Answer:
commensalism and herbivore
Explanation:
To be able to grasp the concept of the answer, let us discuss a bit on what commensalism; herbivore is.
Commensalism as a word is basically biological phrase in which during the relationship between creatures of different species or the same specie( for instance, lets say we have Specie A and Specie B).
It is a situation whereby members of specie A get benefits of the the relationship between the two species while specie B does not get any benefit from the relationship neither is it harmed by virtue of the relationship.
Herbivore: This can be classifies as animal category that specializes in the consumption of plants, roots and herb. Basically, plant makes up the majority of their diet.
Now, relating this definitions to the question asked, we can clearly see that The trophic facilitation phenomenon described by Hacker and colleagues involves direct interactions between two salt marsh plant species (Juncus and Iva) in the form of commensalism with indirect effects benefiting an herbivore of one of the plants