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Abstract: In recent years, there has been an increasing interest in the study of climate change effects on plant phenology. However, the effects of other more localized components of global change such as land degradation have been almost completely ignored. In this paper we evaluate the phenological patterns of 10 plant species at three sites with contrasting levels of land degradation due to overgrazing in the Patagonian Monte, Argentina, and their relationship with plant morphology, browsing intensity, and plant competition. Plant phenology differed among sites in eight species, but plant responses were species-specific. In six species the dormancy and senescence periods were shorter indicating longer growing cycles at high degradation than at low degradation site. Generally, plants growing at high degradation site present longer and frequently incomplete vegetative periods and shorter and less dominant reproductive periods than those at low degradation site. However, in some species the duration of reproductive periods was greater in the high degradation site. Plant size (i.e. height, area, and/or internal cover) affected plant phenology in seven species. In contrast, browsing and neighbor''s cover were rarely related to plant phenology. Our results suggest that other global change components such as land degradation may affect plant phenology. [Copyright &y& Elsevier]

Abstract: We provide a position paper, using a brief literature review and some new modelling results for a subset of succulent plant species, which explores why Namaqualand plant diversity might be particularly vulnerable to anthropogenic climate change despite presumed species resilience under arid conditions, and therefore a globally important test-bed for adaptive conservation strategies. The Pleistocene climate-related evolutionary history of this region in particular may predispose Namaqualand (and Succulent Karoo) plant endemics to projected climate change impacts. Key Succulent Karoo plant lineages originated during cool Pleistocene times, and projected air temperatures under anthropogenic climate change are likely to exceed these significantly. Projected rainfall patterns are less certain, and projections of the future prevalence of coastal fog are lacking, but if either of these water inputs is reduced in concert with rising temperatures, this seems certain to threaten the persistence of, at least, narrow-endemic plant species. Simple modelling approaches show strong reduction in spatial extent of bioclimates typical of Namaqualand within the next five decades and that both generalist species with large geographic ranges, and narrow-range endemics may be susceptible to climate change induced loss of potential range. Persistence of endemics in micro-habitats that are buffered from extreme climate conditions cannot be discounted, though no attempts have been made to address this shortcoming of broader scale bioclimatic modelling. The few experimental data available on elevated temperature and drought tolerance suggest susceptibility of leaf succulent species, but high drought tolerance of non-succulent shrubs. Both species-level monitoring and further experimental work is essential to test and refine projections of climate change impacts on species persistence, and the implications for conservation. [Copyright &y& Elsevier]

Abstract: The climatic controls on decomposition rates have gained considerable interest in recent years because of a perceived risk that elevated global temperatures could lead to positive green house gas feedbacks from soil ecosystems. Previous relationships between decomposition rates and abiotic variables like temperature and moisture have been proved confounding, particularly for dryland ecosystems. Decomposition rates of two grass species, Pseudoroegneria spicata (Pursh) Á. Löve and Calamagrostis rubescens Buckley, which represent dominant understory cover at either end of a semi-arid grassland to forest ecocline near Kamloops, British Columbia, Canada, were measured. Despite differences in %N and C:N, decomposition rates between the two species were similar. Elevation was strongly correlated with rate of decomposition for both species. We provide evidence of a positive correlation of water availability and a negative correlation of temperature on decomposition rates along the elevational ecocline. Decomposition rates were higher during the wetter spring period than during summer, at higher elevations and in more mesic ecosystems. We found no ‘home-field’ advantage for P. spicata and C. rubescens on decomposition rates. Our results provide evidence that available moisture is an important control on decomposition rates in dryland ecosystems. [Copyright &y& Elsevier]