User: | Open Learning Faculty Member:
Blog Post 3: Ongoing Field Observations
October 2, 2017 15:45
Sunny, moderate winds, 20°C
The organisms that I plan to study are the mosses on the ground in my study plot. These include step moss (Hylocomium splendens), big red stem (Pleurozium shreberi), broom moss (Dicranium scoparium), spear moss (Callienganella cuspidata), and roadside rock moss (Racomitrium lanuginosum).
The environmental gradient that I have chosen to look at is related to the position of the ground on which the mosses grow. As the ground is made up of undulations of bedrock, I have chosen to look at the different aspects on these undulations, including the west face of a rock outcrop, the crest of the outcrop, the east face of the outcrop, and the depression between the rock outcrop and the next one (Photo 1). I sampled an approximately 1 m by 1 m square plot in each of these locations and estimated percentage cover of each species (Photo 2). As there are multiple rock outcrops within my study area, I will be able to analyse multiple replicates.
I observed that spear moss was the most abundant species on the sides of the rock outcrops (60% cover on the west aspect and 40% cover on the east aspect), while broom moss was the most abundant species in the crest position (75% cover), and big red stem was the most abundant species in the depression (60% cover). Total moss cover also varied with position, changing from 100% on the west face, 92% on the crest, 61% on the east aspect, and 88% in the depression. On the rock outcrop itself, the remaining area was made up of exposed bedrock and lichens, while in the depression, this also included shrub cover from salal (Gaultheria shallon).
I expect that multiple factors contribute to the variation in distribution of the different species, including aspect and sun exposure, substrate (rock versus soil), and moisture and nutrient availability. My hypothesis is that the variation in species cover is correlated to the slope position and substrate.
The predictor variable that I will use is the slope position (i.e. west face, crest, east face, depression), which is a categorical variable. The response variable will be the percent cover of each species of moss, which are continuous variables. As such, the experimental design will be an ANOVA test.
ok good start. Closely related to slope of course is the concept of aspect. you may want to include that in your Discussion, even if you aren’t measuring specific aspects in degrees or percent at each of your sample plots. Oh, and now I just went back over your past and see aspect is mentioned! good – it is a main driver in many cases.
Please take a look at the guidelines around posting photos – they should be reduced in resolution for web display so that they are kb rather than mb. You can do that simply by taking a screenshot of a photo and then posting. Thanks for not filling up our online memory!