Environmental constraints on life histories in Antarctic ecosystems: tempos, timings and predictability

first_imgKnowledge of Antarctic biotas and environments has increased dramatically in recent years. There has also beena rapid increase in the use of novel technologies. Despite this, some fundamental aspects of environmental controlthat structure physiological, ecological and life-history traits in Antarctic organisms have received little attention.Possibly the most important of these is the timing and availability of resources, and the way in which this dictatesthe tempo or pace of life. The clearest view of this effect comes from comparisons of species living in differenthabitats. Here, we (i) show that the timing and extent of resource availability, from nutrients to colonisable space,differ across Antarctic marine, intertidal and terrestrial habitats, and (ii) illustrate that these differences affect therate at which organisms function. Consequently, there are many dramatic biological differences between organismsthat live as little as 10 m apart, but have gaping voids between them ecologically.Identifying the effects of environmental timing and predictability requires detailed analysis in a wide context,where Antarctic terrestrial and marine ecosystems are at one extreme of the continuum of available environmentsfor many characteristics including temperature, ice cover and seasonality. Anthropocentrically, Antarctica isharsh and as might be expected terrestrial animal and plant diversity and biomass are restricted. By contrast,Antarctic marine biotas are rich and diverse, and several phyla are represented at levels greater than globalaverages. There has been much debate on the relative importance of various physical factors that structure thecharacteristics of Antarctic biotas. This is especially so for temperature and seasonality, and their effects onphysiology, life history and biodiversity. More recently, habitat age and persistence through previous ice maximahave been identified as key factors dictating biodiversity and endemism. Modern molecular methods have alsorecently been incorporated into many traditional areas of polar biology. Environmental predictability dictatesmany of the biological characters seen in all of these areas of Antarctic research.last_img

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