JSC Latvija's State Forests agreement No. 5-5.5_0019_101_16_38
Hardwood broad-leaved trees have valuable wood, and have a specific economic niche compared to widely used pine, spruce, birch and aspen wood. Broad-leaved forest stands in Latvia account for approximately 1% of the total forest area; the main species are Fraxinus excelsior, Quercus robur, Ulmus glabra & U. laevis, Tilia cordata, Acer platanoides, Carpinus betulus, and plantations also include the introduced species Fagus sylvatica, Acer pseudoplatanus, Quercus rubra and Juglans ailanthifolia. Natural stands of broad-leaved trees in Latvia have high genetic, species, ecosystem and landscape diversity, as well as maintaining high levels of biodiversity.
The distribution of local broad-leaved species forest stands in Latvia is mainly related to the edaphic conditions of the natural sites. Broad-leaved stands are characterised by a mosaic distribution. Modern environmental transformations (synanthrophisation, eutrophication, climate change, etc.) contribute to the development and distribution of broad-leaved tree stands, the vector of the transformation of the stands aspires to the closing stages of forest stands (climax) in eutrophic sites, which occupy ~30% of the forest area in Latvia. Studies of broad-leaved forest stands in Latvia have been carried out at a regional and local level. According to State Forest cadastre data, an atlas of broad-leaved and other forest tree species, as well as forest types, has been developed, which also reflects the relationship between the distribution of tree species and forest types with the three geographical gradients, Western-Eastern, Southern-Northern and elevation.
To study the structure and dynamics of broad-leaved forest stands, a network of permanent plots (48 plots, located throughout the territory of Latvia) have been established, in which productivity, forest health, recovery, the composition of all forest stands (vascular plants, moss and lichen) and the physical-chemical properties of the soil have been assessed.
It has been established that the average standing volume of mature linden stands (over 100 years) is 700 m3/ha (maximum 1050 m3/ha), elm stands (>80 years) 590 m3/ha (maximum 700 m3/ha), oak stands (>120 years) 560 m3/ha (maximum 770 m3/ha), beech stands (>80 years) 540 m3/ha), hornbeam stands (>80 years) 450 m3/ha, maple stands (>80 years) 430 m3/ha. The amount of deadwood in broad-leaved stands is 40–60 m3/ha. Linden, maple, elm and oak stands are vital, the defoliation of tree crowns is small (<25%), but ash stands are severely damaged. Natural rejuvenation in broad-leaved stands, including in collapsed ash stands, occurs with broad-leaved trees species of (linden, maple, elm, ash).
In natural conditions in Latvia, broad-leaved trees tend to form mixed stands. Stable stands corresponding to the climax stage are formed by linden (Tilia cordata) in automorphic sites and by elm (Ulmus laevis) in high floodplains and terraces. Maple (Acer platanoides) and elm (Ulmus glabra) stands form typical broad-leaved forest pioneer communities in Latvia. Oak (Quercus robur) and hornbeam (Carpinus betulus) stands are quasi-stable.
