TY - JOUR
T1 - Effects of resource availability on seedling recruitment in a fire-maintained savanna
AU - Iacona, Gwenllian D.
AU - Kirkman, L. Katherine
AU - Bruna, Emilio M.
N1 - Funding Information:
Acknowledgments We would like to thank many members of the Ichauway plant lab for assistance in the Weld. These people include M. Kaeser, M. Creech, K. Stuble, S. Wiggers, K. CoVey, and many others. Assistance with statistical analyses was provided by M. Brennan with the University of Florida Institute of Food and Agricultural Science Statistics Department. W. Cropper and M. Creech provided helpful comments on an early version of this manuscript. The suggestions of R. Mitchell, H. Stevens, and an anonymous reviewer signiWcantly improved the Wnal version and pointed out some relevant studies that had been overlooked. The University of Florida’s Department of Wildlife Ecology and Conservation and the J. W. Jones Ecological Research Center provided logistical support throughout the project. Funding was provided by the J. W. Jones Ecological Research Center, The Robert WoodruV Foundation, and The University of Florida College of Agriculture and Life Sciences. All experiments and Weld work comply with the current laws of the USA.
PY - 2010/5
Y1 - 2010/5
N2 - The herbaceous ground cover of the longleaf pine ecosystem harbors the highest plant species richness in North America, with up to 50 species per square meter, but the mechanisms that regulate this diversity are not well understood. In this system, variability in seedling recruitment events may best explain the extremely high small-scale species richness and its relationship to soil moisture and system net primary productivity. To understand the potential mechanistic controls on species richness, we used a long-term resource manipulation study across a natural soil moisture gradient to assess environmental controls on seedling recruitment. We considered the availability of resources to be an indicator of seedling safe-site supply, and also manipulated seed availability to examine the relative importance of recruitment limitations on seedling diversity. We found that water availability regulated the number of species in the seedling community regardless of the underlying natural moisture gradient, and that this effect may result from differential responses of seedling guilds to resource availability. Water supply was more important than seed supply in determining seedling establishment, suggesting that appropriate sites for regeneration are a factor limiting seedling success. This is the first study that shows that the episodic supply of microsites for recruitment could influence species richness in the highly threatened and biodiverse longleaf pine savanna.
AB - The herbaceous ground cover of the longleaf pine ecosystem harbors the highest plant species richness in North America, with up to 50 species per square meter, but the mechanisms that regulate this diversity are not well understood. In this system, variability in seedling recruitment events may best explain the extremely high small-scale species richness and its relationship to soil moisture and system net primary productivity. To understand the potential mechanistic controls on species richness, we used a long-term resource manipulation study across a natural soil moisture gradient to assess environmental controls on seedling recruitment. We considered the availability of resources to be an indicator of seedling safe-site supply, and also manipulated seed availability to examine the relative importance of recruitment limitations on seedling diversity. We found that water availability regulated the number of species in the seedling community regardless of the underlying natural moisture gradient, and that this effect may result from differential responses of seedling guilds to resource availability. Water supply was more important than seed supply in determining seedling establishment, suggesting that appropriate sites for regeneration are a factor limiting seedling success. This is the first study that shows that the episodic supply of microsites for recruitment could influence species richness in the highly threatened and biodiverse longleaf pine savanna.
KW - Longleaf pine savanna
KW - Recruitment limitation
KW - Resource limitation
KW - Safe-site limitation
KW - Seed limitation
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U2 - 10.1007/s00442-009-1502-y
DO - 10.1007/s00442-009-1502-y
M3 - Article
C2 - 19921271
AN - SCOPUS:77951022021
VL - 163
SP - 171
EP - 180
JO - Oecologia
JF - Oecologia
SN - 0029-8519
IS - 1
ER -