Eremalche Kernensis: Malvaceae) Field, Laboratory, and Greenhouse Work in March 1992 - June 1993 I
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| . ,;-,ANGEREDPLANTPROGRAM i I i Final Report to the I State of California Depa,:tt_ent ofFish andGame Contract# FG 1460 I I Demography and Reproductive Biology of I Kern Mallow (Eremalche kemensis: Malvaceae) Field, Laboratory, and Greenhouse Work in March 1992 - June 1993 I Report prepared by: Dr. Susan J: Mazer I Gretchen l._Buhn • Daniel E. Meade l_pattment of Biological Sciences I SantUniva Barbaersirtya,CofalCalififorniaornia93106 Telephone: (805) 893-8011 I FAX: (805)-893-4724 July 31, 1993 I I I I I | I | | Final Report to the State of California Depa_'m_entof Fish and Game I Contract#FG1460 I DemographyandReproductiveBiologyof I Kern Mallow (Eremalche kernensis: Malvaceae) Field, Laboratory, and Greenhouse Work in March 1992 - June 1993 I I Report prepared by: Dr. Susan J. Mazer I Gretchen LeBuhn • Daniel E. Meade Department of Biological Sciences SantaUniversityBarbara, ofCaliforniaCaliforni93106a Telephone: (805) 893-8011 FAX: (805)-893-4724 July 31, 1993 I I I ! i m i I TableofContents I Acknowledgements .......................................................................................... ............... 1 i Chapter 1. Project Outline: Questions Addressed ........................................................ 2 Natural History and Life History of Eremalche kernensis: Brief Overview ...... 3 I Chapter 2. betweenSources ofieldf variatipopulationson in reprofoduEremalchective succekernensss withiis n.....................................and 8 i Overview .................................................... :....._........................................................ 8 2.1. Field Methods: 1992and 1993 .................................................................. 10 Population 1............................................................................................ 10 I Population 2............................................................................................ 13 2.2. Greenhouse and Laboratory Methods ........................................................ 16 I Results ...................................................................................................................... 17 i 2.1. Variaticombinedon betweendata fromindividuals,both populationsgenders,......................................................flower colors and dates: 17 2.2. Differences between the two populations .................................................. 30 I 2.3. Effects of date, gender and flower color in each population: three-way analyses of variance .................................................................. 41 I 2.4. Variation within populations: each date evaluated separately .................. 54 2.5. Does E. kernensis require insect visitors for seed set?: I results of bagging experiment .................................................................. 106 2.6. Seed weight and abortion: I effects of seed number per fruit, gender, and flower color ...................... 109 2.7. Vegetative data: branch number predicts reproductive output ................. 125 I 2.8. Interspecific competition: effects of removing competitors ..................... 131 2.9. Intraspecific competition: effects of local population density .................. 137 I 2.10. Effects of grazing on growth ..................................................................... 142 i 2.11. Emergence of E. kernensis seedlings from seed bank ............................... 147 Chapter 3. Sources of variation in reproductive components in the greenhouse .......... 153 I Questions addressed ........................................................................................... 153 I Methods and experimental design ..................................................................... 155 I ii I Results ...................................................................................................................... 157 I 3.1. Effects of gender on seed traits ................................................................. 157 3.2. The effect of pollen donor and recipient on reproductive components .... 165 I 3.3. crossesEffects onof sseedelfingnumberand within-populand seed massation.....................................................vs. between-population 252 I 3.4. Reproductive compatibility of Eremalche kernensis and E. parryi .......... 269 Chapter 4. Summary and Recommendations..: ......... .................................................... 295 Literature Cited ...................................... .i..._........... _......_,.............................................. 299 Appendix A" Raw data from field populations .............................................................. 301 I Appendix B: Raw data from greenhouse populations ................................................... 418 ! I I | | i I I ! ! | ! | 1 I Acknowledgements | | We would like to thank the California Department of Fish & Game for supporting this I research. I Bseedeth bankHenderistudiescksontocobserveontributedseedlingher skillemergences in the fieinldtheandgreenhouse.greenhouse; she conducted the I ThelasonbrPrice.eeding experiments reported in Chapter 3 were conducted in the greenhouse by i Gwen Bell and Thek Moua provided assistance weighing and counting seeds. ! I | ! ! I I ! I I I ! 2 I Chapter 1 I Project Outline I In March of 1992 we proposed to the California Department ofFish and Game (CDFG) to study the demography and reproductive biology of the federally listed I candidateendangeredforplantlistingspecies,by theKernCDFG.MallowThis(Ereportremalchcoverse kerntheenslabois; rMatory,alvaceagreenhouse,e). This plantand is a field work conducted in the summer and fall of 1992, and the spring and summer of 1993. I Previous reports have covered field data collection (June 30, 1992), and laboratory and greenhouse work (November 1, 1992) conducted in 1992. This report summarizes all greenhouse and field work conducted between February 1992 - June 1993. I General questions addressed in this study are: I Whatof Eremalcheare sourceskernensisof variation? in reproductive success in field populations i Spe1. cHowifically,doeswetheaskedphenotypic: variation in flower color and gender influence components of reproduction? Do white-flowered and pink-fiowered morphs differ with repect to ovule I withand seedrespectproductionto these petraits?r floweIsrthis? Dovariationhermaphroditicconsistentandacrossmale-sterilepopulatimons?orphs differ 2. HowEremalchemuch pkernensishenotypiconvaria particularation is theredate?amWhichong rancomponentsdomly sampledof fitnesflowserams anmostd fruits of variable and which are most consistent ? Do individual plants vary with respect to trait means? Do gender and flower color influence components of reproductive success? 3. Do components of reproduction change across the season? Within a population of Eremalche kernensis sampled on a specific date, how much phenotypie variation is i theremost variableamong rananddomlywhichsamamplmosted flowersconsistentand fruits?over theWhicoursech compof oneonentsgrowingof fitnesseason?s are Do individual plants change significantly over time with respect to trait means? I 4. Dperoesfruit,the nuthembernumberof viableor proportionseeds peroffruitabortacecuratelyd seeds,predictand themeantotal individseed weightual seeperd wfruit?eight Is there any trade-off between seed number per fruit and mean individual seed weight? I Does this relationship differ between field and greenhouse populations? 5. Does the number of reproductive branches accurately predict the number of flowers, i buds, fruits, or potential fruits produced by an individual? 6. How do populations differ in density? Does population density influence lifetime fruit production? I 7. What is the effect of interspecific competition on survivorship, growth or reproduction in Eremalche kernensis ? | | ! 3 I 8. What is the effect of grazing on average branch length, branch number and plant size? Does sheep grazing influence survivorship, density, or plant reproductive success? ! and ! What are sources of varia•tion in reproductive components in the greenhouse? I Specifically, we asked: I 1. Whatother arewords,the effectssince Eremalcheof gender onkernensisseed numberis gynodiecous,per fruit andwhatindividualdifferencesseed inmasfemales? In reproduction are observed between hermaphroditic plants and male-sterile plants? I 2. Whatviableisseedsthe effectproduced,of pollenmeandonorsindividualand ofseedindividualweight, recipienttotal seedplantsweighton perthe flower,number of number of aborted seeds per flower, and the proportion of aborted seeds per flower? I 3. What is the effect of selfing, and within-population vs. between population crosses on seed number per fruit and seed mass? I 4. Are Eremalche kernensis and E. parryi reproductively incompatible? I Natural History and Life History: Brief Overview | Study sites i The two field study sites for the 1992-1993 season were located in Kern County approximately 6.1 miles north of McKittrick, California. Population 1 is located 50 meters south of Ix)kern Road approximately 1.6 miles east of State Highway 33. Population 2 is I oflocatedthe trianearngletheformedintersectionby theseof StwotateroadsHighwanday an33oilandpipelineIx)kernroad.RoadThenearterrthezinsouthernis mostlyendfiat with scattered drainage depressions 1 to 2 meters deep. Vegetation is a combination of saltbush scrub (Atripex spp.) and mixed grassland. These sites are described in greater I detailinChapter 2. Sheep grazing is practiced in this area in the spring following seasonal rains. I years.PopulationSheep2