The role of plant traits and their plasticity in the response of pasture grasses to nutrients and cutting frequency.

BACKGROUND AND AIMS 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. METHODS Monocultures of the grass species were grown in a fully factorial block design combining plant species, cutting frequency and N supply as factors. KEY RESULTS 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. CONCLUSIONS 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.

[1]  D. Briske.  Strategies of Plant Survival in Grazed Systems : A Functional Interpretation , 2012 .

[2]  C. Roscher,et al.  Differential effects of functional traits on aboveground biomass in semi-natural grasslands. , 2009 .

[3]  Nicolas Gross,et al.  Trade-off between root nitrogen acquisition and shoot nitrogen utilization across 13 co-occurring pasture grass species , 2009 .

[4]  J. Funk.  Differences in plasticity between invasive and native plants from a low resource environment , 2008 .

[5]  H. Kroon,et al.  Variation in petiole and internode length affects plant performance in Trifolium repens under opposing selection regimes , 2008, Evolutionary Ecology.

[6]  P. Carrère,et al.  Seasonal productivity and nutritive value of temperate grasses found in semi-natural pastures in Europe: responses to cutting frequency and N supply , 2007 .

[7]  S. Lavorel,et al.  Incorporating plant functional diversity effects in ecosystem service assessments , 2007, Proceedings of the National Academy of Sciences.

[8]  Frédérique Louault,et al.  Leaf traits affect the above-ground productivity and quality of pasture grasses , 2007 .

[9]  S. Lavorel,et al.  Leaf dry matter content and lateral spread predict response to land use change for six subalpine grassland species , 2007 .

[10]  Eric Garnier,et al.  Components of nutrient residence time and the leaf economics spectrum in species from Mediterranean old‐fields differing in successional status , 2007 .

[11]  Daniel G. Milchunas,et al.  Plant trait responses to grazing – a global synthesis , 2007 .

[12]  S. Lavorel,et al.  PLANT TRAITS IN A STATE AND TRANSITION FRAMEWORK AS MARKERS OF ECOSYSTEM RESPONSE TO LAND-USE CHANGE , 2007 .

[13]  Valentí Rull,et al.  Unexpected biodiversity loss under global warming in the neotropical Guayana Highlands: a preliminary appraisal , 2006 .

[14]  Laíse da Silveira Pontes.  Diversité fonctionnelle des graminées prairiales: conséquences pour la productivité et pour la valeur nutritive , 2006 .

[15]  V. Eviner.  Plant trait responses to grazing – a global synthesis , 2006 .

[16]  S. Sugiyama.  Relative contribution of meristem activities and specific leaf area to shoot relative growth rate in C3 grass species , 2005 .

[17]  Are grazing increaser species better tolerators than decreasers? An experimental assessment of defoliation tolerance in eight British grassland species , 2005 .

[18]  S. Plantureux,et al.  Variation in leaf traits through seasons and N-availability levels and its consequences for ranking grassland species , 2005 .

[19]  P. Reich,et al.  Assessing the generality of global leaf trait relationships. , 2005, The New phytologist.

[20]  J. Soussana,et al.  Plant traits and functional types in response to reduced disturbance in a semi‐natural grassland , 2005 .

[21]  G. Posse,et al.  Plant functional traits, herbivore selectivity and response to sheep grazing in Patagonian steppe grasslands , 2005 .

[22]  Universitde Bordeaux.  Stress tolerance abilities and competitive responses in a watering and fertilization field experiment , 2005 .

[23]  Eric Garnier,et al.  PLANT FUNCTIONAL MARKERS CAPTURE ECOSYSTEM PROPERTIES DURING SECONDARY SUCCESSION , 2004 .

[24]  Sean C. Thomas,et al.  The worldwide leaf economics spectrum , 2004, Nature.

[25]  Mark Westoby,et al.  A leaf-height-seed (LHS) plant ecology strategy scheme , 1998, Plant and Soil.

[26]  P. Reich,et al.  A handbook of protocols for standardised and easy measurement of plant functional traits worldwide , 2003 .

[27]  H. Schnyder,et al.  Components of leaf elongation rate and their relationship to specific leaf area in contrasting grasses , 2003 .

[28]  Peter B Reich,et al.  Variation in growth rate and ecophysiology among 34 grassland and savanna species under contrasting N supply: a test of functional group differences. , 2003, The New phytologist.

[29]  Katharine N. Suding,et al.  RELATIONSHIPS AMONG SPECIES TRAITS: SEPARATING LEVELS OF RESPONSE AND IDENTIFYING LINKAGES TO ABUNDANCE , 2003 .

[30]  G. Ågren,et al.  Leaf senescence and resorption as mechanisms of maximizing photosynthetic production during canopy development at N limitation , 2002 .

[31]  S. Lavorel,et al.  Predicting changes in community composition and ecosystem functioning from plant traits: revisiting the Holy Grail , 2002 .

[32]  P. Reich,et al.  Functional traits, productivity and effects on nitrogen cycling of 33 grassland species , 2002 .

[33]  E. Garnier,et al.  A standardized protocol for the determination of specific leaf area and leaf dry matter content , 2001 .

[34]  Michel Loreau,et al.  Partitioning selection and complementarity in biodiversity experiments , 2001, Nature.

[35]  S. Díaz,et al.  Can grazing response of herbaceous plants be predicted from simple vegetative traits , 2001 .

[36]  David Tilman,et al.  The relationships among root and leaf traits of 76 grassland species and relative abundance along fertility and disturbance gradients , 2001 .

[37]  S. Sultan.  Phenotypic plasticity for plant development, function and life history. , 2000, Trends in plant science.

[38]  A. S. Evans,et al.  The Evolution of Plant Ecophysiological Traits: Recent Advances and Future Directions , 2000 .

[39]  P. S. Karlsson,et al.  Leaf life span and nutrient resorption as determinants of plant nutrient conservation in temperate‐arctic regions , 1999 .

[40]  K. Thompson,et al.  Specific leaf area and leaf dry matter content as alternative predictors of plant strategies , 1999 .

[41]  Hendrik Poorter,et al.  A comparison of specific leaf area, chemical composition and leaf construction costs of field plants from 15 habitats differing in productivity , 1999 .

[42]  V. Gutschick.  Biotic and abiotic consequences of differences in leaf structure , 1999 .

[43]  M. Westoby.  The LHS strategy scheme in relation to grazing and fire , 1999 .

[44]  S. Lavorel,et al.  Plant functional classifications: from general groups to specific groups based on response to disturbance. , 1997, Trends in ecology & evolution.

[45]  P. Reich,et al.  The Influence of Functional Diversity and Composition on Ecosystem Processes , 1997 .

[46]  Peter Ryser,et al.  The importance of tissue density for growth and life span of leaves and roots: a comparison of five ecologically contrasting grasses , 1996 .

[47]  P. Reich,et al.  Leaf Life‐Span in Relation to Leaf, Plant, and Stand Characteristics among Diverse Ecosystems , 1992 .

[48]  D. Tilman.  Relative Growth Rates and Plant Allocation Patterns , 1991, The American Naturalist.

[49]  Roderick Hunt,et al.  Comparative Plant Ecology: A Functional Approach to Common British Species , 1989 .

[50]  J. P. Grime,et al.  Evidence for the Existence of Three Primary Strategies in Plants and Its Relevance to Ecological and Evolutionary Theory , 1977, The American Naturalist.

[51]  H. Akaike,et al.  Information Theory and an Extension of the Maximum Likelihood Principle , 1973 .