We investigated relationships between population dynamics and microclimate, physiology, and the degree of mycorrhizal colonization, for three species (
Piscidia piscipula L.(Sarg.)) (Fabaceae),
Bunchosia swartziana Griseb. (Malpighiaceae) and
Psidium sartorianum (Bergius) Nied. (Myrtaceae)) of a tropical sub deciduous forest in Yucatan, Mexico that
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We investigated relationships between population dynamics and microclimate, physiology, and the degree of mycorrhizal colonization, for three species (
Piscidia piscipula L.(Sarg.)) (Fabaceae),
Bunchosia swartziana Griseb. (Malpighiaceae) and
Psidium sartorianum (Bergius) Nied. (Myrtaceae)) of a tropical sub deciduous forest in Yucatan, Mexico that were growing in plots of different successional ages. We hypothesized that abundance and persistence were related to increased plasticity in CO
2 assimilation. We found that
Piscidia piscipula had greater abundance in intermediate plots (18 to 21 years), presented higher levels of plasticity in CO
2 assimilation (greater variability among individuals, plots, and seasons), presented the highest CO
2 assimilation rates, and presented greater drought resistance (higher water potentials and capacitance). Conversely,
Psidium sartorianum had greater abundance in older plots (more than 50 years of secondary succession), lower assimilation rates, and low levels of plasticity in CO
2 assimilation.
Bunchosia had intermediate values. Locally, the degree of mycorrhizal colonization was consistent with abundance across plots. Regionally (but not locally), plasticity in CO
2 assimilation was consistent with abundance. We found differences in microclimates among plots and within plots among species. Physiological adjustments appeared to play an important role in the capacity to regenerate and in the successional persistence of these species in this tropical dry forest.
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