6 research outputs found
Presence of competitors influences photosynthesis, but not growth, of the hard coral Porites cylindrica at elevated seawater CO2
Changes in environmental conditions, such as those caused by elevated carbon dioxide (CO2), potentially alter the outcome of competitive interactions between species. This study aimed to understand howelevated CO2 could influence competitive interactions between hard and soft corals, by investigating growth and photosynthetic activity of Porites cylindrica (a hard coral) under elevated CO2 and in the presence of another hard coral and two soft coral competitors. Coralswere collected from reefs around Orpheus and Pelorus Islands on the Great Barrier Reef, Australia. They were then exposed to elevated pCO2 for 4 weeks with two CO2 treatments: intermediate (pCO2 648) and high (pCO2 1003) compared with a control (unmanipulated seawater) treatment (pCO2 358). Porites cylindrica growth did not vary among pCO2 treatments, regardless of the presence and type of competitors, nor was the growth of another hard coral species, Acropora cerealis, affected by pCO2 treatment. Photosynthetic rates of P. cylindrica were sensitive to variations in pCO2, and varied between the side of the fragment facing the competitors vs. the side facing away from the competitor. However, variation in photosynthetic rates depended on pCO2 treatment, competitor identity, and whether the photosynthetic yields were measured as maximum or effective photosynthetic yield. This study suggests that elevated CO2 may impair photosynthetic activity, but not growth, of a hard coral under competition and confirms the hypothesis that soft corals are generally resistant to elevated CO2. Overall, our results indicate that shifts in the species composition in coral communities as a result of elevated CO2 could be more strongly related to the individual tolerance of different species rather than a result of competitive interactions between species
Unusual ionospheric variations before the strong Auckland Islands, New Zealand earthquake of 30th September, 2007
Learning in small manufacturing firms: the case of investment decision-making behaviour
This article is concerned with investment decision-making processes in small manufacturing enterprises.The study, on which the article is based, used `insider accounts' as an innovative, qualitative methodology, involving in-depth, semi-structured interviews and direct observation, conducted longitudinally in eight case study companies. It is a research method which includes detailed accounts from the actors themselves, incorporating their actual motives and behaviour. Data from two case study firms is presented in the article to demonstrate different types of learning behaviour.The findings suggest that conceptualizing investment decision-making processes in small firms within the context of organizational learning holds promise as an explanatory framework for investment behaviour in small firms