Role of dispersal in the recruitment limitation of neotropical pioneer species

Summary 1 We examined the importance of seed dispersal in predicting the pioneer seedling composition in recent gaps in a forest plot on Barro Colorado Island (BCI), Panama. We characterize seed dispersal for 13 taxa from seed rain data collected over 13 years in 200 mesh traps, and for an additional species from germination from soil samples collected in one year. We describe seedling distribution patterns from a complete census of all seedlings of these 14 taxa present in 36 treefall gaps. 2 A maximum likelihood model, incorporating both distance to adult trees and tree size, fitted observed seed rain to traps quite well for all taxa. 3 The ability to predict seedling recruit number per gap varied greatly among taxa. For 8 of 14 taxa, regression models incorporating predicted seed rain were significantly better predictors of seedling recruitment than models in which recruitment probability was assumed constant in all sites. 4 To see if variation in local dispersal patterns determined the community composition of gaps, we examined the relative abundances of these 14 pioneer taxa in the 36 gaps. We found that taxon abundances were significantly positively correlated with abundances predicted from seed dispersal models and seed–seedling regressions for 27 out of 36 gaps. 5 Overall, we find evidence that limited seed dispersal is an important factor contributing, together with factors affecting post-dispersal recruitment success, to seedling distribution patterns in gaps.

[1]  Lawrence R. Walker,et al.  Differential seedling responses to litter after Hurricane Hugo in the Luquillo Experimental Forest, Puerto Rico , 1991 .

[2]  Kyle E. Harms,et al.  Pervasive density-dependent recruitment enhances seedling diversity in a tropical forest , 2000, Nature.

[3]  M. Swaine,et al.  Effect of soil depth on seedling emergence in tropical soil seed-bank investigations , 1995 .

[4]  S. Pacala,et al.  SEEDLING RECRUITMENT IN FORESTS: CALIBRATING MODELS TO PREDICT PATTERNS OF TREE SEEDLING DISPERSION' , 1994 .

[5]  M. Tabarelli,et al.  Gap-phase regeneration in a tropical montane forest: the effects of gap structure and bamboo species , 2000, Plant Ecology.

[6]  G. Orians,et al.  Internal heterogeneity of gaps and species richness in Costa Rican tropical wet forest , 1988, Journal of Tropical Ecology.

[7]  D. Burslem,et al.  GERMINATION ECOLOGY OF NEOTROPICAL PIONEERS: INTERACTING EFFECTS OF ENVIRONMENTAL CONDITIONS AND SEED SIZE , 2002 .

[8]  Stephen J. Wright,et al.  Light-Gap disturbances, recruitment limitation, and tree diversity in a neotropical forest , 1999, Science.

[9]  Samuel M. Wilson.  Structure and History , 1993 .

[10]  Thomas B. Croat.  Flora of Barro Colorado Island , 1978 .

[11]  K. Cremer.  DISSEMINATION OF SEED FROM EUCALYPTUS REGNANS , 1966 .

[12]  S. Hubbell,et al.  Assessing recruitment limitation: concepts, methods and case-studies from a tropical forest. , 2002 .

[13]  N. Garwood.  Constraints on the timing of seed germination in a tropical forest , 1986 .

[14]  W. Hoppes.  Seedfall pattern of several species of bird-dispersed plants in an illinois woodland , 1988 .

[15]  Ran Nathan,et al.  Spatial patterns of seed dispersal, their determinants and consequences for recruitment. , 2000, Trends in ecology & evolution.

[16]  D. Teketay,et al.  Germination ecology of forest species from the highlands of Ethiopia , 1997, Journal of Tropical Ecology.

[17]  V. Barradas,et al.  Light Beneath the Litter in a Tropical Forest: Effect on Seed Germination , 1990 .

[18]  S. Levin,et al.  Comparing Classical Community Models: Theoretical Consequences for Patterns of Diversity , 2002, The American Naturalist.

[19]  Stephen P. Hubbell,et al.  Diversity of canopy trees in a neotropical forest and implications for conservation , 1983 .

[20]  N. Brokaw.  Gap-Phase Regeneration of Three Pioneer Tree Species in a Tropical Forest , 1987 .

[21]  S. Levin.  Dispersion and Population Interactions , 1974, The American Naturalist.

[22]  S. Hubbell,et al.  Assessing the response of plant functional types to climatic change in tropical forests , 1996 .

[23]  W. Platt,et al.  Resource Partitioning and Competition within a Guild of Fugitive Prairie Plants , 1977, The American Naturalist.

[24]  A. Hastings.  Disturbance, coexistence, history, and competition for space , 1980 .

[25]  C. Augspurger,et al.  Input of wind–dispersed seeds into light–gaps and forest sites in a Neotropical forest , 1988, Journal of Tropical Ecology.

[26]  D. Windsor.  Climate and moisture variability in a tropical forest : long-term records from Barro Colorado Island, Panamá , 1990 .

[27]  Stephen P. Hubbell,et al.  Sapling Survival, Growth, and Recruitment: Relationship to Canopy Height in a Neotropical Forest , 1991 .

[28]  D. Tilman.  Competition and Biodiversity in Spatially Structured Habitats , 1994 .

[29]  Manuel R. Guariguata,et al.  Seed and seedling ecology of tree species in neotropical secondary forests: management implications. , 2000 .

[30]  Janneke HilleRisLambers,et al.  Seed Dispersal Near and Far: Patterns Across Temperate and Tropical Forests , 1999 .

[31]  S. Hubbell,et al.  Seed dispersal, seedling establishment and gap partitioning among tropical pioneer trees , 1998 .

[32]  S. Wright,et al.  THE EL NINO SOUTHERN OSCILLATION, VARIABLE FRUIT PRODUCTION, AND FAMINE IN A TROPICAL FOREST , 1999 .

[33]  J. Clark,et al.  Interpreting recruitment limitation in forests. , 1999, American journal of botany.

[34]  M. Swaine,et al.  DISPERSAL PATTERNS AND SEED BANK DYNAMICS OF PIONEER TREES IN MOIST TROPICAL FOREST , 1998 .

[35]  M. Swaine,et al.  Soil seed bank community dynamics in seasonally moist lowland tropical forest, Panama , 1997, Journal of Tropical Ecology.

[36]  Lindsay A. Turnbull,et al.  Seed mass and the competition/colonization trade‐off: a sowing experiment , 1999 .

[37]  N. Brokaw.  Gap-phase regeneration in a tropical forest. , 1985 .

[38]  James S. Clark,et al.  STAGES AND SPATIAL SCALES OF RECRUITMENT LIMITATION IN SOUTHERN APPALACHIAN FORESTS , 1998 .

[39]  David R. Anderson,et al.  Model Selection and Inference: A Practical Information-Theoretic Approach , 2001 .

[40]  Lindsay A. Turnbull,et al.  Are plant populations seed-limited? A review of seed sowing experiments. , 2000 .

[41]  George C. Hurtt,et al.  The consequences of recruitment limitation: reconciling chance, history and competitive differences between plants , 1995 .

[42]  J. Molofsky,et al.  The Effect of Leaf Litter on Early Seedling Establishment in a Tropical Forest , 1992 .

[43]  D. Levey,et al.  Directed seed dispersal by bellbirds in a tropical cloud forest. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[44]  P. J. Edwards,et al.  The Ecology of a Tropical Forest. , 1985 .

[45]  C. Augspurger,et al.  Seed and Seedling Ecology of a Monocarpic Tropical Tree, Tachigalia Versicolor , 1989 .

[46]  Osvaldo Calderón,et al.  Phylogenetic patterns among tropical flowering phenologies , 1995 .

[47]  J. Rice.  Mathematical Statistics and Data Analysis , 1988 .

[48]  S. Hubbell,et al.  Seed size, growth rate and gap microsite conditions as determinants of recruitment success for pioneer species , 2002 .

[49]  Charles D. Canham,et al.  Seed abundance versus substrate limitation of seedling recruitment in northern temperate forests of British Columbia , 2000 .

[50]  S. Hubbell,et al.  THE UNUSUAL LIFE HISTORY OF ALSEIS BLACKIANA: A SHADE-PERSISTENT PIONEER TREE? , 2001 .

[51]  D. Levey,et al.  COMPLEX ANT-PLANT INTERACTIONS: RAIN FOREST ANTS AS SECONDARY DISPERSERS AND POST-DISPERSAL SEED PREDATORS' , 1993 .

[52]  The Plant , Slow Disturbance.