Effect of Changes in Land Use During the 20th Century on Woodland and Calcareous Grassland Vegetation in Southern Poland

In the modern agricultural landscape major threats to plant species diversity are loss and fragmentation of habitats and communities. During the last century natural and semi-natural communities have faced also cessation of tradition management and increased load of nutrients. This paper presents a survey of studies on vegetation dynamics of woodlands in the northern part of the Carpathian foothills and of calcareous grasslands on limestone hills near Kraków. The causes of fargoing changes observed in communities of these types and possible management for their conservation are discussed. The nature conservation value of woods can be assessed by means of ancient woodland plant species indicators

Vegetation diversity of conventional and organic hedgerows in Denmark

Many attempts have been made to reduce the impact of modern conventional farming on the environment and semi-natural ecosystems. One of them is organic farming, known primarily for the absence of pesticides and artificial fertilisers. The objective of this study was to study and test the differences in the spontaneous vegetation of comparable hedgerows in the same area situated within organic and conventional farming systems. The hedge bottom vegetation was surveyed during August 2001 in 13 hedgerows of each farming system. Farming type had not changed on either side of the hedgerows for the lifetime of the hedges (10-14 years). Sampling was associated with a set of 16 measured environmental variables. In the two farming systems hedgerows were comparable in terms of landscape, age, soil type, nutrient status and width. A mixed analysis of variance found no significant difference in measured soil and radiation variables between farming types. Farming types only differed in the use of pesticides. Significant differences between farming types in plant species diversity at alpha, beta and gamma levels were found. Also more species that normally occur in semi-natural habitats were found on organic farms. There was an overlap in species composition between farming type, but a slightly higher species turnover on conventional farms. The ordination axes were highly correlated with calibrated Ellenberg values of fertility, light and soil moisture. Soil fFertility and farming type were important factors to explain variation in species composition. Organic farming had a significantly reduced impact on hedge bottom vegetation compared to conventional farming. Higher extinction rates due to pesticide drift and immigration rates due to pesticide drift rates oin conventional farminsg may be responsible for the significantly higher species diversity and different species composition in hedges on organic farms. The differences in species diversity and plant types are briefly discussed

Importance of ancient woodlands for biodiversity conservation : need to conduct their survey and inventory

The mass clearing of natural woodlands for agricultural purpose and their fragmentation was one of the most frequent disturbances in European landscape in the past centuries. At present remnants of ancient woodlands as a rule occupy smaller or larger, frequently isolated areas. Many of them contain a typical and rich woodland biodiversity and can be regarded as local biodiversity hotspots. Recent studies have shown that natural regeneration of woodland communities is very slow in new sites. Considering value of ancient woodlands for nature conservation, their inventories should be created at last for chosen regions, and for national parks and others protected areas in Poland. Ancient woodland indicator plants are an useful and easy tool to determine these woodlands

Contribution of Bogumił Pawłowski (1898-1971) to phytosociology development

Professor Bogumił Pawłowski was one of the greatest Polish botanist of the 20th century. He contributed greatly to the development of plant taxonomy, plant geography, and phytosociology in Poland, and he was a master and a teacher to many young scientists. In this article the activity and achievements of B. Pawłowski in phytosociology are presented

Simulated N deposition negatively impacts sugar maple regeneration in a northern hardwood ecosystem

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90216/1/j.1365-2664.2011.02090.x.pd

The effects of stand characteristics on the understory vegetation in Quercus petraea and Q. cerris dominated forests

The shelterwood system used in Hungary has many effects on the composition and structure of the herb layer. The aim of our study was to identify the main variables that affect the occurence of herbs and seedlings in Turkey oak-sessile oak (Quercus cerris and Q. petraea) stands. The study was carried out in the Bükk mountains, Hungary. 122 sampling plots were established in 50-150 year old oak forests, where we studied the species composition and structure of the understorey and overstorey. The occurence of herbs was affected by canopy closure, the heterogenity and patchiness of the stand, the slope and the east-west component of the aspect. The composition of saplings was significantly explained by the ratio of the two major oak species in the stand and the proximity of the adult plants. An important result for forest management was that sessile oaks were able to regenerate almost only where they were dominant in the overstorey

Impact of weather on dynamics of plant functional groups in an abandoned limestone grassland

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

Impact of weather on dynamics of plant functional groups in an abandoned limestone grassland

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

Recovery of the herbaceous layer in the young silver birch and black alder stands that developed spontaneously after a forest fire

The studies, which were conducted in southern Poland, focused on the recovery of the herb layer in 17-year-old post-fire silver birch and black alder forests. Although both types of stands, which are of the same age, developed spontaneously, the alder stands occupied damper sites (with thicker A horizons that survived the fire) than those in the birch forests. We surveyed the migration rates of 44 woodland species, primarily ancient woodland indicators, into both forests and the potential differences in these rates depending on their moisture regime and the community type represented by unburned forests, which were treated as the source of the woodland species pool. Additionally, the role of local depressions with high humidity that were covered by post-fire alder woods in the colonization process, as well as species survivorship and recolonisation, were estimated. Woodland species showed diverse migration paces among the sites; most of them migrated faster on more fertile sites with a higher humidity. Small patches of post-fire alder woods contributed to the recolonisation process since many woodland species in the herb layer survived the fire due to its high humidity, which inhibited the intensity of the forest fire. The recovery of woodland species in post-fire woods is the combined effect of regeneration, which relies on autochthonic propagules, and secondary succession, which is based on allochthonic propagules. Local depressions, which provide refuges for fire-sensitive, dispersal-limited species, contribute to their survivorship and thus to the successive recovery of herbaceous layers after a fire