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It remains unclear whether the latitudinal diversity gradients of micro-and macro-organisms are driven by the same macro-environmental variables. We used the newly completed species catalog and distribution information of bryophytes in China to explore their spatial species richness patterns, and to investigate the underlying roles of energy availability, climatic seasonality, and environmental heterogeneity in shaping these patterns. We then compared these patterns to those found for woody plants. We found that, unlike woody plants, mosses and liverworts showed only weakly negative latitudinal trends in species richness. The spatial patterns of liverwort richness and moss richness were overwhelmingly explained by contemporary environmental variables, although explained variation was lower than that for woody plants. Similar to woody plants, energy and climatic seasonality hypotheses dominate as explanatory variables but show high redundancy in shaping the distribution of bryophytes. Water variables, that is, the annual availability, intra-annual variability and spatial heterogeneity in precipitation, played a predominant role in explaining spatial variation of species richness of bryophytes, especially for liverworts, whereas woody plant richness was affected most by temperature variables. We suggest that further research on spatial patterns of bryophytes should incorporate the knowledge on their ecophysiology and evolution.Key words: biogeography, environmental determinants, latitudinal gradient of diversity, liverworts, micro-organism diversity, mosses.The gradient of increased diversity toward the tropics is observed at various spatial scales and for many taxonomical groups (Willig et al., 2003;Hillebrand, 2004;Field et al., 2009). Understanding the underlying mechanisms of this latitudinal diversity gradient is a major goal in ecology and biogeography (Lomolino et al., 2010). Several hypotheses have been proposed to explain the observed spatial variation of species richness at broad scales (Brown et al., 2004;Wiens & Donoghue, 2004). Among these hypotheses, available energy, climatic seasonality, and environmental heterogeneity have been used most frequently to account for the spatial variation in species richness of plants and animals (Hawkins et al., 2003;Clarke & Gaston, 2006;Kreft & Jetz, 2007;Tello & Stevens, 2010;Chen et al., 2014;Dalby et al., 2014;Stein et al., 2014). The available energy (or energy-water dynamics) hypothesis states that regions with higher energy availability harbor more species. However, the form of the species-energy relationship and the mechanisms involved depend on the spatial scale (Evans et al., 2008), taxonomic group (Chen et al., 2011), taxonomic rank (Mao et al., 2013), and the currency of energy (Evans et al., 2005) under study. This, in turn, has led to several specific hypotheses focusing on different aspects of energy availability (Hawkins et al., 2003;Clarke & Gaston, 2006;Wang et al., 2010), such as the productivity hypothesis (or more individuals hypothesis)...

The extent shape of organisms (body size and the allometry of specific parts) is not only the base for taxonomy, but also the key functional traits for understanding the interaction between organisms and environmental conditions. The geographical variance of body size, allometry, and the underlying mechanisms are fundamental for insect biogeography, but have not been fully documented. In this paper, we compiled data on body size (body length and body width), aspect ratio (body length/body width), and distribution of ladybirds in 28 provinces in China. Meanwhile, we obtained environmental variables representing temperature and precipitation from freely available data. To explore the spatial variance and environmental correlates of body size and aspect ratio in different species groups with various trophic positions, correlation and regression analyses were performed separately on herbivorous and predaceous ladybirds. Our results show that there is evident latitudinal gradient for body size of ladybirds, i.e., body length or width increases with increasing latitude. This is consistent with Bergmann's rule. Temperature-related variables are the main drivers of geographic variance of body size, because ladybirds usually overwinter as adults, and those with larger •研究报告• 776 生 物 多 样 性 Biodiversity Science 第 23 卷

Understanding the drivers of geographic variation in species richness is one of the fundamental goals in ecology and biogeography. Fish is the key element in freshwater ecosystem and the focus of fishery production and biological conservation. Chinese freshwater fish fauna is rich and largely endemic due to variable geography and climate. By compiling the published data on fish richness for 86 nature reserves, and taking environmental predictors into consideration, we aimed to test latitudinal and longitudinal gradients in fish richness and the relative roles of energy availability, physiological tolerance, climatic seasonality and habitat heterogeneity hypotheses in explaining geographic fish richness pattern. Fish richness in China's nature reserves decreases with latitude and showed a hump-shaped relationship with longitude. Latitudinal fish richness is mainly shaped by mean temperature of the coldest month. Mean elevation and associated changes in temperature lead to longitudinal fish richness gradient. Among the four hypotheses tested, physiological tolerance hypothesis performs best and accounts for 55.4 % of the spatial variance in fish richness. Minimum temperature and precipitation are the primary determinants of fish species richness. Habitat heterogeneity is not negligible since adding river density to physiological tolerance model can explain additional 2 % variance in fish richness. Our results can provide useful information for regional fish production and conservation.