Institut National de la Recherche Agronomique UR874, Unité de Recherche sur l'Ecosystème Prairial, Clermont-Ferrand, France.
Ann Bot. 2010 Jun;105(6):957-65. doi: 10.1093/aob/mcq066. Epub 2010 Mar 30.
Although plant functional traits (PFTs) appear to be important indicators of species' responses to land use changes, there is no clear understanding of how the variations in traits and their plasticity determine variations in species performance. This study investigated the role of functional shoot traits and their plasticity for variation in above-ground net primary productivity (ANPP) due to changes in N supply and in cutting frequency for 13 native perennial C(3) grass species.
Monocultures of the grass species were grown in a fully factorial block design combining plant species, cutting frequency and N supply as factors.
Four major trait associations were obtained by reducing the dimensions of 14 PFTs with a principal component analysis (PCA).Variations in species' productivity in response to an increase in cutting frequency was mainly explained by traits linked to the first PCA axis, opposing high plant stature from lower shoot cellulose and lignin contents and high leaf N content. Variation in species productivity in response to change in N supply was mainly explained by a set of predictor variables combining traits (average flowering date) and a trait's plasticity (tiller density per unit land area and leaf dry matter content, i.e. mg dry matter g fresh mass(-1)). These traits involved are linked to the second PCA axis ('nutrient acquisition-conservation'), which opposes distinct strategies based on response to nutrient supply.
Variations in ANPP of species in response to an increase in cutting frequency and a decrease in N supply are controlled by a group of traits, rather than by one individual trait. Incorporating plasticity of the individual traits into these trait combinations was the key to explaining species' productivity responses, accounting for up to 89 % of the total variability in response to the changes in N supply.
尽管植物功能性状（PFTs）似乎是物种对土地利用变化响应的重要指标，但对于性状变异及其可塑性如何决定物种表现的变异，仍缺乏明确的认识。本研究调查了功能枝性状及其可塑性在 13 种本地多年生 C(3) 草本植物因氮供应变化和刈割频率变化导致的地上净初级生产力（ANPP）变化中的作用。
采用完全析因设计，结合植物种类、刈割频率和氮供应作为因素，对草本植物进行单种栽培。
通过主成分分析（PCA）将 14 种 PFT 降维，得到了四个主要性状关联。物种生产力对刈割频率增加的响应变化主要由与第一 PCA 轴相关的性状决定，高植物株高与低枝纤维素和木质素含量以及高叶片氮含量相反。物种生产力对氮供应变化的响应变化主要由一组结合性状（平均开花日期）和性状可塑性（单位土地面积的分蘖密度和叶片干物质含量，即 mg 干物质 g 鲜质量(-1))的预测变量解释。这些涉及的性状与第二 PCA 轴（“养分获取-保护”）相关，该轴与基于养分供应的响应的不同策略相对立。
物种对刈割频率增加和氮供应减少的 ANPP 变化受一组性状控制，而不是由单个性状控制。将个体性状的可塑性纳入这些性状组合是解释物种生产力响应的关键，占氮供应变化总可变性的 89%。
