In Mediterranean regions like ours, riparian forests—or gallery forests—are highly productive ecosystems. They grow on both sides of river courses, so they rarely lack water, and their soils are very rich in nutrients. They are therefore home to a great diversity of flora and fauna.

Its vegetation plays a very important role for the ecosystem, as it serves as a refuge for flora and fauna, functions as a biological corridor (very important in areas highly fragmented by human infrastructure), acts as a filter for river water, functions as a flood buffer, improves the recharge of aquifers, etc.

The Sant Llop stream collects the waters of part of the southern slope of the Baier mountain range and the entire area of ​​the Les Agudes forest. The natural values ​​of the stream are much better preserved in the higher area, within the limits of the Montseny Natural Park, than in the lower part, which is much more altered by human action, especially in the vicinity of urban areas. The vegetation of the stream is the forests and riparian groves, mainly beech forests, dominated by alders (Alnus glutinosa) and other tree species, accompanied by herbaceous plants characteristic of these forests, such as the small comfrey (Symphytum tuberosum) or the dead nettle (Lamium flexuosum). Associated with this vegetation is also a large amount of fauna: amphibians, reptiles, and various birds stand out.

Following the itinerary of the northern path (GR-83), at several points you will cross or walk alongside the Sant Llop stream. You can enjoy the natural values ​​of the stream, but always do so respecting the environment and having civic behavior so as not to disturb these fragile and, at the same time, necessary ecosystems.