Webpages tagged with «UMB»

Published Feb. 6, 2013 3:46 PM

Competition is an important factor shaping plant communities, but plants also help, or facilitate, each other. Facilitation is especially important in areas with high levels of abiotic stress, for instance in alpine areas. Nitrogen fixing legumes are potentially important facilitators, as nitrogen is the limiting factor for plant growth in most ecosystems. Alpine soils generally have low nitrogen levels, and additional nitrogen from legumes could affect growth of alpine plants. In my master thesis I study the effect of two alpine legumes, Astragalus alpinus and Oxytropis lapponica, on the establishment, growth and reproduction of the alpine herb Thalictrum alpinum and how the presence of legumes affect species diversity along a gradient of abiotic stress at Sanddalsnuten, Finse.

 

Published Feb. 6, 2013 3:39 PM

Who are the pioneers on a fresh moraine? Predators like certain carabid beetles, spiders and Opiliones are present almost immediately, before any vegetation occurs. It is a paradox that predators are first. May be they eat springtails, which are also pioneers. Among plants, small moss colonies are typical pioneers.

Published Feb. 6, 2013 3:28 PM

Plant reproductive success is depending on temperature and climate during growth season, pollinator availibility and visitation rate, and interactions among plants, e.g. competition for resources and facilitated pollinator attraction. Plants in alpine regions face even larger climatic constraints and may also suffer from pollination limitation because of decrease in available pollinators with altitude. By including abiotic conditions, mutualistic interactions (pollination) and population qualities in elevational gradient consisting of 21 populations of the obligate out-crossing, lateflowering species Leontodon autumnalis var. taraxaci (Mountain Hawkweed) I wish to find out which predictors explain the observed variance in reproductive success. The fieldwork was performed at southfacing slopes of Sandalsnut and Kvanjolnut, Finse, Ulvik municipality – Norway.

 

Published Feb. 6, 2013 2:19 PM

A climate change experiment with open top chambers (OTCs) was established in the Dryas octopetala heath on Sanddalsnuten in 2000. Combined warming and nutrient addition has increased productivity and grass dominance at the cost of mosses, lichens, and small herbs, resulting in decreased diversity. In a seed sowing experiment we examined the relative role of dispersal and local interactions for alpine plant community diversity under climate warming. The long term effects of warming and local interactions on species recruitment and community dynamics will be examined in the coming years. This project is part of the International Tundra Experiment (ITEX).

Published Feb. 4, 2013 12:31 PM

A climate change experiment with open top chambers (OTCs) was established in the Dryas octopetala heath on Sanddalsnuten in 2000. Combined warming and nutrient addition has increased productivity and grass dominance at the cost of mosses, lichens, and small herbs, resulting in decreased diversity. In a seed sowing experiment we examined the relative role of dispersal and local interactions for alpine plant community diversity under climate warming. The long term effects of warming and local interactions on species recruitment and community dynamics will be examined in the coming years. This project is part of the International Tundra Experiment (ITEX).

Published Feb. 4, 2013 12:31 PM

Competition is an important factor shaping plant communities, but plants also help, or facilitate, each other. Facilitation is especially important in areas with high levels of abiotic stress, for instance in alpine areas. Nitrogen fixing legumes are potentially important facilitators, as nitrogen is the limiting factor for plant growth in most ecosystems. Alpine soils generally have low nitrogen levels, and additional nitrogen from legumes could affect growth of alpine plants. In my master thesis I study the effect of two alpine legumes, Astragalus alpinus and Oxytropis lapponica , on the establishment, growth and reproduction of the alpine herb Thalictrum alpinum and how the presence of legumes affect species diversity along a gradient of abiotic stress at Sanddalsnuten, Finse.

Published Feb. 4, 2013 12:31 PM

Who are the pioneers on a fresh moraine? Predators like certain carabid beetles, spiders and Opiliones are present almost immediately, before any vegetation occurs. It is a paradox that predators are first. May be they eat springtails, which are also pioneers. Among plants, small moss colonies are typical pioneers.

Published Feb. 4, 2013 12:31 PM

Plant reproductive success is depending on temperature and climate during growth season, pollinator availibility and visitation rate, and interactions among plants, e.g. competition for resources and facilitated pollinator attraction. Plants in alpine regions face even larger climatic constraints and may also suffer from pollination limitation because of decrease in available pollinators with altitude. By including abiotic conditions, mutualistic interactions (pollination) and population qualities in elevational gradient consisting of 21 populations of the obligate out-crossing, lateflowering species Leontodon autumnalis var. taraxaci (Mountain Hawkweed) I wish to find out which predictors explain the observed variance in reproductive success. The fieldwork was performed at southfacing slopes of Sandalsnut and Kvanjolnut, Finse, Ulvik municipality – Norway.