Memoria para optar al Título Profesional de Ingeniero de la Madera / Nothofagus obliqua (Mirb.) Oerst (roble o pellín), es una especie que se distribuye desde la Región de Valparaíso hasta la Región de Los Lagos; también habita en Argentina. Esta especie se caracteriza por la alta durabilidad natural que presenta su madera en individuos adultos. Sin embargo, para la madera proveniente de renovales, con diferentes características de color y densidad, no existen antecedentes sobre su comportamiento frente al ataque de hongos de pudrición u otros agentes de biodeterioro. Actualmente, la madera de renovales de roble es sometida a un tratamiento de “vaporizado”, el que tiene como objetivo igualar el color rosado a rojizo del duramen de la madera de renoval, con el rojo oscuro del duramen de roble pellín, mucho más apreciado en el mercado. Con el objetivo de proporcionar antecedentes sobre la durabilidad natural de la madera de renoval de roble y de la influencia del tratamiento de cambio de color (vaporizado), se evaluó la resistencia de estas maderas frente a la acción de hongos de pudrición mediante la pérdida de peso, solubilidad en soda y el % de lignina. Para realizar el estudio se utilizó madera de renoval de roble, empleándose 40 probetas de albura y 40 de duramen. Se aplicó el proceso de vaporizado a 20 probetas de cada grupo, de manera de compararlas con el comportamiento de la madera sin vaporizar frente al ataque del hongo de pudrición blanca Polystictus versicolor y de pudrición café Poria monticola, utilizando además, 20 probetas de roble adulto como testigo. La mitad de las probetas de cada conjunto fue evaluada a los 2 meses (T1) y el resto a los 4 meses (T2) desde el inicio del ataque fúngico. Los resultados indicaron que el vaporizado no tuvo influencia sobre la resistencia de la madera de renoval frente al ataque de P. versicolor, que generó el %PP más alto para todos los tipos de madera a los 2 meses de acción fúngica. Así mismo, el % de solubilidad en soda indicó que el hongo de pudricion blanca provocó el mayor biodeterioro en comparación con el hongo de pudricion café. Para el caso de P. monticola, se observó que el vaporizado tampoco tuvo efecto sobre la resistencia al ataque de pudrición, generándose el mayor biodeterioro a los 4 meses (T2) que a los 2 meses (T1). Esto señaló finalmente, que la madera de renoval de roble no es una madera durable, considerando su resistencia frente al ataque de hongos de pudrición. / Nothofagus obliqua (Mirb.) Oerst (roble o pellín), is a specie allocated from Valparaiso Region to Los Lagos Region, Chile, also it can be found in Argentina. This kind is characterised by its high natural durability of its wood in adults members. Nevertheless, there are not history, for wood from secondary forests, with different characteristics of color and density, about its behaviour against the fungal attack or other biodeterioration agents. Nowadays, the roble wood from secondary forests is subjected to a “steaming” treatment, which aims to equalize pink to reddish heartwood color of the wood from secondary forests, with the dark red of the roble pellin heartwood, much more appreciated in the market. In order to provide history about the natural durability of the roble secondary forest wood, and of the influence of the color change treatment (steaming), the resistance of these woods against the action of fungal through weightloss, soda solubility and the lignin percentage was evaluated. Roble wood (renoval) was used to carry out the research, using 40 test tubes for sapwood and 40 test tubes for heartwood. Steaming process was tested in 20 test tubes of each group to do the comparison with those samples that were not under the process but under the white rot fungi attack Polystictus versicolor and the brown fungi Poria monticola. Also 20 test tubes of old roble were used as reference sample. Half of the samples of each group was checked at two months (T1) and the remaining samples at four months (T2) since the attacks of fungi started. The results shown that the steaming did not affect the wood resistance against the attack of P. versicolor produced the highest %PP for all the samples at 2 months of the test. Moreover, the %S indicated that the white fungi produced a bigger biodeterioration than the brown one. In the case of P. Monticola, it was observed that the steaming had no effect neither about the resistance of fungal attack, generating the greatest deterioration at 4 months (T2) than 2 months (T1). This finally pointed that the roble secondary forest wood is not a durable one, considering its resistance against the fungal attack

Three continuous terrestrial high-resolution palaeoenvironmental records for the Late-glacial and the Holocene have been reconstructed for different ecosystems in Fuego-Patagonia on a longitudinal transect at latitude 53°S. The records describe the nature and extent of environmental and climatic changes inferred from palynological evidence supported by lithostratigraphy, tephrochronology and radiocarbon dating. The environmental changes recorded at the three sites displays a significant degree of synchrony in response to similar large-scale climatic changes. Clear stratigraphical evidence alongside the pollen record indicates a shift to warmer interstadial conditions between c. 14,800 Cal yr BP and 14,400 Cal yrs BP. During the period coeval with ACR the vegetation was dominated by cold resistant dry land herbs such as Poaceae, Asteraceae (Suf. Asteroideae) and Acaena, by c. 13,200 Cal yr BP the vegetation changed from the dominance of cold resistant dry land herbs towards more mesic conditions and the expansion of steppe dominated by Poaceae with patches of Nothofagus forest. The establishment of the forest and an eastward shift of the forest-steppe ecotone by c. 12,500 Cal yr BP from which a gradual shift from colder to warmer conditions and the relatively stronger influences of the SSWs is inferred. The sequence of Late-glacial environmental changes places Fuego-Patagonia within the new palaeoecological data provided by this study includes “the earliest” evidence for the establishment of subantarctic Nothofagus forest during the LGIT in Fuego-Patagonia. During the Early-Holocene two major phases of Nothofagus forest expansion were registered between c. 11,700 - 10,500 Cal yr BP and c. 9,500 - 8,200 Cal yr BP. These intervals of expansion of Nothofagus forest are separated by an interval of forest contraction in response to lower effective moisture between c. 10,500 - 9,500 Cal yr BP. An intense arid phase is inferred between c. 8,250 Cal yr BP and 6,800 Cal yr BP and probably leading to an increase in the amount of dry fuel available during the mid-Holocene in Fuego-Patagonia leading to the highest fire activity promoted by very weak SSWs at this time. The later Holocene was characterised by an increase in humidity and an inferred intensification of the SSWs.

A sustainable approach to restoration of the post-mining landscape involves creating conditions where a viable growth medium can be established with the minimal amount of fertiliser inputs over a period of time. Ideally, this growth medium should comprise a combination of minerals, organic matter, and biological components with have the capacity to retain and release nutrients over time. When combined with a re-vegetation scheme appropriate to the biogeographic area, a self-sustaining ecosystem can be established. Regulatory requirements for mine restoration typically require the use of topsoil, which is often in limited supply. However, overburden is commonly present in vast quantities and has the potential to be used as a restoration substrate with appropriate amendments. There are significant gaps in our understanding of factors relating to the use and amendment of overburden as a growing medium. The main objective of this study was to investigate and quantify the effects of inorganic and organic amendments and weathering on nutrient availability and plant growth in topsoil and overburden material obtained from the OceanaGold Globe Progress mine at Reefton, New Zealand. A series of glasshouse experiments were carried out on topsoil, fresh overburden and mullock (old waste rock) amended with biosolids, green manure, sawdust, lime and mineral fertiliser nutrients (nitrogen (N) and phosphorus (P)). R esults demonstrated that 300 kg N ha⁻¹ was sufficient to overcome N deficiency in topsoil, while 100 kg P ha⁻¹ was required to overcome P deficiency. Addition of biosolids to topsoil and overburden increased plant biomass production, without increasing heavy metal concentrations. Amendment of overburden significantly affected weathering rates by accelerating the formation of secondary minerals. In particular, lupin green manure accelerated the formation of organic iron (Fe) and aluminium (Al) organic complexes, resulting from the decomposition of the green manure and release of Fe from primary minerals. Results revealed that wineberry and red beech required 200 kg N ha⁻¹ for optimum growth. Overall, the findings of this research identified key parameters for effective utilisation of overburden as a restoration substrate. A sustainable restoration method for managing the topsoil and/or any overburden or waste rock material remaining at mine sites can be achieved by careful selection of organic amendments and allowing an initial weathering period.

Using trap data the Hawdon, Poulter and South Branch valleys, a spatial distribution model was created for Stoats (Mustela erminea), Ship Rats (Rattus rattus) and Weasels (Mustela nivalis) in the North Branch of the Hurunui River. Ten spatial attributes were analysed in this thesis as potential spatial predictors of Stoats, Ship rats or Weasels; four of which were distance related measurements (distance from ecotonal edge, distance from river, distance from river tributary and distance from trapping edge); three were climate based variables (mean maximum temperature, mean minimum temperature and mean precipitation) and three were topographical based variables (elevation, aspect and slope). Relationships that existed between each spatial attribute and the number of Stoats, Ship Rats and Weasels caught were quantified by comparing the significance of the mean trapping rate with each spatial attribute and expressed spatially as maps in a Geographical Information System (GIS). Results from this thesis found elevation, aspect and distance from ecotonal edge as potential spatial predictors of Stoat populations. Elevation and aspect were found to be potential predictors of Ship rat and Weasel populations. GIS is able to predict the spatial distribution of pest species to a similar (or better) level compared to more formal associative models. The potential of GIS is however, restrained by the same limitations associated with these models. By using a larger trapping data set and identifying a number of social interactions between Stoats, Ship Rats and Weasels, one can improve the accuracy of spatially modelling each species within a Beech forest environment. Therefore, improve our understanding how landscapes influence the distribution of each pest species.

New Zealand’s isolation and periods of marine transgression have limited its biota to an extent which can be considered depauperate, even by island standards. Endemic vertebrates are rare and prominent invertebrate families, such as the renowned forest defoliators of the Lymantriidae, are absent. The proven vulnerability of the flora to introduced vertebrates reaffirms a belief in the invasiveness of islands and fuels the contingency plans aimed at averting similar devastation from further alien invertebrate defoliators. Nothofagus is a dominant element of the climax forests of New Zealand and the larger landmasses bordering the South Pacific Ocean. Assessments of the resistance to defoliation of continental and New Zealand species of Nothofagus, and a range of other forest genera endemic to New Zealand, was undertaken using bioassays of naïve polyphagous defoliators. The bioassays were undertaken in Europe, utilising gypsy moth, Lymantria dispar (Lepidoptera: Lymantriidae) and the fall webworm, Hyphantria cunea (Lepidoptera: Arctiidae) as defoliators, fed foliage plants growing in European arboreta. In New Zealand, bioassays utilised Australian painted apple moth, Teia anartoides (Lepidoptera: Lymantriidae) and tree species from local arboreta, gardens and natural populations. Larval growth rate was the primary parameter recorded to assess plant resistance. The relevance of growth rate was investigated by comparison with other recorded parameters and resistance to a surrogate pathogen, in the form of commercially available bio-insecticide. Larval growth rate was positively correlated with survivorship, potential fecundity, mating success and resistance to disease. The growth rate of larvae fed Nothofagus was positively correlated to the species-specific leaf nitrogen content. The results of the bioassays showed that despite the accepted paradigms, New Zealand’s flora was largely resistant to exotic defoliators. As an explanation of this apparent anomaly, the Island Resource Allocation (IRA) hypothesis was developed and posits that ‘the palatability iv of a plant to invertebrate herbivores is proportional to the geographic range of the plant’. The basis for the IRA hypothesis proposes a redefinition of the fundamental ecological principle of the species: area relationship. Islands, or similarly geographically constrained ecosystems, which support lower biodiversity, have impoverished trophic levels and consequently have weaker top-down regulation of herbivores by natural enemies. The IRA hypothesis argues that island ecosystem stability is achieved through the bottom-up process of plant defence. The IRA hypothesis was tested intra-specifically using bioassays using painted apple moth in which larvae were offered foliage of specimens from naturally discontinuous populations of Nothofagus truncata. The results supported the hypothesis in that the smallest populations of N. truncata exhibited the greatest resistance to the defoliator. The IRA hypothesis and a demonstrated mechanism for a differential resistance in Nothofagus species could resolve a number of enduring debates in ecology. Habitat area appears to explain the relative strengths of top-down and bottom-up regulation of herbivores. It also predicts the strengths of reciprocal evolution within the geographic mosaic of co-evolution and highlights the influence of biodiversity in invasive ecology. It may also help to resolve the contentious and extremely relevant debate of the role of biodiversity in ecosystem function.

Using trap data the Hawdon, Poulter and South Branch valleys, a spatial distribution model was created for Stoats (Mustela erminea), Ship Rats (Rattus rattus) and Weasels (Mustela nivalis) in the North Branch of the Hurunui River. Ten spatial attributes were analysed in this thesis as potential spatial predictors of Stoats, Ship rats or Weasels; four of which were distance related measurements (distance from ecotonal edge, distance from river, distance from river tributary and distance from trapping edge); three were climate based variables (mean maximum temperature, mean minimum temperature and mean precipitation) and three were topographical based variables (elevation, aspect and slope). Relationships that existed between each spatial attribute and the number of Stoats, Ship Rats and Weasels caught were quantified by comparing the significance of the mean trapping rate with each spatial attribute and expressed spatially as maps in a Geographical Information System (GIS). Results from this thesis found elevation, aspect and distance from ecotonal edge as potential spatial predictors of Stoat populations. Elevation and aspect were found to be potential predictors of Ship rat and Weasel populations. GIS is able to predict the spatial distribution of pest species to a similar (or better) level compared to more formal associative models. The potential of GIS is however, restrained by the same limitations associated with these models. By using a larger trapping data set and identifying a number of social interactions between Stoats, Ship Rats and Weasels, one can improve the accuracy of spatially modelling each species within a Beech forest environment. Therefore, improve our understanding how landscapes influence the distribution of each pest species.

Minimising the potential impact of forest management requires an understanding of the key elements that maintain forest diversity and its role in ecological processes. Invertebrates are the most diverse of all biota and play important roles in maintaining forest processes. However, little is known about invertebrates in New Zealand's beech forests or the degree to which selective beech harvest might impact on their diversity and ability to carry out ecosystem processes. Studying ecosystem responses to disturbance is considered vital for understanding how ecosystems are maintained. One of the main objectives of this research was to assess whether litter-dwelling invertebrates were susceptible to the impacts of selective harvest and, if so, whether they could be used as indicators of forest health. Changes in invertebrate diversity could have important implications for nutrient cycling and primary production in forests. Litter-dwelling invertebrates contribute to the process of decomposition by increasing the surface area of the leaves, mixing soil organic matter and by infecting leaf particles with soil microbes. This investigation into the function of invertebrates in beech forest was carried out in the context of ecological theories which relate diversity to ecosystem stability and resilience. A replicated study was established in Maruia State Forest (South Island, New Zealand) to assess the potential biotic and abiotic impacts of sustainable beech harvest. Litter-dwelling invertebrates and environmental factors were monitored during 1997, before harvest, to determine how much variability there was between study sites. Specifically, litter pH, light intensity, litter fall, litter temperature, moisture as well as invertebrate abundance and diversity were compared before and after selective harvest. On 17 January 1998, two to three trees were selectively harvested from three of the nine study sites. On 15 February 1998 a similar number of trees were winched over or felled manually to create artificial windthrow sites. The remaining three undisturbed sites were used as controls. Invertebrates belonging to the detritivore guild were assessed from litter samples and a series of litter-bags containing pre-weighed leaf litter which were placed in each of the sites to assess rates of litter decomposition. Millipedes (Diplopoda: Polyzoniidae, Schedotrigonidae, Dalodesmidae, Habrodesmidae, Sphaerotheridae), earthworms (Oligochaeta: Annelida), tipulid larvae (Diptera: Tipulidae), weevils (Coleoptera: Curculionidae), moth larvae (Lepidoptera: Oecophoridae, Tortricidae and Psychidae), slaters (Isopoda: Styloniscidae), Oribatid mites (Acarina: Cryptostigmata) and landhoppers (Crustacea: Amphipoda) were extracted from the litter-bags and their abundance and diversity was compared between the three treatments. Weight loss from the litter-bags and the carbon and nitrogen content of litter were used to measure the rate of decomposition in each treatment. An additional study investigated whether exclusion of invertebrates from leaf litter resulted in reduced rates of decomposition. The results indicated that there was an increase in light intensity and a small increase in temperature following selective harvest and artificial windthrow. There was no significant difference in litter moisture or the amount of litter fall between the treatments. Invertebrate abundances were significantly affected by season but did not appear to be affected by selective harvest or artificial windthrow. The diversity of invertebrates remained relatively constant throughout the year, as did the rate of decomposition. When invertebrates were excluded from the leaf litter there was no consequential effect on the rate of litter decomposition. This suggests that there may be compensatory mechanisms taking place between the trophic levels of the food web to maintain processes and that direct links between invertebrates and decomposition are relatively weak. In conclusion, it appears that the effects of selective beech harvest on forest-floor processes were minimal and are comparable to those created by natural windthrow disturbance. It also appears that macroclimatic effects such as seasonal climatic effects have a large effect on forest biota. As none of the invertebrates studied appeared to be detrimentally affected by selective harvest and as there was no direct link demonstrated with decomposition, it was considered inappropriate to advocate the use of this group of invertebrates as indicators of sustainable forest management. The results from this study provide information which may help inform decisions on the future management of diversity in beech forest ecosystems.