Search for dissertations about: "seedling survival"

Showing result 1 - 5 of 20 swedish dissertations containing the words seedling survival.

2. 1. Effects of seed size and habitat on recruitment patterns in grassland and forest plants

   Author : Karin Lönnberg; Ove Eriksson; Per Milberg; Stockholms universitet; []
   Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Seed size; seedling establishment; seedling survival; recruitment; seed removal; co-existence; game-theory; Plant Ecology; växtekologi;

   Abstract : A trade-off between seed size and seed number is central in seed ecology, and has been suggested to be related to a trade-off between competition and colonization, as well as to a trade-off between stress tolerance and fecundity. Large seeds endure hazards during establishment, such as shading, drought, litter coverage and competition from other plants, better than do small seeds, due to a larger amount of stored resources in the seed. READ MORE

4. 2. Plant Population Dynamics of Dodonaea angustifolia and Olea europaea ssp. cuspidata in Dry Afromontane Forests of Ethiopia

   Author : Tesfaye Bekele; Ingvar Backéus; Karin Bengtsson; Uppsala universitet; []
   Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Demography; Dodonaea angustifolia; Elasticity; Establishment; Germination; Natural regeneration; Olea europaea ssp. cuspidata; Population structure; Recruitment; Seed bank; Survival; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; Ecological Botany; Ekologisk botanik;

   Abstract : Human disturbance has led to excessive deforestation and to a very limited forest cover in the Afromontane zone of Ethiopia, which forms a large part of the country. Thus urgent conservation measures are required to ameliorate the situation. READ MORE

5. 3. Reproductive patterns of birches (Betula spp.) in northern Sweden

   Author : Stig-Olov Holm; Umeå universitet; []
   Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Reproduction; Betula; seed-quality; seed-set; pollination; pollen-limitation; pollen-competition; tree-line; environmental gradient; seed weight; seedling survival; Semudobia;

   Abstract : The aim of this thesis was to study patterns of reproduction of Betula pendula and B. pubescens coll. along an altitudinal, coastal-inland, gradient in northern Sweden. The altitudinal variation was related to the distribution of the birch taxa along the gradient. READ MORE

6. 4. Mosses as mediators of climate change : implications for tree seedling establishment in the tundra

   Author : Signe Lett; Ellen Dorrepaal; David Wardle; Marie-Charlotte Nilsson; Vigdis Vandvik; Umeå universitet; []
   Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; arctic; alpine; B. pubescens; bryophytes; competition; facilitation; mosses; P. sylvestris; precipitation changes; seedlings; traits; tree line; warming;

   Abstract : Alpine and arctic tree line expansion depends on the establishment of tree seedlings above the current tree line, which is expected to occur with climate warming. However, tree lines often fail to respond to higher temperatures. Other environmental factors are therefore likely important for tree seedling establishment. READ MORE

7. 5. Consequences of bushmeat hunting in tropical forests

   Author : Edu Efiom; Biodiversitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Tropical rainforests; bushmeat hunting; primates; seedling recruitment; interseedling competition; community composition; functional traits; ecosystem services; human livelihoods;

   Abstract : This thesis evaluates the effect of bushmeat hunting in southeastern Nigerian rainforests on: 1) adult tree, seedling, and animal community compositions 2) germination and survival among seedlings in association with competition 3) changes in community composition at multiple trophic levels 4) leaf nitrogen concentration (LNC), leaf mass per area (LMA) and stem specific density (SSD) 5) on human reliance on forest resources and rural people use forest resources. Data for the first four evaluations were obtained from surveys, manipulative experiments in seedling plots and collected leaf samples in three pairs of sites with high (hunted sites) and low (protected sites) hunting pressure but with similar adult tree composition. READ MORE