OBJECTIVES:
For you to practice science through conducting a hands-on, scientific investigation. For you to gain further experience and confidence in your ability to do science and to critically think. For you to gain experience in writing and presenting scientifically.
ASSIGNMENT:
You will be assigned into a desert ecology group.
Through collecting data in the desert your group will produce the following:
A research question, proposal, and presentation
RESEARCH QUESTION:
This is a question that can be answered (considering the time and resources available) through collecting data in the field. Ask yourself whether your question can be answered by just analyzing the data you collect in the field (without a literature review). Hint: for this assignment, your initial question should be an “Are…” question (descriptive) rather than a “Why…” question (causal). For example, ask, “Are there more spines on one side of a cactus than on the other sides?” Don’t ask, “Why are there more spines on one side of a cactus than on the other sides?” Before you can legitimately ask a “Why” question, you need to answer the “Are” question (maybe there aren’t more spines on one side of a cactus than on the other sides. You will ask the “Why” question and create multiple hypotheses after you answer your descriptive question.
Definitions of useful terms:
Density: the number of individuals occurring in a given area (e.g., 50 plants per 2000 square meters).
Richness: the number of different species (e.g., 18 plant species)
Hypotheses: possible answers to a question; possible explanations for a set of observations.
Null Hypothesis (H0): states that the data sets are not significantly different
Alternate Hypotheses (H1, H2, ...): state the data sets are significantly different.
Example:
Question: Does saguaro density differ between a north- and south-facing slope?
H0: Saguaro density does not differ significantly between a north- and south-facing slope.
H1: Saguaro density is significantly greater on the north-facing slope.
H2: Saguaro density is significantly greater on the south-facing slope.
Sample questions:
- How many groups of spines are on prickly pear pads, are there more spines on one side of the pad than the other, does spine length differ on opposite sides of the pads, what is the distribution of spine lengths, do the pads orient a particular direction?
- Do the number of species, number of individuals, size of individuals, length of leaves, etc. differ between plants in the wash versus outside the wash, flat slope versus south-facing slope versus north-facing slope, etc?
- How does temperature change from the ground upward, between sun and shade?
- How far apart do different plant species grow from each other?
- How fast do ants run, what affects their running speed, how do they know where to go, how many ants are there in that ant hole?
- Which direction do the holes in saguaros face?
- What is the ratio of trees to shrubs to cacti to forbs to grass, does it differ in different places?
- How many animal burrows are there, where are they, what are their dimensions?
- How long does it take for a “fly” sunning itself to move after you’ve shaded the “fly” with your hand from a distance away?
- How many flowers does a butterfly visit, how long does it stay at each flower, does it prefer certain flowers, how does it hold its wings relative to the sun when it has landed?
- The world is open to you as far as questions go, but you must be able to collect sufficient numerical data
SCORING RUBRIC FOR DESERT ECOLOGY LAB
- Proposal (5 pts): Participated fully in writing proposal
- Contains all headings
- Introduction: title (informative), names, research question, biological interest (when doing a comparison, what relevant factors will be different), and hypotheses (null and all alternative hypotheses).
- Contains Methods: repeatable; includes all subheadings and complete information under each subheading; the data analysis section must include how you will summarize and statistically analyze data.
- Contains Results: Tables/Graphs must have a name (Table 1, Graph 1, etc.), must have a complete caption (what are the data, sample size, location, dates/times, statistics used), must be fully labeled, and must include summary rows/columns.
- Failed to meet all in-class meetings (up to -5 pts)
- Data Collection (10 pts): Participated fully in collecting data
- PowerPoint (5 pts): Participated fully in production of PowerPoint presentation
- Complete and meets all tips to PowerPoint presentations given online
- Failed to meet all in-class meetings (up to -5 pts)
- Presentation (10 pts): see presentation rubric in syllabus
TOTAL: 30 points |