A major goal of evolutionary biology and ecology is to understand why species richness varies among clades. Previous studies have suggested that variation in richness among clades might be related to variation in rates of morphological evolution among clades (e.g., body size and shape). Other studies have suggested that richness patterns might be related to variation in rates of climatic-niche evolution. However, few studies, if any, have tested the relative importance of these variables in explaining patterns of richness among clades. Here, we test their relative importance among major clades of Plethodontidae, the most species-rich family of salamanders. Earlier studies have suggested that climatic-niche evolution explains patterns of diversification among plethodontid clades, whereas rates of morphological evolution do not. A subsequent study stated that rates of morphological evolution instead explained patterns of species richness among plethodontid clades (along with "ecological limits" on richness of clades, leading to saturation of clades with species, given limited resources). However, they did not consider climatic-niche evolution. Using phylogenetic multiple regression, we show that rates of climatic-niche evolution explain most variation in richness among plethodontid clades, whereas rates of morphological evolution do not. We find little evidence that ecological limits explain patterns of richness among plethodontid clades. We also test whether rates of morphological and climatic-niche evolution are correlated, and find that they are not. Overall, our results help explain richness patterns in a major amphibian group and provide possibly the first test of the relative importance of climatic niches and morphological evolution in explaining diversity patterns.

The state energy conception sets the direction in energy industry and outlines main instruments and trends in this area. The priority of the state energy conception is to reach energy security of the country, which can be ensured by more energy resources of the fuel mix. The main component of the domestic energy mix is brown coal, which is mostly used in brown coal electric works for generating electric energy and heat. Coal mining is and was one of the main elements of Czech Republic's national industry, but there are also negative ecological impacts connected with coal winning. Further coal mining is restricted by so-called territorial ecological limits for brown coal mining that protect the environment and community against the mining consequences. Many of the brown coal supplies can, however, also in future represent an important energy resource, which will enable security, production independence and price availability of energy. At work is further explanation of the limits and progress of breaking the limits. Other energy resources are nuclear energy and renewable energy resources, whose importance rises and which contribute to a balanced energy mix.