Publication Year
2005
Source
Proceedings of the California Academy of Sciences
Abstract
Terrestrial ecosystems of the late Paleozoic form a distinct global hierarchy of organizational
levels, paralleling that seen in the modern world. At the highest level are
at least three biotic provinces delimited by geographic and very broad scale climatic
factors. Within each province are several biomes, reflecting substrate and climatic
controls. Biomes are roughly equivalent to plant “species pools,” those plants
capable of colonizing available resource spaces within the physical area of the biome,
and within which many species are roughly ecologically equivalent. Biome boundaries
tend to be rather sharp. Within biomes are recurrent species associations, or
communities, among which there is significant overlap in composition but that differ
in dominance-diversity patterns. These patterns are examined here primarily in
ancient tropical systems. The patterns of spatial partitioning of Permo-Carboniferous
landscapes conform broadly to those predicted by the unified neutral theory of
Hubbell (2001). However, species ecological equivalence is not “global” but rather
appears to be restricted to biomes/species pools. The complexity of this hierarchical
organization appears to have increased and deepened from the time vascular plants
appeared on the land surface in the Late Silurian through the late Paleozoic and
beyond. This may be related, in part, to increased “energy” input into the system,
driving spontaneous organization of complexity and progressively restricting the
spatial scale of species equivalence.
levels, paralleling that seen in the modern world. At the highest level are
at least three biotic provinces delimited by geographic and very broad scale climatic
factors. Within each province are several biomes, reflecting substrate and climatic
controls. Biomes are roughly equivalent to plant “species pools,” those plants
capable of colonizing available resource spaces within the physical area of the biome,
and within which many species are roughly ecologically equivalent. Biome boundaries
tend to be rather sharp. Within biomes are recurrent species associations, or
communities, among which there is significant overlap in composition but that differ
in dominance-diversity patterns. These patterns are examined here primarily in
ancient tropical systems. The patterns of spatial partitioning of Permo-Carboniferous
landscapes conform broadly to those predicted by the unified neutral theory of
Hubbell (2001). However, species ecological equivalence is not “global” but rather
appears to be restricted to biomes/species pools. The complexity of this hierarchical
organization appears to have increased and deepened from the time vascular plants
appeared on the land surface in the Late Silurian through the late Paleozoic and
beyond. This may be related, in part, to increased “energy” input into the system,
driving spontaneous organization of complexity and progressively restricting the
spatial scale of species equivalence.
Research Track Category