Genetic resource impacts of habitat loss and degradation; reconciling empirical evidence and predicted theory for neotropical trees

The theoretical impacts of anthropogenic habitat degradation on genetic resources have been well articulated. Here we use a simulation approach to assess the magnitude of expected genetic change, and review 31 studies of 23 neotropical tree species to assess whether empirical case studies conform to theory. Major differences in the sensitivity of measures to detect the genetic health of degraded populations were obvious. Most studies employing genetic diversity (nine out of 13) found no significant consequences, yet most that assessed progeny inbreeding (six out of eight), reproductive output (seven out of 10) and fitness (all six) highlighted significant impacts. These observations are in line with theory, where inbreeding is observed immediately following impact, but genetic diversity is lost slowly over subsequent generations, which for trees may take decades. Studies also highlight the ecological, not just genetic, consequences of habitat degradation that can cause reduced seed set and progeny fitness. Unexpectedly, two studies examining pollen flow using paternity analysis highlight an extensive network of gene flow at smaller spatial scales (less than 10 km). Gene flow can thus mitigate against loss of genetic diversity and assist in long-term population viability, even in degraded landscapes. Unfortunately, the surveyed studies were too few and heterogeneous to examine concepts of population size thresholds and genetic resilience in relation to life history. Future suggested research priorities include undertaking integrated studies on a range of species in the same landscapes; better documentation of the extent and duration of impact; and most importantly, combining neutral marker, pollination dynamics, ecological consequences, and progeny fitness assessment within single studies.

Customers as spatial and social influencers on other customers in the social-servicescape

In marketing, considerable attention has been devoted both to the understanding of consumer behaviour and the impact of the physical environment on the behaviour of consumers within these settings. Yet surprisingly, little attention has been given to the influence of customers on other customers in such settings. But within the environment it could be argued that social stimuli are likely to receive more attention than non-social or physical stimuli (Guerin, 1993). Psychologists have asserted that the mere presence (or absence) of people will affect the behaviour of others. Thus we argue in this paper that customers impact on other customers within the social servicescape. This paper presents the findings of an observational study of 225 episodes which took place within a selected servicescape - four cafes. We found that the presence of other customers appeared to positively influence duration of the stay (social influence), and that customers appeared to exhibit a desire for the presence of other customers in this social setting in that customers appeared to be drawn spatially to where customers were already seated (spatial influence). We draw from psychology, in particular, social facilitation theory (Platania and Morin, 2001; Zajonc, 1965), affiliative conflict theory (Argyle and Dean 1965; Knowles 1980, 1989) and from psychology and sociology in terms of the basic emotional need for a “sense of belonging” (Hagerty, Williams and Oe 2002) in order to develop the conceptual framework for this study. Theoretical and managerial implications of our findings are discussed, as well as directions for further research.