Summary1. Nutrient availability, defoliation and soil disturbance are important factors that influence the richness of plant communities. However, few studies have examined the interactions between these factors, especially in harsh environments. We therefore examined the effects of fertilization, defoliation and soil disturbance on plant species richness in an alpine meadow in northern Sweden. 2. From 2002 to 2005, plots were fertilized, mowed and disturbed annually in a factorially designed experiment. Plant species richness, colonization and extinction were recorded in permanent subplots. Seedling densities and recruitment from seed of Potentilla crantzii were also estimated in order to examine the mechanisms whereby these treatments influence colonization by new species. 3. Species richness peaked in the absence of disturbance in unfertilized plots and with light disturbance in fertilized plots. Colonization by new vascular plant species, seed recruitment and seedling density were all increased by soil disturbance, suggesting that colonization was increased because conditions were more favourable for seed recruitment following the disturbance treatment. Extinction of species was highest in the mowed, intensively disturbed and unfertilized plots and lowest in the fertilized, lightly disturbed and unmowed plots. 4. Local extinction was negatively correlated with both moss and vascular plant biomass. Local colonization, seedling density and recruitment of P. crantzii were all strongly negatively correlated with the biomass of mosses. In contrast, the biomass of vascular plants was only weakly correlated with local colonization, seedling density and recruitment of P. crantzii. 5. This study suggest that the level of disturbance at which species richness peaks should move towards higher disturbance levels when productivity increases. However, lower extinction rates rather then higher colonization rates seem to be causing the increase in species richness following disturbance.
Up to 7% of eyes implanted with FineVision trifocal IOLs had a hyperopic shift of greater than +0.75 D approximately 2 weeks to 3 months postoperatively. Using a CTR in MicroF eyes had no statistically significant effect on refractive stability. Placing a CTR with POD FT IOLs appeared to reduce refractive stability, although not significantly. [J Refract Surg. 2017;33(12):802-806.].
A clinically and statistically significant difference in PCO development between CeeOn Edge and SI40NB IOLs at 2 and 3 years postoperatively was found. These findings support earlier studies indicating that a sharp edge of the optic is a more important factor in IOL design than IOL material in the prevention of PCO.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.