The organism under consideration is an invasive species called Canada Thistle ( Cirsium arvense).
From the chosen area, a trend was observed from the South-West end to the North-East end. The organism under consideration i.e. Canada Thistle is abundant to such an extent that it is the only found species in the South-Western side of the area. As we proceed towards the North-Eastern part, the abundance declines but still Canada Thistle remains the dominant species with other species spread out in a random fashion.
I think the reason for the above mentioned trend is the nature of the Canada Thistle as an invasive species. Entire area has been dominated by these species with other species found only in places with less Canada Thistle abundance. Despite the dominance, it’s not as if there are no other species. There are plenty of other species in the proximity but the abundance is much less than the Canada Thistle. The prediction is that the presence of invasive species is affecting the growth and persistence of other species in the area and if this is beneficial or harmful for the ecosystem in the long term or not.
A potential response variable is the presence and abundance of other species (excluding Canada thistle) in the area and a potential predictor variable is the abundance of Canada thistle in the area. I think both the variables will be continuous as we are dealing with actual numbers of the species.