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Research on the effect of birch regeneration on changes occurring in the environment on former farmlands included a quantitative and qualitative analysis of the biomass growing on the research plots. Five experimental plots were selected in the Mazovia region: two in Dobieszyn and the Kampinos National Park and one in Kozienice. The analysis performed on each plot was concerned with the amount and chemical composition of biomass in four patches of vegetation, characterised by the different ages of the birch trees growing there. The vegetation patches were classified according to age group, i.e. I: 1–4 years old, II: 5–8 years old, III: 9–12 years old and IV: over 12 years old. Biomass samples were collected in the field and determined in kg DM/ha using the following components: roots, stem, bark,branches, assimilation apparatus, litterfall and the total biomass of the other (except birch) plants. For all the above-mentioned groups, the content of the elements N, C, S, Ca, K, Mg, Na, P, Mn, Cu, Fe, Zn, Pb, and Cd was determined. This allowed us to obtain both the values of the concentrations of particular substancesand their allocation in both the organic matter and litterfall. The aim of theresearch was to discover whether the allocation of elements changes with the age of birch growing on former farmland.
After abandonment many species-rich limestone grasslands have been overgrown by tall grasses and forbs, and often by shrubs and trees. As a result, communities with many regionally rare and endangered species are vanishing. We examined to what extend changes in the cover of sociological species groups and plant functional types in an unmanaged grassland depend on fluctuations in climatic conditions. Vegetation data from permanent plots in an abandoned grassland in southern Poland collected over 12 years were used. Relations between weather variables, time, and the cover of species groups were analysed using multiple linear regression and canonical correspondence analysis (CCA). The climatic data included mean temperatures and precipitation sums for each month from January to December (for the current year from January to July), and for 2, 3 and 4 consecutive months, with time lags of 0, 1, 2 and 3 years. It was found that both inter-annual fluctuation of climatic conditions and successional processes considerably influenced species composition of the study grassland. The fluctuations in precipitation and temperature explained from 0.8% to 27.1% of the variation in the cover of various sociological groups. The greatest effect on the cover dynamics of all species and majority of sociological groups had precipitation in spring and early summer in the current year. Most of species groups were affected also by temperature in spring and/or summer in the previous years, but its effect as lower than precipitation. The obtained results suggest that climatic conditions have also a significant impact on the rate of changes in abandoned limestone grasslands. Higher precipitation in spring and summer favour growth and spread of tall meadow grasses and forbs, accelerating changes from less compact communities dominated by smaller xerothermic species to more compact vegetation with a closed structure. In consequence the role of xerothermic calcareous species decreases and many of them may locally extinct within decades.
Ectomycorrhizal (ECM) fungi and their symbiotic associations with forest trees are among major drivers of key ecosystem functions such as carbon and nitrogen cycling, plant nutrient and water uptake from soil, plant-plant facilitation/competition and diversity regulation via common mycorrhizal networks. Through their functional traits and interactions with both abiotic and biotic environment, they also significantly affect the process of open land colonization by trees as well as vegetation succession coupled with soil and ecosystem development. Here we review the role of ECM fungi in the early primary and secondary succession following major anthropogenic disturbances. Based on the examples of mine spoils and post-agricultural lands, we demonstrate key ecosystem services provided by ECM fungi in the processes of forest restoration. We point out ecological mechanisms and adaptations which underpin ECM fungal community successional interactions, particularly life histories, dispersal, spatial structure, host preferences, and sensitivity to environmental filters. We emphasize the need of better understanding the role of ECM fungi in the forest restoration practice as it seems crucial for afforestation success and biodiversity rehabilitation. Thus, ectomycorrhizal traits should be a prime consideration in afforestation and carbon sequestration polices, sustainable forest management and biodiversity conservation practices.
In July, 1992, fire swept through the Jelonka Reserve (52o35'33"N; 23o22'10"E). Litter, herbs layer and juniper shrubs were razed and the tree trunks of Pinus sylvestris and Populus tremula damaged, which resulted in their death the following year. Five research plots of 25 m2 each were established in the post-fire area. The species present there and their degrees of coverage were listed on the Londo scale between 1993 and 2002. The calculation of average degrees of coverage for individual populations allowed for the establishing of a chronological pattern of post-fire succession. The following findings have been made: 1) the primary function in colonization belongs to species of guerilla strategy of growth whose dormant buds survived fire underground (Holcus mollis, Calluna vulgaris and Populus tremula) or phalanx strategy of growth (Corynephoms canescens); 2) the dominants of the initial succession stage are perennial grasses, not therophytes; 3) the spatial pattern of succession is influenced by the occurrence of H. mollis or C. canescens in a particular location; 4) the initial stage terminates with the occurrence and further growth of C. vulgaris clumps; the post-fire succession in the Jelonka Reserve attained a brushwood stage faster in comparison to secondary succession, formerly triggered by the cessation of cultivation on arable land.
Studies on the soil seed banks of fallow lands of different ages were carried out on poor soil abandoned fields and in a fresh coniferous forest in north-eastern Poland. The size and diversity of seed banks was studied with the seedling emergence method. Species abundance (i), density (ii), number of species from different biological groups (iii) and distribution and mean LI value (iv) were analysed as the function of fallow land age. It was found that: (i) species diversity, number of species and ln of density are linear declining function of the fallow land age; (ii) for approx. 25 years the share of diaspores of identified species groups has been relatively similar. Seed banks of 40-50-year-old fallow lands are dominated by Calluna vulgaris, while the seed bank of the old fresh coniferous forest is dominated by dicotyledonous perennials and grasses; (iii) within the first 50 years of succession the persistence of seed banks measured by the Longevity Index increases gradually.
The recovery of species composition typical for ancient forests in recent woods is a very slow process and may last for decades or even centuries. It is enhanced only when postagricultural woods are adjacent to ancient ones. However, even in such a situation of the spatial contact of both forest types, colonization of recent woods by true forest species is a gradual process. According to studies focusing on the behaviour of individual species and their colonization rates into recent woods, it can be concluded that in more fertile habitats the migration process proceeds faster than on poorer sites. Thus, studies were conducted on light, acidic soils both in ancient and in adjoining post-agricultural pine woods (the Dicrano-Pinion Libb. 1933 alliance) and were focused on the process of the colonization of the herbaceous layer by woodland flora in recent woods. In eight transects 80 m in length perpendicular to the ancient/recent ecotone and consisting of 10 sample plots of 16 m2 laid out at intervals of 4 m, the percentage cover of herb layer species was recorded. The migration rates (based on the occurrence of the farthest individual and on the occurrence of the maximum cover of a species) for 12 forest species were calculated. The mean migration rate for all species reached 0.54 m yr–1 when based on maximum cover and 0.67 m yr–1 when based on the farthest individual and appeared to be lower than those reported in investigations in more fertile and moister habitats. The migration rates for individual species ranged from 0 to 1.21 m yr–1 and were also lower than in more fertile, black alder woodlands. The migration pattern of Vaccinium myrtillus L., the most abundant species in pine woods, fits the model based on the establishment of isolated individuals. The cover of most woodland species increased with the increasing age of a recent wood. Herb layer recovery on such sites is slower than in the more productive, fertile habitats of broadleaved forests. The ancient and recent pine woods investigated here differed in herb layer species composition despite the secondary succession having lasted for over 50–60 years.
We examined to what extend the rate and direction of changes in unmanaged grassland depend on fluctuations in climatic conditions. Vegetation data from permanent plots in a semi-natural grassland in southern Poland collected over 12 years were used. Relations between weather variables, time, and the cover of 41 more frequent species and 14 plant functional groups were analysed. The greatest effect on the dynamics of species and functional groups had precipitation in spring and/or early summer, particularly in the current year. The majority of plant groups were significantly affected also by the temperature in spring and early summer in one of the three previous years. During 12 years, the cover of annuals and biennials, short plants, and plants with small leaves decreased, while the cover of taller plants, plants with larger leaves, and with vegetative spread increased. The analyses suggest that these successional changes were not directly associated with climatic conditions but were affected by them indirectly through interspecific competition. The fluctuations in climatic conditions, chiefly precipitation, had a significant effect on both the composition and the rate of changes in abandoned grassland. The increase in the cover of tall perennial species with broad leaves hindered succession towards woodland despite of the presence of woods in the closed vicinity. It can be expected that during drier periods colonisation of grassland by later successional species could be easier.
The paper analyses the production and allocation of biomass in young, spontaneoussilver birch afforestation occurring on post-agricultural lands in the Mazowszeregion (central Poland). We investigated 114 sample plots of age varying from 1 to 19 years. During the first 15 years after their establishment on abandoned farmland, the naturally regenerated silver birch stands produced on average approximately 75 tons of dry biomass per hectare. The major (50–70%) part of this biomass was stored in the tree stems and this share increased with age. The fractions of biomass in the foliage and roots decreased over time, while the share of biomass in the branches remained rather constant. The significant age-dependency of the allometric relationships suggested the need to use age-sensitive biomass expansion factors to estimate the biomass from the stem volume.
A study of the life-history traits and seedling recruitment in small and isolated populations of a rare clonal species, Dianthus superbus L., was carried out in the years 2011–2012 in Kraków-Kostrze (Southern Poland). Observations were conducted in unmanaged Molinietum caeruleae meadows situated along the successional gradient. The patch representing the initial stage of succession (P1) was dominated by small species creating delicate erect or procumbent stems, the patch representing the temporary stage of succession (P2) was prevailed by large-tussock grasses and tall-growing macroforbs, while the patch representing the terminal stage of succession (P3) was partly overgrown by bushes and trees. The number of generative shoots, flowers, fruits and seeds of Dianthus superbus L. diminished gradually from P3 via P2 to P1. The increase in abundance of generative shoots and flower number in the vicinity of tall plants contributes to increased visibility of inflorescences and may enhance the chances for nocturnal pollinator visits. A significant production of fruits and seeds in competitive neighborhood may augment the chances for successful dispersal and colonization of new, perhaps more favorable habitats. The recruitment of seedlings occurred only in artificially created gaps in plant canopy and litter. The appearance of seedlings and their survivorship were better in P1 than in P2 and P3. Such a phenomenon might be due to the locally rising water level and the diminishing amount of light reaching to the soil area along the successional gradient. Concluding, it should be asserted that a low production of generative shoots, flowers, fruits and seeds by the population of Dianthus superbus L. established in the patch dominated by small meadow species is compensated by the highest seedling recruitment and their survival. On the other hand, a substantial production of generative structures is not sufficient to ensure the persistence of populations in meadows in advanced stages of secondary succession.
The effects of the colonization of an abandoned grassland by forest trees and the associated microenvironmental changes on soil properties and the microbial activity of soil were studied along a 170 m transect established on a former pasture colonized by Norway spruce (Picea abies Karst.) in Central Slovakia. The transect with a 5×5 m grid of sampling points crosses all successional stages from a closed forest to an open grassland, representing 50 years of secondary succession. Changes of basal soil respiration, substrate-induced respiration and soil catalase activity in association with tree density, light and temperature regime were examined, and their relationships with chemical soil properties were documented. Generally, light conditions, tree influence and soil temperatures were highly significantly correlated with the distance from the lower transect edge, but the correlation coefficients were not very high (|r| ranged between 0.37 and 0.70), indicating that the microsite conditions within the transect are strongly heterogeneous. With the advance of colonization, the amount of soil organic matter was found to increase, probably in association with a higher amount and a lower quality of litter. Catalase activity exhibits a linear trend along the transect, which is explained by a lower direct insolation of soils (r = 0.28***) and decreasing temperatures (r = 0.36***) in the upper part. Basal respiration is the lowest in the middle of the transect, where colonizing spruces form a dense closed stand with soil covered by a thick layer of raw litter. Both in the lower part covered by species-rich grassland communities and in the upper part, where forest herb species begin to establish, basal respiration is higher, probably due to higher amounts of easily decomposable plant material. In addition to these transect-wide trends, stationary spatial patterns were observed for most soil variables. Generally, microbial activity rates as well as chemical soil properties exhibited spatial continuity up to the distance of approx. 40 to 60 m.
The research, in 2004, was focused on the whole population of Anemone sylvestris (Snowdrop Windflower) present in the area of a kettle hole (0.8 km2) in north-eastern Poland (52°50’00’’N; 23°11’20’’E). The location of 56 clumps of generative specimens was surveyed. They numbered from several to approx. 1500 specimens. The number of generative specimens in this population exceeded 10 000. On account of this, it is a unique stand of A. sylvestris in Poland. The relationship between the occurrence of the Snowdrop Windflower and the presence of kame hills and ridges has been proven. Low slopes of kame with an inclination of 10-20o, and a north-eastern or eastern exposition has been found as the local ecological optimum for this species. Research carried out in 1970-2001 on 5 permanent plots (25 m2 each) has shown that: 1) Anemone sylvestris is an essential element of xerothermic grasslands of the order Festucetalia valesiacae; 2) the species suddenly withdraws from the parts of land on which woody species have already reached the shrub layer; 3) the greatest danger for the population of A. sylvestris in this area is the process of secondary succession initiated by the discontinuation of grazing on the kame hills.
The study was carried out in 1999–2000 in midfield shelterbelts located in mosaic agricultural landscape near village Turew (West Poland) with the aid of transect method (total length amounted to 4520 m). Five shelterbelts (transect length – 3070 m) have been planted in 1993 and one shelterbelt (transect length – 1450 m) in 1998. All the shelterbelts have been planted on arable land. Twenty seven species of butterflies (imagines) were recorded during the study period. Pieris napi and P.rapae dominated in all shelterbelts. Their dominance in 6–7 years old shelterbelts amounted to 30 and 24%, respectively, while in younger one (1–2 years old) – 34 and 32%. Total mean density of butterflies in older shelterbelts was equal to 91.9 ind. km⁻¹ of transect (width 5 m) – and was about 40% higher than in the younger one. Lower dominance of Aphantopus hyperantus (8%) observed in 6–7 years shelterbelts (when compared to several tens years ones) was most likely caused by small share of grasses and perennial dicotyledons, which are important for this species. The butterflies recorded in shelterbelts may be assigned to four ecological groups: ubiquistic species (7 spp.), species typical for open area (10 spp.), species linked to afforestations (3 spp.) and woodland (7 spp.). In all studied shelterbelts most abundant were ubiquistic species and open areas species (Pieris rapae and P. napi) with no respect to age of shelterbelt. Also some rare species with higher environmental demands were recorded, i.e., Polyommatus amandus and Carterocephalus palaeon, which have not been previously observed in the study area.
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