ABSTRACT Prumnopitys andina is a conifer tree species with a narrow distribution in Chile and Argentina. Despite its ecological importance, knowledge about the structure and dynamics of the forests where P. andina grows is limited. We aim to describe the structure and regeneration of forest with high presence of P. andina. Forests near Lonquimay (38°1' S, 71º3' W - 38°3'S, 71°3' W) were sampled by measuring trees, regeneration and vascular flora through 24 plots. We found that P. andina predominantly occurs in the upper canopy (15-18 m), usually in company of Nothofagus obliqua and/or Austrocedrus chilensis, in addition to Maytenus boaria and Lomatia hirsuta that occur in the mid-canopy (4-8 m). Based on forest structure, we identified three types of P. andina forests: open, secondary-mature, and pure. Pure P. andina forests reached basal areas among the largest reported for for temperate forests southern South America (230 m2/ha). P. andina regeneration ranged from 1,550 individuals/ha in open forests to 25,000 individuals/ha in pure forests. P. andina exhibited a continuous regeneration strategy, which in the absence of human disturbances, such as grazing by cattle or selective logging, suggests that its populations are self-sustaining.

RESUMEN Prumnopitys andina (lleuque) es una especie de conífera con una distribución restringida en Chile y Argentina. A pesar de su importancia ecológica, los conocimientos sobre la estructura y dinámica de los bosques donde crece P. andina son limitados. El objetivo de este trabajo fue describir la estructura y regeneración de bosques con alta presencia de P. andina. Se muestrearon bosques cercanos a Lonquimay (38°1' S, 71º3' O - 38°3'S, 71°3' O) midiendo árboles, regeneración y flora vascular a través de 24 parcelas. Se encontró que P. andina ocurre predominantemente en el estrato superior (15-18 m) acompañado por Nothofagus obliqua y/o Austrocedrus chilensis, además de Lomatia hirsuta y Maytenus boaria en estratos intermedios (4-8 m). En base a la estructura, se identificaron tres tipos de bosques de P. andina: bosques abiertos, bosques secundarios adultos y bosques puros. Los bosques puros de P. andina o “lleuquerías” alcanzaron áreas basales entre las más grandes reportadas para bosques templados del sur de Sudamérica (230 m2/ha). La regeneración de P. andina osciló entre 1.550 individuos/ha en bosques abiertos y 25.000 individuos/ha en bosques puros. P. andina exhibió una estrategia de regeneración aparentemente continua, y en ausencia de disturbios antrópicos como pastoreo de ganado o tala selectiva, sus poblaciones serían autosuficientes.

Background: The biobed is a simple biopurification system used to prevent the point-source pesticide contamination that occurs at farm level. The typical composition of the biomixture used in this system is soil, peat and straw in volumetric proportions of 1:1:2. The principal component is straw due to its positive effects on biological activity and thus pesticide degradation. However, access to straw can be limited in some regions, so it must be replaced by other more readily available lignocellulosic residues. Results: Therefore, two alternate lignocellulosic materials (barley husks and pine sawdust) were evaluated as partial substitutes for straw. The degradation of a repeatedly applied mixture of six pesticides by these alternates was assessed. The microbial respiration and fluorescein diacetate (FDA) hydrolysis activity were also assessed. The results showed that the highest degradation efficiency was found in mixtures containing straw and barley husks. Each biomixtures tested achieved a high degradation (50 to 90%) of all the pesticides used except iprodione. Repeated applications of pesticides resulted in a slowing of the degradation rate of all pesticide types in all biomixtures. FDA activity and microbial respiration were higher in the biomixtures containing barley husks and straw compared to the mixture with pine sawdust, a result consistent with the pesticide degradations observed. Conclusions: This paper demonstrates that the straw in the traditional biomixture can be partially replaced by other lignocellulosic materials to efficiently degrade a mixture of pesticides, even when the pesticides are added in successive applications and high concentrations.

Six strains of white-rot fungi isolated from southern Chile were evaluated for their ergosterol/biomass correlation and ligninolytic potential in solid medium to formulate pellets for Reactive Orange 165 (RO165) decolourization. The fungus Anthracophyllum discolor was selected to formulate complex pellets (fungal mycelium, sawdust, and activated carbon), coated pellets (complex pellet + alginate) and simple pellets (fungal mycelium). The activity of ligninolytic enzymes (laccase, manganese peroxidase, manganese-independent peroxidase, and lignin peroxidase) was evaluated in both the complex and coated pellets in modified Kirk medium, and the morphology of the pellets was studied using scanning electron microscopy (SEM). Complex pellets of A. discolor showed a higher enzymatic production mainly MnP (38 U L-1 at day 15) compared to coated and simple pellets. Examinations using SEM showed that both pellets produced a black core that was entrapped by a layer of fungal mycelium. Decolourization of RO165 was demonstrated with all the pellets formulated. However, the highest and fastest decolourization was obtained with complex pellets (100% at day 8). Therefore, complex pellets of A. discolor can be used for the biological treatment of wastewater contaminated with RO165.

Água residual proveniente de uma indústria de tabuleiro de fibra dura caracterizada por ter um elevado conteúdo orgânico (15-30 g/L DQO) foi estudada utilizando um sistema arejado seqüêncial de forma a definir uma estratégia de start up. A concentração de DQO na entrada do sistema variou na faixa de 0,5-25 g/L e o tempo de residência hidráulico foi mantido em 5 dias. O sistema seqüêncial proposto reduziu DBO, DQO, SST e fenol sobre 90% quando a concentração de DQO na entrada foi menor a 25 g/L.

Wastewater from a hardboard mill characterized by a high organic content (15-30 g/L COD) was studied in a bench scale sequential aerated system in order to define a start up strategy. Inlet COD concentration varied from 0.5 to 25 g/L and the hydraulic retention time was maintained at 5 days. The sequential system proposed could reduce BOD, COD, TSS and phenol over 90% except when the inlet COD concentration was lower than 25 g/L.