Problem:
You design an experiment to test the effects of biodiversity on colonization by a fouling community. You deploy a series of blank tiles on floating docks so that each tile starts as empty space suspended in the water. To some replicate tiles, you add one of three 'monoculture' treatments: three snails, three crabs, or three starfish; to 'polyculture' treatment tiles, you add one snail + one crab + one starfish. Your hypothesis is these species consume juvenile fouling organisms (barnacles, mussels, sponges). You also hypothesize a biodiversity-ecosystem function (BEF) relationship, with more diverse communities of grazers better at keeping tiles cleared of fouling species that otherwise quickly occupy all available space. After one month, you pull up the tiles and count two response variables for each treatment: (a), left panel: the mean number of barnacle recruits that have settled per tile; and (b), right panel: the total % area of the tile now occupied by fouling organisms (barnacles, sponges, mussels, oysters, and algae). A) Do the results for barnacle recruitment (left panel) support the expected BEF relationship? Why or why not, or to what extent? B) Do the results for total space occupied (right panel) support the expected. Need Assignment Help?