Humans increase the number, magnitude, and pace of environmental stressors on ecological communities, yet we do not know how natural communities will respond. Functional trait-based analyses are powerful tools for understanding how species and communities may respond to future stress. In many regions, winter weather is changing faster than weather in other seasons and although cold tolerance has long been a trait of interest to ecologists, it is often overlooked in many temperate systems. Here, we examine the relationship between cold tolerance and other common plant functional traits related to persistence and dispersal. We predicted that for prairie species, cold tolerance would be positively correlated with traits associated with persistence and a conservative growth strategy. We also predicted that bird-dispersed woody plants would exhibit greater cold tolerance than species with other dispersal modes. To test our first prediction, we measured cold tolerance and persistence traits for 120 prairie species. To test our second prediction, we measured cold tolerance of woody vines and trees with different dispersal modes.
Results/Conclusions
Among the 120 prairie plant species tested, cold tolerance, measured as LT50 of leaf tissues, ranged from -6 to -12 °C and was associated with the traits of the leaf economic spectrum in predictable ways. Leaves with greater internal structure (e.g., high leaf dry matter content and leaf mass per area) were also more cold tolerant. In addition, more cold tolerant species were also more often found in sites with frequent prescribed fire. Regional patterns of dispersal mode of woody vine species indicated that northern species are primarily bird-dispersed while southern communities are a mix of biotically and abiotically dispersed species. Bird-dispersed species may be more cold tolerant than abiotically dispersed species. For temperate ecosystems, knowing both species cold tolerance and its relation to other traits, such as persistence and dispersal ability, can help us understand the composition of future communities in an era of global change.