Trends in research on the possible effects of climate change concerning aquatic ecosystems with special emphasis on the modelling approach

Knowledge on the expected effects of climate change on aquatic ecosystems is defined by three ways. On the one hand, long-term observation in the field serves as a basis for the possible changes; on the other hand, the experimental approach may bring valuable pieces of information to the research field. The expected effects of climate change cannot be studied by empirical approach; rather mathematical models are useful tools for this purpose. Within this study, the main findings of field observations and their implications for future were summarized; moreover, the modelling approaches were discussed in a more detailed way. Some models try to describe the variation of physical parameters in a given aquatic habitat, thus our knowledge on their biota is confined to the findings based on our present observations. Others are destined for answering special issues related to the given water body. Complex ecosystem models are the keys of our better understanding of the possible effects of climate change. Basically, these models were not created for testing the influence of global warming, rather focused on the description of a complex system (e. g. a lake) involving environmental variables, nutrients. However, such models are capable of studying climatic changes as well by taking into consideration a large set of environmental variables. Mostly, the outputs are consistent with the assumptions based on the findings in the field. Since synthetized models are rather difficult to handle and require quite large series of data, the authors proposed a more simple modelling approach, which is capable of examining the effects of global warming. This approach includes weather dependent simulation modelling of the seasonal dynamics of aquatic organisms within a simplified framework.

Bizonytalanság, stratégia és teljesítmény – Kvalitatív kutatás innovatív kis- és középvállalatok vezetői körében (Uncertainty, strategy and performance – Qualitative research in innovative SMEs)

A szerző kvalitatív kutatási módszerekkel vizsgálja a kis- és középvállalatok (kkv-k) innovatív tevékenységeinek korlátait és lehetőségeit. A vizsgálat tárgyai (legalább) Magyarország szintjén új terméket vagy szolgáltatást nyújtó kkv-k, melyek határozott növekedési szándékkal rendelkeznek. Az eredmények egységes vizsgálati keretben, 41 vezető véleménye alapján születtek meg, három területre fókuszálva: (1) a környezeti bizonytalanság megítélése, (2) a szervezet követett stratégiája, kettős képessége, kiaknázó és felderítő tevékenysége, és (3) a versenyképes teljesítménycélok, konfigurációk. A cikk a kutatás lépéseit részletesen bemutatja, fontos eredményének tekinthető, hogy rámutat arra, hogy a kutatási és fejlesztési, valamint az innovatív tevékenységek legfontosabb gátja leginkább a vezetési és szervezési képességek és a stratégiai gondolkodás hiányára vezethető vissza a kis- és középvállalkozásokban. ______ The author conducted a qualitative research on the innovation potential of small and medium size enterprises (SMEs). SMEs with new products and services and with growth orientation are in the focus of the research. The standardized research design is based on 41 owner managers’ responses. It is focusing on 3 main areas: (1) environmental uncertainty, (2) the strategy followed by the organization, its ambidextrous capability, exploitative and explorative behavior, and (3) competitive performance and configurations. The paper describes a qualitative research design in detail. The main finding of the research is that the lack of managerial skills and strategic thinking inhibit SMEs to conduct innovation as well as to engage in research and development activities.

Climate change and plankton phenology in freshwater: current trends and future commitments

A solid body of empirical, experimental and theoretical evidence accumulated over recent years indicated that freshwater plankton experienced advance in phenology in response to climate change. Despite rapidly growing evidence for phenological changes, we still lack a comprehensive understanding of how climate change alters plankton phenology in freshwater. To overcome current limitations, we need to shed some light on trends and constraints in current research. The goal of this study is to identify current trends and gaps based on analysis of selected papers, by the help of which we can facilitate further advance in the field. We searched the literature for plankton phenology and confined our search to studies where climate change has been proposed to alter plankton phenology and rates of changes were quantified. We did not restrict our search for empirical ontributions; experimental and theoretical studies were considered as well. In the following we discuss the spatio-temporal setting of selected studies, contributions of different taxonomic groups, emerging methodological constraints, measures of phenological trends; and finally give a list of recommendations on how to improve our understanding in the field. The majority of studies were confined to deep lakes with a skewed geographical distribution toward Central Europe, where scientists have long been engaged in limnology. Despite these findings, recent studies suggest that plankton in running waters may experience change in phenology with similar magnitude. Average rate of advancement in phenology of freshwater plankton exceeded those of the marine plankton and the global average. Increasing study duration was not coupled either with increasing contribution of discontinuous data or with increasing rates of phenological changes. Future studies may benefit from i) delivering longterm data across scientific and political boundaries; ii) extending study sites to broader geographical areas with a more explicit consideration of running waters; iii) applying plankton functional groups; iv) increasing the application of satellite data to quantify phytoplankton bloom phenology; v) extending analyses of time series beyond the spring period; vi) using various metrics to quantify variation in phenology; vii) combining empirical, experimental and theoretical approaches; and last but not least viii) paying more attention to emergence dynamics, nonresponding species and trophic mismatch.