showing 27 related works from this author
Age and spatial structure of natural Pinus sylvestris stands in Latvia
2005
Abstract The age and spatial structure of six natural old growth Pinus sylvestris stands in Latvia were investigated, to attempt to identify retrospectively the past features of development. In each stand, one or two plots of size 200–900 m2 were established. Tree locations were mapped, stem diameter was measured, and tree age was determined from cores or by counting branch whorls. Tree distribution was assessed by Ripley's K function. A clumped spatial pattern was shown for P. sylvestris younger than 100 years. The temporal patterns of establishment could be partly linked to favourable climatic periods. The major disturbance affecting pine stands along the coast was windblown sand, which p…
The importance of the moss layer in sustaining biological diversity of Gamasina mites in coniferous forest soil
2008
Summary The feather moss layer of boreal coniferous forests is known to buffer the underlying soil temperature and to be a major component in the nitrogen and phosphorus cycles by efficient scavenging of nutrients from throughfall and direct precipitation. Through indirect or direct effects the feather moss layer may also play a significant role in forming soil organism communities. In this 4-year experimental field study, the predatory Gamasina mite diversity was estimated in plots where the feather moss layer was removed or disturbed by turning over, in relation to that in control plots. Species richness, Shannon's diversity and equitability in spring but not autumn were decreased when th…
Use of an artificial model of monitoring data to aid interpretation of principal component analysis
2000
Abstract An artificial data matrix of element concentrations at sampling locations was created which included six simulated gradients of correlated variables (Ca+Mg, Ni+V, Pb+Cu+Zn, Cd, Fe and K), representing a simplified model of a National survey. The data matrix model was used to explore the efficiency with which Principal Components Analysis (PCA), without and with Varimax rotation, could derive the imposed gradients. The dependence of PCA on outliers was decreased by log-transformation of data. The Components derived from non-rotated PCA were confounded by bipolar clusters and oblique gradients, both resulting in superimposition of two independent gradients on one Component. Therefore…
Litter quality, land-use history, and nitrogen deposition effects on topsoil conditions across European temperate deciduous forests
2019
Topsoil conditions in temperate forests are influenced by several soil-forming factors, such as canopy composition (e.g. through litter quality), land-use history, atmospheric deposition, and the parent material. Many studies have evaluated the effects of single factors on physicochemical topsoil conditions, but few have assessed the simultaneous effects of multiple drivers. Here, we evaluate the combined effects of litter quality, land-use history (past land cover as well as past forest management), and atmospheric deposition on several physicochemical topsoil conditions of European temperate deciduous forest soils: bulk density, proportion of exchangeable base cations, carbon/nitrogen-rat…
Light availability and land‐use history drive biodiversity and functional changes in forest herb layer communities
2020
International audience; A central challenge of today's ecological research is predicting how ecosystems will develop under future global change. Accurate predictions are complicated by (a) simultaneous effects of different drivers, such as climate change, nitrogen deposition and management changes; and (b) legacy effects from previous land use. We tested whether herb layer biodiversity (i.e. richness, Shannon diversity and evenness) and functional (i.e. herb cover, specific leaf area [SLA] and plant height) responses to environmental change drivers depended on land-use history. We used resurvey data from 192 plots across nineteen European temperate forest regions, with large spatial variabi…
Assessment of site-specific drivers of farmland abandonment in mosaic-type landscapes: A case study in Vidzeme, Latvia
2018
Abstract Farmland abandonment, which causes changes in rural life and farming practices, can be observed throughout Europe. Over the last decades natural afforestation has decreased the area of farmland used for agricultural production, thereby leading to landscape homogenization and polarization. This process is explicitly evident in mosaic type landscapes consisting of highly complex land cover patterns, soil composition and topography. The aim of the study was to determine the site-specific driving forces of farmland abandonment at landscape scale in relation to agro-ecological and geographic factors, in a post-Soviet country in Eastern Europe. An extensive field survey approach with sta…
Forest Naturalness in Northern Europe: Perspectives on Processes, Structures and Species Diversity
2011
Saving the remaining natural forests in northern Europe has been one of the main goals to halt the ongoing decline of forest biodiversity. To facilitate the recognition, mapping and efficient conservation of natural forests, there is an urgent need for a general formulation, based on ecological patterns and processes, of the concept of âforest naturalnessâ. However, complexity, structural idiosyncracy and dynamical features of unmanaged forest ecosystems at various spatio-temporal scales pose major challenges for such a formulation. The definitions hitherto used for the concept of forest naturalness can be fruitfully grouped into three dimensions: 1) structure-based concepts of natural …
Changes in soil organic matter and soil humic substances following the afforestation of former agricultural lands in the boreal-nemoral ecotone (Latv…
2019
Abstract Abandonment of agricultural land is a widespread process in Northern Europe, which is associated with changes in content and distribution of organic matter in soil, including C stocks. There is insufficient information on changes in soil organic matter properties during afforestation of these lands. The aim of the study was to determine and describe the influence of afforestation on organic carbon (CORG) content and properties of soil organic matter (SOM) in mineral topsoil in the boreo-nemoral ecotone in Latvia. We studied soils in 4 model territories that represented abandoned farmlands and territories where mixed or coniferous forests were established at different times on forme…
Life-form adaptations and substrate availability explain a 100-year post-grazing succession of bryophyte species in the Moricsala Strict Nature Reser…
2013
Bryophyte species composition, richness and life-form distributions were studied in a succession after termination of land-use as meadows and pasture in the Moricsala Strict Nature Reserve. Detailed lists of bryophyte species in various vegetation types, which were produced in the early 1900s by Karl Reinhold Kupffer, were compared with those prepared from 2006 to 2010 to determine changes in species composition. Colonisations and extinctions of bryophyte species and life forms could be explained by increases in available substrates (living trees, dead wood, ground layer disturbance patches), and increasingly shaded conditions. In each forest type, the species diversity (alpha diversity) in…
Distribution ofLeprariain Latvia in Relation to Tree Substratum and Deciduous Forest Type
2012
The aim of the study was to evaluate the distribution of Lepraria lichen species in dry deciduous forests, in relation to tree substratum and forest characteristics. In total, 34 localities with 1020 trees (13 tree species) were studied in different parts of Latvia. Lepraria spp. were found on 642 trees: L. eburnea on 8 trees, L. incana on 80 trees, and L. lobificans on 568 trees. Lepraria eburnea was recorded for the first time in Latvia. Tree species, tree bark crevice depth, inclination, pH and forest type were the most important variables explaining the presence of Lepraria species. Lepraria incana was associated with Quercus robur and Tilia cordata, while L. lobificans was associated w…
Drivers of above-ground understorey biomass and nutrient stocks in temperate deciduous forests
2020
The understorey in temperate forests can play an important functional role, depending on its biomass and functional characteristics. While it is known that local soil and stand characteristics largely determine the biomass of the understorey, less is known about the role of global change. Global change can directly affect understorey biomass, but also indirectly by modifying the overstorey, local resource availability and growing conditions at the forest floor. In this observational study across Europe, we aim at disentangling the impact of global-change drivers on understorey biomass and nutrient stocks, from the impact of overstorey characteristics and local site conditions. Using piecewi…
The spatial dynamics of atmospheric pollution in Latvia and the Baltic Republics, as measured in mosses, topsoil and precipitation
1994
Atmospheric pollution in the Baltic countries of Estonia, Latvia, and Lithuania has been mapped using measurements of pollutant concentrations in mosses, topsoil and precipitation. Air masses from western Europe deposit industrial pollutants in the Baltic region and concentrations depend on meteorological conditions. Superimposed on this background is the pattern of deposits from local sources. Large areas receive neutral to basic precipitation due to cement industries and fly ash emissions from fossil fuel combustion. The burning of oil-shale in NE Estonia results in precipitation with pH values over 7.0, and high concentrations of V, Fe, and Cd. Heavy metal concentrations in the topsoil a…
Impact of climate variability, drainage and land-cover changes on hemiboreal streamflow
2017
ABSTRACTThe aim of the study was to determine the effects of climate variability, agricultural land drainage and afforestation of agricultural land on river discharge. The study was conducted in the Vienziemīte stream basin (6 km2), where discharge was monitored on a daily basis during the time period of 1946–2010. In the stream basin, natural afforestation of agricultural land began in the 1950s, and in the mid-1970s artificial drainage systems were installed in all agricultural land (70% of the total basin area). Climate variability and artificial drainage were the main factors observed to be affecting stream discharge. The changes were most evident in annual and seasonal mean, minimum an…
Drought-induced positive feedback in xylophagous insects: Easier invasion of Scots pine leading to greater investment in immunity of emerging individ…
2012
Abstract We studied the infestation rate of Scots pine Pinus sylvestris by xylophagous insects in relation to distance from forest lakes in eastern Latvia, northern Europe. In summers of 2008 and 2009, we felled 72 pines of approximately 65 years age. Sections of the logs were incubated in insect emergence traps. The trees located near lakes were significantly less infested by xylophagous insects than those sampled at greater distances from the lakes. We also tested the ability of Tomicus piniperda , the most abundant species of xylophagous insects in our samples, to resist the entomopathogenic fungus Beauveria bassiana . The results show that beetles captured near lakes were more susceptib…
Stand structure and spatial pattern of regeneration of Pinus sylvestris in a natural treed mire in Latvia
2009
We examined the regeneration patterns of Pinus sylvestris L. in a natural treed mire in the hemiboreal zone in Latvia. Data on tree stem age and size was collected in 207 fine-scale plots (10 m) and 4 medium-scale plots (400 m). Size structure of living and dead trees was also estimated on transects 180-m and 250-m length and 10-m width. In addition, the vegetation was described in 1-m plots to determine preferred microsites for P. sylvestris establishment. Pinus sylvestris showed continuous regeneration by an inverse J-shaped age and size structure. Pulses of mortality induced by fire were also evident. Regeneration of P. sylvestris was mostly on Sphagnum magellanicam Brid. hummocks free o…
Dynamics of natural hemiboreal woodland in the Moricsala Reserve, Latvia: the studies of K. R. Kupffer revisited
2010
Abstract Karl Reinhold Kupffer (1872–1935), an outstanding botanist and plant ecologist, took the initiative that led to the establishment of the first nature reserve in Latvia, on Moricsala Island in 1912. The reserve provided an excellent reference area for natural hemiboreal woodland for future generations. There have been very few studies on the dynamics of natural broadleaved forest in Europe, probably owing to lack of primeval forests of this type. However, Kupffer produced a map of forest types in the reserve with accurate descriptions of the vegetation by layers, and his descriptions include interpretations of forest dynamics processes. This information, together with the present ag…
Environmental drivers interactively affect individual tree growth across temperate European forests
2019
Forecasting the growth of tree species to future environmental changes requires a better understanding of its determinants. Tree growth is known to respond to global-change drivers such as climate change or atmospheric deposition, as well as to local land-use drivers such as forest management. Yet, large geographical scale studies examining interactive growth responses to multiple global-change drivers are relatively scarce and rarely consider management effects. Here, we assessed the interactive effects of three global-change drivers (temperature, precipitation and nitrogen deposition) on individual tree growth of three study species (Quercus robur/petraea, Fagus sylvatica and Fraxinus exc…
Effect of soil and canopy factors on vegetation of Quercus robur woodland in the boreo-nemoral zone: A plant-trait based approach
2013
Abstract The aim of the study was to determine the effect of soil and canopy on the understory vegetation of Quercus robur stands in Latvia, located in the boreo-nemoral zone. To determine the main processes regulating formation of the plant communities, the understory vegetation of Q. robur stands was described using plant traits. Vegetation and soils were described in 24 plots representing contrasting soil types and tree species composition. Redundancy analysis was used to determine the relation between vegetation, described using plant traits (proportion of species with each trait), and soil and canopy factors. About 50% of the variation in vegetation described by plant traits was explai…
Challenges of ecological restoration: Lessons from forests in northern Europe
2013
The alarming rate of ecosystem degradation has raised the need for ecological restoration throughout different biomes and continents. North European forests may appear as one of the least vulnerable ecosystems from a global perspective, since forest cover is not rapidly decreasing and many ecosystem services remain at high level. However, extensive areas of northern forests are heavily exploited and have lost a major part of their biodiversity value. There is a strong requirement to restore these areas towards a more natural condition in order to meet the targets of the Convention on Biological Diversity. Several northern countries are now taking up this challenge by restoring forest biodiv…
Loss of habitats, naturalness and species diversity in Eurasian forest landscapes
2010
Abstract Man has exploited land and forests in Western and Central Europe longer and more intensively than in Northern Europe and further east in Eurasia. We estimated forest naturalness and modelled expected biodiversity loss in seven different landscapes (2500 km2 each) in the Netherlands, Sweden, Finland, Poland, St. Petersburg (Western European Russia), Perm (Eastern European Russia), and Irkutsk (Central Siberia) across the distribution of Pinus sylvestris L. in Eurasia. Field inventories showed that the mean living tree volumes were relatively similar in the studied sites, but the volumes of dead wood differed greatly. In Irkutsk and Perm the volume of dead trees per ha was about 5–10…
Seventy-year changes in tree species composition and tree ages in state-owned forests in Latvia
2011
Abstract During the last 100 years, forest management in Latvia has gradually become more and more focused on industrial logging, which can be expected to have affected the tree species composition and age distribution across the landscape. These changes need to be considered in forest management and conservation of biological diversity. The aim of the study was to use forest records to reconstruct the tree species composition and age distribution in the North Vidzeme Biosphere Reserve in northern Latvia for the period, 1929–1941. These data were compared to a data-set from 2008, to determine the changes that transpired during a period of intensification of forest management. The silvicultu…
Comparison of input data with different spatial resolution in landscape pattern analysis – A case study from northern Latvia
2017
A suitable spatial scale needs to be selected in geographical and landscape ecological research, and this requires great consideration as different scales have profound effect on derived landscape spatial patterns. Numerous studies have investigated the effects of different scales on landscape metrics using simulated patterns, but few have been conducted to compare different data sources with variable scale for regional- and landscape-scale assessments. Possibly this has occurred because researchers have been prone to use the best available source, a well-known standard, and easiest to use. This study was conducted to assess the impact of input data resolution on values of landscape pattern…
The implications of stand composition, age and spatial patterns of forest regions with different ownership type for management optimisation in northe…
2015
Abstract Forests with different ownership type often form complex mosaics of stands, thus adding new challenges to the spatial planning of sustainable management in forested landscapes. This study attempted to analyse the spatial patterns and age structures of forest regions with different ownership type and to formulate suggestions for the optimisation of tactical planning of forest management planning by addressing ecological functionality at the landscape level. We hypothesised that structure of forests of various ownership groups differs significantly. National forest inventory data from 2011 was used in this study to compare spatial patterns of forest stands and clearcuts, as well as f…
Past and Contemporary Changes in Forest Cover and Forest Continuity in Relation to Soils (Southern Latvia)
2014
A set of medium-scale historical maps was used to reconstruct changes in spatial patterns of forest area during the last 220 years in an agricultural matrix of northeastern Europe (Zemgale region, Latvia). Changes in total forest area by soils were determined, as well as the time period of continuous forest cover. Proportion of protected area for each soil trophic group was also calculated. Patterns of recent forest development differed between soil trophic groups. Afforestation occurred mainly on wet and poor soils in the 19th and 20th centuries, while the proportion of woodland area on fertile soils typical for nemoral forests was fairly stable. Only 1% of the fertile soil area has been c…
Vegetation changes in boreo–nemoral forest stands depending on soil factors and past land use during an 80 year period of no human impact
2016
Information on the long-term changes in plant communities that occur without human interference is limited, due to insufficient studies where vegetation can be resurveyed. In 1912, a strict nature protection reserve, with non-intervention management, was established on Moricsala Island in Latvia, located in the boreo–nemoral forest zone. Prior to establishment of the nature reserve, part of the island area was used for agriculture. The island is now covered almost entirely by forest dominated by Quercus robur L. and Tilia cordata Mill. on sandy soils. Resurvey was conducted in 2011 in 17 plots in which tree layers and the understory vegetation had been described in 1930. The plots were cla…
Effects of stand-level and landscape factors on understorey plant community traits in broad-leaved forest of the boreo-nemoral zone in Latvia
2019
Abstract Knowledge of the limiting processes shaping the composition of plant communities of woodland is important in conservation of biological diversity. The aim of our study was to examine the effect of stand-level factors (soil and canopy composition, age and area) and landscape factors (fragmentation of broad-leaved forest, distance to a historical manor house, and past history) on plant community trait composition in broad-leaved forest. We hypothesized that the plant functional community is shaped by both dispersal filtering due to landscape factors and by environmental characteristics. We recorded all vascular plants, described canopy composition and estimated soil characteristics i…
Evaluating structural and compositional canopy characteristics to predict the light-demand signature of the forest understorey in mixed, semi-natural…
2020
Questions: Light availability at the forest floor affects many forest ecosystem processes, and is often quantified indirectly through easy-to-measure stand characteristics. We investigated how three such characteristics, basal area, canopy cover and canopy closure, were related to each other in structurally complex mixed forests. We also asked how well they can predict the light-demand signature of the forest understorey (estimated as the mean Ellenberg indicator value for light [“EIVLIGHT”] and the proportion of “forest specialists” [“%FS”] within the plots). Furthermore, we asked whether accounting for the shade-casting ability of individual canopy species could improve predictions of EIV…