A review of studies applying environmental impact assessment methods on fruit production systems

Although many aspects of environmental accounting methodologies in food production have already been investigated, the application of environmental indicators in the fruit sector is still rare and no consensus can be found on the preferred method. On the contrary, widely diverging approaches have been taken to several aspects of the analyses, such as data collection, handling of scaling issues, and goal and scope definition. This paper reviews studies assessing the sustainability or environmental impacts of fruit production under different conditions and identifies aspects of fruit production that are of environmental importance. Four environmental assessment methods which may be applied to assess fruit production systems are evaluated, namely Life Cycle Assessment, Ecological Footprint Analysis, Emergy Analysis and Energy Balance. In the 22 peer-reviewed journal articles and two conference articles applying one of these methods in the fruit sector that were included in this review, a total of 26 applications of environmental impact assessment methods are described. These applications differ concerning e.g. overall objective, set of environmental issues considered, definition of system boundaries and calculation algorithms. Due to the relatively high variability in study cases and approaches, it was not possible to identify any one method as being better than the others. However, remarks on methodologies and suggestions for standardisation are given and the environmental burdens of fruit systems are highlighted.     

Adaptive speciation theory: a conceptual review

Speciation—the origin of new species—is the source of the diversity of life. A theory of speciation is essential to link poorly understood macro-evolutionary processes, such as the origin of biodiversity and adaptive radiation, to well understood micro-evolutionary processes, such as allele frequency change due to natural or sexual selection. An important question is whether, and to what extent, the process of speciation is ‘adaptive’, i.e., driven by natural and/or sexual selection. Here, we discuss two main modelling approaches in adaptive speciation theory. Ecological models of speciation focus on the evolution of ecological differentiation through divergent natural selection. These models can explain the stable coexistence of the resulting daughter species in the face of interspecific competition, but they are often vague about the evolution of reproductive isolation. Most sexual selection models of speciation focus on the diversification of mating strategies through divergent sexual selection. These models can explain the evolution of prezygotic reproductive isolation, but they are typically vague on questions like ecological coexistence. By means of an integrated model, incorporating both ecological interactions and sexual selection, we demonstrate that disruptive selection on both ecological and mating strategies is necessary, but not sufficient, for speciation to occur. To achieve speciation, mating must at least partly reflect ecological characteristics. The interaction of natural and sexual selection is also pivotal in a model where sexual selection facilitates ecological speciation even in the absence of diverging female preferences. In view of these results, it is counterproductive to consider ecological and sexual selection models as contrasting and incompatible views on speciation, one being dominant over the other. Instead, an integrative perspective is needed to achieve a thorough and coherent understanding of adaptive speciation.     

Policy expectations and the use of market mechanisms for regulatory OSH certification and testing regimes

Governments strive increasingly to reduce the ‘burden of legislation’ by shifting responsibilities to private institutions, thereby making use of ‘the market’ as regulating mechanism, and striving to base the relationship with industries on trust, rather then stringent enforcement. This makes mandatory certification and testing arrangements in occupational safety and health (OSH) an attractive alternative for traditional legislation and enforcement. The functioning of such OSH market arrangements has, however, hardly been investigated so far.The research described in this paper elaborated on the same cases that were used in the twin article (Zwetsloot et al., this issue) on risk control in mandatory occupational safety and health certification and testing regimes. In this research we carried out additional analyses on the functioning of market mechanisms in (mandatory) OSH regimes.Other market interests may prevail over the OSH aspect, and the conditions for good market functioning (a well-functioning supply and demand side, independency of the agents, informedness and transparency of the agents, and the added-value of the certificate expressed in the price), are not always met. The results show that policy makers are often too optimistic in their assumptions about the functioning of the market mechanisms in mandatory certification and testing.This does not imply that mandatory certification cannot be an interesting policy option. However, there seems to be a need for a second generation of mandatory certification arrangements, whereby the limitations of the market regulation are recognised, and the consequences are digested.