The northern slope of Monte Caslano, characterized by fertile soils and good water capacity, is home to a dense mixed forest of broadleaf trees, dominated by Wild Linden and Lime, accompanied by Mountain Elm and, to a lesser extent, Ash, Cherry, Hornbeam and Chestnut. The undergrowth is lush. Shrubs are relatively abundant, especially the hazelnut, which is associated for example with the Elder and the European Spindle. Ivy is frequent and grows both vertically on tree trunks and horizontally, covering the ground.
The spring flowering species are all well represented in the herbaceous layer, including the Common Primrose, Hepatica, Tuberous Comfrey, Lungwort and Dog’s Mercury. It also hosts some species not widespread in the North of the Alps, such as the fragrant Cyclamen. The northern exposure and the moister soil favour the development of some ferns, as well as a layer of species-rich moss.
The Limes, the predominant species, act as a host plant for many insects, including the Lime Hawk-moth, a moth whose caterpillar feeds on the leaves of these trees, although it can also be found on other species of broadleaf trees, such as the Elm. This moth, the adults of which fly at night, can last up to two generations a year.
This type of forest prefers warm locations (thermophilic forest) and in our canton this is found almost exclusively in southern Ticino, at low altitudes, in marginal areas where the Beech tree cannot settle. Lime trees are also found north of the Alps in the valleys subject to the Foehn wind.
In the past, this type of forest was coppice exploited for the production of firewood. For about half a century it has been mostly abandoned and has mainly a naturalistic function and, in some cases, offers protection.
