Population: Trends in Population Increase and Distribution During 1920-30

1931 ◽  
Vol 36 (6) ◽  
pp. 865-879
Author(s):  
P. K. Whelpton
PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0244670
Author(s):  
Marianne Tønnessen ◽  
Siddartha Aradhya ◽  
Eleonora Mussino

In an increasingly interconnected world, the demographic effects of wars are not confined only to war zones and neighbouring areas; wars and conflicts may also change populations far away. Without the war in Syria under President Assad and the associated mass exodus of Syrian refugees, the population trends in distant countries like Sweden and Norway over the last few years would have been different. We create hypothetical scenarios of the population developments in Sweden and Norway without a war in Syria from 2011 onwards, where excess immigration due to the war and associated excess births are removed. The results indicate that population growth in 2016 would have been roughly 36% lower in Sweden and 26% lower in Norway without the Syrian war. The number of births in 2017 would have been about 3% lower in Sweden and 1% lower in Norway. One in ten municipalities would have had a population decline in 2016 instead of a population increase, and the largest immigrant group in Sweden by January 2019 would still be of Finnish origin.


1986 ◽  
Vol 43 (3) ◽  
pp. 553-564 ◽  
Author(s):  
Derek Roff ◽  
W. Don Bowen

We examined changes in the age structure of the northwest Atlantic harp seal (Phoca groenlandica) population from 1967 to 1983. Through this period there has been a statistically significant population increase in the proportion of seals aged 2–6 yr. Precise estimation of the rate of increase is hindered by a tendency for immature seals to be overrepresented in samples of molting males. Two methods were developed to correct for this bias; these provide a minimum estimate of the proportion of seals aged 2–6 yr present in 1967. Utilizing a simulation model, we showed that the unadjusted and adjusted age distributions are both extremes and that the correct distribution probably lies between them. In both cases the data are more consistent with an increasing than a decreasing population, given the level of catch experienced by this population up to 1982. Recent total catches of 75 000 or less in 1983 and 1984 are substantially below the most conservative estimates of replacement yield in 1985 and will result in a further, more rapid population increase.


2021 ◽  
Vol 13 (12) ◽  
pp. 6636
Author(s):  
Rosanna Salvia ◽  
Luca Salvati ◽  
Giovanni Quaranta

The long-term impact of demographic transitions on the spatial distribution of human settlements was occasionally evaluated in Europe. Assuming the distinctive role of urban–rural divides, our study investigates local-scale population trends (1861–2017) in Southern Italy, a disadvantaged region of Mediterranean Europe, as a result of long-term socioeconomic transformations. A quantitative analysis of municipal-scale population data based on descriptive and exploratory multivariate statistics, mapping, inferential approaches, and regression models identified four time intervals with distinctive demographic dynamics: (i) a spatially homogeneous population growth between 1861 and 1911, (ii) a moderate population increase rebalancing a traditional divide in coastal and internal areas (1911–1951), (iii) accelerated population growth enlarging spatial divides in urban and rural districts (1951–1981), and (iv) population stability (or slight decline) leading to heterogeneous demographic patterns since the early 1980s. The first three stages reflect a prolonged transition from high fertility and mortality to high fertility and low mortality, with accelerated population growth typical of the latest stage of the first demographic transition. Outcomes of time interval (iv) reflect the early stages of the second demographic transition, with lowest-low fertility and rising life expectancy. While the first transition reflected spatially homogeneous population trends along a considerable time spam, the second transition has been associated with heterogeneous (leapfrog) demographic patterns as a result of socially mixed (and spatially) fragmented dynamics of growth and change.


2000 ◽  
Vol 3 (6) ◽  
pp. 479-482 ◽  
Author(s):  
J.M. Kean ◽  
N.D. Barlow

2007 ◽  
Vol 34 (2) ◽  
pp. 307-317 ◽  
Author(s):  
J. SEITZ

Modernization of agriculture, economic development and population increase after the end of the Thirty Years' War caused authorities in many parts of Germany to decree the eradication of so-called pest animals, including the House Sparrow. Farmers were given targets, and had to deliver the heads of sparrows in proportion to the size of their farms or pay fines. At the end of the eighteenth century German ornithologists argued against the eradication of the sparrows. During the mid-nineteenth century, C. L. Gloger, the pioneer of bird protection in Germany, emphasized the value of the House Sparrow in controlling insect plagues. Many decrees were abolished because either they had not been obeyed, or had resulted in people protecting sparrows so that they always had enough for their “deliveries”. Surprisingly, various ornithologists, including Ernst Hartert and the most famous German bird conservationist Freiherr Berlepsch, joined in the war against sparrows at the beginning of the twentieth century, because sparrows were regarded as competitors of more useful bird species. After the Second World War, sparrows were poisoned in large numbers. Persecution of sparrows ended in Germany in the 1970s. The long period of persecution had a significant but not long-lasting impact on House Sparrow populations, and therefore cannot be regarded as a factor in the recent decline of this species in urban and rural areas of western and central Europe.


2020 ◽  
Vol 57 ◽  
pp. 3-34
Author(s):  
Ulf Schiefelbein ◽  
Frieda Engel ◽  
Franziska Masberg ◽  
Svea Lübke ◽  
Johann Schiefelbein ◽  
...  

Die Flechtendiversität und -quantität wurde in den Jahren 2017/2018 in Rostock an 53 Bäumen erfasst. Die Ergebnisse wurden mit den Ergebnissen einer Kartierung von 1994/1995 verglichen. Ferner wurden die Feuchtigkeitsverhältnisse und der Grad der Eutrophierung bzw. die Luftqualität an den Bäumen der Gattungen Tilia und Acer anhand des bekannten Verhaltens der nachgewiesenen Flechten bezüglich Luftfeuchtigkeit/Niederschlägen, Eutrophierung und pH-Verhältnissen bewertet. 2017/2018 wurden 79 Flechtenarten und 14 lichenicole Pilzarten nachgewiesen. Die Gesamtzahl der im Untersuchungsgebiet nachgewiesenen epiphytischen Flechtenarten erhöhte sich damit auf 80. Die meisten Flechtenarten kommen an Tilia spec. (60), Acer pseudoplatanus (43) und A. platanoides (34) vor. Die häufigsten Arten sind Phaeophyscia orbicularis, Physcia adscendens, Ph. tenella und Xanthoria parietina. Candelariella xanthostigmoides, Flavoparmelia soredians, Hyperphyscia adglutinata, Intralichen lichenum, Lecanora subcarpinea, Parmelia serrana, Parmelina quercina und Taeniolella delicata sind Neufunde für Mecklenburg-Vorpommern. Hinsichtlich der Verbreitung und des Charakters der Fundorte können die nachgewiesenen Flechten und lichenicolen Pilze drei Gruppen zugeordnet werden: 1. Arten, die auch an stark befahrenen Straßen oder in eng bebauten Wohngebieten mit wenig Grünflächen und in den Stadtgebieten Kröpeliner Tor-Vorstadt oder Stadtmitte vorkamen, 2. Arten, die auch noch in locker bebauten, grünreichen Wohngebieten und in kleineren Grünlagen der Neubaugebiete vorkamen, aber nicht mehr in der Kröpeliner Tor-Vorstadt und Stadtmitte nachgewiesen wurden, 3. Arten, die nur an Bäumen vorkamen, die sich in der Nähe zum Offenland befinden. Der ersten Gruppe wurden 22, der zweiten Gruppe 32 und der dritten Gruppe 25 Flechtenarten zugeordnet. Dem Verhältnis zwischen der Frequenzsumme der stark nitrophytischen Arten und der Frequenzsumme der a-, schwach und mäßig nitrophytischen Arten auf den Bäumen entsprechend, wird die Luftqualität an 15 Bäumen der Gattungen Acer und Tilia für gut, an 14 Bäumen für mäßig und an 13 Bäumen für schlecht befunden. Auf der Grundlage des Verhältnisses zwischen der Anzahl basiphytischer Arten und der Summe an Arten an sauren oder/und subneutralen Borken wurden sechs Standorte als wenig, 21 Standorte als mäßig und 15 Standorte als stark schadstoffbelastet eingestuft. Meso- bis hygrophytische Flechten kamen an zehn Standorten mit nur ein oder zwei Arten, an 21 Standorten mit drei bis fünf Arten und an elf Standorten mit mehr als fünf Arten vor. Die epiphytische Flechtenflora hat sich in Rostock seit 1995 gravierend verändert. Es nahmen 69 Flechten im Bestand zu, von denen sich 52 Arten erst nach 1995 angesiedelt haben. Bei 32 Flechten ist eine schwache, bei 19 Flechten eine mäßige und bei 18 Flechten eine starke Zunahme zu verzeichnen. Lecanora conizaeoides kam 2017/2018 nicht mehr vor, vier Arten haben im Bestand abgenommen. Changes in the epiphytic lichen flora in the urban area of Rostock between 1994/1995 and 2017/2018 In 2017/2018, diversity and quantity of lichens were studied on 53 trees in Rostock city. The results were compared with the results of a mapping project in 1994/1995. Humidity conditions and degree of eutrophication at trees of the genera Tilia and Acer were interpreted with reference to the known indicator characteristcs of the lichen species concerning air humidity/precipitation, eutrophication and pH conditions. In 2017/2018, 79 lichen species and 14 lichenicolous fungus species were found. The total number of lichens increased to 80 species. Most species were found on Tilia spec. (60), Acer pseudoplatanus (43) and A. platanoides (34). The most common species are Phaeophyscia orbicularis, Physcia adscendens, Ph. tenella and Xanthoria parietina. Candelariella xanthostigmoides, Flavoparmelia soredians, Hyperphyscia adglutinata, Intralichen lichenum, Lecanora subcarpinea, Parmelia serrana, Parmelina quercina and Taeniolella delicata are new to Mecklenburg-Western Pomerania. The distribution and characteristics of the collection sites allow for deviding the species into three groups: 1. species also present along streets with heavy traffic or in densely populated residential areas with a lack of green areas and in the districts Kröpeliner Tor-Vorstadt or City Centre, 2. species still present in sparse residential areas and smaller green areas but not in the districts Kröpeliner Tor-Vorstadt or City Centre, 3. species only colonizing trees close to the open landscape. Twenty-two species were assigned to the first, 32 species to the second and 25 species to the latter group. According to the proportion between the sum of frequencies of the strongly nitrophytic lichens and the sum of frequencies of the anitrophytic and moderately nitrophytic lichens on trees, air quality was indicated to be good at 15 trees of the genera Acer and Tilia, moderate at 14 trees and bad at 13 trees. Based on the proportion between the number of basiphytic lichen species and the sum of species colonizing acidophytic and subneutrophytic bark, six locations were categorized as little, 21 locations as moderately and 15 locations as strongly polluted. Mesophytic or hygrophytic lichens were present with only one or two species at ten locations, three to five species at 21 locations and over five species at 11 locations. Within the period under consideration, the epiphytic lichen flora of the Rostock urban area changed considerably. The populations of 69 lichen species increased, with 52 lichens newly establishing after 1995. In 32 lichen species a slight, in 19 species a moderate, and in 18 species a strong population increase was recorded. Lecanora conizaeoides disappeared and the populations of four species decreased.


2020 ◽  
Vol 27 (1) ◽  
pp. 56-63
Author(s):  
Jong-Gil Park ◽  
Chang-uk Park ◽  
Kyoung-Soon Jin ◽  
Yang-Mo Kim ◽  
Hee-Young Kim ◽  
...  

2009 ◽  
Vol 160 (11) ◽  
pp. 334-340 ◽  
Author(s):  
Pierre Mollet ◽  
Niklaus Zbinden ◽  
Hans Schmid

Results from the monitoring programs of the Swiss Ornithological Institute show that the breeding populations of several forest species for which deadwood is an important habitat element (black woodpecker, great spotted woodpecker, middle spotted woodpecker, lesser spotted woodpecker, green woodpecker, three-toed woodpecker as well as crested tit, willow tit and Eurasian tree creeper) have increased in the period 1990 to 2008, although not to the same extent in all species. At the same time the white-backed woodpecker extended its range in eastern Switzerland. The Swiss National Forest Inventory shows an increase in the amount of deadwood in forests for the same period. For all the mentioned species, with the exception of green and middle spotted woodpecker, the growing availability of deadwood is likely to be the most important factor explaining this population increase.


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