Impact of abundance weighting on the response of seed traits to climate and land use

1 Many studies have identified relationships between plant reproductive behaviour and environmental conditions. However, they have all been based on cross‐species analysis and take no account of the relative abundance of species with vegetation. 2 Using two reproductive traits – seed mass and dispersal vector – as examples, a range of previously identified relationships were tested using both unweighted and weighted‐by‐abundance data collected from land‐use transitions at 12 sites across Europe. 3 Seed mass was correlated positively with most measures of temperature (stronger relationships for unweighted data) and declined against measures of disturbance (stronger relationships with weighted data). It was not related consistently to measures of water availability. 4 There was some evidence that endozoochory was associated with damper environments, hoarding with drier ones and exozoochory with more fertile habitats. 5 Weighting reduced the slope of relationships between seed mass and environmental variables, possibly indicating that dominance within vegetation is determined by land use after the operation of a climatic filter. Fewer significant relationships were detected for weighted dispersal mechanisms compared to unweighted ones, indicating less difference of the dominants from other species with regard to this trait. 6 Synthesis. This analysis shows that weighting by abundance in the vegetation (compared to unweighted analysis) has a significant impact on the relationships between key species traits and a range of environmental parameters related to climate and land use, and that this impact was not consistent in its effects.

[1]  K. Thompson.  SEEDS AND SEED BANKS , 2008 .

[2]  Eric Garnier,et al.  Assessing the effects of land-use change on plant traits, communities and ecosystem functioning in grasslands: a standardized methodology and lessons from an application to 11 European sites. , 2007, Annals of botany.

[3]  R. Pakeman,et al.  Sampling plant functional traits: What proportion of the species need to be measured? , 2007 .

[4]  A. Pitman,et al.  Global patterns in seed size , 2006 .

[5]  J. P. Grime,et al.  Trait convergence and trait divergence in herbaceous plant communities: Mechanisms and consequences , 2006 .

[6]  Campbell O. Webb,et al.  Factors that shape seed mass evolution. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[7]  O. Eriksson,et al.  Fleshy fruits – origins, niche shifts, and diversification , 2005 .

[8]  Ken Thompson,et al.  The Ecology of Seeds by Michael Fenner , 2005 .

[9]  K. Thompson,et al.  The Ecology of Seeds: References , 2005 .

[10]  T. Young,et al.  Effects of leaf litter depth on the emergence and seedling growth of deciduous forest tree species in relation toseed size1 , 2005 .

[11]  R. Pakeman.  Consistency of plant species and trait responses to grazing along a productivity gradient: a multi‐site analysis , 2004 .

[12]  M. Westoby,et al.  Seedling survival and seed size: a synthesis of the literature , 2004 .

[13]  M. Westoby,et al.  Small‐seeded species produce more seeds per square metre of canopy per year, but not per individual per lifetime , 2004 .

[14]  J. P. Grime,et al.  The plant traits that drive ecosystems: Evidence from three continents , 2004 .

[15]  C. Dickman,et al.  Geographical gradients in seed mass in relation to climate , 2004 .

[16]  Lindsay A. Turnbull,et al.  Seed mass and the competition/colonization trade‐off: competitive interactions and spatial patterns in a guild of annual plants , 2004 .

[17]  Michelle R. Leishman,et al.  Simple traits do not predict grazing response in Australian dry shrublands and woodlands , 2004 .

[18]  A. Mouissie.  Seed dispersal by large herbivores , 2004 .

[19]  A. Mouissie.  Seed dispersal by large herbivores: Implications for the restoration of plant biodiversity , 2004 .

[20]  R. Reader.  Relationship between species relative abundance and plant traits for an infertile habitat , 2004, Plant Ecology.

[21]  S. Levin,et al.  The Ecology and Evolution of Seed Dispersal: A Theoretical Perspective , 2003 .

[22]  M. Westoby,et al.  Seed size and survival in the soil in arid Australia , 2003 .

[23]  D. Foster,et al.  Response of forest plant species to land‐use change: a life‐history trait‐based approach , 2003 .

[24]  C. Lusk,et al.  Interspecific variation in seed size and safe sites in a temperate rain forest. , 2003, The New phytologist.

[25]  J. Kigel,et al.  Effects of grazing on soil seed bank dynamics: An approach with functional groups , 2003 .

[26]  M. Westoby,et al.  Latitude, seed predation and seed mass , 2003 .

[27]  Kai Jensen,et al.  Effects of litter on establishment of grassland plant species: the role of seed size and successional status , 2003 .

[28]  M. Westoby,et al.  ECOLOGICAL STRATEGIES : Some Leading Dimensions of Variation Between Species , 2002 .

[29]  Eva Kisdi,et al.  Dispersal: Risk Spreading versus Local Adaptation , 2002, The American Naturalist.

[30]  Peter Poschlod,et al.  Conservation management of calcareous grasslands. Changes in plant species composition and response of functional traits during 25 years , 2002 .

[31]  Lindsay A. Turnbull,et al.  Are differences in seed mass among species important in structuring plant communities? Evidence from analyses of spatial and temporal variation in dune‐annual populations , 2002 .

[32]  O. Eriksson,et al.  Seed size and frequency patterns of understory plants in Swedish deciduous forests , 2002 .

[33]  P. W. Lane,et al.  GenStat release 6.1 reference manual. Part 1. Summary , 2002 .

[34]  Aj Bohonak,et al.  Software for reduced major axis regression , 2002 .

[35]  R. Hunt,et al.  Herbaceous plant strategies in disturbed habitats , 2001 .

[36]  R. Pakeman.  Seeds: The Ecology of Regeneration in Plant Communities, 2nd edn , 2001 .

[37]  M. Leishman.  Does the seed size/number trade‐off model determine plant community structure? An assessment of the model mechanisms and their generality , 2001 .

[38]  L. Aarssen,et al.  Between-species patterns of covariation in plant size, seed size and fecundity in monocarpic herbs , 2001 .

[39]  B. Graae,et al.  The impact of forest continuity and management on forest floor vegetation evaluated by species traits. , 2000 .

[40]  O. Eriksson,et al.  Seed Size, Fruit Size, and Dispersal Systems in Angiosperms from the Early Cretaceous to the Late Tertiary , 2000, The American Naturalist.

[41]  P. Reich,et al.  SEED SIZE, NITROGEN SUPPLY, AND GROWTH RATE AFFECT TREE SEEDLING SURVIVAL IN DEEP SHADE , 2000 .

[42]  P. Parolin.  Seed mass in Amazonian floodplain forests with contrasting nutrient supplies , 2000, Journal of Tropical Ecology.

[43]  M. Westoby,et al.  The Evolutionary ecology of seed size , 2000 .

[44]  K. Thompson,et al.  The functional ecology of soil seed banks. , 2000 .

[45]  J. Lepš,et al.  Comparative ecology of seedling recruitment in an oligotrophic wet meadow , 1999 .

[46]  U. Dieckmann,et al.  The evolutionary ecology of dispersal , 1999 .

[47]  Ian J. Wright,et al.  Differences in seedling growth behaviour among species: trait correlations across species, and trait shifts along nutrient compared to rainfall gradients , 1999 .

[48]  J. P. Grime,et al.  Benefits of plant diversity to ecosystems: immediate, filter and founder effects , 1998 .

[49]  J. Bakker,et al.  Ecological correlates of seed size in the British flora , 1998 .

[50]  Michelle R. Leishman,et al.  Seed size and shape are not related to persistence in soil in Australia in the same way as in Britain , 1998 .

[51]  P. Poschlod,et al.  Plant species richness in calcareous grasslands as affected by dispersability in space and time , 1998 .

[52]  J. Bakker,et al.  Ecological correlates of seed persistence in soil in the north‐west European flora , 1998 .

[53]  O. Eriksson,et al.  Seedling recruitment in semi-natural pastures: the effects of disturbance, seed size, phenology and seed bank , 1997 .

[54]  K. Thompson,et al.  Integrated screening validates primary axes of specialisation in plants , 1997 .

[55]  M. Rees.  Evolutionary ecology of seed dormancy and seed size , 1996 .

[56]  D. S. Hammond,et al.  Seed Size of Woody Plants in Relation to Disturbance, Dispersal, Soil Type in Wet Neotropical Forests , 1995 .

[57]  Michelle R. Leishman,et al.  Predicting dispersal spectra: A minimal set of hypotheses based on plant attributes , 1994 .

[58]  Robert V. O'Neill,et al.  Spatio-Temporal Dispersal Strategies and Annual Plant Species Coexistence in a Structured Landscape , 1994 .

[59]  Michelle R. Leishman,et al.  The role of seed size in seedling establishment in dry soil conditions - Experimental evidence from semi-arid species , 1994 .

[60]  M. Westoby,et al.  The role of large seed size in shaded conditions: experimental evidence , 1994 .

[61]  Peter J. Grubb,et al.  Physiological basis and ecological significance of the seed size and relative growth rate relationship in Mediterranean annuals , 1993 .

[62]  J. Laffarga,et al.  Strategies in Mediterranean grassland annuals in relation to stress and disturbance , 1993 .

[63]  R. Reader.  Control of seedling emergence by ground cover and seed predation in relation to seed size for some old-field species , 1993 .

[64]  M. Westoby,et al.  Seedling growth in relation to seed size among species of arid Australia , 1992 .

[65]  D. L. Venable,et al.  Size-Number Trade-Offs and the Variation of Seed Size with Plant Resource Status , 1992, The American Naturalist.

[66]  M. Fenner.  Seeds: The Ecology of Regeneration in Plant Communities , 1992 .

[67]  Mark Westoby,et al.  Seed Size and Plant Growth Form as Factors in Dispersal Spectra , 1990, Ecology.

[68]  M. Westoby,et al.  Seed dispersal spectra: a comparison of temperate plant communities , 1990 .

[69]  S. Mazer.  Ecological, Taxonomic, and Life History Correlates of Seed Mass Among Indiana Dune Angiosperms , 1989 .

[70]  Joel s. Brown,et al.  The Selective Interactions of Dispersal, Dormancy, and Seed Size as Adaptations for Reducing Risk in Variable Environments , 1988, The American Naturalist.

[71]  J. P. Grime,et al.  Comparative Plant Ecology , 1988, Springer Netherlands.

[72]  R. Buckley.  Seed Size and Seedling Establishment in Tropical Arid Dunecrest Plants , 1982 .

[73]  Henry Howe,et al.  Ecology of Seed Dispersal , 1982 .

[74]  Christopher C. Smith,et al.  The Optimal Balance between Size and Number of Offspring , 1974, The American Naturalist.

[75]  J. P. Grime,et al.  Seedling Establishment in Vertical Gradients of Sunlight , 1965 .

[76]  J. Black.  Competition between plants of different initial seed sizes in swards of subterranean clover (Trifolium subterraneum L.) with particular reference to leaf area and the light microclimate , 1958 .

[77]  C. W. Thornthwaite.  An Approach Toward a Rational Classification of Climate , 1948 .

[78]  E. J. Kraus.  The Reproductive Capacity of Plants , 1943, Ecology.

[79]  D. T.,et al.  The Reproductive Capacity of Plants , 1943, Nature.