced long-term settlement patterns and demographic structures in Europe. Southern Europe is considered a relatively homogeneous region as far as settlement characteristics and population dynamics are concerned. Within-country local variability in the spatial distribution of population is high, and inherent differences across countries may outline distinct demographic patterns at regional scale. A comparative, local-scale analysis of population distribution in five countries (Spain, Italy, Croatia, Greece, and Cyprus) over a relatively long time period (1961–2011) contributes to identify latent demographic trends in Mediterranean Europe at the spatial scale of Local Administrative Units (LAU). A spatially-explicit analysis of basic indicators of population density and demographic change allows identification of territorial disparities, reflecting local-scale settlement patterns common to different countries (e.g., population growth along coastal districts). These patterns consolidate a metropolitan hierarchy centered on large—mainly compact—cities and more dispersed conurbations along coastal areas. At the same time, the examined countries present different territorial contexts resulting in distinct population dynamics in turn influenced by internal (e.g., national policies, culture and local identity, class segregation) and exogenous (e.g., economic cycle, urbanization models) factors. A spatially-explicit analysis of demographic trends at local scale may contribute to rethinking urban strategies and adapting spatial planning to heterogeneous socioeconomic contexts across Europe.

scholarly journals Spatio-temporal point processes as meta-models for population dynamics in heterogeneous landscapes

2021 ◽  
Author(s):  
Patrizia Zamberletti ◽  
Julien Papaix ◽  
Edith Gabriel ◽  
Thomas Opitz
Keyword(s):  
Population Dynamics ◽  
Point Processes ◽  
Temporal Dynamics ◽  
Landscape Heterogeneity ◽  
Marked Point ◽  
Local Scale ◽  
Agricultural Landscapes ◽  
Spatially Explicit ◽  
Regression Equations ◽  
Spatio Temporal

Landscape heterogeneity affects population dynamics, which determine species persistence, diversity and interactions. These relationships can be accurately represented by advanced spatially-explicit models (SEMs) allowing for high levels of detail and precision. However, such approaches are characterised by high computational complexity, high amount of data and memory requirements, and spatio-temporal outputs may be difficult to analyse. A possibility to deal with this complexity is to aggregate outputs over time or space, but then interesting information may be masked and lost, such as local spatio-temporal relationships or patterns. An alternative solution is given by meta-models and meta-analysis, where simplified mathematical relationships are used to structure and summarise the complex transformations from inputs to outputs. Here, we propose an original approach to analyse SEM outputs. By developing a meta-modelling approach based on spatio-temporal point processes (STPPs), we characterise spatio-temporal population dynamics and landscape heterogeneity relationships in agricultural contexts. A landscape generator and a spatially-explicit population model simulate hierarchically the pest-predator dynamics of codling moth and ground beetles in apple orchards over heterogeneous agricultural landscapes. Spatio-temporally explicit outputs are simplified to marked point patterns of key events, such as local proliferation or introduction events. Then, we construct and estimate regression equations for multi-type STPPs composed of event occurrence intensity and magnitudes. Results provide local insights into spatio-temporal dynamics of pest-predator systems. We are able to differentiate the contributions of different driver categories (i.e., spatio-temporal, spatial, population dynamics). We highlight changes in the effects on occurrence intensity and magnitude when considering drivers at global or local scale. This approach leads to novel findings in agroecology where the organisation of cultivated fields and semi-natural elements are known to play a crucial role for pest regulation. It aids to formulate guidelines for biological control strategies at global and local scale.

scholarly journals Long-Term Demographic Trends in Prehistoric Italy: Climate Impacts and Regionalised Socio-Ecological Trajectories

2021 ◽  
Author(s):  
Alessio Palmisano ◽  
Andrew Bevan ◽  
Alexander Kabelindde ◽  
Neil Roberts ◽  
Stephen Shennan
Keyword(s):  
Population Dynamics ◽  
Iron Age ◽  
Population Change ◽  
Regional Scale ◽  
Climate Impacts ◽  
Demographic Trends ◽  
Radiocarbon Dates ◽  
The Holocene ◽  
Italian Peninsula

AbstractThe Italian peninsula offers an excellent case study within which to investigate long-term regional demographic trends and their response to climate fluctuations, especially given its diverse landscapes, latitudinal range and varied elevations. In the past two decades, summed probability distributions of calibrated radiocarbon dates have become an important method for inferring population dynamics in prehistory. Recent advances in this approach also allow for statistical assessment of spatio-temporal patterning in demographic trends. In this paper we reconstruct population change for the whole Italian peninsula from the Late Mesolithic to the Early Iron Age (10,000–2800 cal yr BP). How did population patterns vary across time and space? Were fluctuations in human population related to climate change? In order to answer these questions, we have collated a large list of published radiocarbon dates (n = 4010) and use this list firstly to infer the demographic trends for the Italian peninsula as a whole, before addressing each of five sub-regions in turn (northern, central, and southern Italy, Sicily, Sardinia). We also compare population fluctuations with local paleoclimate proxies (cave, lake, marine records). At a pan-regional scale, the results show a general rapid and substantial increase in population in the Early Neolithic with the introduction of farming at around 8000 cal yr BP and further dramatic increases during the Bronze and Iron Age (~ 3800–2800 cal yr BP). However, different regional demographic trajectories exist across different regions of Italy, suggesting a variety of localised human responses to climate shifts. Population and climate appear to have been more closely correlated during the early–mid Holocene (Mesolithic–Neolithic), while later in the Holocene (Bronze–Iron Ages) they decouple. Overall, across the Holocene the population dynamics varied by region and depended on the long-term socio-ecological dynamics prevailing in a given area. Finally, we include a brief response to the paper ‘Radiocarbon dated trends and central Mediterranean prehistory’ by Parkinson et al. (J Word Prehist 34(3), 2021)—synchronously published by Journal of World Prehistory but wholly independently developed—indicating how our conclusions accord with or differ from one another.

scholarly journals Necromys lasiurus: Lessons From a 38-Year Study in an Amazonian Savanna

2021 ◽  
Vol 9 ◽  
Author(s):  
Clarisa Alves Rosa ◽  
Pedro Henrique Salomão Ganança ◽  
Albertina Pimentel Lima ◽  
William Ernest Magnusson
Keyword(s):  
Population Dynamics ◽  
Global Climate ◽  
Regional Scale ◽  
Local Scale ◽  
Population Fluctuations ◽  
Plant Interactions ◽  
Seed Disperser ◽  
Mammal Fauna ◽  
Long Term Studies

Amazonian savannas are isolated patches of open habitats within an array of extensive tropical forest. The mammal fauna of the savannas in the Alter do Chão region (Santarém Municipality), is dominated by Necromys lasiurus, whose populations have been studied by researchers of the National Institute of Amazonian Research since 1983. Here, we summarize the studies and advances made so far to better understand aspects related to population dynamics and ecology of savanna rodents and the strategies they use to persist in an environment with frequent fires subject to global climatic influences. In the Amazonian savannas the species acts as a seed disperser and population fluctuations are related to invertebrate availability, but not with fire or vegetation structure. Global climate appears to affect N. lasiurus population dynamics at local scale (i.e., plot scale) but not at the regional scale of the Alter do Chão savannas. The long-term studies in Alter do Chão generated many advances about Necromys lasiurus population dynamics and ecology, including aspects relating to feeding, home range, animal-plant interactions, the effects of fire and climate change.

Implementation of multispecies ecological networks at the regional scale: analysis and multi-temporal assessment

2021 ◽  
Vol 289 ◽  
pp. 112494
Author(s):  
Giuseppe Modica ◽  
Salvatore Praticò ◽  
Luigi Laudari ◽  
Antonio Ledda ◽  
Salvatore Di Fazio ◽  
...  
Keyword(s):  
Regional Scale ◽  
Ecological Networks ◽  
Scale Analysis ◽  
Multi Temporal ◽  
Temporal Assessment

scholarly journals Arthropod community structure in pastures of an island archipelago (Azores): looking for local–regional species richness patterns at fine-scales

2004 ◽  
Vol 94 (2) ◽  
pp. 111-121 ◽  
Author(s):  
P.A.V. Borges ◽  
V.K. Brown
Keyword(s):  
Species Richness ◽  
Regional Scale ◽  
Local Scale ◽  
Local Species Richness ◽  
Β Diversity ◽  
Arthropod Species ◽  
Α Diversity ◽  
Local Species ◽  
Richness Patterns

AbstractThe arthropod species richness of pastures in three Azorean islands was used to examine the relationship between local and regional species richness over two years. Two groups of arthropods, spiders and sucking insects, representing two functionally different but common groups of pasture invertebrates were investigated. The local–regional species richness relationship was assessed over relatively fine scales: quadrats (= local scale) and within pastures (= regional scale). Mean plot species richness was used as a measure of local species richness (= α diversity) and regional species richness was estimated at the pasture level (= γ diversity) with the ‘first-order-Jackknife’ estimator. Three related issues were addressed: (i) the role of estimated regional species richness and variables operating at the local scale (vegetation structure and diversity) in determining local species richness; (ii) quantification of the relative contributions of α and β diversity to regional diversity using additive partitioning; and (iii) the occurrence of consistent patterns in different years by analysing independently between-year data. Species assemblages of spiders were saturated at the local scale (similar local species richness and increasing β-diversity in richer regions) and were more dependent on vegetational structure than regional species richness. Sucking insect herbivores, by contrast, exhibited a linear relationship between local and regional species richness, consistent with the proportional sampling model. The patterns were consistent between years. These results imply that for spiders local processes are important, with assemblages in a particular patch being constrained by habitat structure. In contrast, for sucking insects, local processes may be insignificant in structuring communities.

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