Continuous Cover Forestry (CCF) has become increasingly popular since the early 1990s. CCF utilises several silvicultural techniques in order to promote and enhance forest structural diversity and favours natural regeneration. As CCF is relatively new to the UK there are still areas of knowledge regarding management interventions that need to be improved upon. This study utilises simple models, seedling physiology and a hybrid gap model and applies them to the Glentress Trial Area which has been under transformation from even-aged forestry since 1952. These efforts have led to an improved understanding of thinning interventions and the effects they may have on future stand structure. Since the formation of the Forestry Commission in 1919, clearfell-replant forestry has been the main form of management practiced in the UK. CCF management differs in several respects and is commonly practiced using expert knowledge in Continental Europe. In the UK the knowledge-base is still growing and therefore simple models can prove useful for guiding management. This study investigated the use of the idealised reverse-J and the Equilibrium Growing Stock (EGS). This study found that the reverse-J shaped diameter distribution is maintained at the Trial, Block and sub- Block scale indicating that an irregular structure is being approached. In addition, the diminution coefficient, a parameter of the reverse-J distribution, falls within values typical of continental Europe. Comparison of the actual diameter-frequency distribution against an ideal reverse-J distribution can inform both thinning intensity and which diameter classes to target. The EGS, which is a volume–diameter distribution, examines standing volume and how that volume is distributed across three broad diameter classes. Typical distributions from the Swiss Jura indicate that percentage volume should be split 20:30:50 across diameter classes. The EGS analysis showed that standing volume in the Trial Area is much lower than European values at just 174 m3 ha-1. In addition, the classic 20:30:50 percent split was not observed. The 1990 data set showed a 49:43:8 distribution but by 2008 it was 40:41:19. As natural regeneration is favoured in CCF a better understanding of seedling physiology is essential. This study established open (15-35 m2 ha-1) and closed canopy plots (>35 m2 ha-1). Plot characteristics were recorded and then seedlings were selected for physical measurements, chlorophyll fluorescence and gas-exchange measurements. There were clear differences between the physical characteristics with a mean Apical Dominance Ratio (APR) of 1.41 for the open plots and 0.9 for the closed plots which is consistent with previous studies suggesting an APR of 1 is needed for successful regeneration. The chlorophyll fluorescence measurements showed a linear relationship with PAR. However, although the results of the gas-exchange measurements showed an increase in photosynthetic rates with PAR for open plots, there was no obvious relationship in the closed plots. As a result, the study did not find a linear relationship between photosynthetic rate and chlorophyll fluorescence. Finally a complex, hybrid gap model was used to investigate the effects of management on predicted future stand structure. The hybrid gap model, PICUS v1.41, was parameterised for Sitka spruce. The model was used to explore different management scenarios on stand structure over two time periods; 1954-2008 and 1952- 2075. The output from the group selection with underplanting scenario, which resembled the actual management, produced realistic output that was comparable to the stand characteristics measured during the 2008 assessment. The output from the 1952-2075 runs suggested that thinning to a residual basal area suitable to allow natural regeneration (<30 m2 ha-1) or a group selection with underplanting were the best management options for maintaining structural diversity.

As alterações no uso do solo decorrentes das atividades humanas modificam as condições ambientais, o que pode levar a mudanças na estrutura de comunidades locais. A expansão da silvicultura ao redor do mundo tem causado uma crescente preocupação em termos de conservação da biodiversidade. Isto por que ela resulta em uma simplificação e homogeneização do habitat originalmente nativo. Este estudo avaliou a estrutura da assembleia de aves em áreas de silvicultura e em floresta nativa, sendo que os principais objetivos foram: 1) avaliar o possível impacto da silvicultura sobre a riqueza, abundância e composição de espécies de aves, considerando diferentes idades de plantio; 2) avaliar se as espécies de aves registradas em áreas de silvicultura representam um subconjunto daquela registrada na floresta nativa; 3) analisar as respostas da diversidade funcional e dos atributos funcionais morfológicos e comportamentais das espécies de aves. Foram amostrados plantios de eucalipto de quatro idades de cultivo assim como áreas de floresta nativa num total de 150 pontos de escuta. A riqueza, a abundância de espécies de aves e a diversidade funcional foram significativamente maiores na floresta nativa. A composição de espécies também apresentou diferença significativa entre a floresta e os plantios de diferentes idades. Entretanto apesar da diferença na composição, as espécies que ocorrem nos plantios de eucalipto representam subconjuntos daquelas encontradas na floresta nativa, com um elevado índice de aninhamento para os plantios de idade mais avançada. Os resultados deste estudo indicam a ação de um filtro ambiental imposto pela silvicultura, selecionando espécies com requerimentos de habitat e atributos similares, assim como um maior número de espécies generalistas de habitat. Pode-se inferir então que áreas de silvicultura oferecem um habitat pouco complexo para a avifauna com um nível limitado de recursos e com isso, uma perda de funções ecológicas essenciais ao ambiente, como a dispersão de sementes. / Changes in land use resulting from human activities modify the environmental conditions, which can lead to changes in the structure of local communities. The expansion of silviculture around the world has caused a growing concern for biodiversity conservation. This is because it results in a simplification and homogenization of originally native habitat. This study evaluated the structure of the assembly of birds in areas of native forest and silviculture, and the main objectives were : 1) to evaluate the possible impact of silviculture on the richness, abundance and composition of bird species, with different ages of planting and 2) assess whether the bird species recorded in areas of silviculture represent a subset that recorded in native forest, 3) analyze the responses of functional diversity and functional morphological and behavioral traits of birds species. Eucalyptus plantations four ages of cultivation as well as areas of native forest in a total of 150 point counts were sampled. The richness, abundance of bird species and functional diversity were significantly higher in the native forest. The species composition also showed a significant difference between the forest and plantations of different ages. However despite the difference in composition, species that occur in eucalyptus plantations represent subsets of those found in the native forest, with a high level of nestedness for plantations older age. The results of this study indicate the action of an environmental filter arising for silviculture, selecting species with similar habitat requirements and traits, as well as a greater number of generalist species habitat. It can be inferred then that silviculture areas offer a bit complex habitat for birdlife with a limited amount of resources and thus, a loss of ecological functions essential to the environment, such as seed dispersal.

In anticipation of widespread planting of putatively blight-resistant hybrid chestnuts (Castanea spp.), it is critical to understand the silvics and competitive ability of the species. This dissertation examines preliminary growth and survival of several species and genetic crosses of chestnut grown as 1-0 high-quality nursery seedlings and planted in two study sites: Southeastern Kentucky (Daniel Boone National Forest; chapter 2), and Northeastern Connecticut (Yale-Myers Forest; chapter 4). The effects of three silvicultural treatments on the Daniel Boone National Forest (DBNF), and four silvicultural treatments on the Yale-Myers Forest (YM) were evaluated. Furthermore, the effect of initial seedling size on seedling performance was tested. In both studies, seedlings grew largest in height and root collar diameter in silvicultural treatments with the most available light. High mortality at the DBNF planting was caused by Phytophthora cinnamomi, ink disease, and high mortality at the YM planting was caused by repeated deer, Odocoileus virginianus, browsing and competition from hay-scented fern, Dennstaedtia punctilobula. Additionally, seedlings at the DBNF study were repeatedly defoliated by Craesus castaneae, chestnut sawfly, during the first growing season (chapter 3). Seedlings with larger root collar diameters at planting demonstrated greater survival and growth in the DBNF study while seedlings larger in height and RCD added less growth and were more likely to die in the YM study, likely due to the high deer population and dense understory competition. These results indicate that silvicultural treatments that create high-light environments are ideal for chestnut, however the species can establish successfully under a variety of light conditions, from low light [10% photosynthetically active radiation (PAR)] to high light (65% PAR). Ink disease will present a formidable obstacle to chestnut reintroduction efforts in the south, while northern efforts will be challenged by deer browsing due to overpopulated deer herds.

Optimum brood cover for wild turkeys is composed of herbaceous cover <0.5 m tall that conceals poults from predators and allows travel underneath. On tracts of hardwoods where early succession stages and young forest cover are scarce, a lack of understory development can limit turkey populations. Additionally, retaining oak on these sites after logging or habitat enhancement is important to provide future timber value and hard mast. I compared the effects of silvicultural practices (multiple fires [F], shelterwood cutting [S], shelterwood cutting with one fire [SF], retention cutting [R], retention cutting with multiple fires [RF], retention cutting with herbicide application [RH], and retention cutting with herbicide application and multiple fires [RHF]) with controls (C) on wild turkey brood habitat and oak regeneration in upland central hardwood stands. I measured structure and food resources to quantify the quality of wild turkey brood cover. Shelterwood and retention cuts increased photosynthetically active radiation. However, herbaceous, vine, and bramble groundcover did not increase. Woody regeneration was greater following canopy reduction and understory disturbance compared to C. Disturbance (fire or herbicide) was required to maintain vegetation at the ideal height for wild turkey broods. Soft mast production increased after canopy reduction with and without fire. Invertebrate biomass did not increase following any treatment, but availability exceeded the dietary requirements of a wild turkey brood. I also counted stem density of oak and competitor regeneration in response to these treatments. Seedlings <12.7 cm were ephemeral. S and SF had a greater density of oak stems >1.4 m than C and F. However, S and SF also had the greatest density of oak >1.4 m prior to treatment. Canopy reduction increased oak competitors, but prescribed fire reduced competitors. I recommend canopy reduction, followed by repeated low-intensity prescribed fire to maintain low groundcover to enhance brood habitat for wild turkeys in mature closed-canopy upland hardwood stands.

Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv. / Härtill 5 uppsatser.

Climate change is an undeniable global event. Widely believed to be caused by human activities that release greenhouse gases, this change in climate will occur over a very short period of time when it is compared to natural climate variations. The effect the change will have on environments is somewhat unknown and any predictions are best guess scenarios. In British Columbia the mountain pine beetle has destroyed millions of pine trees but the infestation is not yet done. This may be one of the early symptoms of global warming on the British Columbia environment. Climate change will warm temperatures in BC and increase the annual precipitation. These warmer temperatures allow for longer growing seasons and in many cases, more favorable growing conditions. Studies on Sitka Spruce have found increases in volume growth by as much as 20% and growth in the boreal has been found to increase with higher CO2 levels and warmer temperatures. Climate change does not have to mean beetle epidemics and dying ecosystems. With proactive management British Columbia may actually find benefits in a warming climate.

Wildfire is the primary natural disturbance in Interior Cedar-Hemlock (ICH) forests, and since the mid-20th century, forest harvesting (clearcutting, in this case) has become the primary anthropogenic disturbance type. Forest management in British Columbia is currently governed by a paradigm that maintains that biological diversity can be preserved by utilizing forest harvesting regimes that closely mimic "natural" disturbance regimes, but a question remains as to how closely these regimes mimic wildfire disturbances. More specifically, how do clearcutting and wildfires compare in their effects on the structure and composition of early-successional ICH plant communities? This study compares vegetation structure, composition, relative abundance and diversity among 39 sites that experienced either a stand-replacing fire or a clearcut within the last 40 years. Sites of different ages and disturbance types were located within the wet cool ICHwkl and very-wet cool ICHvk I biogeoclimatic variants near Revelstoke, B.C. For each site, overstory structural characteristics (tree and snag diameters, basal area and density), overstory composition, and surface fuels (volume of coarse woody debris (CWD)) were assessed. Understory vegetation percent cover, species richness, composition and diversity were also determined. Linear regression analysis was used to examine differences in each of these variables between disturbance types, over time. The trends in structural legacies (especially snag and CWD dynamics) varied greatly between wildfire and clearcut sites. Compared to burned sites, clearcut sites exhibited patterns of accelerated succession in several characteristics (overstory tree regeneration, vegetation cover and understory species richness) due to planting treatments and pre-disturbance relicts. Understory species composition also varied between disturbances, with clearcut sites containing more shade-tolerant survivors initially. Both disturbance types had similar levels of floristic diversity during early succession. These results suggest that clearcut harvesting may not emulate stand-replacing fires in terms of impact on early ICH plant succession in any aspect but diversity. However, it is unclear if these early-successional differences will continue through time. There is a need for further research in this ecosystem, as well as any other ecosystems where emulation silviculture is applied, in order to confirm that silvicultural effects mimic those of natural disturbance regimes.

Managed pine forests are central to the economic vitality of the southeastern US. Over the past fifty years, the productivity of managed pine forests of this region have increased significantly with the development of new silvicultural technologies and the use of improved tree genetic material. Of the pine species present in the southeastern US, loblolly pine has arguably been the most intensively studied and widely planted by forest managers. Efficient operational deployment of improved genetic materials requires an understanding of how possible site conditions and silvicultural treatment may interact to affect maximum yield. There are a wide range of site conditions in the south as the result of regional climate gradients, soil type and soil drainage patterns. On the western edge of loblolly pine’s natural extent, Texas has a drier climate than areas to the east, and in Louisiana, there are also poorly drained Ultisols that are found in areas with little relief and are prone to flooding. However, on the basis of 10-year forest inventory data of pure-family plots from three different sites and under two levels of cultural regime intensity, my study found that superior genotype, Lob 5 from South Carolina, still showed best performance in the Western Gulf area, and high intensive treatment could improve stand growth and resistance to wind damage significantly. Further, my study compared the stand production and dynamics between pure- and mixed-family plots. I found that Lob 5 and Lob 4 showed the growth traits of competitive ideotype, and low intensive treatment increased the deployment effect significantly for competitive ideotype. Finally, my study examined leaf area index (LAI) and foliar nitrogen concentration (foliar N). The result showed that fast growing genotype had lower LAI and foliar N than slow growing one. It indicated that fast growing genotype had high resource use efficiency and nutrient requirement. This research provided critical information to guide industrial forest management in the WG (Western Gulf) area. First, introduced superior genotype continued to show good performance in this area. Second, combination of good genotype and high intensive treatment would increase plantation production significantly. Third, identification of ideotype would increase the accuracy of growth potential estimation in progeny test.

Wildfire is the primary natural disturbance in Interior Cedar-Hemlock (ICH) forests, and since the mid-20th century, forest harvesting (clearcutting, in this case) has become the primary anthropogenic disturbance type. Forest management in British Columbia is currently governed by a paradigm that maintains that biological diversity can be preserved by utilizing forest harvesting regimes that closely mimic "natural" disturbance regimes, but a question remains as to how closely these regimes mimic wildfire disturbances. More specifically, how do clearcutting and wildfires compare in their effects on the structure and composition of early-successional ICH plant communities? This study compares vegetation structure, composition, relative abundance and diversity among 39 sites that experienced either a stand-replacing fire or a clearcut within the last 40 years. Sites of different ages and disturbance types were located within the wet cool ICHwkl and very-wet cool ICHvk I biogeoclimatic variants near Revelstoke, B.C. For each site, overstory structural characteristics (tree and snag diameters, basal area and density), overstory composition, and surface fuels (volume of coarse woody debris (CWD)) were assessed. Understory vegetation percent cover, species richness, composition and diversity were also determined. Linear regression analysis was used to examine differences in each of these variables between disturbance types, over time. The trends in structural legacies (especially snag and CWD dynamics) varied greatly between wildfire and clearcut sites. Compared to burned sites, clearcut sites exhibited patterns of accelerated succession in several characteristics (overstory tree regeneration, vegetation cover and understory species richness) due to planting treatments and pre-disturbance relicts. Understory species composition also varied between disturbances, with clearcut sites containing more shade-tolerant survivors initially. Both disturbance types had similar levels of floristic diversity during early succession. These results suggest that clearcut harvesting may not emulate stand-replacing fires in terms of impact on early ICH plant succession in any aspect but diversity. However, it is unclear if these early-successional differences will continue through time. There is a need for further research in this ecosystem, as well as any other ecosystems where emulation silviculture is applied, in order to confirm that silvicultural effects mimic those of natural disturbance regimes.

Submitted by RAONI XAVIER DE MELO null (raonimelo@hotmail.com) on 2016-05-16T12:12:19Z No. of bitstreams: 1 RAONI_DEFINITIVO_FINAL.pdf: 2675385 bytes, checksum: 082419f2fd50aacd7928c9746ddabbde (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-05-16T17:45:56Z (GMT) No. of bitstreams: 1 melo_rx_me_bot.pdf: 2675385 bytes, checksum: 082419f2fd50aacd7928c9746ddabbde (MD5) / Made available in DSpace on 2016-05-16T17:45:56Z (GMT). No. of bitstreams: 1 melo_rx_me_bot.pdf: 2675385 bytes, checksum: 082419f2fd50aacd7928c9746ddabbde (MD5) Previous issue date: 2016-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A preocupação com as questões ambientais e o desenvolvimento de diversos tipos de energias alternativas estimula a participação cada vez maior de fontes renováveis de energia. A energia gerada por meio da queima da biomassa é o maior destaque dentre as fontes renováveis, sendo uma das mais exploradas atualmente. O aumento da demanda de biomassa aumentou a necessidade de gerar uma maior quantidade de material em menor tempo e em áreas cada vez mais reduzidas. O presente estudo avaliou o crescimento e a produção da biomassa aérea em plantio de Eucalyptus grandis (Clone G21), no sistema de talhadia com enfoque na produção de biomassa florestal ao fim do ciclo de dois anos. O trabalho foi realizado na Universidade Estadual Paulista (UNESP), em área experimental da Fazenda Lageado, localizada no município de Botucatu – SP. A floresta de Eucalyptus grandis foi implantada em março de 2012 no sistema florestal de curta rotação em espaçamento de 3 x 1 m e colhida com a colhedora florestal FR 9060 da New Holland. A segunda rotação foi conduzida a partir da rebrota do plantio anterior com início em de outubro de 2013. A área foi subdivida em quatro tratamentos, os quais foram dispostos em dois fatores: com a desbrota e sem a desbrota; e com a aplicação da adubação comercial e sem a aplicação de adubação. O trabalho foi desenvolvido em um experimento inteiramente casualizado e considerou-se um esquema fatorial (2 x 2) com dois fatores, desbrota e adubação, foi realizado a ANOVA e quando apresentou diferença significativa foi realizado o teste TUKEY para a comparação entre as médias. A produção de biomassa florestal seca resultou em uma média geral dentre os tratamentos de 17,34 toneladas por hectare e o fuste foi o componente arbóreo que mais produziu tanto biomassa fresca quanto biomassa seca por hectare, o qual representa cerca de 91 % de toda a biomassa produzida na área. A densidade básica da madeira também não apresentou diferença estatística quando comparado os fatores silviculturais, obtendo uma média de 369 kg m-3. A umidade apresentou-se maior no componente fuste seguido das folhas e os galhos. Para os materiais voláteis e o teor de cinzas apenas apresentaram diferença no componente fuste, que apresentou maior média de materiais voláteis e menor média de carbono fixo. As folhas apresentaram o maior poder calorífico dentre os componentes, mas representam apenas 4,1% do total de biomassa por hectare. Nenhuma prática silvicultural comparada neste trabalho, desbrota e a adubação, apresentou um resultado com diferença significativa a 5% de probabilidade para a produção de biomassa e para a produção de energia. Desse modo, pode-se afirmar que para a talhadia de sistemas florestais de curta rotação com o enfoque para a produção de biomassa e bioenergia não faz necessário realizar as adubações e nem a desbrota, sendo que estas duas operações são onerosas, tanto economicamente como no dispêndio energético, mas para que isso ocorra devem-se atentar as boas práticas silviculturais no primeiro ciclo, principalmente para o fator adubação. / The power generated by biomass burning is the biggest highlight from renewable sources, one of the most currently used. With the increasing use of biomass, the need arises to produce more biomass in less time in a smaller area. This study aims to evaluate the growth and biomass production of Eucalyptus grandis, G21 clone, the coppice system, with a focus on production of forest biomass. The study was conducted at São Paulo State University (UNESP) in the experimental area of Lageado Farm, located in Botucatu SP. The Eucalyptus grandis forest was established in March 2012 in forest system of short rotation with spacing of 3 x 1 m at 18 months of age was held the first thinning in total area, with forest harvester FR 9060 New Holland, which gathers all the tree components, stem, branches and leaves. After harvesting the area was subdivided into 4 equal parts where set 4 treatments, which are arranged on two factors: With the completion of thinning and without the use of thinning; and the application of commercial fertilizer or without the application of commercial fertilizer. The study was conducted in a completely randomized experiment and considered a factorial arrangement (2 x 2) with two factors, thinning and fertilizing. It was found that the thinning and fertilization influenced some physical properties of forest biomass. The components of biomass differed in all the treatments. Especially the leaves which had the highest average values of the gross calorific value (20.9 MJ kg-1 ), higher fixed carbon (15 %). The highest dry matter yield, 18,690 kg, was presented by the treatment without thinning and fertilization. The same treatment also showed the highest amount of energy potential, 336.06 GJ ha-1 . Fertilization worked significantly in the production of dry biomass and consequently the energy potential per area.