• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • Tagged with
  • 3
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Retained Woody Structure In 1-Year-Old Loblolly Pine Plantations In Mississippi, Louisiana, And Arkansas

Neu, Justin 09 December 2011 (has links)
I evaluated effects of 4 common site preparation techniques on residual structure while comparing 2 techniques commonly used to estimate CWD volume in Southeast loblolly pine (Pinus taeda) commercial pine plantations in 2 ecoprovinces. The strip plot method (SPM) estimated greater volume than the line intercept method (LIM; 9.7 m3/ha and 11.4 m3/ha respectively). The SPM had lesser volume estimate variability and appears more appropriate for the Southeast. Mechanical sites had the greatest densities of green trees and fewest snag retention and overall were least decayed. Chemical preparation combinations had lesser green tree densities but greater snag densities. Piled CWD volumes were greatest in mechanical treatments and least in chemical plus burn treatments. The Outer Coastal Plain Mixed Forest Ecoprovince had 20% less volume than the Southeastern Mixed Forest Ecoprovince. Chemical plus burn site preparations had the least densities of remnant trees, snags, piled and individual CWD pieces.
2

Hur påverkas markberedningsresultatet vid harvning och högläggning av faktorer som lutning, ytstruktur och markfuktighet?

Wikner, Frida January 2015 (has links)
Soil scarification means lot to the regeneration of the forest because a good soil scarification boost the increment of the plants and it also makes the plants less attractive to dangerous insects. The surveys purpose was to investigate how different site factors influence the soil scarifications results. The goal was to see if any scarification method was better adapted to a certain site then the other. In order to see a result the survey investigated the bearing capacity of the stands, the surface structure and the slope of the terrain. The surveys material has been collected during august - October 2013 on SCA: s forest in Ångermanland in Sweden. Totally has 65 harrowed sites and 35 scalped sites been visited and material collected from. The survey result shows that the scarification quality after scalping was higher than after harrowed sites. The number of 5: s and 4: s was more frequent after scalping but the number of mineral 3: s was higher after harrowing. The analysis of the results shows that scalping was more sensitive to the site slope and surface structure then harrowed sites, but when used on the the right ground it will provide a better quality result. The conclusion of the survey was that harrowing is the better choice of the scarification methods because it showed a more stable result then scalping that is more depending on the terrain conditions. Harrowing should not be used on moist ground due to the risk of Hylobius abietis attacking the plants. Scalping on the other hand showed a better result of the scarification quality and on the right ground it is the optimal choice.
3

Birds and small mammals, intensively established pine plantations, and landscape metrics of the Coastal Plain

Hanberry, Brice Bond 15 December 2007 (has links)
I evaluated effects of 5 treatments for pine plantation establishment on breeding and wintering birds and small mammals during years one through 5 post-treatment in the Lower Coastal Plain of Mississippi. I modeled relationships between 8 vegetation variables and avian abundance to identify influential habitat components in pine plantations. At the landscape scale, I compared avian abundance of regionally important species with land class variables in the Coastal Plain of Georgia. In pine plantations, species richness, total abundance, and 2 conservation bird metrics generally decreased with increasing intensity of stand establishment. Thus, this study suggests that increasing standmestablishment intensity can reduce avian habitat quality in Coastal Plain pine plantations. Presence of residual trees retained after timber harvest was the most influential variable related to avian abundance, and tree retention may reduce the negative impacts of intensive stand establishment on avian communities. There were minimal treatment effects on common small mammals of young pine plantations. For the Coastal Plain landscape, a mixture ofn area and edge variables were influential in avian models for 10 species, although area or edge each were important for 2 species. Hardwood forests were important vegetation types for all but one modeled species. Assessment of habitat conditions that affect avifauna and small mammals on managed timber production lands can assist natural resource managers with integration of timber production and conservation of biological diversity.

Page generated in 0.1307 seconds