Sökning: "Seed rain"
Visar resultat 1 - 5 av 9 avhandlingar innehållade orden Seed rain.
1. Seed mobility and connectivity in changing rural landscapes
Sammanfattning : The success or failure of many organisms to respond to the challenges of habitat destruction and a warming climate lies in the ability of plant species to disperse between isolated habitats or to migrate to new ranges. European semi-natural grasslands represent one of the world's most species-rich habitats at small scales, but agricultural intensification during the 20th century has meant that many plant species are left only on small fragments of former habitat. LÄS MER
2. Plant community assembly in grazed grasslands
Sammanfattning : Species assembly into local communities from the surrounding region can be caused either by species failure to reach the site (i.e. seed limitation) or to establish (i.e. LÄS MER
3. Population management of cone and seed insects in spruce seed orchards
Sammanfattning : Seed orchards have been established in order to produce high quality seeds for reforestation and forestation. However, seed production in spruce (Picea abies (L.) Karst.) seed orchards is severely hampered by cone- and seed-feeding insects. LÄS MER
4. Seed dynamics and the ecological restoration of hill slopes of Kondoa Irangi, Central Tanzania
Sammanfattning : Improper agricultural practices such as bill slope cultivation, extensive clearing of vegetation using fire over a long period, and to some extent overgrazing have converted the once fertile hill slopes of Kondoa Irangi in central Tanzania into unproductive marginal land. It is 25 years now since reclamation measures were introduced to save the hills from further degradation, but the regeneration process, has been rather slow. LÄS MER
5. Effects of climate change on boreal wetland and riparian vegetation
Sammanfattning : Models of climate change predict that temperature will increase during the 21th century and the largest warming will take place at high northern latitudes. In addition to warming, predictions for northern Europe include increased annual precipitation and a higher proportion of the precipitation during winter falling as rain instead of snow. LÄS MER