Landscape fragmentation and dispersal in a model of riparian forest dynamics

Abstract Although several computer simulation models of forest tree growth have been developed at the stand level, they do not address the impact of mainland landscape structure and forest fragmentation on the forest dynamics of spatially extensive areas. To model forest dynamics at the landscape level, a model must explicity consider the dispersibility of tree species within the landscape. A computer simulation model, seedflo , is constructed which models tree species dispersal based on empirical evidence. The analyses test the hypothesis that a model with seed dispersal differs in its projections from a model that assumes ubiquitous dispersal. For species in a riparian corridor, seedflo projects lower diversity in more fragmented landscapes and increases the abundance of those species with higher dispersal probabilities, especially bird-dispersed species, and toward species with average dispersal abilities which normally compete with species with low dispersal probabilities. The effects of considering landscape fragmentation and dispersal are amplified when environmental stress, in this case flooding, is increased. The results conform to theoretical expectations and indicate that seed dispersal should be incorporated in landscape simulation models.

[1]  W. Baker.  Macro‐ and Micro–scale Influences on Riparian Vegetation in Western Colorado , 1989 .

[2]  Rebecca L. Schneider,et al.  Hydrochory and Regeneration in A Bald Cypress‐Water Tupelo Swamp Forest , 1988 .

[3]  J. R. Wallis,et al.  Some ecological consequences of a computer model of forest growth , 1972 .

[4]  Herman H. Shugart,et al.  A computer model of succession and fire response of the high‐altitude Eucalyptus forest of the Brindabella Range, Australian Capital Territory , 1981 .

[5]  D. E. Fields,et al.  Modeling seed dispersal and forest island dynamics. , 1981 .

[6]  J. Ranney,et al.  Propagule Dispersal Among Forest Islands in Southeastern South Dakota , 1977 .

[7]  C. S. Shopmeyer.  Seeds of woody plants in the United States , 1974 .

[8]  H. McAllister,et al.  Principles of Dispersal in Higher Plants , 1970, Springer Berlin Heidelberg.

[9]  D. Peart.  The Quantitative Representation of Seed and Pollen Dispersal , 1985 .

[10]  D. Murray.  CHAPTER 2 – Seed Dispersal by Water , 1986 .

[11]  R. Macarthur,et al.  The Theory of Island Biogeography , 1969 .

[12]  Richard L. Phipps,et al.  Simulation of wetlands forest vegetation dynamics , 1979 .

[13]  Tim R. McClanahan,et al.  Seed dispersal from vegetation islands , 1986 .

[14]  Wiley M. Kitchens,et al.  MODELLING THE IMPACTS OF A RIVER DIVERSION ON BOTTOMLAND FOREST COMMUNITIES IN THE SANTEE RIVER FLOODPLAIN, SOUTH CAROLINA , 1985 .

[15]  J. Ranney.  Forest island edges-their structure, development, and importance to regional forest ecosystem dynamics , 1977 .

[16]  D. DeAngelis,et al.  Persistence and stability of seed-dispersed species in a patchy environment. , 1979, Theoretical population biology.