Status of wetland forests and their structural richness in Latvia

Abstract

Wetland forest communities are seriously reduced and degraded throughout most of Europe, but significant areas still survive in the east and north-east. Data from 91 forest structures that support biodiversity are analysed in 369 relevés of Latvian wetland forests. These structures include variations in topography, stand composition, water movement and dead wood features occurring in semi-natural conditions undisturbed by management. There is clear structural differentiation between coniferous and deciduous wetlands. The study supports the widely held views on European forest quality: low volume of high-diameter (>50 cm) snags and logs, too few overmature trees, and the threat to pattern heterogeneity caused by traditional forestry and silviculture. Twenty areas (totalling c. 3800 ha) are identified as reserves that should be strictly protected in Latvia in order to maintain representative and intact samples of wet forest belonging to Eurosiberian alder swamps (Alnetea glutinosae), broad-leaved forests (Querco-Fagetea) and boreal forest (Vaccinio-Piceetea) communities. Based on habitat features and site ecology, the concept of sustainable forestry must be incorporated widely in utilization of European wetland forests in order to prevent further loss of biodiversity.

Re-evaluation of stand indicators for the assessment of the representativity status of the Natura 2000 habitat type forests

“…*9010 and *9020 (old broad-leaved deciduous forests), while moist habitats have been ignored because of their small presentday frequency in Western Europe and their structural specificity (e.g. *91D0, *9080) (Prieditis, 1997(Prieditis, , 1999Andersson et al, 2003). In the studied swamp and bog forests, the used list of indicators effectively recognized extreme quality classes, while in intermediate-grade forests the drainage and fertilization of forest soils caused very confusing results by supporting a structure that is unnatural to those wet forests (Pikk, 2003;Kaasik et al, 2008).…”

“…Drainage also increases the competitiveness of spruce, which over time will change stand composition as well as light conditions and microclimate. Further research is needed to find out which substrates and microhabitats are critical for habitat-specific species in intact deciduous swamp forests to balance those processes in valuation (Prieditis, 1997(Prieditis, , 1999.…”

Effect of climate on extreme radial growth of Scots pine growing on bogs in Latvia

“…All of the study sites have evidence of human disturbance. The main anthropogenic activity in bogs has been ditching for peat harvesting and forestry carried out in the 20th century, particularly between 1960 and 1980 (Prieditis, 1999). In Cena Mire this influence is presently most visible as peat extraction is conducted about 1 km from the study site.…”

Stand structure and spatial pattern of regeneration of Pinus sylvestris in a natural treed mire in Latvia

“…A large part of wetland forests in Latvia have been drained, particularly in the 1970s and 1980s (Prieditis 1999). However, today many of the drainage systems are old, overgrown and not functioning (Ministry of Agriculture 2009), thus still supporting natural vegetation and biodiversity.…”