Current issue: 58(4)
The aim of the study is to find out how do the peatlands develop after drainage and how does the type of peat affect the growing conditions of the forest on it. Study is based on measurements made in summer 1919 in about middle Finland (districts of Loppi, Yläne, Kihniö, Nerkoo, Orivesi, Vilppula, Multia and Karstula). The macroscopic identified content of the peat was analyzed: the different peat types were categorized according the species of the most abundant plant remains. The characteristics of the studied peat types are represented.
The conclusion of the study is that when deciding about the suitability of the drained peatland for afforestation, the thickness and content of the peat must be considered in addition to peat type.
Impact of drainage of organic soils in forest land on soil carbon (C) stock changes is of high interest not only to accurately estimate soil C stock changes, but also to provide scientifically based recommendations for forest land management in context of climate change mitigation. To improve knowledge about long-term impact of drainage on nutrient-rich organic soils in hemiboreal forests in Latvia, 50 research sites representing drained conditions (Oxalidosa turf. mel. (Kp) and Myrtillosa turf. mel. (Ks) forest site types) and undrained conditions as control areas (Caricoso-phragmitosa, Dryopterioso-caricosa and Filipendulosa forest site types) were selected. Soil C stock changes after drainage was evaluated by comparing current C stock in drained organic soils to theoretical C stock before drainage considering impact of soil subsidence. During the 53-years period after drainage, the peat subsidence was higher in nutrient-rich Kp forest site type compared to moderate nutrient-rich Ks forest site type (peat subsided by 37.0 ± 4.8 and 23.3 ± 4.8 cm, respectively). In nutrient-rich Kp forest site type, soil C stock decreased by 4.98 ± 1.58 Mg C ha-1 yr-1 after drainage, while no statistically significant changes in soil C stock (0.19 ± 1.31 Mg C ha-1 yr-1) were observed in moderate nutrient-rich soils in Ks forest site type. Thus, in Ks forest site type, the main driver of the peat subsidence was the physical compaction, while in Kp forest site type contribution of organic matter decomposition and consequent soil C losses to subsidence of the peat was significant.