For some forest landowners in the southern USA, multiple ecological and economic objectives are met through the conversion of longleaf pine (Pinus palustris) plantations to uneven-aged stands. This study was conducted in eight similarly-aged longleaf pine plantations at The Jones Center at Ichauway in southwestern Georgia. The stands were disturbed by commercial thinning in 2014 and partially disturbed by Hurricane Michael in 2018 and half of the stands were seeded with native grasses and a forb in 2015. I developed explanatory models of groundcover biomass and longleaf pine seedling occurrence and density. I detected a community composition difference in groundcover species assemblages between seeded and unseeded stands. For recruited longleaf pine regeneration, my model indicated that lower amounts of groundcover biomass were correlated with greater occurrence and density of pine regeneration. Partial stand disturbances and restoration of native groundcover set stands on a trajectory to resemble a more natural condition.

Forests are the dominant terrestrial ecosystem in Ontario and were once widespread throughout much of eastern North America; in southern Ontario, forest cover has declined from 90% to approximately 17% in the past 200 years. Conversion of the surrounding landscape to urban and agricultural land uses creates edge effects which increase the impact of forest cover loss and threaten ecological integrity. Other impacts on forest ecological integrity include incompatible human activities, a generally inhospitable landscape matrix, and microenvironment changes, including those from chemical pollution and heat island effects. Coupled with direct degradation from human activities like free-riding, the altered forest microenvironment can facilitate increased invasion by opportunistic and competitive plant species, e.g. Alliaria petiolata (Brassicaceae). This tends to be worse in urban areas because of greater visitation that creates soil compaction, trampling, and more vectors to introduce the seeds of invasive species. Active management is often necessary in areas which have been degraded. Ecological restoration represents an important active management tool for urban forest protected area managers. The ecological restoration of the forest understory in altered and threatened habitats represents an important aspect of forest restoration. For this study, I tested the effectiveness of an ecological restoration using a multi-species assemblage approach with three native understory species to restore the herbaceous layer in Natchez Hills, an Environmentally Sensitive Policy Area in Kitchener, Ontario. The ecological restoration site was degraded and this reduced native plant species in the forest understory. The species selected, Caulophyllum giganteum (Farwell) Loconte & W.H. Blackwell (Berberidaceae), Podophyllum peltatum Linnaeus (Berberidaceae) and Maianthemum racemosum subsp. racemosum (Linneaus) Link (Asparagaceae), are widespread throughout eastern North America, and were selected for use in this study because of their persistence and relative abundance in Natchez Hills ESPA. Adult transplants were planted into 2 metre by 2 metre quadrats in different densities and shoot populations were monitored for two field seasons to determine if density played a role in early ecological restoration success. The methodology I designed for the ecological restoration was as practical as possible, given the real world financial and logistical constraints faced by many urban forest managers. Statistical analysis using repeated measures multivariate analysis of variance showed aerial shoot density did not have a significant effect on early restoration success rates (p > 0.05). However, there was a significant increase in restored species. Caulophyllum giganteum and Podophyllum peltatum shoot populations increased by over 97% at the ecological restoration site one year after transplanting. Maianthemum racemosum subsp. racemosum shoot populations increased by 51% at the site. For comparison, another study in the same forest reported early ecological restoration rates of 92% to 100% for herbaceous understory species, including C. giganteum and P. peltatum. Other North American studies using transplanted perennial herbaceous material reported average survival rates of 16.6% two years after planting (varying from 1.25% to 51.4% using eight herbaceous species in the Boston area), to 91% one year after restoration (varying from 42.1% to 100% using 19 herbaceous species of the deciduous forest in the Midwest). In instances where protected areas are degraded, active management and ecological restoration are often necessary tools. This ecological restoration demonstrated that the native herbaceous species used in this study are suitable for use in early ecological restorations in maple beech upland forests in the City of Kitchener. Using a practical and cost-effective methodology this ecological restoration experiment showed that it is possible to implement urban restoration of the forest understory in degraded areas, and to achieve success in early ecological restoration using native herbaceous forest understory species.

Forests are the dominant terrestrial ecosystem in Ontario and were once widespread throughout much of eastern North America; in southern Ontario, forest cover has declined from 90% to approximately 17% in the past 200 years. Conversion of the surrounding landscape to urban and agricultural land uses creates edge effects which increase the impact of forest cover loss and threaten ecological integrity. Other impacts on forest ecological integrity include incompatible human activities, a generally inhospitable landscape matrix, and microenvironment changes, including those from chemical pollution and heat island effects. Coupled with direct degradation from human activities like free-riding, the altered forest microenvironment can facilitate increased invasion by opportunistic and competitive plant species, e.g. Alliaria petiolata (Brassicaceae). This tends to be worse in urban areas because of greater visitation that creates soil compaction, trampling, and more vectors to introduce the seeds of invasive species. Active management is often necessary in areas which have been degraded. Ecological restoration represents an important active management tool for urban forest protected area managers. The ecological restoration of the forest understory in altered and threatened habitats represents an important aspect of forest restoration. For this study, I tested the effectiveness of an ecological restoration using a multi-species assemblage approach with three native understory species to restore the herbaceous layer in Natchez Hills, an Environmentally Sensitive Policy Area in Kitchener, Ontario. The ecological restoration site was degraded and this reduced native plant species in the forest understory. The species selected, Caulophyllum giganteum (Farwell) Loconte & W.H. Blackwell (Berberidaceae), Podophyllum peltatum Linnaeus (Berberidaceae) and Maianthemum racemosum subsp. racemosum (Linneaus) Link (Asparagaceae), are widespread throughout eastern North America, and were selected for use in this study because of their persistence and relative abundance in Natchez Hills ESPA. Adult transplants were planted into 2 metre by 2 metre quadrats in different densities and shoot populations were monitored for two field seasons to determine if density played a role in early ecological restoration success. The methodology I designed for the ecological restoration was as practical as possible, given the real world financial and logistical constraints faced by many urban forest managers. Statistical analysis using repeated measures multivariate analysis of variance showed aerial shoot density did not have a significant effect on early restoration success rates (p > 0.05). However, there was a significant increase in restored species. Caulophyllum giganteum and Podophyllum peltatum shoot populations increased by over 97% at the ecological restoration site one year after transplanting. Maianthemum racemosum subsp. racemosum shoot populations increased by 51% at the site. For comparison, another study in the same forest reported early ecological restoration rates of 92% to 100% for herbaceous understory species, including C. giganteum and P. peltatum. Other North American studies using transplanted perennial herbaceous material reported average survival rates of 16.6% two years after planting (varying from 1.25% to 51.4% using eight herbaceous species in the Boston area), to 91% one year after restoration (varying from 42.1% to 100% using 19 herbaceous species of the deciduous forest in the Midwest). In instances where protected areas are degraded, active management and ecological restoration are often necessary tools. This ecological restoration demonstrated that the native herbaceous species used in this study are suitable for use in early ecological restorations in maple beech upland forests in the City of Kitchener. Using a practical and cost-effective methodology this ecological restoration experiment showed that it is possible to implement urban restoration of the forest understory in degraded areas, and to achieve success in early ecological restoration using native herbaceous forest understory species.

No description available.

Thesis (M. En.)--Miami University, Institute of Environmental Sciences, 2008. / Title from first page of PDF document. Includes bibliographical references (p. 16-21-Xx).

Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2015-06-23T15:19:36Z No. of bitstreams: 1 TiagoClossDeMarchi.pdf: 3447572 bytes, checksum: 384491c29d57ca52c59ea0cda6879c8b (MD5) / Made available in DSpace on 2015-06-23T15:19:36Z (GMT). No. of bitstreams: 1 TiagoClossDeMarchi.pdf: 3447572 bytes, checksum: 384491c29d57ca52c59ea0cda6879c8b (MD5) Previous issue date: 2011 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A mudança do uso da terra decorrente de atividades agrícolas provoca uma modificação na paisagem que leva à criação de fragmentos florestais isolados que se mantém imersos em uma matriz que pode apresentar uma maior ou menor agressividade de acordo com o seu uso. Este estudo foi realizado em duas fazendas vizinhas localizadas no município de Eldorado do Sul, RS. A Fazenda Terra Dura, pertence à empresa Celulose Riograndense S/A e a maior parte da área é utilizada para a monocultura de eucalipto (Eucalyptus spp.). Os remanescentes de floresta nativa estão exclusivamente associados aos diversos cursos d’água que cruzam a área e cercados pelo plantio de eucalipto de diversas idades e estágios de produção. A área é utilizada para o plantio de eucalipto há cerca de 30 anos e há 20 foi isolada do gado. A Fazenda Eldorado destina-se à criação extensiva de gado e sua cobertura vegetal é caracterizada por um predomínio de campo com fragmentos de florestas ripárias que o gado utiliza como local de pastejo e desedentação. Em cada uma das dez áreas selecionadas foram alocados dois transectos paralelos ao curso d’água a 20 metros de distância um do outro nos quais foram aleatorizadas cinco unidades amostrais de 10 x 10m para amostragem do componente arbóreo dos fragmentos. Em cada unidade amostral foram registradas a circunferência de todos os indivíduos com diâmetro a altura do peito maior ou igual a 5 cm (DAP ≥ 5cm). O componente juvenil foi amostrado em unidades amostrais de 5 x 5m concêntricas em cada parcela de 10 x 10m, onde foram amostrados todos os indivíduos com mais de um metro de altura e com menos de 5 cm de diâmetro e estimou-se sua altura total e seu diâmetro à altura do solo (DAS). A densidade e composição do estrato herbáceo foi amostrada em parcelas de 1 x 1 m concêntricas às unidades amostrais de 5 x 5 m. Nestas unidades amostrais foi removida toda vegetação de até 1 m de altura e identificadas taxonômicamente as espécies e separadas em formas de vida (árvore, arbusto, erva, gramíneas, pteridófita, trepadeiras, epífitos). Para avaliação do sub-bosque nos plantios de eucalipto foram selecionados quatro talhões onde foram alocados três transectos de 100 m de comprimento em diferentes distâncias da borda (5, 25 e 50 m) e dois transectos (5 e 25 m) para o interior da mata ciliar. Em cada transecto foram sorteadas cinco unidades amostrais de 5 x 5 m e amostrados todos os indivíduos juvenis utilizando os mesmos critérios anteriormente citados para este estrato. Nos fragmentos adjacentes aos plantios de eucalipto, foram encontradas 61 espécies para os adultos e 77 para os juvenis e o estoque de carbono estimado foi de 106 Mg.ha-1 para os indivíduos adultos e de 4,3 Mg.ha-1 para os herbáceos. Nas áreas com presença de gado foram amostradas 62 espécies para os adultos e 48 para juvenis, com um estoque de carbono de 85,5 Mg.ha-1 para adultos e 0,9 Mg.ha-1 para herbáceo. No sub-bosque dos plantios de eucalipto foram amostradas 32 espécies, sendo 16 exclusivas e 71 no interior da floresta ripária, com 55 exclusivas. Os resultados mostraram que florestas em pequenos fragmentos incorporados em plantações de eucalipto parecem ser melhor preservadas do que aqueles expostos à pecuária. Além disso, áreas com presença de gado apresentaram uma redução no estoque de carbono de 23,8% para o estrato arbóreo e de 79,4% no estrato herbáceo em relação às áreas sem a presença de gado. A plantação de eucalipto possui um importante papel, embora restrito devido ao curto período de corte das árvores, para a manutenção da diversidade de espécies de florestas nativas adjacentes em seu sub-bosque e podem atuar como uma catalizadoras da regeneração da vegetação nativa e na manutenção da diversidade local. / The change in land use due to agricultural activities causes a landscape change that leads to the creation of isolated forest fragments that remain embedded in a matrix that may present a greater or lesser aggressiveness according to their use. The environmental quality of this matrix can affect species composition and forest structure through several factors that impact the surrounding environment, but on the other hand, depending on its type, the array can act as an important source of biodiversity conservation. This study was conducted in two neighboring farms located in Eldorado do Sul, RS. Terra Dura Farm, owned by Celulose Riograndense S/A and most of the area is used for the monoculture of eucalyptus (Eucalyptus spp.). The remnants of native forest are exclusively associated with the various streams that cross the area and surrounded by eucalyptus plantations of various ages and stages of production. The area is used for the planting of eucalyptus during 30 years. The cattle was isolated 20 years ago. Eldorado Farm is intended for extensive cattle ranching and its vegetation is characterized by a predominance of field with fragments of riparian forests that livestock use for grazing. We survey ten riparian fragments, five in each farm, were allocated two transects parallel to the stream to 20 m away from each other in which five were randomized plots of 10 x 10 m sampling of the tree component of the fragments. In each sampling unit circumference were recorded for all individuals with diameter at breast height greater than or equal to 5 cm (DBH ≥ 5 cm). The juvenile component was sampled in 5 x 5 m plots concentric in each plot of 10 x 10 m was sampled all individuals with more than one meter in height and less than 5 cm in diameter and estimated its total height, and its diameter at ground level (DAS). The density and composition of the herbaceous layer was sampled in plots of 1 x 1 m plots of concentric to 5 x 5 m. In these sample units of all vegetation was removed up to 1 m high, which were taxonomically identified and separated in life forms (tree, shrub, herb, grass, fern, lianes and epiphytes). To evaluate the understory in the eucalyptus plantations were selected four plots were allocated three transects of 100 m length at different distances from the edge (5, 25 and 50 m) and two transects (5 and 25 m) into the riparian vegetation. In each transect were randomly selected five samples of 5 x 5 m and sampled all juveniles using the same criteria previously cited for this stratum. In fragments adjacent to eucalyptus plantations, 61 species were found for adults and 77 for juveniles and the estimated carbon storage was 106 Mg.ha-1 for adults and 4.3 Mg.ha-1 for the herbs. In areas with presence of cattle were sampled for 62 adults and 48 for juveniles, with a carbon stock of 85.5 Mg.ha-1 for adults and 0.9 Mg.ha-1 for herbaceous. In the understory of the eucalyptus plantations were found 32 species, with 16 exclusive and 71 within the riparian forest, with 55 exclusive. Our results showed that in small forest fragments embedded in eucalypt plantations seem to be better preserved than those exposed to livestock. In addition, areas with the presence of cattle showed a reduction in carbon stock of 23.8% for the upper stratum and 79.4% in the herbaceous layer compared to areas without the presence of livestock and the planting of eucalyptus has an important role, although limited, due to shortcut the trees for the maintenance of species diversity of native forest adjacent to their understory and can act as a catalyst of the regeneration of native vegetation and maintenance of local diversity.

Human activities are increasing the occurrence of megafires that have the potential to alter the ecology of forest ecosystems. The objective of this study was to understand the impact of a 610 km2 megafire on patterns of forest regeneration and herbivory of three forest types (aspen/fir, oak/maple, and pinyon/juniper) within the burn scar. Sapling density, meristem removal, and height were measured across a transect network spanning the area of the burn scar over three years from 2019-2021. The network consisted of 17 burned/unburned transect pairs in adjacent burned/unburned forest stands (6 aspen/fir, 5 oak/maple, and 6 pinyon/juniper). Species that regenerated through sprouting generally responded positively to fire while regeneration from seed showed very little post-fire response. Browse pressure was concentrated on deciduous tree species and tended to be greater in burned areas but the effect diminished over time. Meristem removal of sprouting species was below the critical threshold resulting in positive vertical growth across years. Our results indicate that forest regeneration within the megafire scar was generally positive and experienced sustainable levels of ungulate browsing that are likely to result in forest recruitment success. Novel fire regimes are becoming increasingly common and megafires have burned across ecotonal boundaries across multiple forest types. Plant community structure and composition may be critically affected by changing fire regimes. Our objective was to investigate how a megafire that burned across multiple forest types impacted understory plant community assembly and biodiversity. Paired vegetation transects were installed in burned and unburned areas across aspen/fir, oak/maple, and pinyon/juniper forests within the 2018 Pole Creek Megafire burn scar. Percent cover of understory plants was measured in the summer of 2022 and plants were identified to the species level. Richness and diversity indices were then calculated and analyzed using mixed effects models. Fire decreased species richness of the aspen/fir forest understory and increased plant cover in pinyon/juniper forests, while not significantly impacting oak/maple understories. The significant effects of fire were largely driven by changes in forb species. Fire decreased the richness of native plants in aspen/fir forests but increased the richness of non-native plants in oak/maple and pinyon/juniper forests. Non-native plant abundance also increased in post-fire pinyon/juniper forests. Our results suggest that forest understory communities show variable responses to megafires that burn across multiple forest types with important implications for post-fire plant community structure, diversity, and invasibility. Large mammal herbivores (ungulates) are increasing in number and spreading into novel habitats throughout the world. Their impact on forest understory plant communities is strong and varies by herbivore, plant growth form, and season. The objective of this study was to determine the individual and collective herbivory impacts of native versus domestic ungulates on the understory plant community composition of post-fire aspen forests. Four-way fencing treatments were installed in 2012 to separate ungulate species, and Daubenmire frames were used to collect percent cover estimates for each understory plant species. Vegetation data were later used to calculate richness and diversity indices. Total understory plant cover, richness, and diversity were not significantly impacted by the herbivory fencing treatment. However, woody plant species' percent cover was 90% greater in full ungulate exclusion plots than in the fenceless controls. Herbivores likely targeted woody plant species due to their high nutrient levels that last longer into the winter than those of forb or graminoid species. Herbivory treatment did not affect non-native species. Our results indicate that herbivore fencing can protect forest understory plant communities, particularly the woody species. Successful regeneration of woody species can benefit the diversity of the entire understory plant community and preserve forest structure.