Sökning: "population dynamics"

Visar resultat 6 - 10 av 564 avhandlingar innehållade orden population dynamics.

1. 6. A contribution to population dynamics in space

   Författare :Nikias Sarafoglou; Å.E. Andersson; Umeå universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Population growth; population age structure; migration; labour market; housing market; production function; stochastic differential equations; partial differential equations;

   Sammanfattning : Population models are very often used and considered useful in the policy-making process and for planning purposes. In this research I have tried to illuminate the problem of analysing population evolution in space by using three models which cover a wide spectrum of complementary methodologies:a The Hotell. LÄS MER

3. 7. Making the Most of It? : Understanding the social and productive dynamics of small farmers in semi-arid Iringa, Tanzania

   Författare :Peter Gregersen; Sociologi; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Social changes; Malthus; Boserup; Tanzania; semi-arid Africa; Iringa; conservation; sustainability; soil fertility; degradation; population; Matthew principle; social differentiation; farmerisation; de-peasantisation; livelihood diversification; rural change; agrarian change; agricultural change; small farmers; dynamics; theory of social work; Sociala förändringar; teorier om socialt arbete; Malthus; Boserup; Tanzania;

   Sammanfattning : While much of semi-arid Africa is still sparsely populated with unused land, there are everywhere pockets of high and increasing population density in attractive locations. Small-scale farmers can respond to beginning land-scarcity in a number of ways. LÄS MER

4. 8. Population dynamics of tundra-living grey-sided voles

   Författare :Per Ekerholm; Lauri Oksanen; Rolf Anker Ims; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Population dynamics; Tundra; Grey-sided vole; Cycles; Vole specialist predators; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; zooekologi; Animal Ecology;

   Sammanfattning : This thesis deals with the dynamics of tundra living voles with emphasis on the most common one, the grey-sided vole (Clethrionomys rufocanus). The tundra area chosen for the study was Finnmarksvidda, a vast flatland in northernmost Norway. LÄS MER

5. 9. Population viability analysis for plants : practical recommendations and applications

   Författare :Satu Ramula; Kari Lehtilä; Patrik Dinnétz; Esa Ranta; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; demography; matrix population models; population viability analysis; population growth rate; stochastic models; Biology; Biologi;

   Sammanfattning : Population viability analysis (PVA) is commonly used in conservation biology to predict population viability in terms of population growth rate and risk of extinction. However, large data requirements limit the use of PVA for many rare and threatened species. LÄS MER

7. 10. Life histories and population dynamics

   Författare :Annie Jonsson; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : During the last decades there has been a growing interest and attention to random variation in population densities and their causes. It has been shown that even in constant environments (deterministic population growth) the dynamics of populations can display random like behaviour depending on parameter values. LÄS MER