Appropriate management of mid-rotation pine plantations can improve habitat for early successional and pine-grassland adapted avian species. I tested effects of Imazapyr selective herbicide and prescribed fire on plant and avian communities in thinned, mid-rotation pine stands contracted under the Conservation Reserve Program. Within 12 replicate sites, 2 8.1-ha plots were assigned either herbicide and prescribed fire treatment or control. I described components of vegetation structure and composition in 2006. I tested effects of herbicide and prescribed fire treatment on avian relative abundance, species richness, total avian conservation value, and density of select species during 2003 - 2006. Hardwood midstory decreased and abundances of grasses and forbs increased following treatment. A shift occurred in the bird community from closed-canopy forest species to early successional and pine-grassland species. Treatment stands benefited many avian species exhibiting negative population trends.

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Ekträd har en central roll i den biologiska mångfalden, där de utgör både livsrum och födkrok för ett stort antal insekter, lavar, svampar och fåglar under sin långa livstid och därefter i den döda veden. Ek har minskat dramatiskt under de senaste 200 åren, men orsakerna till detta är inte helt klarlagda. I östra Nordamerika har den försämrade föryngringen av ek kopplats till de betydligt färre skogsbränderna och ur detta har den s.k. brand-ek-hypotesen uppstått. Denna säger att branden spelar en viktig roll i ekens föryngring i östra USA och i Nordamerika p.g.a. att eken är bättre anpassad än många andra träd för att klara brand, vilket ger den en konkurrensfördel som gör att den inte bara gynnas av brand, utan också kan vara beroende av den. Jag har studerat hur föryngring av ek påverkats av en naturvårdsbränning som genomförts i Krogölen i Allgunnens naturreservat i sydöstra Sverige. Hypotesen är att brand har en gynnsam effekt på ekföryngring även i Sverige och att brand-ek-hypotesen är tillämpbar också här. Detta kunskapsområde är relevant för naturvården i Sverige när det gäller att planera naturvårdsbränningar i områden med förekomst av ek. Eftersom studien har genomförts som en pilotstudie, där endast ett brandområde studerats, kan inga slutsatser om generella brandfältseffekter dras. Mina resultat talar för att krontäckning har en effekt på tätheten av fröplantor i Krogölen, och att den har större betydelse i brandfältet än i det obrända området, vilket talar emot brand-ek-hypotesen. Effekten av brand och krontäckning förklarar i denna studie 21,8% av variationen i den rottransformerade fröplanttätheten per 12,6 m2. Det går inte att se någon ökning av fröplantor eller rotskott i det brända området jämfört med det obrända. För framtida studier skulle det vara intressant att titta på fröplantors dödlighet i olika livsstadier under varierande ljusförhållanden, effekten av predation i brandfält, hur olika brandintensitet kan inverka på ekens föryngring samt bestående effekter av brand över tid och betydelsen av i vilket utvecklingsstadie branden skett. / Oak trees have a central role in biodiversity, where they serve as both a habitat and a feeding ground for a large number of insects, lichens, fungi and birds during its long life and thereafter in the dead wood. Oak has declined dramatically over the past 200 years, but the reasons for this are not entirely known. In eastern North America, the deteriorating regeneration of oak has been linked to the significantly less forest fires and from this the so-called fire-oak hypothesis have emerged. It states that the fire plays an important role in the regeneration of the oak in the eastern United States and North America due to the oak being better adapted than many other trees to endure fire, which gives it a competitive advantage that makes it not only benefit from fire, but also possibly depend on it. I have studied how the regeneration of oak has been affected by a prescribed fire in Krogölen in the Allgunnen nature reserve in the south-east of Sweden. My hypothesis is that fire has a favorable effect on oak regeneration also in Sweden and that the fire-oak hypothesis is also applicable here. This area of ​​knowledge is relevant for nature conservation in Sweden in planning prescribed fires in oak areas. As the study has been carried out as a pilot study, studying only one burned area compared to a none burned area, no conclusions about general fire effects can be drawn. My results suggest that canopy cover has an effect on the density of seed plants in Krogölen, and that it is more comprehensive in the fire field than in the unburned area, which is not conclusive with the fire-oak hypothesis. The effect of fire and canopy cover in this study explains 21.8% of the variation in the root-transformed seed plant density per 12.6 m2. There is no increase in seed plant density or root sprout density in the burned area compared to the unburned area. For future studies, it would be interesting to look at seed plant mortality in different life stages under varying light conditions, the effect of predation in fire fields, how different fire intensities can affect oak regeneration, lasting effects of fire over time and the significance of the oak developmental stage when the fire occurs.

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Heathlands typically experience regimes consisting of frequent and intense fires. These fire regimes play important roles in the lifecycles and population dynamics of all species in these communities. Prescribed fire is commonly applied to heathlands to minimise the risk of wildfires as well as to promote biodiversity. Ignitions in heathlands tend to either be unsustainable, or quickly develop into rapidly spreading intense fires. This presents a major problem for the application of prescribed fire and is the primary focus of this thesis. Heathland ignition has been investigated in three sections; litter ignition; vertical development of fire into the shrub layer; and horizontal spread through the shrub layer. These were studied in laboratory experiments using miniature versions of field fuels. Ignition success in litter layers was related to the dead fuel moisture content. Litter type, ignition source, and presence of wind were found to affect the range of ignitable fuel moisture contents of a litter bed. The effect of litter type was best explained by density. Dense litter beds required drier conditions for ignition than low density litter beds. The vertical development of fire into shrubs was mostly dependent on live fuel moisture content, but crown base height, presence of wind, ignition source, shrub height and the percentage of dead elevated fuel were also important. Horizontal spread of fires through shrub layers was most affected by the presence of a litter layer, with nearly all ignitions successful when there was an underlying litter fire. Fire spread would only occur in shrubs without a litter layer when the shrub layer was dense and dry, or had a substantial dead fuel component. Spread was more likely to be sustained when there was wind. Models predicting the moisture content of dead fuels were tested in heathlands, and as would be expected those that can be calibrated for different fuel types were found to have the best performance. Fuel moisture content and fuel load models were reviewed for heathlands, and a number of recommendations for future research were made.

Terrestrial ecosystems in the southeastern United States have evolved with fire as a common disturbance and as a result many natural communities require the presence of fire to persist over time. Human development precludes natural fires from occurring within these communities; however, prescribed fire is considered to be a critical tool in the effort to restore fire-dependent ecosystems after decades of fire exclusion. Direct effects of fire on individual floral and faunal species as well as benefits to biodiversity at the landscape (gamma diversity) level have largely been supported in previous research. However, information on the effects of natural and prescribed fire on plant diversity at the local level (alpha diversity) is limited, particularly for southeastern forests. The applicability of the Intermediate Disturbance Hypothesis (IDH), which suggests that the highest levels of biodiversity are found at intermediate levels of disturbance, is also untested for North Florida upland plant communities. This study compared the effects of fire on local scale mean plant species diversity by examining burned and unburned portions of three fire-dependent communities to determine if there is an effect of prescribed fire on in alpha biodiversity. Alpha biodiversity was not significantly different (p=0.433) between burned and unburned fire-dependent plant communities in northern Florida, suggesting that prescribed fire does not affect plant species diversity in these communities and/or the IDH for plant communities is not supported at the time scale tested. However, the application of prescribed fire did result in changes in abundance of species, particularly with species such as Dicanthelium acuminatum, Quercus myrtifolia, and Vaccinium myrsinites, that respond positively to fire, which may have implications for associated faunal diversity.

<p dir="ltr">To examine how forest management affects terrestrial salamanders, this dissertation: (1) examines the effects of timber harvesting strategies on salamanders; (2) examines the effects of prescribed fire for oak regeneration on salamander populations; and (3) explores the influence of artificial cover object (ACO) wood type, size and shape, and placement on salamander monitoring results. These projects were conducted at the Hardwood Ecosystem Experiment (HEE) and Martell Experimental Forest in Indiana. Long-term salamander monitoring data from the HEE were used to examine the effects of clearcuts, shelterwoods, and patch cuts on salamander captures collected up to eleven years post-harvest and were analyzed with a before-after-control-impact (BACI) design. Clearcuts and patch cuts had negative effects on salamanders 4-6 years post-harvest, which coincided with a drought; however, preparatory and establishment shelterwood harvests showed no effects on salamander captures, suggesting that retaining canopy cover may protect salamanders from compound disturbances such as drought. Also at the HEE, capture-recapture techniques were used to examine salamander population estimates before and after fire. Only two of three fires affected salamander populations. In the short term, prescribed fire effects on salamanders may be weak and intermittent and microclimate may have a greater effect on populations, although the longer-term effects of fire remain unknown. At Martell Experimental Forest, salamander numbers were compared beneath ACOs of different wood types, sizes and shapes, and grid arrays of different spacings. Pine ACOs were preferred over ash, while several small ACOs yielded equal salamander numbers to one large ACO of equal total area. High ACO density may increase capture probability but reduce the area sampled by each ACO, while lower density ACO grids may cover a larger area with the same sampling effort and produce more comparable results, but with less precision; choice of ACO experimental design will therefore require careful consideration of management goals. This dissertation also suggests strategies to support salamander populations as guidelines for managers to consider in management planning.</p>