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An experiment comprising seven clones with four levels of weed competition was established on a semiarid site on the Canterbury plains, New Zealand, during September 1996. Previous experiments showed that trees subjected to little competition from weeds did not always respond to their favourable environments, resulting in more variation amongindividuals subjected to less competition. The aim of this experiment was to determine whether the variable response to competitive environment is partly a genetic effect. The main plots consisted of four levels of competition: no competition and cleared spots: 3.14, 0.75, and 0.03 m2. Within each plot there were 10 individuals of each clone. Trees generally grew more rapidly with increasing amountsof clear ground, but increasing spots beyond 3.14 m2 did not increase growth during the first year. Variation, expressed as coefficient of variation, was greater among trees subjected to more competition. Within clone coefficient of variation was not related to level of competition. [ABSTRACT FROM AUTHOR]

Data from 27 site preparation experiments were used to construct a model that predicts growth, survival and size class distributions of radiata pine with respect to altitude, weed control, cultivation, fertilisation, and initial stocking during the first five years after planting. Only stand values, however, are used in this paper. The question of linking the model with existing growth and yield models for older crops is discussed, and a theoretical structure is proposed that clarifies assumptions required if the models are jointly used to evaluate the worth of establishment practices throughout complete crop rotations. It was found that the initial growth model generally predicted similar basal area growth rates to those of the Pumice Plateau Model (PPM88), a growth model for older crops, in age ranges where the two models overlapped, but some of the assumptions required for rotation-length analyses need further testing. Measurements over 8 years in a designed experiment examining alternative site preparation strategies showed that PPM88 was insensitive to the effects of site preparation in predicting growth that occurred after the establishment phase. [ABSTRACT FROM AUTHOR]

Aims: Use of synthetic cannabinoids is associated with a range of mental health harms. The 2013 Psychoactive Substances Act (PSA) was intended to limit retail availability of synthetic cannabinoids which had acceptable safety profiles. We evaluated numbers and clinical characteristics of patients presenting with mental health harms associated with use of synthetic cannabinoids for three months before and after implementation of the PSA on 18July 2013., Methods: Retrospective audit of case notes of patients presenting to an emergency psychiatric service (EPS) in Dunedin., Results: In the three months post-PSA, there was a 42% reduction in EPS contacts and 52% reduction in patient presentations, compared with the three months pre-PSA. Patient demographics (predominantly young males with prior contact with mental health services), presenting symptoms (mood and psychotic symptoms and suicidality), and management and disposition were identical in both periods., Conclusions: The decrease in mental health harms, as measured by frequency of EPS contacts, appeared to be due to reduced retail availability of synthetic cannabinoids rather that reduced toxicity of available products.