From ancient times, Romans have regarded groves to be sacred. Besides Silvanus (the God of Forests), other Gods are worshipped in groves. Diana (Goddess of the Hunt) and Dea Dia (the Good Goddess) had dedicated groves where sacrifices were made. At other places, travelers would stop, rest, and then make offerings of fruit. I do that when I visit parks.
Romans have different classes of woodlands. A locus is a small wooded area with beams of light breaking through it. A nemus could be either an arboretum or a clearing in the woods. It could be consecrated or simply be a place of inspiration. In contrast, the lucar is the cool, dark and silent part of the woods. The natural forest is the silva, and the saltus, the wilderness. As a rule, Romans do not go into forests (lucar, silva) because of the strange spirits who lived there. Odd noises that come from the forest are often unnerving messages for them.
Silvanus, the God of Forests, Groves and Wild Fields, guards the forests. He governs the Children of Fauna and Faunus who dwell in the deep woods (saltus). Popular among Romans, Silvanus still receives much veneration. Although He has never had a temple, Silvanus is worshiped in the forests receiving the first fruits.
Note: Silvanus has other aspects:
Silvanus Domesticus: Guardian of the house
Silvanus Agrestis: the flocks
Silvanus Orientalis: the boundaries of the property