The chapter summarises the research data on cultivating forest crops in abandoned and marginal farmlands (AL). The course of growth and productivity of different tree species in the local climatic conditions is clarified in a variety of agricultural soils. The research results show the most appropriate tree species for short-rotation or special end-use monoculture or mixed plantations, using Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) Karst.), silver birch (Betula pendula Roth.), pedunculate oak (Quercus robur L.), grey alder (Alnus incana (L.) Moench), alder (Alnus glutinosa (L.) Gaertn.), wild cherry (Cerasus avium (L.) Moench syn. Prunus avium), aspen (Populus tremula L.), hybrid aspen (Populus tremula x tremuloides), and small-leaved lime (Tilia cordata Mill.). At the same time, research results show sustainability of management of plantation forests-positive impact on soil agrochemical properties, proportionate changes on above-ground vegetation, and improvement of economic benefits of farmlands.

Abstract. The growth data and the potential returns from 15-year-old plantations of pine Pinus sylvestris L. (6 trial sites), spruce Picea abies Karst L. (9 trial sites) and silver birch Betula pendula Roth (13 trial sites), established in abandoned agricultural lands in a variety of soil types (sod calcareous, anthrosols, podzolic, podzols, gley, podzolic gley, alluvial), using the planting density 2,500 and 3,300 and also 5,000 trees/ha are analysed. For tree plantations in agricultural soils (alluvial sod-gley, gley-sod podzolic, sod-podzolic gley, typic podzol) at the survival of 80-98% the stock volume for 15-year pine is as high as 102-155 m Plantation cultivation of pine, spruce and birch in agricultural lands may by the age of 15 years yield with a profit such forest products as pulpwood, fire wood and woody biomass. The gross income gained from first commercial thinnings of plantation pine, utilizing pulpwood, fire wood and logging residue biomass, may vary from 679-2267 EUR ha -1 , for spruce the same indices are 1644-3272 EUR ha -1 , for birch -683-2188 EUR ha -1 .

The distribution of sweet cherry (Prunus avium L. syn. Cerasus avium Moench.) in natural woodlands of Latvia was studied. The growth, vitality and stem quality of the first-generation plantations established in Latvia in different agricultural soils using the planting stock of local origin was assessed. In woodlands, sweet cherry is found in 11 Forest Resource Monitoring plots in the administrative regions of Madona, Kuldīga, Alsunga, Saldus, Cīrava, and Kazdanga. In the last decade, interest in sweet cherry as a wood producer has increased and plantations with a total area of 21.92 ha were established in 22 localities (Priekule, Kazdanga, Durbe, Talsi, Ventspils, Kuldīga, Tukums, Saldus, Dobele, Bauska, Cēsis, Pārgauja, and Krāslava). Survey was made of sweet cherry plantations established between 1997 and 2019, using both local and foreign origin clonal stock (Danish clone Truust and Swedish clones nos. 9 and 10) in different agricultural soils (typic sod-calcareous soil; sod-podzolic soil; stagnogley sod-podzolic soil) in the districts of Priekule, Kuldīga, Dobele, Bauska, Ķegums, and Smiltene. In plantation forests with optimal growing conditions (typical sod-calcareous soil; pH 6 to 7), 22-year-old sweet cherries of local origin had height (H) of 15.1 m, the diameter at breast hight (DBH) — 16.4 cm and stem volume 157.7 dm3 on average. The maximum H and DBH observed for the largest trees reached 17.6 m and 25.3 cm, respectively. The Danish clone Truust and the Swedish clones nos. 9 and 10 of sweet cherries were promising for growing in Latvian climatic conditions. Selection of perspective clones for establishment of second-generation plantations was made for sweet cherries of local origin.

No abstract