pics

[mossy oak]

what is the black stuff under the moss, posted this in the plants section also but not getting any responses. Is this type of mold harmeful to moss.

[mellowvision]

it could just be discoloration from water saturation, or an area that's too wet for the moss, but it also looks like it could be a spot of algae developing, which can happen if there's enough water. I doubt it's harmful to the moss, but could stop it from spreading. I do have a small paludarium with a cork drip wall, growing moss, HC, and mini pellia, and areas of that do get clogged up with algae from time to time. it doesn't seem to stop the spread of the plants, but can be unsightly when it gets to be too much.