Biodiversity enhances individual performance but does not affect survivorship in tropical trees.

We developed an analytical method that quantifies the relative contributions of mortality and individual growth to ecosystem function and analysed the results from the first biodiversity experiment conducted in a tropical tree plantation. In Sardinilla, central Panama, over 5000 tree seedlings were planted in monoculture and mixed-species plots. After 5 years of growth, mixed-species plots yielded, on average, 30-58% higher summed tree basal area than did monocultures. Simulation models revealed that the increased yield of mixed-species plots was due mostly to enhancement of individual tree growth. Although c. 1500 trees died during the experiment, mortality was highly species-specific and did not differ consistently between biodiversity treatments. Our results show that the effects of biodiversity on growth and mortality are uncoupled and that biodiversity affects total biomass and potentially self-thinning. The Sardinilla experiment suggests that mixed-species plantings may be a viable strategy for increasing timber yields and preserving biodiversity in tropical tree plantations.

[1]  J. Canadell,et al.  Tropical Forests and Climate Policy , 2007, Science.

[2]  David Cyranoski.  Biodiversity: Logging: the new conservation , 2007, Nature.

[3]  Jordi Vayreda,et al.  Species richness and wood production: a positive association in Mediterranean forests. , 2007, Ecology letters.

[4]  Bradley J. Cardinale,et al.  Effects of biodiversity on the functioning of trophic groups and ecosystems , 2006, Nature.

[5]  P. Balvanera,et al.  Quantifying the evidence for biodiversity effects on ecosystem functioning and services. , 2006, Ecology letters.

[6]  J. D. Nichols,et al.  Five year results from a mixed-species spacing trial with six subtropical rainforest tree species , 2006 .

[7]  P. Erskine,et al.  Tree species diversity and ecosystem function: Can tropical multi-species plantations generate greater productivity? , 2006 .

[8]  J. Vanclay,et al.  Mixed-species plantations: Prospects and challenges , 2006 .

[9]  J. Vanclay,et al.  Improving productivity in mixed-species plantations , 2006 .

[10]  Michael D. Collins,et al.  Supporting Online Material Materials and Methods Figs. S1 to S3 Tables S1 and S2 References Plant Genotypic Diversity Predicts Community Structure and Governs an Ecosystem Process , 2022 .

[11]  A. Bouchard,et al.  Survival and growth of under-planted trees: a meta-analysis across four biomes. , 2006, Ecological applications : a publication of the Ecological Society of America.

[12]  Thiago F. Rangel,et al.  Towards an integrated computational tool for spatial analysis in macroecology and biogeography , 2006 .

[13]  J. Ewel,et al.  Allometric equations for four valuable tropical tree species , 2006 .

[14]  D. Srivastava,et al.  Biodiversity-Ecosystem Function Research: Is It Relevant to Conservation? , 2005 .

[15]  D. M. Newbery,et al.  Evidence of species-specific neighborhood effects in the dipterocarpaceae of a Bornean rain forest , 2005 .

[16]  F. Chapin,et al.  EFFECTS OF BIODIVERSITY ON ECOSYSTEM FUNCTIONING: A CONSENSUS OF CURRENT KNOWLEDGE , 2005 .

[17]  United Kingdom,et al.  GLOBAL FOREST RESOURCES ASSESSMENT 2005 , 2005 .

[18]  J. Koricheva,et al.  The Design of Experimental Tree Plantations for Functional Biodiversity Research , 2005 .

[19]  S. Hubbell,et al.  A spatially explicit model of sapling growth in a tropical forest: does the identity of neighbours matter? , 2004 .

[20]  B. Goldfarb,et al.  Nursery and field establishment techniques to improve seedling growth of three Costa Rican hardwoods , 2001, New Forests.

[21]  W. Zech,et al.  Site factors, foliar nutrient levels and growth of Cordia alliodora plantations in the humid lowlands of Northern Costa Rica , 1994, Plant and Soil.

[22]  Markku Kanninen,et al.  Performance of forest plantations in small and medium-sized farms in the Atlantic lowlands of Costa Rica , 2003 .

[23]  Nicholas J. Gotelli,et al.  SPECIES CO‐OCCURRENCE: A META‐ANALYSIS OF J. M. DIAMOND'S ASSEMBLY RULES MODEL , 2002 .

[24]  M. Loreau,et al.  Overyielding in grassland communities: testing the sampling effect hypothesis with replicated biodiversity experiments , 2002 .

[25]  Shahid Naeem,et al.  ECOSYSTEM CONSEQUENCES OF BIODIVERSITY LOSS: THE EVOLUTION OF A PARADIGM , 2002 .

[26]  P. Reich,et al.  Diversity and Productivity in a Long-Term Grassland Experiment , 2001, Science.

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

[28]  F. Montagnini,et al.  Biomass and nutrient accumulation in pure and mixed plantations of indigenous tree species grown on poor soils in the humid tropics of Costa Rica , 1999 .

[29]  Shahid Naeem,et al.  Biodiversity enhances ecosystem reliability , 1997, Nature.

[30]  S. Hubbell,et al.  Mortality Rates of 205 Neotropical Tree and Shrub Species and the Impact of a Severe Drought , 1995 .

[31]  Stephen P. Hubbell,et al.  Identifying fast-growing native trees from the neotropics using data from a large, permanent census plot , 1993 .

[32]  D. Botkin.  Forest Dynamics: An Ecological Model , 1993 .

[33]  Donald E. Weller,et al.  A Reevaluation of the ‐3/2 Power Rule of Plant Self‐Thinning , 1987 .

[34]  B. Trenbath,et al.  Biomass Productivity of Mixtures , 1974 .