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Understanding the relationship among environmental factors, overstory and understory is a key step for the improvement of sustainable forest management. Our aim was to understand how environmental features (topographic factors) and overstory (tree species) composition affect understory (shrub and herb species) assemblage in sub-Mediterranean coppiced woods. The study area lies in the Monti Sibillini National Park (central Italy). In 205 plots (20 × 20 m) we collected topographic features and species cover values; moreover, we defined the Social Behaviour Type (SBT — i.e. species ecological and dynamic features) of each understory species. Data were analysed using Redundancy Analysis and Generalized Linear Modeling. We found that topographic factors shaped percentage cover of different tree species and hence determined forest community type. Topography-related factors were further mediated by the tree layer composition, in filtering understory assemblage, on the basis of species SBT. We found no effect of overstory species diversity on understory species diversity. However, the presence of tree species different from the dominant ones increased understory species richness. This effect was particularly notable in evergreen woods, dominated by Quercus ilex. We conclude that, to improve the management sustainability, coppicing management should be focused on the achievement of the greater tree species diversity.
Traditional forest management as coppicing and coppicing-with-standard are recently considered as beneficial for biodiversity in woodlands. Cessation of coppicing leads to changes in stand structure and often loss of biodiversity. In contemporary Polish forestry coppicing is not applied, however some stands of coppice origin persist in Silesia until present. The overgrown coppice oak forests that cover the southern slopes at the foothills of the Sudetes Mountains (Silesia, Central Europe) are considered to be Euro-Siberian steppic woods with a Quercus sp. habitat (91I0): a priority habitat in the European Union, according to the Natura 2000 system. They support one of the largest populations of wild service tree (Sorbus torminalis Crantz) in Poland. In this study we investigated the relation of stand structure and trees parameters with environmental variables. The results showed considerable variability of stand volume, tree density and stems’ size correlated mostly with soil texture, but not nutrient content. We attributed it to soil dryness which seems to be the crucial factor controlling growth of trees. The natural regeneration of trees concentrated mostly on non-exposed sites on less acidic soils, but seedlings of wild service tree were present almost exclusively on most insolated sites, with shallow acidic soils. However, the regeneration of trees in sapling stage was restrained by browsing. Results suggest that maintaining of Sorbus torminalis requires protection against browsing, and some kind of active management is necessary to retain the observed stand structure with high proportion of wild service trees in stands on more fertile soils.
Plantations of energy plants are the alternative form of post-agricultural and degraded land management. Particularly, small-area plantations of the tree species, including the willow Salix sp., raise local natural values of degraded habitats and are a dwelling place for numerous entomofauna, birds and mammals. Herbaceous vegetation accompanying short-rotation coppice (SRC) constitutes at the beginning a competition for energy species plantings and therefore is subject to chemical and mechanical control. In successive years, it may increase local biodiversity at the level of plant species and associations, both in ruderal habitats and extensively used agricultural lands. In the presented paper, results of the study referring to evaluation of the floristic and phytosociological diversity of herbaceous vegetation accompanying selected 4–5-year-old willow short-rotation coppices (SRC) situated on lands adjacent to the Odra River estuary (Western Pomerania) in different soil-habitat conditions are showed. Investigations were carried out in willow SRCs located on degraded sandy silts and sewage sludge-fertilised silts, fallow post-farmland and degraded grassland. The largest number of species onfirmed by the highest Shannon-Wiener’s diversity index (H) and species evenness index (J) was characteristic of SRCs set on sandy silt fertilised with sewage sludge, wet grassland and fallow post-farmland when compared to those on sandy silt and over-dried grassland. The analysis of vegetation showed a strong predominance of anthropogenic associations (synanthropic and seminatural) over autogenic (natural) ones.
Assimilation and photosynthetic efficiency (maximal quantum yield) of young oaks were compared in coppice and standard sessile oak stands of comparable age (100 years) under different light intensity categories: under minimum light – ISF < 20%, low light – 20%30% during favourable and drought conditions. Measurements of maximal assimilation rates were performed at a constant temperature of the measurement block (20°C), a CO2 concentration of 400 μmol/l, flow 500 μmol/s and different light intensities: 0, 50, 250, 600, 1200 and 1800 μmol/m2s during three consecutive growing seasons (2012, 2013 and 2014). In every category at least 8 young naturally regenerated seedlings and sprouts of different coppice stools were measured. The quantum yield in optimal conditions in standards was highest in the category of closed canopy, while in coppices in medium light category. During severe drought in 2013 the drop in efficiency of standards was evident in all categories, while in coppices no differences in efficiency were observed between favourable 2012 and 2013 with expressed drought stress, proving the advantage of young coppices over standards in this particular light category. However, the beneficial effects of restoration coppicing are not guaranteed. It is our belief that in time such advantage might decrease; it would be therefore interesting to compare responses in time and define, when response abilities of both studied systems become equal.
In temperate forest ecosystems, management is one of the most relevant factors that can drive the temporal pattern of species. As species in an ecosystem show susceptibility to stress and disturbance, it is useful to take into account the plant community “compositional dimension”, which derives from species behaviour and ecological attributes and provides information on the mechanisms underlying species assemblages. Taking into account the influence of environmental factors on species diversity and composition, in order to determine the most suitable ecological behaviour type of each species, the research aim was to generate a model for Ostrya carpinifolia coppiced woods (central Italy) that describes forest ecosystem regeneration after coppicing by the assessment of change in the composition of ecological behaviour types. Vascular species cover percentage, field data, soil data, light intensity at the undergrowth, dominant tree layer cover and time since last logging were recorded for 63 plots covering 400 m2 each (20 x 20 m), randomly selected within a set of homogeneous macro-environmental conditions. Low species richness is related to stressing factors (acid soil, high soil skeleton percentage), while high species richness is linked to high light intensity at the undergrowth level due to scarce canopy cover soon after coppicing. The driving forces affecting floristic composition, highlighted through multi-response permutation procedures (MRPP) were light intensity at the undergrowth, regenerative phase, dominant tree layer cover, acidity, presence/absence of outcropping rock or rock fragments and total nitrogen content. Six species groups, each one characterized by homogeneous ecological behaviour, were defined by indicator species analysis (ISA) and tested using bioindication values analysis. Floristic successional change, related to time since last coppicing, turned out to follow an ecological cycling process characterized by cyclical occurrence/disappearance of species belonging to the six groups.
Coppicing is uncommon in Poland; however, some remnants of a previously coppiced oak forest persist in the foothills of the Sudety Mountains (southern Poland). Some of these forests are considered as a kind of thermophilous oak forest, classified as habitat 91I0 in the European programme Natura 2000. As an example of previously coppiced sessile oak (Quercus petraea (Matt.) Liebl.) forest in Poland, the vegetation and environmental factors in the “Wąwoz Lipa” reserve (area 101 ha, altitude ca. 400 m a.s.l.) were surveyed. Canonical correspondence analysis showed a basic compositional gradient of vegetation related to the content of coarse fragments in the soil, light availability and soil pH. The number of species per plot was not correlated with any particular environmental variable; in general, the plant species number and cover decreased in the most exposed sites, where the heat load was highest. We hypothesize that the higher number of species in some plots was the results of an edge effect: this occurred in transitional zones between the most exposed sites, which work as refuges for light-demanding, drought-tolerant species, and less exposed sites, with vegetation typical of acidophilous oak forests. The land relief also allowed the spread of species typical of mesophilous forests, which found refuge in the shaded, wet gorges. Thus, the specific land relief, along with previous coppice management, allowed the coexistence, probably temporally, of species of plants considered typical of different habitats.
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