Logging Impacts by Site Type (LIST)
LIST was established in 2005 as a comparative study based on 116 forest plots organized in a block design over mainland Estonia. Different blocks represent a total of five site-type groups (in 5-6 replications) and there are four silvicultural treatments (old growth; mature managed forest; retention cut; clear-cut) in each block. The design has been used for addressing five main stand-scale research issues: (i) describing reference conditions in hemiboreal natural forests and estimating their structural and biological impoverishment by clear-cutting forestry; (ii) exploring the phenomenon and mechanisms of old-forest dependency of species, with implications for indicator species concepts; (iii) describing the functioning of retention-cuts and clear-cuts as habitats for early-successional species; (iv) exploring the interaction between logging impacts and forest type in the framework of evolutionary disturbance ecology; (v) developing rapid standard survey methods for biodiversity assessments at the stand scale. As nine years have passed from the initial surveys there are now opportunities to additionally address structural and biodiversity change by repeating the surveys.
Each of the 29 blocks represents a cluster of four plots (four silvicultural treatments of one site-type group) on a particular landscape, and each plot is at least 2 ha in size. For each site-type group, there are 5-6 clusters. The site-type groups are: (1) dry boreal forests (mostly Vaccinium type) on higher fluvioglacial landforms and till mounds with Podzols (pH 3.5–5.0) where water rises to the soil surface only sporadically and the top layer is periodically dry; (2) mesoeutrophic forests (mostly Oxalis type) on till mounds or rolling plains with Podzols or Stagnic Luvisols (pH 3.2–4.2) where ground water is deeper than 2 m; (3) eutrophic boreonemoral forests (mostly Aegopodium type) predominantly on undulating sandy till plains with favourably moist (in springtime anaerobic) Gleyic Gambisols or Luvisols (pH 4.7–6.5) and almost no organic horizon; (4) mobile-water swamp forests on thin flooded Eutric Histosols and Fluvisols (pH 5.0–6.5) in lowlands and valleys along rivers or around bogs; and (5) artificially drained swamp forests (Oxalis type), which represent long-term drainage effects and are considered transitional from site-type group 4 to group 2. The stands of Vaccinium type are dominated by Scots pine (Pinus sylvestris), whereas the other types represented conifer–deciduous mixtures with Norway spruce (Picea abies) or (in some Oxalis-type stands) Scots pine. The reference treatment is old growth, with most trees, 100–180 years old (coniferous trees >125 years old) and stand ages up to at least 300 years. The three management options for comparison (as of 2006) were mature (65–95 years) semi-natural commercial forests (both recently thinned and unthinned, most documented to be secondary stands of clearcut origin); and cutovers (usually 3–7 years after harvesting) with and without retention trees. The retention cuts had on average 20 m3·ha–1 of live retention trees.
- developing research-based sets of focal species for forest management;
- assemblage-change trajectories and succession rates on clear-cuts and retention cuts;
- using rapid surveys for estimating population sizes and conservation status of forest species with scattered distributions.
PhD projects involved
- Ann Kraut „The impact of site type and harvesting on beetle diversity“;
- Liina Remm “Impact of artifical forest drainage on biodiversity”;
- Jaanus Remm (completed) “Tree-cavities in forests: density, characteristics and occupancy by animals”
 Remm, J., Lõhmus, A., Rosenvald, R. 2008. Density and diversity of hole-nesting passerines: dependence on the characteristics of cavities. Acta Ornithologica 43: 83–91.
 Lõhmus, P., Lõhmus, A. 2009. The importance of representative inventories for lichen conservation assessments: the case of Cladonia norvegica and C. parasitica. The Lichenologist 41: 61–67.
 Lõhmus, A., Kraut, A. 2010. Stand structure of hemiboreal old-growth forests: characteristic features, variation among site types, and a comparison with FSC-certified mature stands in Estonia. Forest Ecology and Management 260: 155–165.
 Lõhmus, P., Turja, K., Lõhmus, A. 2010. Lichen communities on treefall mounds depend more on root-plate than stand characteristics. Forest Ecology and Management 260: 1754–1761.
 Lõhmus, A., Lõhmus, P. 2011. Old-forest species: the importance of specific substrata vs. stand continuity in the case of calicioid fungi. Silva Fennica 45: 1015–1039.
 Lõhmus, A., Kull, T. 2011. Orchid abundance in hemiboreal forests: stand-scale effects of clear-cutting, green-tree retention, and artificial drainage. Canadian Journal of Forest Research 41: 1352–1358.
 Rosenvald, R., Lõhmus, A., Kraut, A., Remm, L. 2011. Bird communities in hemiboreal old-growth forests: the roles of food supply, stand structure, and site type. Forest Ecology and Management 262: 1541–1550.
 Lõhmus, A., Kraut, A., Rosenvald, R. 2013. Dead wood in clearcuts of seminatural forests in Estonia: site-type variation, degradation, and the influences of tree retention and slash harvest. European Journal of Forest Research 132: 335–349.
 Remm, L., Lõhmus, P., Leis, M., Lõhmus, A. 2013. Long-term impacts of forest ditching on non-aquatic biodiversity: conservation perspectives for a novel ecosystem. PLOS ONE: e63086.
 Runnel, K., Põldmaa, K., Lõhmus, A. ‘Old-forest fungi’ are not always what they seem: the case of Antrodia crassa. Fungal Ecology (under minor revision, February 2014).
 Lõhmus, A., Rosenvald, R. 2005. Breeding bird fauna of the Järvselja Primeval Forest Reserve: long-term changes and an analysis of inventory methods. Hirundo 18: 18–30.
 Lõhmus, A. 2006. Relative abundance of amphibians and reptiles in forests and clear-cuts of different types. Eesti Looduseuurijate Seltsi Aastaraamat 84: 207–217.
 Saar, I., Lõhmus, A., Parmasto, E. 2007. Mycobiota of the Poruni old-growth forest (Estonia, Puhatu Nature Reserve). Forestry Studies 47: 71–86.
 Suija, A., Lõhmus, P. , Jüriado, I. 2007. The lichen biota of the Agusalu and Puhatu reserves (Estonia): the first overview. Forestry Studies 47: 99–116.
LIST was established in the frame of the project ETF6457 “The impact of residual trees on biodiversity in relation to natural disturbance regimes“ (2005–2007) funded by the Estonian Science Foundation.
Photo 1. Describing deadwood pool in a clearcut. Aegviidu, Harju county. Photo: A. Lõhmus, 15.08.2009
Photo 2. In this fertile Oxalis-type plot in Järvselja, the early successional habitat has disappeared 13 years post clearcutting due to rapid natural regeneration. The thicket has already been thinned for the first time. Photo: A. Lõhmus, 13.06.2013.
Photo 3. An old-growth swamp forest, which has hardly changed in composition since at least the 1930s. Photo: A. Lõhmus, summer 2005.