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Fine roots are an important component of forest soil as they play a key role in fundamental processes like plant nutrition and water supply. As with all the features of forest soil, the compaction related to the forest operations and, in particular, to the wood extraction via ground‐based technologies could lead to a significant impact on the presence of fine roots in the soil affected by the passage of the machines. Considering the lack of a review, we used a meta‐analytic approach to synthesise effect sizes of ground‐based extraction technologies affecting the presence of fine roots in the soil, using a multivariate mixed‐effects meta‐analytic model. The obtained results revealed that the presence of fine roots in the soil affected by the passage of the machines was significantly reduced by both skidding (g = −1.23, 95%CI ‐1.87, −0.60) and forwarding (g = −1.37, 95%CI ‐2.01, −0.74). Due to the higher soil compaction caused by forwarding, this method had a marginally but statistically significant greater impact than skidding. We further confirmed the hypothesis that soil compaction and the presence of fine roots were strongly correlated, with the latter being greatly reduced in compacted soils characterised by higher bulk density. What is more, even more than 20 years after a harvesting intervention, the presence of fine roots was significantly lower in both strip roads (forwarding) and skid trails (skidding) as compared to areas which were not impacted by the machine passage. This shows that fine roots are particularly vulnerable to forest operations. On the other hand, the majority of the trails in the database used for the meta‐analysis were created in countries that favour the creation of a small number of widely used trails. Therefore, it would be scientifically valuable to do a comparative evaluation in various forestry contexts, such as in the Mediterranean area, where the development of the forest trails network is oriented on creating a large number of trails with low traffic volumes. Because machinery‐induced soil compaction is the major driver of the decrease in fine roots in skid trails and strip roads, both the application of best management practices as well as of a smarter planning of the trail network to limit soil compaction are strongly recommended. Both applications are highly recommended to be used in the planning phase and in the practical implementation of logging activities. [ABSTRACT FROM AUTHOR]

Habitat loss and fragmentation are among the most influential factors responsible for recent biodiversity decline. The key to understanding the changes in ecosystem functioning is the analysis of the relationship between species diversity and environmental gradients such as those found near streamside forests. We used soil mites (Mesostigmata) as model species as they are predators in soil ecosystems, they occur in high relative abundance, their communities are species‐rich and are robust toward sampling and extraction methods. The main goals of this study were to (1) check how the plant community and associated environmental variables (light conditions, litter accumulation, and soil acidity) along mountain streams affect soil Mesostigmata abundance and diversity, and (2) to analyze the distance from mountain streams to which the ecosystem functions (Mesostigmata diversity) are affected, based on a distance gradient. We systematically established 31 study plots (500 m2) every 200 m along the watercourses, representing three habitat types along the stand composition gradient (ash‐sycamore [Fraxinus excelsior–Acer pseudoplatanus], European beech [Fagus sylvatica], and Norway spruce [Picea abies] forests) for measurements of soil litter thickness, soil acidity, and light conditions. We extracted soil Mesostigmata mites from samples in Tullgren funnels and identified them to the species level. We found that Mesostigmata abundance in forests decreased in the following order: Norway spruce forest > European beech forest > ash‐sycamore forest. Additionally, changes in Shannon diversity were associated with light conditions. In conclusion, streamside mountain forests maintained abundant, diverse and species‐rich Mesostigmata communities, which were associated with a plant community‐light condition gradient. Additionally, more abundant mite communities occurred in forests with higher soil pH values, and under higher light conditions. [ABSTRACT FROM AUTHOR]

Proper estimation of the herb layer annual net primary production (ANPP) can help to appreciate the role of this layer in carbon assimilation and nutrient cycling. Simple methods of ANPP estimation often understate its value. More accurate methods take into account biomass increments of individual species but are more laborious. We conducted our study in an oak-hornbeam forest (site area 12 ha) dominated by beech in NW Poland during two growing seasons (2010 and 2011). We collected herb layer biomass from 7 to 10 square frames (0.6 × 0.6 m). We collected plant biomass every week in April and May and every two weeks for the rest of the growing season. We compared six methods of calculating ANPP. The highest current-year standing biomass (1st method of ANPP calculation) was obtained on May 15, 2010—37.8 g m−2 and May 7, 2011—41.0 g m−2. The highest values of ANPP were obtained by the 6th method based on the sum of the highest products of shoot biomass and density for individual species: 74.3 g m−2 year−1 in 2010 and 94.0 g m−2 year−1 in 2011. The spring ephemeral Anemone nemorosa had the highest share of ANPP with 50% of the total ANPP. Two summer-greens, Galeobdolon luteum and Galium odoratum, each had a ca. 10% share of ANPP. The best results of ANPP calculation resulted from laborious tracking of dynamics of biomass and density of individual shoots. [ABSTRACT FROM AUTHOR]

Trees are promoters of forest ecosystems and tree species differ in their manners of shaping the habitat conditions on reclaimed areas. We compared effects of pure forest stands of Alnus glutinosa, Betula pendula, and Pinus sylvestris (age 20–31 years) planted on sandy, loamy sand, sandy loam, and loam soils, on chemical properties of the soil and vascular plants species composition of the herb layer. Studied properties were assessed in pairs of plots located less than 50 m apart, that differed in species composition of the canopy but were characterized by similar abiotic conditions. Forest stands of A. glutinosa were distinguished by a higher SOC content in soil (2.3% vs. 1.4% under B. pendula and P. sylvestris), higher contribution of species typical for fertile forest edges (11.4 species vs. 5.9 species on average under B. pendula and P. sylvestris) and lower number of species of the family Fabaceae (1.5 species vs. 5.2 species on average under B. pendula and P. sylvestris). Effects of P. sylvestris stands depended on soil texture. On soils with more than 15% of silt and clay, generally, no effects were observed. However, on sandy soils (more than 85% of sand) we reported lower soil reaction (pH 6.3 in aqueous solution vs. 7.3 under B. pendula) and smaller number of plant species (17 vs. 28 on average under B. pendula). Our results showed that the tree species used for afforestation significantly influenced the characteristics of the forest ecosystems, even more than abiotic conditions. [ABSTRACT FROM AUTHOR]

Seasonal fluctuations of light availability, nutrient concentrations, and moisture affect plant population traits like density, standing biomass, and flowering. We analyzed seasonal changes of density and shoot biomass of the four most frequent herb species growing in an oak–hornbeam forest community, i.e., Anemone nemorosa, Ficaria verna, Galeobdolon luteum, and Galium odoratum. In 2010 and 2011 plant biomass was harvested from 7 to 10 randomly situated square sample plots (0.36 m2) in the homogenous oak–hornbeam forest community every week in the spring and every two weeks in the summer and autumn. The highest abundance of Anemone nemorosa reached over 1000 shoots per m2, of Ficaria verna 459.5 shoots per m2, of Galium odoratum 83.6 shoots per m2, and of Galeobdolon luteum 98.4 shoots per m2 (means for 2010 and 2011, based on all sample plots). We did not observe negative correlation between density and shoot biomass. Growth rates of vegetative shoot biomass amounted to 0.857 mg day−1 for Anemone nemorosa, 0.467 mg day−1 for Ficaria verna, 0.722 mg day−1 for Galium odoratum, and 0.448 mg day−1 for Galeobdolon luteum (means for 2010 and 2011). Spring ephemerals had much higher densities of shoots than summer-greens. Summer-greens reached higher biomass of individual shoots than spring ephemerals. Flowering shoots constituted only 4, 2, and 11% of all shoots for A. nemorosa, F. verna, and G. odoratum, respectively. More resource availability resulting in high shoot biomass did not translate to higher share of flowering shoots. [ABSTRACT FROM AUTHOR]

Although interactions between alien and native plant species are well studied, data on interactions between two co-existing alien species with respect to their invasibility are scarce. The aims of this study were (1) to evaluate three factors shaping abundance of the alien shrub species Cornus alternifolia: abundance of another alien (invasive) shrub species ( Prunus serotina), type of tree stand (coniferous vs. broadleaved) and distance to propagule sources and (2) to assess the potential dispersal distance of the species studied. Densities of both species were assessed within 194 experimental plots (located in experimental plantations of trees) in Rogów Arboretum (Central Poland). P. serotina occurred on 79 and C. alternifolia on 33 of the 194 plots. The furthest distance of C. alternifolia from the propagule source was 338 m. C. alternifolia reached higher densities in coniferous than broadleaved tree stands. Density of C. alternifolia depended on tree stand type and distance from the propagule source, but did not depend on density of P. serotina. Density of C. alternifolia decreased with increasing distance from the propagule source; however, this relationship was modified by the type of tree stand: densities were lower in broadleaved than in coniferous stands. The presence of the invasive species seems to neither facilitate nor limit the dispersal distance of C. alternifolia, as these two species differ in shade tolerance. The study also provided the first information about C. alternifolia potential invasiveness, because earlier this species was noticed only as casually escaping from cultivation in Slovakia. [ABSTRACT FROM AUTHOR]