rangeland ecosystems shift across dynamic thresholds between differentecological states in response to natural or human-induced factors. these differentecological states are the result of interactions among climate, soils, grazing history,and management practices. the notion of a single ‘‘pristine’’ final state is onlyconceptual in nature, and because of this, dynamic thresholds and the effects...

Semi-steppe rangelands are a complex, highly dynamic and often multi-layered mosaic of grassland, shrubland, and intermediate communities. A few recent studies have explicitly or implicitly developed synthetic hypotheses about how interactive effects of human made disturbances initiate dynamic changes in plant community composition to cause a shifting mosaic of vegetation pattern across the lan...

Semi-steppe rangelands are a complex, highly dynamic and often multi-layered mosaic of grassland, shrubland, and intermediate communities. A few recent studies have explicitly or implicitly developed synthetic hypotheses about how interactive effects of human made disturbances initiate dynamic changes in plant community composition to cause a shifting mosaic of vegetation pattern across the lan...

semi-steppe rangelands are a complex, highly dynamic and often multi-layered mosaic of grassland, shrubland, and intermediate communities. a few recent studies have explicitly or implicitly developed synthetic hypotheses about how interactive effects of human made disturbances initiate dynamic changes in plant community composition to cause a shifting mosaic of vegetation pattern across the lan...

We investigate the response of a climate system model to two different methods for estimating snow cover fraction. In the control case, snow cover fraction changes gradually with snow depth; in the alternative scenarios (one with prescribed vegetation and one with dynamic vegetation), snow cover fraction initially increases with snow depth almost twice as fast as the control method. In cases wh...

The presence and continued existence of tidal morphologies, and in particular of salt marshes, is intimately connected with biological activity, especially with the presence of halophytic vegetation. Here, we review recent contributions to tidal biogeomorphology and identify the presence of multiple competing stable states arising from a two-way feedback between biomass productivity and topogra...

We continue investigation of the effect of position in announcements of newly received articles, a single day artifact, with citations received over the course of ensuing years. Earlier work [1, 2] focused on the " visibility " effect for positions near the beginnings of announcements, and on the " self-promotion " effect associated to authors intentionally aiming for these positions, with both...

BACKGROUND Africa is an important part of the global carbon cycle. It is also a continent facing potential problems due to increasing resource demand in combination with climate change-induced changes in resource supply. Quantifying the pools and fluxes constituting the terrestrial African carbon cycle is a challenge, because of uncertainties in meteorological driver data, lack of validation da...

Vegetation modelling has been viewed as a major approach for examining the dynamics of vegetation under climatic change. However, the characterization of uncertainty of model results is still a key issue. In order to improve future model-based research, it is important to synthesize the current approaches and the issues that arise in vegetation modelling and to propose potential strategies for ...