Question

What is a mechanistic reason for why you might expect a negative relationship between native and invasive plant diversity at a local scale of 10m ? And explain how that relationship could be positive at a larger scale ?

Answer 1

Two species can be under a negative, positive or neutral relationship with each other depending upon their mutual distance from each other as one of the abiotic factors. Here, considering that one of the species is native while the other is invasive, it can be clearly understood that when these two species are in close proximity of each other, say leass than 10m, they might compete with each other for space, biotic factors and abiotic resources. Hence, they will tend to develop a negative realtionship.

On the other hand, when the two species are distantly located, they will not tend to develop competetion and hence, will grow independently. Since these two species are able to grow in similar environmental conditions, their respective growths at distant locations will, in turn, add up to the total genetic pool and diversity of the plants. Hence, they will tend to have a positive relationship.