Book contents
- Frontmatter
- Contents
- Contributors
- Preface
- Acknowledgments
- Part I Introduction
- Part II Advances in source–sink theory
- Part III Progress in source–sink methodology
- Part IV Improvement of source–sink management
- 16 Contribution of source–sink theory to protected area science
- 17 Evidence of source–sink dynamics in marine and estuarine species
- 18 Population networks with sources and sinks along productivity gradients in the Fiordland Marine Area, New Zealand: a case study on the sea urchin Evechinus chloroticus
- 19 Source–sinks, metapopulations, and forest reserves: conserving northern flying squirrels in the temperate rainforests of Southeast Alaska
- 20 Does forest fragmentation and loss generate sources, sinks, and ecological traps in migratory songbirds?
- 21 Source–sink population dynamics and sustainable leaf harvesting of the understory palm Chamaedorea radicalis
- 22 Assessing positive and negative ecological effects of corridors
- Part V Synthesis
- Index
- References
21 - Source–sink population dynamics and sustainable leaf harvesting of the understory palm Chamaedorea radicalis
Published online by Cambridge University Press: 05 July 2011
- Frontmatter
- Contents
- Contributors
- Preface
- Acknowledgments
- Part I Introduction
- Part II Advances in source–sink theory
- Part III Progress in source–sink methodology
- Part IV Improvement of source–sink management
- 16 Contribution of source–sink theory to protected area science
- 17 Evidence of source–sink dynamics in marine and estuarine species
- 18 Population networks with sources and sinks along productivity gradients in the Fiordland Marine Area, New Zealand: a case study on the sea urchin Evechinus chloroticus
- 19 Source–sinks, metapopulations, and forest reserves: conserving northern flying squirrels in the temperate rainforests of Southeast Alaska
- 20 Does forest fragmentation and loss generate sources, sinks, and ecological traps in migratory songbirds?
- 21 Source–sink population dynamics and sustainable leaf harvesting of the understory palm Chamaedorea radicalis
- 22 Assessing positive and negative ecological effects of corridors
- Part V Synthesis
- Index
- References
Summary
In this study we assessed the sustainability of leaf harvesting of the palm Chamaedorea radicalis by modeling the dynamics of harvested populations using stage-structured transition matrices. Within the study site, El Cielo Biosphere Reserve, palm demography and population growth is dependent on substrate type; a relationship that is due to the role of rock outcrops as a refuge from herbivory by free-ranging livestock. We accounted for this environmental heterogeneity by using a source–sink model in which non-browsed palms on rock outcrops act as a source population for browsed palms on the forest floor (sink). To evaluate the impact of leaf harvesting on these populations we incorporated the demographic effects of local harvesting practices into population models using data from leaf harvesting experiments. Results showed that when the demographic effects of leaf harvesting were combined with the effects of livestock browsing, population growth dropped significantly below the replacement rate, indicating that the combination of the two was not sustainable. This result is explicable in the context of the source–sink dynamic described above, where browsed palms on the forest floor are dependent on the migration of seeds from protected palms on rock outcrops. Incorporating leaf harvesting into the model reduces the survival and fecundity of all non-browsed palms, including important “source” palms on rock outcrops, with the result that non-browsed rock outcrops are no longer a sufficient source of recruitment for the entire population. The source–sink model was critical in projecting the consequences of this interaction between browsing and harvesting.
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- Information
- Sources, Sinks and Sustainability , pp. 450 - 474Publisher: Cambridge University PressPrint publication year: 2011
References
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