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Summary 1.Gradients of animal impact known as piospheres tend to develop around artificial watering points, particularly in arid zones. Such grazing gradients represent a potential opportunity for differentiating the long-term effects of livestock activity from other environmental patterns. In this study, the impact of watering point provision on the plant cover, species richness and community structure of Karoo shrublands, South Africa, was investigated in the context of the evolutionary history and current grazing management practices of the region. 2. The impacts of watering point provision were investigated by sampling plant cover and composition along transects placed at set distances, ranging from 10 m to 2200 m, from 11 watering points. 3. Karoo vegetation cover and structure are relatively resilient to livestock grazing. Karoo plant diversity, as measured by species richness, evenness and dominance, was not as resilient. Twice as many species decreased as increased near watering points. The majority of species that decreased were regarded as being highly palatable to livestock. Heavy grazing, leading to death or repeated reproductive failure, is the most likely mechanism leading to the decline of such species. 4. The highly disturbed area immediately adjacent to watering points was dominated by forbs and contained a large proportion of alien species. Adjacent to this was a zone dominated by widespread shrub species of medium to low palatability. Areas most distant from watering points contained a greater proportion of species known to be highly palatable to livestock. The ability of dominant Karoo shrubs to tolerate heavy grazing may have allowed rangeland managers to maintain stocking rates above that which can be tolerated by the majority of species but which are supported by a minority of grazing-tolerant species. 5. Synthesis and applications. Highly palatable species are more abundant in areas distant from water points. Larger paddocks therefore provide a refuge for sensitive species that might otherwise be lost from the rangeland as a whole. Species that tend to occur away from watering points represent potentially useful indicators of grazing pressure. The use of these species as indicators of rangeland condition among landowners should be promoted.

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We investigate implicit vocabulary learning by adults who are exposed to a language in their ambient environment. Most New Zealanders do not speak Māori, yet are exposed to it throughout their lifetime. We show that this exposure leads to a large proto-lexicon – implicit knowledge of the existence of words and sub-word units without any associated meaning. Despite not explicitly knowing many Māori words, non-Māori-speaking New Zealanders are able to access this proto-lexicon to distinguish Māori words from Māori-like nonwords. What's more, they are able to generalize over the proto-lexicon to generate sophisticated phonotactic knowledge, which lets them evaluate the well-formedness of Māori-like nonwords just as well as fluent Māori speakers.