How would you design a controlled experiment to measure the effect of falling leaves on net primary

Hey, before we can understand this question, lets look at some definitions. Firstly, a controlled experiment is one in which there is a (1) "control" subject as well as (2) the subject being experimented upon where a single variable is being experimented (i.e. leaves falling).

Now look at the question being asked. There are two ponds. One pond will act as our control while the other will not. Net primary production is the gross primary productivity consumed as energy source in the metabolism of the producers. So the primary producers use the chemicals in the leaves to produce energy. In order to test this in two different nearby ponds, you can measure the primary production in the 1st pond with falling leaves and with the second pond you must have no leaves falling into (somehow cover the pond with nets or have leaf catchers). This way you can see the difference of what happens (for instance, an increase in biodiversity in the pond where leaves had fallen versus a decrease in biodiversity where leaves had been caught (the control group)).

Tell me what you think or any ideas that come to mind so I can elaborate further.

Bio_man