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What are edaphic effects?. Edaphic effects are soil characteristics that modify growth and development of plant species: Organic matter Inorganic minerals Heavy metals Water holding capacity Soil salinity. What is a narrow endemic?.
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What are edaphic effects? • Edaphic effects are soil characteristics that modify growth and development of plant species: • Organic matter • Inorganic minerals • Heavy metals • Water holding capacity • Soil salinity
What is a narrow endemic? • Narrow endemic taxa are species that occur in one or a few small populations • The genus Monarda contains 4 narrow endemics that grow in South Central Texas • M. fruticulosa • M. maritima • M. stanfieldii • M. viridissima
Why study endemism? • To understand biodiversity • To understand speciation in plants • To understand rarity as a means of facilitating conservation • To understand edaphic effects on growth and development of plant species • Endemics are often restricted by edaphic constraints
Species Descriptions • Monarda fruticulosa is a narrowly endemic species found only on the sand plains of central southern Texas • Monarda punctata is a widespread species that is found across Southern, Central, and Eastern North America • Phylogenetic analysis reveals that these two species are very closely related
Monarda punctatadistribution in the USAhttp://plants.usda.gov/cgi_bin/plant_profile.cgi?symbol=MOPUP
Hypotheses • Monarda fruticulosa performs better on M. fruticulosa soils than on M. punctata soils in general • Monarda fruticulosa performs better on native soil from it’s home site than on any other soil • Monarda fruticulosa is a perennial species and as such will have a higher root/shoot ratio than M. punctata
Collection • In May of 2002, Dr. Alan Prather collected soil and mature inflorescences from native plants growing on the coastal plains of southern Texas • 10 inflorescences each from 3 different populations of M. punctata • 10 inflorescences each from 3 different populations of M. fruticulosa • 60 inflorescences and 6 soil samples were brought back to MSU
Materials and Methods • A reciprocal soil trial was performed using three populations each of Monarda puncata and Monarda fruticulosa along with the soils upon which they were collected • We selected 60 seeds from each population and planted them on each of the six soils upon which the plants grew
Watering and Light Application • Plants were put under 12 hours light and 12 hours dark in the lab • Plants were top watered daily with distilled, deionized water • Plants were bottom watered on the weekends to prevent the soil from drying out • Lab temperature was approximately 72 degrees Fahrenheit
Data Collection • Germination date recorded for each seed • If applicable, date of natural seedling death recorded • 10 day intervals of growth recorded for each seedling • At 40 days of growth, each seedling was harvested and weighed
Data Analysis • 4 measures of fitness were considered for data analysis: • Germination • Height • Survivorship • Biomass
Statistical Test for the Difference between Two Population Proportions(Binomial Data)π = Probability of Successn = sample size Z= ( π – π ) π ( 1 – π ) π ( 1 – π ) + n n
Germination Results M. punctata on M. fruticulosa Soil (n=91) 85.70% M. punctata on M. punctata Soils (n=90) 70%
Survivorship Results M. fruticulosa on M. fruticulosa Soils (n=58) 82.80% M. fruticulosa on M. punctata Soil (n=58) 61.80%
Height and Biomass Results • There were no significant data supporting nor opposing our hypotheses • M. fruticulosa did perform better on M. fruticulosa soil in terms of height • M. punctata performed better overall in both respects
Height ResultsM. Fruticulosa on M. Fruticulosa Soils (n=89) 27.49 mm M. Fruticulosa on M. Punctata Soil (n=90) 25.32 mmAnalysis of variance by Anova
Root to Shoot Ratio TestResults show that M. punctata has a higher root/shoot ratio than M. fruticulosa
Hypotheses Analysis • Hypothesis supported: • Monarda fruticulosa performs better on M. fruticulosa soils than on M. punctata soils • Supported significantly in terms of survivorship • Trends support this hypothesis in terms of germination and height • Monarda fruticulosa did germinate better on its own native soil than on soil from any other site, but not significantly • Hypotheses not supported: • Monarda fruticulosa performs better on native soil from it’s home site than on any other soil • Monarda fruticulosa is perennial and therefore will have a higher root/shoot ratio than Monarda punctata
Conclusions • Survivorship data supports the hypothesis that M. fruticulosa performs better on M. fruticulosa soil than on M. punctata soil. • M. punctata is a better performer overall, out performing M. fruticulosa in terms of germination, survivorship, biomass, and root/shoot ratio • This may have to do with the fact that M. punctata is an annual and genetically programmed to complete it’s lifecycle within a season, requiring rapid growth • Whether or not the narrow endemic, Monarda fruticulosa, is edaphically constrained to it’s habitat, requires more research
Future Research • Soil analysis • Organic matter • Heavy metals • Salts • Water availability tests • Large scale reciprocal trials in nature • Survival to reproduction • Hybrid studies
Special Thanks To: • Jan Szyren • Greenhouse and moral support • Victor Bato • Mapping • Tao Sang • Analytical balance • Uwe Rossbach • Computer lab use and consulting • Deb Trock and Alan Fryday • Moral support
Dr. Alan Prather and graduate studentsJessie Keith, Orlando Alvarez, Rachel Williams, and Nate Sammons