Search results for "Population growth"
showing 10 items of 109 documents
A Bayesian Reconstruction of a Historical Population in Finland, 1647–1850
2020
This article provides a novel method for estimating historical population development. We review the previous literature on historical population time-series estimates and propose a general outline to address the well-known methodological problems. We use a Bayesian hierarchical time-series model that allows us to integrate the parish-level data set and prior population information in a coherent manner. The procedure provides us with model-based posterior intervals for the final population estimates. We demonstrate its applicability by estimating the long-term development of Finlands population from 1647 onward and simultaneously place the country among the very few to have an annual popula…
Urbanization and forest degradation in east Africa - a case study around Dar es Salaam, Tanzania
2016
In this paper we examine the impact of the growing urbanization of Dar es Salaam, Tanzania, on the forest areas around the city. Since 1990 the city has seen an annual population growth rate of over 4%. We document the expansion of the city over the last 30 using the Global Human Settlement Layers, derived from the global Landsat archive. At the same time we show the depletion, of the surrounding forests that has occurred to meet the growing demand for agricultural land, fuel wood and construction material over the same period. The impact on these forests as a result of the demand from an expanding urban conglomeration is higher than would be expected from a dispersed population increase. T…
Managing Metro Manila
2017
Metro Manila residents are confronted everyday with the challenges of flooding, substandard housing and horrendous traffic. In this low altitude plain, any significant rainfall raises water levels in many small streams, and contributes to traffic jams. The rapid population growth of the metropolis has led to the proliferation of squatter areas, including alongside flood-prone rivers and railroad tracks. The lack of discipline and of decent garbage management contribute in turn to a worsening of floods when streams are covered with litter. The fast rise in motorization rates, coupled with the many imperfections of the public transport system, make Manila one of the most congested cities in t…
Cardenolide variation within and among natural populations of Digitalis obscura
1999
Summary Cardenolide content in 49 wild-growing Digitalis obscura plants from six natural populations on the Iberian Peninsula was determined by HPLC. Series A and B glycosides were the predominant cardenolides in all samples, but absolute values varied among and within populations. Hierarchic analysis of variance showed that the proportion of variation attributable to individuals was significantly higher than that attributable to population differences. Furthermore, analyses from greenhouse-grown plants, generated from seeds collected from selected parental genotypes, attributed nearly all the variability in cardenolide content to single plants. Some individual plants showed a leaf content …
Effects of air pollution on dementia over Europe for present and future climate change scenarios.
2020
The scientific literature is scarce when referring to the influence of atmospheric pollutants on neurodegenerative diseases for present and future climate change scenarios. In this sense, this contribution evaluates the incidence of dementia (Alzheimer's disease, AD, and dementia from unspecified cause, DU) occurring in Europe associated with the exposure to air pollution (essentially NO2 and PM2.5) for the present climatic period (1991-2010) and for a future climate change scenario (RCP8.5, 2031-2050). The GEMM methodology has been applied to air pollution simulations using the chemistry/climate regional model WRF-Chem. Present population data were obtained from NASA's Center for Socioecon…
Environmental noise and population dynamics of the ciliated protozoa Tetrahymena thermophila in aquatic microcosms
2003
Population theory predicts that the reddened environmental noise, especially in combination with high population growth rate, reddens population dynamics, increases population variability and strengthens environment–population correlation. We tested these predictions with axenic populations of ciliated protozoa Tetrahymena thermophila. Populations with low and high growth rate were cultured in a stable environment, and in environments with sublethal temperature fluctuations that had blue, white and red spectra (i.e. negatively autocorrelated, uncorrelated, or positively autocorrelated, respectively). Population size and biomass of individuals were determined at 3-h intervals for 18 days. Dy…
Delayed mixis in rotifers: an adaptive response to the effects of density-dependent sex on population growth
2004
In most cyclically parthenogenetic life cycles, sex is needed to produce resting stages. In several species of cyclically parthenogenetic rotifers, some generations of clones are not responsive to a density-dependent signal that triggers sexual female production. These unresponsive rotifers hatch from resting eggs and typically pass 8–12 generations of female parthenogenesis before becoming receptive to the mixis signal. We addressed the selection for mixis delay using a simulation model. A delay of sexual reproduction could increase population growth through parthenogenesis and thus the number of resting eggs ultimately produced. In a monomorphic population without mixis delay, we determin…
Consequences of correlations between habitat modifications and negative impact of climate change for regional species survival
2011
Abstract While several empirical and theoretical studies have clearly shown the negative effects of climate or landscape changes on population and species survival only few of them addressed combined and correlated consequences of these key environmental drivers. This also includes positive landscape changes such as active habitat management and restoration to buffer the negative effects of deteriorating climatic conditions. In this study, we apply a conceptual spatial modelling approach based on functional types to explore the effects of both positive and negative correlations between changes in habitat and climate conditions on the survival of spatially structured populations. We test the…
Drivers of CO2 emissions in the former Soviet Union: A country level IPAT analysis from 1990 to 2010
2013
There are a small number of countries that have managed to decrease emissions over the last two decades e most of them emerged from the FSU (former Soviet Union ). CO2 emissions for these countries combined have decreased by 35% between 1990 and 2010, while global emissions increased by 44%. Most studies investigate the FSU as a single block ignoring the significant and persistent diversity among countries in the region. This study is the first providing detailed country by country analyses determining factors for changes in post-Soviet republics by applying a disaggregated version of the commonly used (IPAT) index decomposition analysis including energy intensity, affluence industrializati…
Measuring the potential for growth in populations investing in diapause
2014
AbstractThe intrinsic rate of population increase (r) is a common performance measure in many ecological and evolutionary studies. However, in life cycles with diapause investment resources are split into a short-term (current population growth) and a long-term (population survival through periods of unsuitable habitat conditions) component, which complicates the use of r as a single performance measure. Here we propose a new measure that integrates both performance components into a single parameter, the potential intrinsic growth rate, rpot. This is the rate of increase that a population/genotype would have if no investment in diapausing stages would occur. We show that rpot can be comput…