Category: Post 5: Design Reflections

Implementation of sampling strategy

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I am hypothesizing that the number and length of projections of Creeping juniper will vary based on their distance from a man-made staircase at Cranberry Flats, Saskatoon. Specifically, along the South-East side of the stair case, where creeping juniper runs immediately perpendicular to the stairs, there will be fewer and shorter projections of Creeping juniper compared to the NW side where the Creeping juniper sits at least a meter from the stair case.

Implementation of my sampling strategy went fairly well. I chose to sample 10 random sites of Creeping juniper on either side of the stair case at Cranberry Flats. At each site I counted and measured the number of projections extending from the main plant body in a 1m span. I intended to randomly measure the length of three of the projections in each 1m span; however, in all cases, there were no more than two projections, at times even zero.

I used a random number generator to determine which projections I would measure at each site. As stated above, I was not able to implement this randomization in the first five replicates. However, to counter this issue in the remaining replicates, if there are 4 projections in the 1m span and I am supposed to measure projections 1, 2 and 5, I will adjust my procedure and measure projections 1, 2, and 4 in order to maximize observations. This will increase the amount of data I have at each replicate site. Although I will still only have ten data points per side of the staircase (mean length of projections), if I am able to measure three instead of two projections, my data will be more representative of what is found in the environment.

Blog Post 5: Design Reflections

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During the month of May is typically the time of year that we see the greatest change in our seasons. Unlike Canada we have two seasons a wet and dry and we are now moving from our wet season towards our drier months (May,June,July,August,September). This has brought cooler temperatures during the day and night as well as different movement of animals, particularly Elephant. It has made data collection hard as the larger herds of Elephants are not moving through the area and the bull elephants are not in great numbers.

The Camera traps have caught a lot of action at the water holes mainly from Impala (the most common antelope in the area), hyena, lion, and warthogs. There have been two instances in the past in the past 9 days where I have caught Elephants drinking at the water holes. Once at Xinatsi dam around 6pm when one elephant bull came and drank and once at Marula pan where two bulls came and drank around 2.30pm. Surprisingly the two most dominant animals in terms of numbers present throughout the day at the water holes are warthog and impala by day and hyena at night, which could have been suspected.

I do plan to continue this method of data collection, as it is the best way to monitor the activity at the water holes without being there day in day out.The use of camera traps to monitor an individuals behaviour in the wild has been a technique used since the 1980’s.  The water holes I have chosen to monitor are non-random points that will be monitored for the presence/absence of elephants which is my response variable. The time of day the elephants drink and the temperature at that specific time will be my predictor values.  However through much contemplation I have decided to try and maximize the amount of elephants to be captured on the camera traps by increasing the amount of water holes to monitored to 10 (see below picture). These water holes are spread out over the 15,000 hectares of traversing area that Motswari uses in the Timbavati Private Nature Reserve. Each camera will be placed once at every water hole for 5 days and 5 nights. This will hopefully increase the opportunity to collect data on the elephants drinking habits.

The elephants being highly mobile creatures and with there being no fences to contain them in one general area has made it hard to collect data as they have 3 million hectares to traverse through but hopefully by increasing the study area it will maximize the data I can obtain to get a better understanding of their drinking habits and how that relates to the maximum temperature during the day.

 

Water holes to be monitored.
Drinking at Xinatsi dam (missing the left hand side tusk)
The warthog watches patiently for a turn at the water hole !

Post 5 – Design Reflections

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The ongoing winter of weirdness that Northwestern BC has been subject to has made the implementation of my sampling strategy interesting and challenging. Temperatures during my sampling period have ranged from well above freezing to close to -30 degrees Celsius. The only precipitation that has occurred since I started collecting data has fallen as rain. My study area has therefore been transformed from a veritable winter wonderland into a poorly-conceived skating rink!

The biggest challenge that the odd weather has presented to me has been maintaining access to my sampling locations. I initially chopped holes in the ice with an axe to create my three sampling locations. I was surprised at the time to find upwards of 50 centimetres of ice at my middle and upstream sampling locations. Since then it has rained and gotten cold. The additional load of the rain water on top of the existing ice has caused it to sag and create a positive pressure when a hole is established in the ice. This pressure forces water to the surface, where it freezes almost instantly. I have therefore had to chop through 15-20 cm of ice each time I set my traps and each time I check them. This takes some time and usually results in me being covered from head to toe in a thin veneer of ice. If I was going to maintain these sites for much longer I would definitely be exploring other means of accessing them!

I was also surprised to find that my upstream location was of moderate depth and minimal velocity. I had initially thought that this site would represent a relatively deep and fast sampling location. Given the time and effort it had taken me to establish the site, I decided to use it and shifted my definition of a relatively deep and fast flowing sampling location to the middle location near the bridge.

The results of my first sampling effort were a relief and a surprise. I was expecting to catch juveniles at the site near the bridge where I had observed them during summer months. I was therefore somewhat surprised and disappointed when I pulled an empty minnow trap from this location after my first sampling effort.  I was equally surprised and relieved to find a juvenile in the trap that I pulled from the upstream location.

Capturing this single fish provided me with some assurance that I would have results to discus and that my project was at least feasible. Prior to this point I was not certain, as a number of people had suggested that my chances of capturing juveniles during the winter months were low.

I took my initial success as a good sign and elected to continue utilizing my initial sample design and collection methods. I have since completed three additional sampling efforts and have captured juveniles each time. My thoughts on why I am catching juveniles where I am catching them are evolving, but my results appear to support my initial hypothesis thus far. I am therefore going to keep on fishing!

My downstream site acting as a drain for rainwater… It dropped to -20C the next day.
Brrrr!

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I had collected the initial data by using a transect sampling with systematically placed units of 32cm by 16cm (divided into 2x8cm sections) both in the residential area and lake area of campus and by the lake. I used these to average how many patches (or average percentage) of the area grass had ceased to grow. The results from my initial field data showed as predicted that there was more area (by percentage) of the ground that grass was not present. In addition, I found more species of ground vegetation such as hieracium and taraxacum (common weeds) in the lake area then the residential area.

 

I recently got some really good feedback on my field study from a comment on my post and have since needed to review my hypothesis and feasibility of my study. In addition to this the weather has drastically changed and it is making it increasingly difficult to explore species abundance and diversity when the grass (my initial vegetation to study) is covered by several inches of snow and ice! I am no longer able to collect the data in the same way as some sampling units are iced over it would require for me the dig through the snow and ice (potentially removing the vegetation in the process) in order to see what I need to collect the data.

 

For these reasons I have chosen to take a new direction of study. Instead of exploring the vegetation I have chosen to test the acidity of the snow (in the same areas as studied previously). I will do this by taking samples of the snow at each sampling unit along the two transects and testing the samples pH level. I hypothesize that the pH will increase due to the run off from the road salt in the residential area and will be neutral where no salt is used. The significance of this study is that the change in pH may cause a change in the soils alkalinity fostering a less viable soil for vegetation.

 

I believe that changing my study is necessary and by sampling the technique for testing I will be able to produce more accurate results. From there, I will be able to do research as to the effects road salt and sand on vegetation to further understand the implications.

Post 5: Design Reflections

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  1. Create a blog post to discuss the collection of the initial data in Module 3. Did you have any difficulties in implementing your sampling strategy? If yes, what were these difficulties? Was the data that you collected surprising in any way? Do you plan to continue to collect data using the same technique, or do you need to modify your approach? If you will modify your approach, explain briefly how you think your modification will improve your research.
  2. Read some of the blogs done by other students in this course and look over the hypotheses that they are investigating. Please offer constructive criticism of one other student’s hypothesis. Post this feedback as a comment on their blog. Topics to consider for feedback include: is the prediction clear and falsifiable, are the pieces and patterns under investigation clearly stated, do the predictor and response variables seem easily measurable in a field setting, and are there any potentially confounding variables that the investigator should be concerned about.

Remember to check the “Categories” box for Post 5: Design Reflections when you post.