Reproductive Ecology and Seed Bank Dynamics of Endangered … · 2009. 10. 8. · Reproductive...
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Christina M. Sloop and Hattie K. Brown Laguna de Santa Rosa Foundation, Santa Rosa, CA, [email protected], www.lagunafoundation.org Acknowledgements Burke’s Goldfields Conclusions Abstract We investigated the reproductive ecology of Burke’s Goldfields (Lasthenia burkei), Sonoma Sunshine (Blennosperma bakeri), and Sebastopol Meadowfoam (Limnanthes vinculans) - three state and federally listed endangered annual plants with rem- nant populations occurring in both natural and constructed ver- nal pool ecosystems predominantly located on the Santa Rosa Plain. Understanding the reproductive ecology, or the interplay between plants, pollinators, and seed production and storage will help manage these species and establish matrices for evalu- ating the health of endangered annual plants. In the first year of a multi-year study, we visited three extant populations of each species, or nine vernal pools - both natural and constructed seasonal wetlands. At each pool we: 1) Installed pollinator exclusion devices to determine if the endangered annual plants are self-incompatible and re- quire insect pollinators to set seed; and 2) Collected seeds from individual inflorescences to deter- mine seed set for each of the three species. We also conducted a pilot study of the soil seed bank to quan- tify the seeds stored in the soil. Reproductive Ecology and Seed Bank Dynamics of Endangered Plants in Constructed and Natural Vernal Pools Study Objectives • Confirm whether Burke’s Goldfields, Sonoma Sunshine, and Sebastopol Meadowfoam are obligate out-crossing species and so depend on insect pollinators for viable seed set in situ. • Determine yearly seed set in natural and constructed pools. • Establish estimates of seed bank numbers through soil cores. • Assess whether yearly seed set estimates suggest a substan- tial addition to the seed bank, or indicate a continual draw down from the seed bank without proper replenishment of seeds each year at natural and constructed sites. Thanks to Kandis Gilmore and Dolly Friedel and Laguna Foundation interns: Betsy Black, Laruen Kerr, Amber Parsons, and Avi Starr-Glass. This work was funded by the CA Dept. of Fish and Game. Preliminary Results Enclosed inflorescence keep insect pollinators out. • Seed set in open pollinated inflorescence varied across species: B. bakeri (4.08 +/- 1.55), L. vinculans (2.06 +/- 1.77), and L. burkei (108.66 +/- 62.27). • Both enclosed and open pollinated inflorescences produced developed seed. • Cover class has no discernible effect on seed set in B. bakeri. Cover class does have a discernible effect on seed set in L. vinculans and L. burkei where increas- ing cover correlated with increasing seed set. • Pool type (constructed or natural) had a discernible effect on seed set in L. vin- culans and L. burkei, but no discernible effect on B. bakeri. Soil auger collects samples to quantify the soil seed bank. L. vinculans in flower L. vinculans in fruit photo K. Gilmore photo K. Gilmore photo K. Gilmore Sonoma Dunshine Sebastopol Meadowfoam • Viable seed production in enclosed inflorescences suggests that all species are able to self fertilize or that our enclosures failed allowing pollen transfer. • Seed collections in the coming years will further elucidate the reproductive ecology of these endangered species, however preliminary results suggest that L. vinculans and L. burkei may produce more seeds in natural vernal pools with dense flower cover whereas B. bakeri seed set is less affected by pool type or cover class. • Preliminary analysis of the soil seed bank suggests that B. bakeri seed are only present in the surface organic matter and the first two inches of soil. photo H. Brown Average seed set per open pollinated inflorescence for each species 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 L. vinculans L. burkei B. bakeri Average Seed Set in Enclosed vs. Open Inflorescences 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 BLBA LIVI 0 20 40 60 80 100 120 B. bakeri L. vinculans L. burkei Average Seed Set in Constructed vs. Natural Vernal Pools CNPS Cover Class BLBA LABU LIVI 10% and below 3.98 90.76 1.48 15% to 35% 4.27 100.30 2.80 50% and above 3.97 121.79 3.38 Grand Total 4.08 108.66 2.06 0 20 40 60 80 100 120 Enclosed Open Natural Constructed
Transcript of Reproductive Ecology and Seed Bank Dynamics of Endangered … · 2009. 10. 8. · Reproductive...
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Christina M. Sloop and Hattie K. BrownLaguna de Santa Rosa Foundation, Santa Rosa, CA, [email protected], www.lagunafoundation.org
Acknowledgements
Burke’s Goldfields
Conclusions
AbstractWe investigated the reproductive ecology of Burke’s Goldfields (Lasthenia burkei), Sonoma Sunshine (Blennosperma bakeri), and Sebastopol Meadowfoam (Limnanthes vinculans) - three state and federally listed endangered annual plants with rem-nant populations occurring in both natural and constructed ver-nal pool ecosystems predominantly located on the Santa Rosa Plain. Understanding the reproductive ecology, or the interplay between plants, pollinators, and seed production and storage will help manage these species and establish matrices for evalu-ating the health of endangered annual plants. In the first year of a multi-year study, we visited three extant populations of each species, or nine vernal pools - both natural and constructed seasonal wetlands. At each pool we: 1) Installed pollinator exclusion devices to determine if the endangered annual plants are self-incompatible and re- quire insect pollinators to set seed; and 2) Collected seeds from individual inflorescences to deter- mine seed set for each of the three species. We also conducted a pilot study of the soil seed bank to quan-tify the seeds stored in the soil.
Reproductive Ecology and Seed Bank Dynamics of Endangered Plants in Constructed and Natural Vernal Pools
Study Objectives• Confirm whether Burke’s Goldfields, Sonoma Sunshine, and Sebastopol Meadowfoam are obligate out-crossing species and so depend on insect pollinators for viable seed set in situ.• Determine yearly seed set in natural and constructed pools.• Establish estimates of seed bank numbers through soil cores.• Assess whether yearly seed set estimates suggest a substan-tial addition to the seed bank, or indicate a continual draw down from the seed bank without proper replenishment of seeds each year at natural and constructed sites.
Thanks to Kandis Gilmore and Dolly Friedel and Laguna Foundation interns: Betsy Black, Laruen Kerr, Amber Parsons, and Avi Starr-Glass. This work was funded by the CA Dept. of Fish and Game.
Preliminary Results
Enclosed inflorescence keep insect pollinators out.
• Seed set in open pollinated inflorescence varied across species: B. bakeri (4.08 +/- 1.55), L. vinculans (2.06 +/- 1.77), and L. burkei (108.66 +/- 62.27).• Both enclosed and open pollinated inflorescences produced developed seed. • Cover class has no discernible effect on seed set in B. bakeri. Cover class does have a discernible effect on seed set in L. vinculans and L. burkei where increas-ing cover correlated with increasing seed set.• Pool type (constructed or natural) had a discernible effect on seed set in L. vin-culans and L. burkei, but no discernible effect on B. bakeri.
Soil auger collects samples to quantify the soil seed bank.
L. vinculans in flower
L. vinculans in fruit
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Sonoma Dunshine Sebastopol Meadowfoam
• Viable seed production in enclosed inflorescences suggests that all species are able to self fertilize or that our enclosures failed allowing pollen transfer. • Seed collections in the coming years will further elucidate the reproductive ecology of these endangered species, however preliminary results suggest that L. vinculans and L. burkei may produce more seeds in natural vernal pools with dense flower cover whereas B. bakeri seed set is less affected by pool type or cover class.• Preliminary analysis of the soil seed bank suggests that B. bakeri seed are only present in the surface organic matter and the first two inches of soil.
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Average seed set per open pollinated inflorescence for each species
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CNPS Cover Class BLBA LABU LIVI10% and below 3.98 90.76 1.4815% to 35% 4.27 100.30 2.8050% and above 3.97 121.79 3.38Grand Total 4.08 108.66 2.06
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