BIOA02 ASSIGNMENT # 1
De-constructing a Scientific Paper
“Declines in Woodland Salamander Abundance
Associated with Non-Native Earthworm and Plant Invasions”
DUE: Feb. 26, 2013 ,by 3 pm . Submit Assignment to
SW403 between 10 am - 1 pm .
HARD COPIES ONLY, no email, no Turnitin.com
Late Assignments WILL NOT BE ACCEPTED
Worksheet totals 40. This Assignment is worth 4% of the total mark in the course.
Student NAME ___Yue Hu_____________: LAB SECTION: _____32___
Student #: _________999816409__________ TA: Jennifer van Eindhoven
PLEASE TYPE YOUR ANSWERS IN THE SPACE PROVIDED. REMEMBER TO ANSWER ALL QUESTIONS IN YOUR OWN WORDS!
1. List two justifications given for this research (motivations, observations, and findings
of past research are all justifications). (2 marks)
1). Past research from Nuzzo et al. (2009) report that 3 non-native plant invations, including
garlic mustard, invasion come with non-native earthworm invasions and reductions of forest leaf
2). Anecdotal reports suggest that area invaded by garlic mustard(Alliaria petiolata) with
significant reduce in woodland salamander abundance.
2. The authors do not directly state the questions that they seek to answer with this research. If
you were to sum up their research in a two concise questions, what would it be? (2 marks)
1). How does salamander prey abundance, excluding earthworm, change as leaf litter layer
reduces and non-native plant cover increases?
2). How does non-native plant cover and leaf litter volume be linked to the abundance of
woodland salamander abundance?
3. The authors give a generalized research hypothesis (H ). Whaa is it? (1 mark)
Non-native plant cover and reduced leaf litter volume are associated with reduced salamander
4. If you were to state a null hypothesis (H ) 0or the above Ha, what would it be? (1
There is no connection between reduced salamander abundance with non-native plant cover and
reduced leaf litter volume. 5. The authors give two predictions. What are they? (2 marks)
1). If the salamander abundance decreases as the loss of leaf litter happens due to earthworm
invasions and non-native plants invasion, then non-native earthworm and non-native plants
invasion are associated with the abundance of salamander.
2). If the woodland salamander prey abundance decreases as the loss of leaf litter happens due to
non-native plant cover and earthworm invasions, then non-native earthworm and non-native
plants invasion are associated with the abundance of prey of woodland salamander.
6. Summarize the experimental design. Fill in or calculate the following: (4 marks – 0.5
How many regions (hint: US states)?
There are 2 regions. (New York and Pennsylvania)
How many forest sites per region?
There are 5 forest sites per region.
How many habitats per site?
There are 2 habitats per site.
What were the two habitat types studied within both regions?
Region with non-native plants and region without non-native plants were studied within
both rehions. How many study plots per habitat per site?
There are 15 study plots per habitat per site.
How many coverboards per plot per habitat?
There are 2 coverboards per plot per habitat.
How many study plots were there in total in this research?
There are 300 study plots in total.
How many coverboards were there in each habitat in this research?
There are 30 coverboards in each habitat.
7. The regions defined in this research differ in two important ways. The first is that
each was invaded by a different plant species. The second is their environment.
Describe one important way that the environment (light, temperature, moisture, etc.)
varied between the two regions described. (1 mark)
Since the trees at the B. thunbergii were shorter with smaller crowns relatively, leading to the
result of greater light penetration and drier soils. However, trees are higher at A. petiolata with
less light penetration. This is the light varied between the two regions. 8. Several assumptions are made about the regions, sites, and habitats sampled. These
assumptions underlie important experimental factors. Name two of these assumptions.
Assumption 1: sites had a history within 60 years, which is sufficient time to keep forest organic
layers and salamander populations to precut levels.
Assumption 2: All environments in each plot are the same so that the environment in one
coverboard is enough to represent the whole plots. In this way, experiment can be performed
9. There are several controlled factors in this research. Give one example of a
controlled factor. (Do not give the experimental design listed above as a controlled
factor). (1 mark)
When researchers are getting samples, they will get samples from uninvited plots before
sampling invaded plots in this site to minimize the transport of invasive plants.
10. The researchers measured old leaf litter before new leaves fell in autumn. Why was
this important? E.g. – what is litter volume actually reflecting in the context of this study?
The leaf litter volume before new leaf fell is measured to determine the maximum cumulative
cover. Also, since soil fauna was greatest but fresh litter was not ready to fall to the forest floor
in the early autumn, the old leaf litter volume was measured at that time.
11. A t-test statistic was used to test data in this research. What were the dependent
variable(s) and independent variable(s)? (3 marks) D