Sökning: "betesdjur"

Hittade 5 avhandlingar innehållade ordet betesdjur.

  1. 1. Land degradation and mitigation in northern China. Evaluated from the biological production

    Författare :Micael Runnström; Institutionen för naturgeografi och ekosystemvetenskap; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; marklära; geomorfologi; Fysisk geografi; climatology; kartografi; klimatologi; cartography; pedology; desertification; China; GPP; Mu Us; LUE-model; overgrazing; Physical geography; geomorphology;

    Sammanfattning : Land degradation is commonly perceived to be severe in many parts of semi arid China. The transition towards market economy since the 1978 reforms, have set marginal dry lands under added pressure in the form of increased livestock numbers and expanding cultivation on erosive soils. LÄS MER

  3. 2. Grassland restoration : Connectivity, plant community change and cows

    Författare :Rozália E. Kapás; Sara Cousins; Adam Kimberley; Lars A. Brudvig; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; biodiversity; colonization; connectivity; dispersal; distance to species pool; diversity; grassland restoration; grassland specialist species; grazing livestock; habitat availability; plant community composition; restoration; semi-natural grassland; species richness; naturgeografi; Physical Geography;

    Sammanfattning : The ecological significance of semi-natural grasslands is high because these habitats provide a home for a diverse flora and fauna and support a range of associated ecosystem services. Due to large-scale land-use changes the extent of grassland habitat has declined. LÄS MER

  4. 3. Plant community assembly during succession from arable fields to semi-natural grassland

    Författare :Barbara Christine Schmid; Biodiversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diversity; arable-to-grassland succession; space-for-time approach; land-use history; plant community assembly; grazing management; connectivity measures; dispersal vector; vascular plants; grassland specialist conservation;

    Sammanfattning : Large areas of grazed, species rich semi-natural grassland were lost in Europe during the last two centuries and as a consequence led to decreases in grassland specialist species. Therefore, today the “restoration” of grassland on previously arable fields is recommended for the protection of grassland specialists. LÄS MER

  5. 4. Recent changes in land use and productivity in agro-pastoral Inner Mongolia, China

    Författare :Sara Brogaard; LUCSUS; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; geomorphology; Physical geography; China; Inner Mongolia; remote sensing; LUE model; primary production; GPP; yield variability; land degradation; farmers’ perception; productivity; Land use; pedology; cartography; climatology; Fysisk geografi; geomorfologi; marklära; kartografi; klimatologi;

    Sammanfattning : This study challenges the prevailing assumption that the expansion of cultivated land areas and increasing number of livestock in the agro-pastoral regions of northern China have aggravated the process of land degradation since the start of the rural reforms in 1978. Land-use and productivity trends in the Inner Mongolia Autonomous Region (IMAR), with special attention to the Keerqin steppe region, have been analysed. LÄS MER

  7. 5. Genetic variation and sexual reproduction in a moss with dwarf males, Homalothecium lutescens

    Författare :Frida Rosengren; Biodiversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; bryophytes; mosses; dwarf males; sexual reproduction; genetic variation; genetic structure; inbreeding; isozymes; allozymes; SNP; sporophytes; spore; fertilization; fertility;

    Sammanfattning : Dwarf males occur in many unrelated groups of organisms. Among land plants they are unique to mosses. Moss dwarf males originate from male spores that land and germinate on the female where their final size is restricted to a few mm. Fertilization in mosses occur over short distances with swimming spermatozoids. LÄS MER