Writing Group Lab Reports

 

Abstract

One paragraph summarizing the report, including the objectives of study, methods, and results.

Hint: One or two sentences to describe each section (intro, methods, results, and conclusions).

 

 Introduction

Give the background necessary to understand the question (use literature where appropriate). Describe the objectives of your study and state your hypotheses.

Hints:

  1. Make it clear why you chose your particular hypothesis by relating it to the background material you provide.
  2. Citing outside references improves your grade! Use our journal articles to learn how to format citations correctly.

 

Methods

Description of the study area and the methods used to carry out the experiment.

Hints:

  1. Write in paragraph format. Don't list the equipment used; but do tell us how they were used.
  2. Include only the pertinent information so someone else can replicate the study.

Results

Present your data in tables and graphs, with a brief text describing the most important values to look at.

Hints:

  1. Do not include ‘raw’ data in the main part of the report. Field data sheets can be appended to the back of the report if you choose.
  2. Please label and give titles to all figures and tables. Refer to labels in the text. (Look at a journal article for proper formatting)

 

Discussion

Explain and interpret the results. Describe whether or not the data supports your hypothesis. Suggest possible explanations for why you obtained these results. Discuss limitations to the study or improvements for future work.

Hint: Be clear on what are facts (your observations) and what is merely a suggestion (ie. Variability in the results MAY be due to…)

Conclusions

Summarize the main conclusion from your study (and reiterate whether you hypothesis was supported). Describe how your conclusions could be applied elsewhere. Are there broader implications for your conclusions (i.e. management implications)?

Here is a silly example of an Introduction, including Objectives and Hypotheses, and Methods:

Tree Mood along an Environmental Gradient

 
Abstract
 
Tree mood is a possible method of evaluating the suitability of tree species to site conditions.  We measured the mood of five tree species along an environmental gradient at Heiberg Experimental Forest, Tully, New York.  We expected to find that trees were happiest at the center of their ranges, as indicated by a mood ring.  , the mood ring was black at every reading of
 
Introduction

Environmental factors, such as climate, soil type, and topographic position, are important in determining the distribution of plant species on the landscape (Perry, 2000).  Plants are adapted to a wide variety of environmental conditions, and different species of plants thrive in different types of sites.  The state of happiness or anxiety of plants has been overlooked as an indicator of plant adaptation to site, although they have been much studied in humans (Antoine, 1997).  Clearly, plants should be most happy when they experience the environmental conditions for which they are best adapted, and they should feel nervous or anxious when the conditions are not suitable for their growth or reproductive success.

In this study, we used plant mood, as indicated by the color of a mood ring (Piscatelli, 1976), to describe the suitability of the environment for five species of trees occurring along an environmental gradient at Heiberg Forest, New York.  We expected to find the happiest plants (dark blue mood) at the center of the range of each species along the gradient, and more stressed plants (gray to black mood) at the extremes of the distribution.

(Notice that the hypothesis is very specific, it doesn't just say that mood will be related to site.  Nor does it state the null hypothesis, that mood is not related to site.)

Methods

We studied trees along a transect from the top to the bottom of a S-facing slope at the Heiberg Experimental Forest near Tully, New York.  We took measurements at 7 points located at approximately 50-ft intervals.  At each point, we measured the mood of three individuals of each of five species, namely Eastern hemlock, red spruce, black cherry, and American beech, using a mood ring.

The mood ring was applied to a leaf and the color recorded using a Munsell color book.  Mood was related to color as follows:
Dark blue: Happy, romantic or passionate
Blue: Calm or relaxed
Blue-green: Somewhat relaxed
Green: Normal or average
Amber: A little nervous or anxious
Gray: Very nervous or anxious
Black: Stressed, tense or feeling harried
 
In addition to testing the mood of the trees, we also measured the mood of the human investigators, to demonstrate the working of the mood ring.
 
Results
 
Contrary to our expectations, the mood of trees as indicated by a mood ring did not vary with the location of the trees.  We observed no differences in mood by species, either.  The mood of every tree we measured (105 trees in total) was "stressed, tense, or feeling harried."  In other words, the mood ring remained black throughout the duration of the experiment.
 
We were afraid that the mood ring we used might be faulty, so we also applied the mood ring to ourselves.  Of our three investigators, we found one "somewhat relaxed," one "normal or average" and one "a little nervous or anxious."
 
Discussion
 
The lack of response in tree mood to site could be attributable to one or more of several factors.
 
First, we doubted that the equipment was working properly.  However, we found that the mood ring responded readily to human fingers, though it never changed color when applied to leaves.
 
Second, we considered whether the tree species we observed were equally suited to all seven of the points along our gradient.  This interpretation seems unlikely, because the distribution of species differs dramatically along the gradient.  Hardwoods dominate at the top of the slope, where the soils are at least moderately well drained.  Hemlock is present only at the bottom of the slope, where the drainage is very poor.  We believe that the reason sugar maple and black cherry are not present on the poorly drained soils is that they cannot tolerate flooding or anaerobic soil conditions.  Individuals growing closer to the unsuitable condition should be physiologically stressed.
 
We believe that a third factor explains our results.  The mood ring uses liquid crystals that change color depending on the temperature (HowStuffWorks, Inc.,http://science.howstuffworks.com/question443.htm).  Human beings, being warm blooded, have temperature changes in their skin that reflect physiological changes associated with mood.  The temperature of trees, in contrast, is mainly determined by the temperature of the environment, and is not much affected by their physiology.
 
We conclude that mood rings are not a good tool for studying the physiological response of trees to environmental conditions.  Stress indicators suitable to trees, such as putrescine and arginine (Minocha et al. 1997) would be better candidates for revealing whether tree species distribution is limited by environmental factors.
 
References
 
Minocha R, W.C Shortle, G.B. Lawrence, M.B. David, and S.C. Minocha. 1997.  A relationship among foliar chemistry, foliar polyamines, and soil chemistry in red spruce trees growing across the northeastern United States. Plant and Soil  191: 109-122.

 

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