Patterns of Spatial Distribution and Seed Dispersal among Bottomland Hardwood Tree Species
2014
Reid, Matthew L. | Allen, Stephanie R. | Bhattacharjee, Joydeep
Patterns of tree species distributions in bottomlands are a result of various environmental and biological factors, including flood tolerance, seed dispersal, and species interactions. We evaluated the patterns of distribution and seed dispersal of tree species in a naturally regenerating bottomland hardwood forest in northeast Louisiana. We used nearest neighbor analysis to determine distribution patterns of the following canopy-dominant tree species: Carya aquatica, Celtis laevigata, Diospyros virginiana, Fraxinus pennsylvanica, Gleditsia triacanthos, and Quercus nigra. Results indicated an aggregated distribution pattern for Q. nigra, G. triacanthos, D. virginiana, and Ce. laevigata, while Ca. aquatica and F. pennsylvanica had random distributions in the study area. Additionally, we designed and used three types of seed traps to assess the seed dispersal of tree species. Modeled patterns of seed dispersal for F. pennsylvanica, Ca. aquatica, and Crataegus viridis indicated aggregated seed dispersal for these species. Low seed captures for all other species prevented modeling of their seed dispersal patterns. These results indicate that many of the tree species characteristic of bottomlands have nonrandom distributions. These distributions could be due to a variety of biotic or abiotic factors. Seed dispersal was similarly aggregated, at least for species where seed capture totals were high enough for modeling. Characterizing patterns in plant distribution and seed dispersal is important for understanding how plant communities develop during succession. Bottomland reforestation efforts should focus on planting species to match their natural distributions in an attempt to restore these communities to a more natural state.
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