PS24a. Cool side
Langhe north-west hilly sides are cool and damp because of their exposure and geological strata. Here woods are luxuriant: natural competition and cuttings made by man accentuate samples growth in height.
The shady mantle of the forest is made up of many arboreal species, among which stand out beech trees (Fagus sylvatica), chestnut trees (Castanea sativa), maples (Acer sp.Pl.), hornbeams (Carpinus betulus), cherry-trees (Prunus avium), oaks (Quercus sp. Pl) and lindens (Tilia platyphylla).
In this watery and little steep sides, man has always placed side by side forest care to agriculture and farming. Therefore, there are cereals arables (barley, wheat, corn), pastures and poliphita meadows which are destined to zootechnics for meat production (Piedmont bovine race), milk for cheese production (Langhe sheep), or also to particular hazel trees cultivations (Langhe “tonda gentile”).
The cool side undergrowth hosts plants that prefer high humidity levels and are pleased with low light that seeps in leafy branches. Because of shadows, species that live in this habitat carry out their reproductive cycle (blooming and fecundation) before trees come into leaf. At the end of february, when snow is melting, there is the blooming of Hellebores (Helleborus foetidus and Helleborus viridis), Dog’s-tooth violet (Erythronium dens-canis), Primrose (Primula vulgaris), Liverleaf (Hepatica nobilis), Wood anemone (Anemone nemorosa), Lily of the valley (Convallaria majalis), Perwinkle (Vinca minor), Solomon’s Seal (Polygonatum multiflorum), etc. Moreover, in dampest places, terrains and trunks are fungi and moss-covered.
PS24b. Dry side
South-east sides are more dry because of layers grade, that directs subsoil water to the opposite slope. Here trees create xerophilic woods, i.e woods populated by organisms that prefer dry lands.
Langhe and Roero dry wood is almost entirely composed by the association between Pine (Pinus sylvestris) and Downy oak (Quercus pubescens), in addition to Manna ash (Fraxinus ornus), the invasive false Acacia (Robinia pseudoacacia) and a set of shrubs (Viburnum lantana, Coronilla emerus, Ligustrum vulgare, Cytisus spp.).
The wood is less dense than the one located in damp sides and leave enough space for clearings that in spring and summer are plenty of luxuriant and colorful blooming, of which Broom yellow (Spartium junceum) and Cupid’s dart blue (Catananche caerulea) stand out.
Moreover, this also is the habitat where the largest part of the characteristic 44 species of Native Orchid is found.
Given that south side is sunny, it is the ideal place for particular cultivations; for this reason man has always tried to create terracings that promoted an high quality viticulture. The exposure to majors winds that came from the sea, the more delicate vegetation and the peculiar dryness ensure that this sides are easily vulnerable to fires.
PS24c. Damp environments
VALLEY FLOORS AND WATERCOURSES
Valley floor areas that are associate with the three main Alba territory watercourses (Tanaro, Belbo and Bormida rivers) show a peculiar flora. Terrains which are next to rivers are periodically submerged by overflows and host an association between shrub-like and bushy plants, known as “Gorreto” (from “gorra”= willow). In addition to different species of willows (Salix caprea, alba, purpurea and triandra) there is also the Tree of heaven (Ailanthus altissima). Where water becomes stagnant or remains several months of the year there is the prevalence of the Bulrush (Typha latifolia) and of the Common reed (Phragmites australis); underfoot there are sedge-grass and reeds. In spring and summer “Coltellaccio” (= “large knife” for leaves shape) (Sparganium erectum) and Purple loosestrife (Lythrum salicaria) blooming is clear. The flat terrain and the presence of water make these environments ideal for agriculture. In this sense the development of forage crops and the Poplar plantation are remarkable.
The last natural swampy area in Langhe is located near sources of the torrent Belbo, in the district of Montezemolo. In this area, protected as a natural reserve, there are many species of botanical interest, as the rare Carex hartmanii.
In the upland that from the top of the Roero cliffs goes as far as Torino man creates many small lakes or “fish farms”, taking advantage of the impermeability of the layers. The majority are destined to irrigation and fish farming (Tinca tinca). Moreover, these host fauna and flora components of high interest, such as Indian Lotus (Nelumbo nucifera) that populates the fish farm of Cascina Gallina in Ceresole d’Alba.
South-east sides are dry and steep and have been fitted for cultivation thanks to a long and impressive work of terracing. The big dry sandstone walls is juxtaposed in order to support terrains which host a peculiar flora from Mediterranean area, such as bush of Red valerian (Centranthus ruber), Snapdragons (Antirrhinum spp.) or the rare Navelwort (Umbilicus rupestris). Not to be negligible is the presence of succulent plants such as the yellow-blooming Sedum or the red Sempervivum.
Where the terracing work meet a waterproof clay layer intercepting a phreatic layer, man has created small products called “Crotin” to collect the precious water.
These cool environments are adorned with elegant bushes of Maidenhair fern (Adiantum capillus-veneris) and perfumed mint (Mentha aquatica). In near terrains, in which some water permeates, we can find the Celandine (Chelidonium majus), the Wall rocket (Diplotaxis muralis) and the certain Upright pellitory (Parietaria officinalis).
The geological phenomenon called “cattura del Tanaro” and the water course erosion have created steep and semi-desert sides in Langhe e Roero: the “Rocche” (i.e. Cliffs). From south to north “rocche” that are more evident are both located in the high Bormida valley and Clavesana, Farigliano, Cherasco and Barbaresco.
Otherwise, Roero is crossed by a unique system of “rocche”, geologically indicated as “Orlo di Terrazzo”. In these dry and poor of nutrients terrains, that are exposed to temperature ranges and wind action, live species adapted to the environment, such as Broom (Spartium junceum), Heather (Calluna vulgaris) and Thyme (Thymus vulgaris).
A very singular environment is the one of Roero Castle Walls (Sommariva Perno, Pocapaglia, Santa Vittoria, Govone, Cisterna d’Asti, etc), that hold considerable colony of Caper bushes (Capparis spinosa) and Sea fennel (Crithmum maritimum).
PS24e. Langhe and Tanaro left side
One of the main museum wealthes is its herbarium. The exsiccata collection reaches up to 11,000 samples that represent 1,515 species. The gathered, prepared, conserved and identified material is the result of research activity that has been coordinated by the researcher as natural continuation of collecting activity and past botanic studies: Carlo Bertero (1789-1831), Teodoro Ferraris (1871-1943) and Ferdinando Vignolo-Lutati (1878-1965).
The relevance of the collection is proved by the inclusion of the museum between locations that have been registered in the New York “Index erbariorum”, under the tag “ALB”.
Langhe and Roero herbarium proves the fact that Alba territory is one of the most studied under the floral area in Italy and highlights the unique features of the territory: more than 1,500 species, i.e. over 27% of italian identified species, live in only 1,400 kms, i.e. less than 0.5% of the whole national landscape.
Old tree tell story: Dendochronology
DENDROCHRONOLOGY (from greek “dendron”= tree, “kronos”= time, “logos”= tale) is the science that studies the arboreal plants growth over time, its modalities and key factors.
The thickness of every single ring depends on:
- Biological factors (species, age, possible diseases,…)
- Geographical factors (soil, exposition, elevation, side slope,…)
- Climatic factors (temperature, dampness, precipitations,…)
All these factors are recorded in the plant annular sequence, giving each ring a particular feature (density, colour, zonationes) and make dendrochronology an absolute and highly precise dating method.
The study of growth rings allows to know not only age and wealth of the plant, but also its developmental climate and environment conditions.
Dendrochronolgy is used in many research fields, from climatology to ecology as well as geomorphology, atmospheric pollution problems, archaeology, art history, architecture.