Effects of disturbance frequency and severity on plant traits: An assessment across a temperate flora

Abstract

Recent analyses of plant traits across large sets of species have revolutionized our understanding of plant functional differentiation. However, understanding of ecological relevance of this differentiation is contingent upon knowledge of environmental preferences of species, namely along gradients of disturbance and productivity for which no quantitative data were available until recently. We examined the relationships of key functional traits (life-history categories, leaf-height-seed (LHS) traits, clonal growth and bud bank traits) in the herb-dominated flora of Central Europe to species niche positions along the gradients of disturbance frequency, disturbance severity and productivity. Life-history categories and bud bank size showed the strongest response to disturbance and productivity, whereas relationship of LHS traits was much weaker. A number of traits, including clonal growth form and bud bank size, showed a significantly unimodal response to disturbance frequency. Responses of many traits to disturbance frequency were different from their responses to disturbance severity. Our findings support the notions that disturbance and productivity are key gradients of species functional differentiation and that disturbance severity and frequency select for different trait suites. Furthermore, the data indicate that in a predominantly herbaceous flora, the traits of life span, clonal growth and resprouting show stronger relationship with the environment than the LHS traits, which are more important in floras with high proportions of woody species. Since most previous trait analyses are based on woody-plant-dominated floras, patterns revealed in a herb-dominated flora deepen our understanding of the full range of variation within the plant kingdom. A plain language summary is available for this article.