Data for this project is from two Parks Canada studies published in 2020. These studies were the result of monitoring programs in the Mingan Archipelago National Park Reserve in Eastern Quebec. Each study aimed to detect changes in the number of colonies and abundance of rare plants in tundra and coastal environments. Rare plants on islands with tundra environments are: Anemone multifida var. multifida, Cerastium alpinum ssp. Lanatum, Cypripedium passerinum, Cystopteris montana, Diapensia lapponica, Draba aurea, Platanthera hookeri, Streptopus X oreopolus, and Woodsia glabella. Rare plants on islands with coastal environments are:Taraxacum laurentianum, Pedicularis palustris, Erigeron lonchophyllus, Rosa blanda, and Rosa acicularis.Sampling plots for known location of each of these rare species are established and surveys of these plots were conducted every 5 years, some going back as far as 1990, and all ending in 2020. For the purposes of this project, we are interested in the diversity and abundance of rare species, and use survey results that showed species name, abundance, island name and survey year. Years where no surveys were conducted are not reflected in our figures. Additionally, island size (in km²) was calculated by satellite imagery using Google Earth Pro. Distance to mainland was also estimated for each island (in km). These values were estimated in Google Maps using the Measure Distance feature across the smallest possible distance between the island and the mainland.
Main Islands in the Mingan Archipelago National Park Reserve
This map denotes how the area was mapped out and measured using Google Earth Pro. The red outlines are where the perimeter of the island was denoted and the area within it was calculated in km².
Statistical Analysis
Species richness and Shannon's Diversity Index of all the rare species were calculated in Microsoft Excel for each island, regardless of habitat type (coastal or tundra). In R, these values were plotted against the predictor variables of island size and distance to mainland and correlation and regression was done to determine if there was any relationship. Pearson correlation analysis was completed for both species richness and Shannon's Diversity Index. A linear regression was run as well, and the regression line, regression function, R² value, and p-value were added to each plot. Although island biogeography theory tends to suggest a more logarithmic relationship between richness versus island size or distance to mainland, a linear regression was used because of our small sample size and preliminary exploration of the data suggesting that a linear model and logarithmic model produced similar R² values.