Hållbart skogsbruk kräver kunskap om skogens tillstånd i nutid samt tänkbara framtida åtgärder. Syftet med studien var att undersöka om det via digitala flygbilder var möjligt att skatta trädålder och SI på beståndsnivå, samt med vilken precision det kan utföras.Endast tall- och/ eller grandominerade bestånd, valdes i Vetlanda och Nybro kommun. Flygbilderna bearbetades av Foran Sverige AB med hjälp av ett program framtaget av Spacemetric AB.De fältinventerade beståndens data jämfördes med medianvärden från de skattade trädhöjderna, vilka matades in i en formel, konstruerad för att göra en kurvanpassning mot de nya höjdutvecklingskurvorna.Metoden för framtagning av höjdvärden via bildmatchning bör förfinas, t.ex. bör laserskanningen bidra med högre precision. Endast mindre delar av landet har mer än en skanningstidpunkt med laser, metoden kräver minst två höjdvärden i serie.Syftet med studien anses uppfyllt, dock hade studien tjänat på en bättre metod för att sålla bort felaktiga data innan analys. Generaliserbarheten är god på liknande bestånd, vidare studier krävs för att kunna påvisa en användarbarhet i olika typer av bestånd, där även olika skötselvarianter bör vägas in.

Increasingly homogenous forest landscapes, with fewer occurrences of wildfires, deciduous trees and dying, decaying wood has led to fewer appropriate habitats and feeding opportunities for several forest dwelling species, including birds. This study sought to assess the species richness, diversity, and evenness of winterbirds in forest stands where conservation methods (planting of alder trees, free development, burning of forest stands and promotion of deciduous dominance) have been applied, as well as a managed stand of lodgepole pine (Pinus contorta), within SCA:s Tjäderbergets diversity park. These stands were compared with managed stands of Scots pine (Pinus sylvestris). Bird species composition was collected by performing regular 25-minute inventories in each stand type at 5 time periods daily over a 6-day period in late March, 2020. Significant differences in species richness was discovered between a stand of free development and the managed stands as well as a stand treated for deciduous dominance and the managed stands. There were no significant differences with regard to neither species diversity between the observed stand types, nor the presence of specialists or generalists. Evenness between the stand types showed little variation. These results may be due to the overall low number of unique species and individuals in each stand type which likely resulted from low statistical power of the statistical tests. Further research into the effects of conservation measures in forests stands on bird fauna are needed to obtain conclusive results on how conservation measures affect local bird assemblages.

Klimatet är föränderligt och jordens medeltemperatur har ökat. Troligen kommer det att leda till större kontraster med perioder av torka och perioder med kraftigt regn. Detta kan påverka skogsbruket genom att leda till en ökad risk för bränder, stormskador och insektsangrepp. Den främsta skogsskötselåtgärden inför ett framtida förändrat klimat är att anpassa trädslagsvalet och sprida riskerna på flera trädslag.   Syftet med studien var att undersöka privata skogsägare i Bohuslän och Dalslands inställning till klimatförändring, intresse av att klimatanpassa sitt skogsbruk över tid samt vad som motiverar dem till det.   En enkätstudie genomfördes och skickades till 400 skogsägare som var medlemmar i Södra Skogsägarna. 69% av skogsägarna trodde att klimatet förändras i sådan omfattning att det avsevärt kommer att påverka deras skog.   Skogsägarna svarade att ett anpassat trädslagsval och att öka andelen blandskog är en lämplig klimatanpassning. Oavsett om de tror på klimatförändringar och dessas påverkan på deras skog eller inte så kan de tänka sig att klimatanpassa sitt skogsbruk.

Maximum size-density relationships (MSDR) are used to quantify differences across sites in the number of trees of a given size and species that can be supported per hectare. These relationships are important to managers who are trying to maximize basal area and wood volume. In my study, I examined MSDR across Alabama, Georgia, Louisiana, and Mississippi using US Forest Service, Forest Inventory and Analysis (FIA) data. I determined the impact of species-specific, specific gravity, functional traits, and environmental factors on MSDR using a quantile regression approach. Overall, I found that climatic factors had the greatest influence on MSDR, and that species shade and drought tolerance were more influential than specific gravity across the southeastern US.

Many landowners in the southeastern United States have invested in southern yellow pine plantations and managed them using traditional management schemes. However, non-industrial private forest landowners often have goals and challenges that make traditional management less desirable or possible. This thesis contains two projects that offer potential solutions for these landowners. The first project is a management option for landowners with small parcels that wish to manage pine plantations and proposes low-density management paired with crown lifting for the production of saw logs without commercial thinning entries. The second proposes a method for incorporating mixed-species management into already existing plantations. This increases biodiversity and could be more ecologically stable than single-species plantations. These options present opportunities for non-industrial private forest landowners who do not fit into the traditional management framework due to differences in management goals or economic constraints on management.

Hur det moderna skogsbruket påverkat biologisk mångfald och artbevarande är omdebatterat. Skogsägare vill generellt bruka skogen vinstdrivande samtidigt som det ställts alltmer krav på hur främst föryngringsavverkning ska ske. Dessa krav har ställts främst i syfte av att minska fragmenteringsgraden för att minska risken för sönderdelning av viktiga habitat vilket i sin tur kan påverka artbevarandet negativt. Med spårinventeringar har data samlats in i ett försök att skapa förståelse för om vilts vandringsmönster påverkats av avverkningsytors storlek, vilka arter vars rörelse hämmats av den förändrade landskapsbilden samt vilken inverkan hänsynsytor har haft på viltets vistelse i skogslandskapet. Resultatet visade på att fler viltträffar hittades utanför föryngringsytan i jämförelse med innanför föryngringsytan, dock utan samband i förhållande till föryngringsytestorlek. Resultatet visade även på att hänsynsytor är viktigt för viltets närvaro. I övrigt kunde ses att arterna ekorre, orre, älg och hare var de som påverkades mest av föryngringsavverkning i denna studie.

No description available.

No description available.

For this dissertation, I measured how plant communities in Appalachian forests responded to disturbances caused by forest management activities. I had two primary objectives including (1) testing theories of biological diversity and invasions by nonnative species; and (2) providing empirical data that will help guide the sustainable use of forest resources. This work is part of the Southern Appalachian Silviculture and Biodiversity (SASAB) experiment that was established in the early 1990s to investigate ecosystem responses to a gradient of timber harvesting disturbances. Ranging from undisturbed controls to silvicultural clearcuts, the disturbance gradient is replicated at sites located throughout the Appalachian mountains of Virginia and West Virginia. The plant community was sampled across a wide range of spatial scales (2 hectares to 1 m2) using a nested sampling design and was also sampled at three times including pre-disturbance, one year post-disturbance, and ten year post-disturbance. For one element of the study I tested modern theories of biological invasions and investigated how the forest disturbance gradient interacted with species diversity to influence invasion by nonnative species (Chapter 2). Contrary to popular ecological theories of biotic resistance, the most diverse sites tended to be more easily invaded following intense canopy disturbance. Interestingly, none of the sites in this study were dominated by invasive plants, which led me to ask whether dominant tree species in forests provided resistance to nonnative plant establishment and growth through the quality of the litter they produce. I also asked how might animals that are known to alter litter layers interact with dominant tree species to influence plant invasions. Therefore, I conducted an experiment investigating how changes in litter from dominant tree species and invasions by nonnative earthworms might influence invasibility of forests using forest floor mesocosms (Chapter 3). I found that plant invasion was inhibited by native oak litter even when earthworms were present, suggesting that oak forests may resist plant invasions via oak tree litter. In contrast, plant invasion was greater under invasive tree litter and earthworm activity tended to facilitate invasive plant success only under invasive tree litter. I was also interested in understanding how disturbance might alter relationships between local and regional diversity. The long-term data of the forest disturbance experiment allowed me to investigate how local species richness is mediated by regional species richness after disturbance and during forest community development (Chapter 4). Local richness depended strongly on regional richness only after disturbance via colonization of species, but this relationship changed during forest aggradation. These results suggest that regional species pools are important to maintain local diversity following disturbance, but that local interactions (through canopy closure of dominant trees) exert control over species diversity during community reorganization. Lastly, I tested current theories on how diversity influences compositional stability after disturbance (Chapter 5). Disturbance consistently resulted in decreased compositional stability, but diversity was associated with stability in complex ways, which depended on how stability was measured and at what scale. Species-rich areas were in some instances less stable; in other instances areas with intermediate levels of diversity were more stable. These results suggest that disturbance causes shifts in species composition via colonization, but the ways in which diversity of sites influences compositional stability is complex and depends on methods used and the scales of observation. Taken together, these results suggest that disturbance influences invasibility, species saturation, and compositional stability of ecological communities. These properties change immediately following disturbance, and during forest development and canopy closure. Data from this project were useful in testing existing theories of community ecology, and may ultimately prove useful for forest managers as they decide how to protect biodiversity while planning for other uses of forest resources. Overall, these results suggest that colonization of species is the primary process driving plant community patterns in Appalachian forests following disturbance. / Ph. D.

The passage of the Federal Water Pollution Control Act of 1972 required states to develop forestry BMPs to help reduce potential nonpoint source pollution from forest operations. Properly applied forestry best management practices (BMPs) have since been proven to protect water quality from forest operations. This research project reviewed BMP effectiveness studies in the U.S., assessed current state developed and implemented of forestry BMPs, and developed a simple method to estimate potential erosion from forest operations for the Piedmont physiographic region based on previous studies. Eighty-one BMP effectiveness studies were reviewed. The review of past effectiveness studies indicates that water quality protection is increased when BMPs are implemented correctly. These effectiveness studies provide states with valuable information on how their BMP guidelines are achieving the goals defined by the Federal Water Pollution Control Act. Every U.S. state has forestry BMP guidelines. These guidelines may be non-regulatory, quasi-regulatory, or regulatory depending on the state. Twenty states reported implementing non-regulatory BMP guidelines, 19 quasi-regulatory BMP guidelines, and 11 regulatory BMP guidelines. State forestry agencies were reported as being the lead agency responsible for BMP monitoring in 35 states. The national forestry BMP implementation rate was 91% (32 states). However, states did report deficiencies for specific BMP guideline categories. Supplementary to the reviewed BMP effectiveness studies, forest erosion studies in the southeastern U.S. that quantified erosion rates from forest operations were also reviewed. Erosion rates obtained from the literature were reviewed by operation categories (timber harvesting, forest roads, skid trails, log landings, stream crossings, and streamside management zones) and physiographic region (Mountains, Piedmont, Gulf Coastal Plain, and Atlantic Coastal Plain). There were numerous research gaps regarding erosion rates from forest operations for all the regions except the Piedmont region. The Piedmont region was selected for developing a method to estimate potential erosion from forest operations. This erosion estimation method is a quick and potentially useful tool for estimating potential erosion; however, it is based on limited data from the Piedmont region only. The basic method approach might be considered for the other physiographic regions, but further research is needed to fill current knowledge gaps. / Ph. D.