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.

Psychic Punishment Costs and Deterrence

In this paper we analyze criminal deterrence in the presence of specific psychic costs of punishments. We consider a dynamic model with three players, analyzing the choices of a representative lawmaker, potential criminal and judge. In our setting the lawmaker decides whether to introduce a fixed punishment enhancement above a chosen threshold of crime level, depending on its popularity among the voters. In reaction, the judge, who is influenced by her own preferences as well as the opinion of her peer group, might change the probability of punishment, through affecting the standard of reasonable doubt. Our results suggest that large discontinuous and mandatory increases in punishment can have unintended effects that are contrary to the stated goal of such punishment enhancements. In equilibrium, when either the judge or her peer group is "anti-punishment" enough, the level of criminal activity might increase in response to the punishment enhancement. This perverse effect is less likely to occur if there is a higher number of peer groups within the "elite", so that a greater extent of self-selection by judges can occur. Our results have relevance for a number of areas outside the traditional criminal justice system as well, such as special courts (such as ecclesiastical or military courts), or the strictness and enforcement of regulations.