Variability of species’ roles in marine communities: change of paradigms for conservation priorities.

The structure and organisation of aquatic communities, moulded in each environment by combinations of abiotic factors, recruitment and productivity rates, rely upon a network of both pairwise and transitive interactions among organisms. In many cases, a few strong interactors drive basic ecological processes by playing a leading role in channelling the available resources. Among these, keystone species may control the outputs of local biodiversity through large indirect effects, disproportionately large relative to their abundance. Functional roles are not fixed labels, and species interactions have variable outputs in both time and space: also, in spite of a growing literature on species interactions, terminology is often poorly applied. This leads to the loss of the informative value of concepts, like the keystone species, which might represent useful trade-offs between science and environmental politics. Species’ roles are often used to set taxonomic conservation priorities, although this might even be regarded as unethical, ecologically wrong, or in disregard of the evolutionary meaning of species coexistence and interaction. A re-assessment of species’ roles is given here, attempting to highlight their limits and applicability. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00227-001-0769-2

The market price of greenness. A factor pricing approach for Green Bonds

Fostered by an empirical literature providing disparate evidence on the green premium, we propose a two-factor model to explain returns on green bonds not only as a function of market risk but also of the bond greenness. The second factor can be interpreted as a greenness premium, which can be either positive or negative depending on the product of the price given by the market to greenness and the sensitivity of the specific green bond to the latter. Based on the model proposed and its Fama-Mac Beth estimation on a sample of Euro-denominated bonds over the period 08.10-2014-31.12.2019, we are able to conclude that the market does price greenness, but the price is very small: including Government green bonds is 0.7 bps, and focusing on corporate green bonds only is – 1.3 bps. In all cases the dynamics of the price for greenness has a positive drift as the market reaches a more mature phase, landing to a positive average value (2 bps), which implies greenness being viewed as a small penalty. However, differences emerge when we look at the issuer sector level and at single bonds, thus our model is able to explain the disparate empirical evidence provided by the literature on the greenium. On the whole, results hint to a market where the difference in pricing between conventional and green bonds is, ceteris paribus, shrinking, which is consistent with greenness becoming a new normal. These results are of interest for many economic agents, including market participants and financial intermediaries, whereby the latter are also called by the regulator to manage their portfolio in consideration of climate risk

Time is an affliction: Why ecology cannot be as predictive as physics and why it needs time series

Ecological systems depend on both constraints and historical contingencies, both of which shape their present observable system state. In contrast to ahistorical systems, which are governed solely by constraints (i.e. laws), historical systems and their dynamics can be understood only if properly described, in the course of time. Describing these dynamics and understanding long-termvariability can be seen as themission of long time series measuring not only simple abiotic features but also complex biological variables, such as species diversity and abundances, allowing deep insights in the functioning of food webs and ecosystems in general. Long timeseries are irreplaceable for understanding change, and crucially inherent system variability and thus envisaging future scenarios. This notwithstanding current policies in funding and evaluating scientific research discourage the maintenance of long term series, despite a clear need for long-term strategies to cope with climate change. Time series are crucial for a pursuit of the much invoked Ecosystem Approach and to the passage from simple monitoring programs of large-scale and long-termEarth observatories — thus promoting a better understanding of the causes and effects of change in ecosystems. The few ongoing long time series in European waters must be integrated and networked so as to facilitate the formation of nodes of a series of observatories which, together, should allowthe long-termmanagement of the features and characteristics of European waters. Human capacity building in this region of expertise and a stronger societal involvement are also urgently needed, since the expertise in recognizing and describing species and therefore recording them reliably in the context of time series is rapidly vanishing from the European Scientific community

Reputational Cues in Repeated Trust Games

The importance of reputation in human societies is highlighted both by theoretical models and empirical studies. In this paper, we have extended the scope of previous experimental studies based on trust games by creating treatments where players can rate their opponents' behavior and know their past ratings. Our results showed that being rated by other players and letting this rating be known are factors that increase cooperation levels even when rational reputational investment motives are ruled out. More generally, subjects tended to respond to reputational opportunities even when this was neither rational nor explainable by reciprocit