DISCLAIMER: This website is for a class project. The dataset used for analysis is preliminary and/or heavily modified. Any conclusions derived from this analysis should be considered fictional.
Summary
The spread of invasive species has become one of the biggest ecological problems and has now become the main cause of extinctions worldwide. The need to understand the drivers of distribution and the vectors of spread of invasive species is essential.
The algae species Didymosphenia geminata is becoming increasingly problematic in streams around the world as it can form enormously thick mats which can significantly alter the ecological properties of that system. D. geminata has recently been observed in streams in the Arctic, particularly in Alaska and most recently in the Yukon. This has the potential for devastating repercussions, as the ecosystems in the Arctic are quite fragile and are vulnerable to any alterations. It is currently unclear what the drivers are of the distribution of D. geminata in the Sub-Arctic region of the Yukon. This study sampled streams over a large latitudinal gradient in the Yukon, where physical, chemical and biological characteristics were recorded along with whether D. geminata was present or not.
Five of these environmental factors were chosen to act as predictor variables in a series of statistical tests to determine if in fact these variables have a role in determining the distribution of D. geminata. Two-tailed t-tests with the proper correction for multiple comparisons were run with measurements of pH, conductivity, temperature, water velocity and stream width of sites with and without the presence of D. geminata. Due to the categorical nature of the data, a logistic regression was also run and the results were compared to those of the t-tests. Both analyses resulted in water velocity and temperature having a role in the whether or not D. geminata is present.
The presence of D. geminata in sub-Arctic Yukon streams seems to be mainly driven by water velocity and temperature.
The algae species Didymosphenia geminata is becoming increasingly problematic in streams around the world as it can form enormously thick mats which can significantly alter the ecological properties of that system. D. geminata has recently been observed in streams in the Arctic, particularly in Alaska and most recently in the Yukon. This has the potential for devastating repercussions, as the ecosystems in the Arctic are quite fragile and are vulnerable to any alterations. It is currently unclear what the drivers are of the distribution of D. geminata in the Sub-Arctic region of the Yukon. This study sampled streams over a large latitudinal gradient in the Yukon, where physical, chemical and biological characteristics were recorded along with whether D. geminata was present or not.
Five of these environmental factors were chosen to act as predictor variables in a series of statistical tests to determine if in fact these variables have a role in determining the distribution of D. geminata. Two-tailed t-tests with the proper correction for multiple comparisons were run with measurements of pH, conductivity, temperature, water velocity and stream width of sites with and without the presence of D. geminata. Due to the categorical nature of the data, a logistic regression was also run and the results were compared to those of the t-tests. Both analyses resulted in water velocity and temperature having a role in the whether or not D. geminata is present.
The presence of D. geminata in sub-Arctic Yukon streams seems to be mainly driven by water velocity and temperature.