Itinerary: A loop route focused on interpretation of the bank's vegetation and the Mediterranean ecosystem around the Arroyo de la Fresneda area.
Highlights: Riverside vegetation, Ornithology, Butterflies, Accessibility.
Length: 2.74 km.
On foot: 45 min
Bicycle: Bicycles are not allowed on part of the path.
Elevation: 663-677 MASL
Average: Average: 2 - 2.5% Maximum: 10.5%
Accessibility: Accessible route with a dirt path in good condition.
This route runs parallel to the Arroyo de la Fresneda, from which it takes its name. Along it you can appreciate the two ecosystems that enrich this area: riverside vegetation and the dehesa, or forested pasture. Flat, the route is an easy one, the most accessible of all the trails in the Monte de Boadilla. The path is furnished with benches, garbage bins, interpretive signs, and illustrative panels all along it, and is not open for use by bicycles.
It begins at the Aula Medioambiental (Environmental Classroom), descending towards the roundabout of the Boadilla-Pozuelo highway (M513). At this point the road runs along a dirt track until reaching the bridge over the Arroyo de la Fresneda. A few meters away is the first information sign on the trail, which welcomes you and provides basic information on the route, which runs parallel to the stream. Along the way you can enjoy the walk and learn about the area by reading various interpretive signs offering information regarding its flora, fauna and ecosystems.
Although currently there is no water flowing along the stream’s bed, the abundant riverbank vegetation and the presence of species such as the willow (Sambucus nigra), elder (Salix spp.) and reeds (Scirpus holoschoenus), serve as indicators of the presence of water in the subsoil, a resource essential for life in the woodland area.
As discussed in this guide's section on the Flora Trail, the riverbank ecosystem is characterised by the existence, on both sides of the watercourse, of a series of plant species, depending on their hydric needs. As these are ecosystems featuring a linear distribution, they function as ecological corridors and biodiversity reserves. In Boadilla del Monte there are numerous watercourses running not only through the woodland, but urban areas too, and they are of great ecological, environmental and social value, as Green Infrastructure.
At the start of this route there is a sign describing the black poplar (Populus nigra), a species not found on this trail, although there is a small silver poplar (Populus alba).
In the next section there are species of shrubs whose fruits are highly appreciated by birds, such as the hawthorn (Crataegus monogyna) and the dog rose (Rosa canina), as well as osyris (Osyris alba), growing at the bases of the holm oaks. The osyris is a species indicative of dry soils, and can be mistaken, due to its leaves, with some types of broom, but its identification is made clear when one spots its small white flowers, and its red fruit, gracing the lower layers of the oak grove with crimson at the end of the summer. It is a hemiparasitic species, as it can draw water and nutrients from the raw sap of other plants, while the green colour of its stems indicates that it can perform photosynthesis too.
Together with them, various species of thistle, mullein and other herbaceous plants found on Mediterranean meadows attract, in the spring and summer, a great diversity of insects. At this point we find a sign indicating some of the most common bird species in the woodland, which may be observed on the bank of the stream, or feeding on the fruits and insects inhabiting the area.
The route follows the course of the streambed, with a small olive grove, on the left, composed of young common elms (Ulmus minor), revealing the presence of larger elm groves in this valley, though they have been decimated by graphiosis. Shortly thereafter we come to a panel with an illustration of the fauna found in this woodland area, and reminding you to remain alert to catch a glimpse of the faunae here, as well as to the traces they leave.
Along the route, a good number of burrows can be observed, especially in less accessible areas, among the blackberry bushes or on the slopes of the streambed. From this point one can clearly appreciate the two ecosystems that predominate along the route: the streamside vegetation, on the left, and the dehesa, with its ash and holm oaks, on the right.
The trail continues on, hugging the streambed. You will find interpretative signs describing the ash, willow, gall oak, and holm oak, species reflecting the hybrid nature of this ecosystem. You will also come across a good number of nesting boxes of different shapes and sizes for bird species, such as tits and chickadees (Paridae), others for nuthatches (Sitta europaea) and the short-toed treecreeper (Certhia brachydactyla); and for larger species, such as the tawny owl (Strix aluco).
At the end of the path, before the wooden bridge over the stream providing access to the dog park, we find an interpretive sign indicating the importance of insects to biodiversity conservation, and you can enjoy the colours and shapes of some of the species of butterflies present here.
At this point the road veers right and leads to the duck pond. In this section you will find an interpretive sign explaining the role that nesting boxes play in the conservation of the woodland, and the significance of the presence of dead or fallen trees along the route, essential for the completion of organic material decomposition cycles, and habitats for numerous invertebrate species.
The duck pond, or lagoon, is an artificial space with an observatory where you can view the range of duck species that have been introduced here, many of them native to Mediterranean areas. After relaxing observing the ducks, it is time to head back, along the main road, also called the Romeral. As soon as you leave the lagoon behind you will come across one of the main attractions and what is, without a doubt, the most famous tree in the Monte de Boadilla: “the fallen tree”, a genuine symbol and reference point for all hikers here, especially children. It is a large, old large stone pine that fell, due to natural causes, and since then has been clambered upon and used as if it were a wooden bridge. You are encouraged to exercise caution, to avoid falls and splinters. In the meadow around it stand some of the largest specimens of this species in the area.
The route continues along on the main road, where a physical fitness circuit has been built. About halfway along the path you will come to La Invencible, one of the oldest holm oaks in the Monte de Boadilla, listed as a Notable Tree by the municipality.