Welcome to Methods in experimental ecology PCB 6466

Instructors: Lina Sánchez Clavijo, Office: Biology Bldg. 409 Office hours: Mon: 4:00-6:00, Thr: 4;30-6:30: Pedro F. Quintana-Ascencio, Office: Biology Bldg. 401 E Office hours : by appointment

First reading

Link to course web site Course Based on: Gotelli, N. J & A.M. Ellison A primer of ecological statistics. Sinauer. Crawley, M.J Statistics: an introduction using R. McCarthy, M Bayesian methods in ecology. Cambridge.

Grading Item % 3 exams homework exercises graded (13 total) 50

Etiquette for communication Do not wait to the last minute. There will not be any response to questions within 24 hours before homework or exam due date. We like our weekends, please no s on Saturday and Sundays. We will respond first come first served on Monday

Exercises a single Word document with your results. All analytical work needs to be done in R (unless otherwise noted). Scripts and output from R should be included in the Word document for full credit. They will be due a week from the day they are assigned. No assignments will be accepted after the start of the class on due date

Species correlates of Florifacies mirabila in playa linda Pedro Quintana-Ascencio Universidad de Cancun, Yucatan, Mexico

Florifacies mirabila Small mammal Feed on insects. It has glandules around the mouth producing a sweet secretion that attract plant pollinators. It is extremely sedentary Endemic to the Yucatan peninsula

Thorny plant (Opuntia sp.)

Objective To evaluate the association between Florifacies and Thorny plant (Opuntia sp.) Hypothesis Because both have flower like structures Florifacies and Thorny plant will be positively associated

Methods I established 59 1 x 2 m plots I counted every individual of Florifacies and Thorny plant (Opuntia sp.) within the plot Data was entered in Excel and analyzed with SPSS software

Florifacies mirabila Thorny plant Nice Palms Pedro Quadrats Sampling design

Are Florifacies and Thorny associated ? FlorifaciesTotal AbsentPresent ThornyAbsent46450 Present459 Total50959 Likelihood ratio = , d.f.= 1, Asymptotic significance (2 sided)= cells (75.0%) have expected count less than 5. The minimum expected count is.17

Florifacies density N=59 quadrats Do Florifacies density correlates with thorny plant density? How?

Conclusions Florifacies and Thorny plant (Opuntia sp.) are associated (P=0.001) Their densities are are positively correlated (P<0.001) My hypothesis was correct

What is wrong? Do you agree with this conclusions? Is the experimental design acceptable? Is the analysis correct?

How can we access this door? Experimental design and Data Analysis

What we need? ?