Generalizing the effect of traits on performance across species may be achievable if traits explain variation in population fitness. However, testing relationships between traits and vital rates to infer effects on fitness can be misleading. Demographic trade-offs can generate variation in vital rates that yield equal population growth rates, thereby obscuring the net effect of traits on fitness. To address this problem, we describe a diversity of approaches to quantify intrinsic growth rates of plant populations, including experiments beyond range boundaries, density-dependent population models built from long-term demographic data, theoretical models, and methods that leverage widely available monitoring data. Linking plant traits directly to intrinsic growth rates is a fundamental step toward rigorous predictions of population dynamics and community assembly.

如果性状可以解释种群适应度的变化，那么概括性状对跨物种表现的影响可能是可以实现的。然而，测试性状和生命率之间的关系以推断对健康的影响可能会产生误导。人口统计学的权衡可能会产生相同的人口增长率的生命率变化，从而掩盖性状对健康的净影响。为了解决这个问题，我们描述了量化植物种群内在增长率的多种方法，包括超出范围边界的实验、根据长期人口统计数据构建的密度依赖种群模型、理论模型以及利用广泛可用的监测数据的方法.