Search for dissertations about: "tree refugia"

Showing result 1 - 5 of 6 swedish dissertations containing the words tree refugia.

2. 1. Palaeoenvironment in North-Western Romania during the last 15 000 years

   Author : Angelica Feurdean; Barbara Wohlfarth; Ann-Marie Robertsson; Leif Björkman; Iustinian Petrescu; Katherine J Willis; Stockholms universitet; []
   Keywords : Northwest Romania; Gutaiului Mountains; pollenstratigraphy; macrofossil remains; Lateglacial; Holocene; tree refugia; tree dynamics; past climate; human influence;

   Abstract : The objectives of this thesis are to establish a chronological framework for environmental changes during the last 15,000 years in northwest Romania, to reconstruct the vegetation development, and to evaluate the underlying processes for forest dynamics. Furthermore, an overview of earlier and ongoing pollenstratigraphic work in Romania is provided. READ MORE

4. 2. Treeline dynamics in short and long term perspectives : observational and historical evidence from the southern Swedish Scandes

   Author : Lisa Öberg; Bengt-Gunnar Jonsson; Leif Kullman; Ulf Segerström; Mittuniversitetet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Betula pubescens ssp. czerepanovii; Picea abies; Pinus sylvestris; climate change; monitoring; treeline advance; clones; megafossils; immigration; Holocene; cryptic refugia; Swedish Scandes; Terrestrial ecology; Terrestrisk ekologi;

   Abstract : Against the background of past, recent and future climate change, the present thesis addresses elevational shifts of alpine treelines in the Swedish Scandes. By definition, treeline refers to the elevation (m a.s.l. READ MORE

5. 3. Treeline dynamics in short and long term perspectives : observational and historical evidence from the southern Swedish Scandes

   Author : Lisa Öberg; Bengt-Gunnar Jonsson; Leif Kullman; Aage Paus; Mittuniversitetet; []
   Keywords : Betula pubescens ssp. czerepanovii; Picea abies; Pinus sylvestris; Larix sibirica; climate; Betula pubescens ssp. czerepanovii; Picea abies; Pinus sylvestris; Larix sibirica;

   Abstract : Treelines in high-mountain regions are constrained by heat deficiency, although the working mechanisms are still not entirely understood. Observational and paleoecological studies on treeline performance may contribute to increased understanding of the treeline phenomenon in general. READ MORE

6. 4. Ecology of lichens in boreal coniferous forests with reference to spatial and temporal patterns

   Author : Per-Anders Esseen; Lars Ericson; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Lichens; epiphytes; Alectoria; Bryoria; Cladonia; Usnea; Picea abies; Pinus sylvestris; dispersal; litterfall; succession; diversity; spatial patterns;

   Abstract : The thesis deals with the ecology of lichens in two contrasting types of forest, epiphytic lichens in old Picea abies forest of the fi re-refugia type and epigeic as well as epixylic lichens in a successional sequence of fire- susceptible Pinus sylvestris forests. Results in five separate papers form the basis for a discussion of general patterns of dispersal, succession and life strategies in lichens. READ MORE

7. 5. Extending dynamic vegetation models to simulate range shifts

   Author : Deborah Zani; BECC: Biodiversity and Ecosystem services in a Changing Climate; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; dynamic vegetation model; range shift; migration; paleovegetation;

   Abstract : In response to rapid climate change and increasing human pressure, a wide variety of taxa have shifted their distribution in the past decades (range shift), with important consequences for ecosystem services and human health and economy. However, it is not yet clear whether most species will be able to track their favourable habitats or lag behind the climate signal (migration lag). READ MORE