Data from: Ecological sorting and character displacement contribute to the structure of communities of Clarkia species

Despite long‐standing interest in the evolutionary ecology of plants that share pollinators, few studies have explored how these interactions may affect communities during both community assembly (ecological sorting) and through ongoing, in situ evolution (character displacement), and how the effects of these interactions may change with community context. To determine if communities display patterns consistent with ecological sorting, we assessed the frequency of co‐occurrence of four species of Clarkia in the southern Sierra foothills (Kern County, CA, USA). To investigate potential character displacement, we measured pollination‐related traits on plants grown in a greenhouse common garden from seed collected in communities with one, two, or four Clarkia species. Among the four species of Clarkia in this region, the two species that are often found in multi‐species communities also co‐occur with one another more frequently than expected under a null model. This pattern is consistent with ecological sorting, although further investigation is needed to determine the role of pollinators in shaping community assembly. Patterns of trait variation in a common garden suggest that these two species have diverged in floral traits and converged in flowering time where they co‐occur, which is consistent with character displacement. Trait variation across community types also suggests that the process and outcome of character displacement may vary with community context. Because community context appears to affect both the direction and magnitude of character displacement, change in more species‐rich communities may not be predictable from patterns of change in simpler communities.

尽管学界长期关注共享传粉者的植物的进化生态学研究，但目前鲜有文献探讨这类物种互作如何在群落构建（生态分选，ecological sorting）阶段，以及通过持续的原位进化（性状替换，character displacement）过程中影响群落结构，且尚未厘清这类互作的效应如何随群落背景发生变化。为验证群落是否呈现符合生态分选的分布模式，我们在美国加利福尼亚州克恩县的内华达山脉南部山麓区域，调查了4种克拉花属（Clarkia）植物的共存频率。为探究潜在的性状替换现象，我们从仅分布有1种、2种或4种克拉花属植物的群落中采集种子，于温室同质园（common garden）中培育植株，并测定其传粉相关性状。在该区域的4种克拉花属植物中，两类常出现在多物种种落中的物种，其彼此间的共存频率高于零模型（null model）下的预期值。这一分布模式符合生态分选的理论预期，尽管仍需进一步研究以明确传粉者在调控群落构建中的具体作用。同质园实验中的性状变异模式显示，这两个物种在共存区域的花部性状发生了分化，而开花时间则趋于趋同，这与性状替换的理论预测相符。不同群落类型间的性状变异也提示，性状替换的过程与结果可能随群落背景产生差异。由于群落背景似乎同时影响性状替换的方向与强度，物种更丰富的群落的变化规律，或无法从结构更简单的群落的变化模式中直接推导得出。