Programa Doctoral conjunto "Desarrollo Sostenible Conservativo de Bosques Tropicales: manejos Forestal y Turístico".

Programa Doctoral conjunto "Desarrollo Sostenible Conservativo de Bosques Tropicales: manejos Forestal y Turístico"

Orientador: Tatiele Anete Bergamo Fenilli. / Dissertação (mestrado) - Universidade Regional de Blumenau, Centro de Ciências Tecnológicas, Programa de Pós-Graduação de Engenharia Florestal.

Orientador: Sérgio Campos / Coorientador: Roberta Thays dos Santos Cury / Banca: Felipe Wanderley de Amorim / Banca: Renata Cristina Batista Fonseca / Resumo: A conversão de florestas naturais em pastagens, lavouras ou reflorestamentos homogêneos com espécies exóticas, pode influenciar processos ecológicos importantes alterando a dinâmica florestal. O trabalho teve como objetivo avaliar se reflorestamentos homogêneos de Pinus elliottii influenciam a remoção de sementes em uma vegetação secundária de Floresta Ombrófila Mista Montana adjacente. Assim, formulamos três hipóteses: (1) a remoção de sementes será maior na vegetação secundária de Floresta Ombrófila Mista Montana adjacente ao plantio de Pinus elliottii, em especial, onde as plantações se encontram em estágio inicial de desenvolvimento; (2) a remoção de sementes na vegetação secundária de Floresta Ombrófila Mista Montana será maior quanto mais distante da borda com plantio de Pinus elliottii; e (3) a remoção de sementes será diferente entre as espécies de Syagrus romanzoffiana, Araucaria angustifolia e Pinus elliottii. Foram selecionadas seis áreas de plantios de Pinus elliottii adjacentes a vegetação secundária de Floresta Ombrófila Mista Montana. Em cada área foram instalados cinco pontos amostrais, distribuídos ao longo de um transecto a uma distância de 0, 10, 25, 50 e 100 metros da borda florestal. Em cada ponto foram depositadas 13 sementes de cada espécie analisada. O monitoramento das sementes foi realizado após dois, sete, nove, 14 e 21 dias. No geral a taxa de remoção foi elevada para todas as espécies (100% para espécie Syagrus romanzoffiana, 98% para Pinus elliot... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Conversion of natural forests to pasture, crop or homogeneous reforestation with exotic species can influence important ecological processes by changing the forest dynamics. The objective of this work was to evaluate the effects of Pinus elliottii plantation on seed predation in a Mixed Ombrophilous Montane secondary forest. Thus, we formulate three hypotheses: (1) seed removal will be greater in the Mixed Ombrophilous Montane secondary forest adjacent to Pinus elliottii plantation, especially where the plantations are in early stages; (2) seed removal will be greater in the Mixed Ombrophilous Montane secondary forest farther from the forest edge; and, (3) seed removal will be different among Syagrus romanzoffiana, Araucaria angustifolia and Pinus elliottii species. Six Pinus elliottii areas adjacent to Mixed Ombrophylous Montane secondary forest were selected. In each area, five plots were distributed along 0, 10, 25, 50 and 100 meters from the forest edge. Were deposited 13 seeds by species in each plot. Seeds were monitored during two, seven, nine, 14 and 21 days. In general the removal rate was high for all species (100% for Syagrus romanzoffiana, 98% for Pinus elliottii and 49% for Araucaria angustifolia). Similarly, all distances from the forest edge showed high seed removal, however, Araucaria angustifolia showed reduced seed removal at the edge, with 33% of removal at 0 m against 70% at 100 m. These rates indicate the presence of forest-associated fauna, which may cause predation and/or secondary dispersal. The reduced seed removal of Araucaria angustifolia, a key species for Atlantic Forest, on the forest edge, may indicate losses in the wildlife associated with the forest edge adjacent to the homogeneous planting. In addition, the removal of Pinus elliottii seeds in the forest, if predated, may indicate a reduction of their invasive potential in natural areas. / Mestre

The Mid-Atlantic coastal forests in Virginia are stressed by episodic disturbance from storms associated with hurricanes and nor'easters. Using annual tree ring data, we adopt a dendroclimatic and statistical modelling approach to understand the response and resilience of a coastal pine forest to slow progressive climate change and extreme storm surge events. Results indicate that radial growth of trees in the study area is influenced by age, vigor, competition, microsite variability, and regional climatic trends, but dominated periodically by disturbance due to storm surges. We evaluated seven local storm surge events to understand the effect of storm surges associated with nor'easters and hurricanes on radial growth. A general decline in radial growth was observed in the year of the storm and three years following it, after which the radial growth starts recovering. Given the projected increase in hurricanes and storm surge severity with changing global climate, this study contributes to understanding declining tree growth response and resilience of coastal forests to past disturbances. This can help predict vegetation response patterns to similar disturbances in the future.

En esta investigación se evaluaron los atributos ecológicos de la población natural de Pinus tropicalis Morelet en Galalón. Se establecieron seis parcelas de 400 m2 para la caracterización del suelo, clima, vegetación, estado de conservación, estructura florística y los atributos morfofisiológicos de la especie. La riqueza florística resultó con 30 géneros, 22 familias botánicas y 31 especies, siendo un área pobre florísticamente donde predomina P. tropicalis asociado con P. caribaea var. caribaea. Se demostró que la existencia de factores ecológicos naturales y antrópicos (huracanes, manejo inadecuado y las prácticas de aprovechamiento forestal) comprometen el grado de conservación de la población de P. tropicalis en Galalón. El bosque se caracteriza por una homogeneidad florística y estructural donde las especies de mayor importancia ecológica, según el índice ampliado (IVIEA), resultaron ser P. tropicalis, P. caribaea var. caribaea, B. crassifolia y M. apetala. El ordenamiento de las unidades de muestreo no distingue un gradiente ambiental. Los atributos morfofisiológicos indicaron que la especie P. tropicalis muestra un patrón adaptativo a condiciones de suelos esqueléticos y ferralíticos amarillentos lixiviados en la localidad de Galalón además de producir una alta biomasa con bajas concentraciones de nutrientes por lo que puede ser considerada una especie frugal.

Dissection and rearing studies of second-year cones disclosed six species of insects associated with the seeds and cones of singleleaf pinyon pine. Those most commonly encountered were: Dioryctria sp. probably albovittella Hulst, Conophthorus monophyllae Hopkins and Pineus coloradensis Gillette. The three remaining species were of lesser importance. These included the gall midge, Asynapta sp., a minor cone pest and two parasites, one of C. monophyllae, Acerocephala atroviolacea Crawford and an unidentified parasite of Dioryctria, of the family Ichneumonidae. D. sp. probably albovittella was regarded as the major insect destroying cones and seeds of P. monophylla in this study. During the 1976 growing season it attained a maximum level of 29 percent infestation. C. monophyllae occurred less frequently in this study, but probably has a higher potential for destruction in years of poor cone crops or high cone beetle populations. P. coloradensis caused negligible damage to seeds and cones, but was encountered frequently. Early in the growing season it infested a maximum of 38 percent of the cones.

Six species of insects were found attacking limber pine cones from July 26, 1968, through October 4, 1969, in Cache National Forest. The three species considered of major importance are: Conophthorus flexilis Hopkins, Dioryctria abietella (D. & S.), and D. sp. near or disclusa Heinrich. The three minor species encountered are; Bradysia sp., Trogoderma parabile Beal, and Asynapta keeni (Foote). In addition to the major and minor cone pests three parasites, Apanteles sp . prob. starki Mason, Elacherus sp., and Hypopteromalus percussor Girault were found associated with the cone pests. C. flexilis, which completely destroys the cone, was ranked as the number one pest on the basis of numbers present plus severity of damage. During 1968 and 1969 C.flexilis destroyed 11.47 percent of the 1500 cones examined, with a mean of 5.87 larvae per infested cone. The cone moths, D. abietella and D. sp. near or disclusa, were ranked second and third in importance respectively. D. sp . near or disclusa was potentially the more important cone moth, as it caused a total destruction of the seed bearing portion of the cones. However, D. abietella infested 15.40 percent of the cones, in contrast to 2.00 percent by D. sp. near or disclusa. There were no significant statistical differences in insect populations between 1968 and 1969, although the percent infestation of C. flexilis and D. sp. near or disclusa increased slightly and D. abietella decreased.

Thesis (Ph. D.)--University of Wyoming, 2006. / Title from PDF title page (viewed on Dec. 20, 2007). Includes bibliographical references.

Los incendios son el tipo de perturbación natural más frecuente en los ecosistemas mediterráneos (Naveh, 1975; Gill et al., 1981; Trabaud, 1981). En un tiempo relativamente corto, y como consecuencia de diferentes factores sociales y climáticos, el efecto de los grandes incendios (mayores de 1000 ha) se ha visto incrementado en los últimos años (Prieto, 1995; Piñol et al., 1998). Así, en el periodo comprendido entre 1987 y 1994 se produjeron en Cataluña (NE Península Iberica) un total de 5279 incendios. El 99.7% de ellos fue menor de 1000 ha y quemó un 30% de la superficie total quemada, mientras que el resto de la superficie se quemó en tan solo 16 incendios de más de 1000 ha (0.3% del total) (Terradas y Piñol, 1996). Los incendios de gran tamaño suelen ser tambien incendios de alta intensidad (Huston, 1994), ya que suelen ir unidos a una cubierta forestal continua y extensa (Huston, 1994; Turner et al., 1994; Piñol et al., 1998), y a determinadas condiciones meteorológicas caracterizadas por largos periodos de sequía y fuertes vientos (Terradas y Piñol, 1996; Turner et al., 1997). Los grandes incendios pueden tener un doble efecto sobre el paisaje. Por un lado, pueden tener un papel homogeneizador, ya que el fuego normalmente arrasa la vegetación independientemente de la densidad, la edad, y la composición específica (Christensen et al., 1989; Bessie y Johnson, 1995), sincronizando en grandes áreas la sucesión de la vegetación (Connell y Slatyer, 1980), y eliminando la heterogeneidad generada por estadios más avanzados de la misma (Huston, 1994). Por otro, los grandes fuegos también pueden tener un efecto heterogenizador que depende de la escala a la que se observan (Turner et al., 1994, 1998): a nivel de paisaje (que correspondería a una escala de 10-104 km2, según McKenzie et al., 1996) se origina un mosaico de áreas quemadas y no quemadas, mientras que a nivel de zona quemada (que correspondería a la escala de bosque/comunidad, es decir, 1-10 km2, según McKenzie et al., 1996), la heterogeneidad espacial es el resultado del mosaico generado por las diferentes severidades con que se quema la vegetación (Turner et al., 1994). Turner et al. (1994) demuestran, en su estudio sobre los efectos del fuego en la heterogeneidad del paisaje del parque nacional de Yellowstone, que el patrón que se crea de áreas quemadas y no quemadas a lo largo del paisaje depende del tamaño del incendio, y que los principales factores que lo controlan son la velocidad y la dirección del viento (Eberhart y Woodward, 1987; Fryer y Johnson, 1988). A una escala espacial más pequeña, las variables ambientales responsables del mosaico de severidades de quema dentro de las zonas quemadas son las variaciones en la cantidad de combustible y de humedad, y la topografía (Christensen et al., 1989; Turner et al., 1994; Glitzenstein et al., 1995), mientras que, a una escala aún más pequeña, de individuo, las variaciones en la intensidad de quema frecuentemente originan una alto grado de heterogeneidad espacial en la supervivencia de las plantas (Christensen et al., 1989; Schullery, 1989). La intensidad del fuego posee un efecto predictible sobre el número y el tipo de plantas que mueren o son dañadas. Este riesgo de mortalidad está relacionada con el tamaño de las plantas (disminuye cuanto mayor es el individuo; Huston, 1994; Johnson, 1992), y con los mecanismos de resistencia al fuego, la inflamabilidad y las estrategias regenerativas de las especies (McKenzie et al., 1996).Entender las causas de la creación de heterogeneidad espacial postincendio, la distribución de áreas quemadas y no quemadas, el patrón de las diferentes severidades de quema y el patrón de supervivencia de las plantas, es básico para comprender la dinámica de la regeneración postincendio de las especies de las áreas quemadas (Turner, 1998). En el presente estudio se examinan, a diferentes escalas, las consecuencias de un gran incendio ocurrido en el nordeste de España en 1994. En concreto, el objetivo principal del estudio es (1) relacionar la heterogeneidad espacial generada por el comportamiento del fuego con las variaciones topográficas y la composición de la vegetación antes del incendio, y (2) ver los efectos directos, los patrones de supervivencia, que produce sobre las principales especies arbóreas (Pinus halepensis Mill.y Quercus ilex L.). / Forest fires are the most frequent type of natural disturbance in Mediterranean-type ecosystems (Naveh 1975; Gill et al. 1981; Trabaud 1991). As a consequence of different climatic and social factors, the effect of large wildfires (i.e., fires larger than ca. 1000 ha) has increased in the last years (Greenpeace, 1995; Piñol et al., 1998). Thus, 99.7% of the 5279 wildfires that burned in Catalonia (NE Iberian Peninsula) between 1987 and 1994, were smaller than 1000 ha, but only affected 30% of the total surface. The remainder 16 wildfires (0.3% of the total) were large wildfires which burned 70% of the total surface (Terradas et al., 1996).wildfires are fires of high intensity (Huston, 1994), because they are associated with a continuous and extensive forest cover (Huston, 1994; Turner et al., 1994; Piñol et al., 1998), and environmental conditions characterized by large drought periods and strong winds (Terradas and Piñol, 1996; Turner et al., 1997). These large wildfires may have a double effect on the landscape. On the one hand, large fires are so extensive and so severe in some areas that they destroy forest vegetation independently of its density, age and composition (Christensen et al., 1989; Bessie and Johnson, 1995). The result is that the burned lanscape appears more homogeneous than it has been before the fire, because the heterogeneous vegetation patterns generated by the different succesion pathways are syncronized in large areas (Connell and Slatyer, 1980; Huston, 1994). On the other hand, large fires often result in a heterogeneous mosaic of burn severities as well of islands of unburned vegetation across the landscape (Turner et al., 1994, 1997). In their study on the effects of large fires on landscape heterogeneity in Yellowstone National Park, Turner et al. (1994) show that this pattern depends on fire size. The main factors responsible of this pattern are wind velocity and direction (Eberhart and Woodward, 1987; Fryer and Johnson, 1988). At a smaller spatial scale, several controlling environmental variables, such as air moisture, fuel type and topography, determine the mosaic of fire severities within the burned area (Christensen et al., 1989; Turner et al., 1994; Glitzenstein et al., 1995). At an even smaller scale, that of individual, fire intensity affects the number and characteristics of plants that are partially or totally burnt, and frequently originates a high degree of spatial heterogeneity in plant survival (Christensen et al., 1989; Schullery, 1989). This mortality risk decreases with plant size (Huston, 1994; Johnson, 1992), and depends on fire-resistance mechanisms, inflamability and regenerative strategies of species (McKenzie et al., 1996).Postfire spatial heterogeneity, which is determined by the distribution of burned and unburned areas and by the patterns of fire severity and plant survival, is basic to understand postfire regeneration in the burned areas (Turner, 1998). In this paper, we examine the characteristics and consequences on vegetation of a large wildfire that occurred in Catalonia (NE Spain) in 1994. The main objectives of this study are (1) to relate the spacial heterogeneity generated by fire behaviour with topography and prefire vegetation composition, and (2) to analyze the main survival patterns shown by the dominant tree species of the area, Aleppo pine (Pinus halepensis Mill.) and holm oak (Quercus ilex L.).