Many indices to assess ecosystem health involve conservatism scores (C-scores), which are assigned to individual plant species by expert regional botanists and are intended to provide a semi-quantitative metric of a species’ tolerance to environmental perturbation. However, C-scores are based on expert opinion and cannot be generalized because they are not based on explicit physiological or ecological information. Here, we examine the relationship between C-scores and plant functional traits to evaluate whether C-scores could be predicted by the morphology, life history, dispersal, reproduction, disturbance tolerance, or resource use efficiency of plant species. We compiled data on 27 such functional traits for 1042 plant species inhabiting the Northern Great Plains ecoregion of USA and Canada. We found significant relationships between C-score and several functional traits. Fire- and salt-tolerant species had C-scores 3.5 and 2 units lower than intolerant species; shade-tolerant species had C-scores 4 units higher than intolerant species. Species sensitive to environmental perturbation (i.e. with high C-score) generally had traits associated with low dispersal ability and germination success, slow growth rates, and high resource use efficiency. For example, species which propagate only vegetatively had average C-scores 4.5 units higher than species which propagate only by seed; germination success was 10% lower for species with the highest versus lowest C-scores; species with slow growth rates had average C-scores 4 units higher than species with fast growth rates; and leaf nitrogen content was 25% lower for species with the highest versus lowest C-scores. These findings illustrate the connection between C-scores and plant functional traits and suggest that C-scores may be extrapolated to other species with consistent traits. Further, linking functional traits to C-scores can improve predictions of how plants might respond to altered environmental conditions.

许多评估生态系统健康的指数都涉及保守性分数（C分数），该分数由专业的区域植物学家分配给单个植物物种，目的是提供一种物种对环境扰动的耐受性的半定量指标。但是，C分数基于专家意见，因此不能一概而论，因为它们不是基于明确的生理或生态信息。在这里，我们研究了C分数与植物功能性状之间的关系，以评估C分数是否可以通过植物的形态，生活史，传播，繁殖，抗干扰性或资源利用效率来预测。我们收集了居住在美国和加拿大北部大平原生态区的1042种植物的27种此类功能性状的数据。我们发现C得分与几个功能性状之间存在显着的关系。耐火和耐盐的物种的C分数比不耐性的物种低3.5和2个单位。耐荫物种的C分数比不耐物种高4个单位。对环境扰动敏感的物种（即具有高C分数）通常具有与低分散能力和发芽成功，缓慢的生长速率以及较高的资源利用效率相关的特征。例如，仅通过营养繁殖的物种的平均C分数比仅通过种子繁殖的物种高4.5个单位；具有最高C分数与最低C分数的物种的发芽成功率降低了10％；生长缓慢的物种的平均C分数比生长迅速的物种高4个单位；C分数最高和最低的物种的叶氮含量降低了25％。这些发现说明了C分数与植物功能性状之间的联系，并暗示C分数可能外推至具有一致性状的其他物种。此外，将功能性状与C评分相关联可以改善对植物可能如何响应环境变化的预测。