Wyniki wyszukiwania - BazTech

1

Habitat preferences of some neophytes with a reference to habitat disturbances

Myśliwy M.

Polish Journal of Ecology

|

2014

|

Vol. 62, nr 3

509--526

EN

The spread of species far from their native range is an important component of global changes. Investigating the ability of alien plants to invade different habitats is one of the most important approaches in the analysis of biological invasion mechanisms. The study was based on floristic research carried out in 1998–2002 in the north-western part of Poland. The habitats sampled were classified according to the EUNIS classification. A dataset of 2638 naturalized neophyte records was compiled based on a total of 2132 floristic lists. Species entries were supplemented with data on taxonomic position (family), origin, frequency, life form and number of habitats a particular species colonises. Ordination analyses showed the level of disturbance in individual habitats to be important in species-habitats relationships. Some of the species (e.g. Chamomilla suaveolens, Galinsoga parviflora, Veronica persica) occurred mainly in man-made, heavily disturbed habitats, while others (e.g. Impatiens parviflora, Padus serotina, Quercus rubra) were present primarily in natural habitats, less affected by humans. The species with the broadest habitat ranges identified included, i.a. Conyza canadensis, Impatiens parviflora, Epilobium ciliatum, and Oxalis fontana. Most of them, however, had different “core” habitats. Some species, e.g. Juncus tenuis, Elodea canadensis, Veronica persica were associated with one or a few habitats. The ability of species to invade numerous habitat types did not depend on their invasive status. The most successful aliens are those which spread dynamically along forest paths as well as those penetrating forest communities. The phytocoenotic role of each naturalized neophyte in plant communities requires a detailed study.Each individual habitat supports well-established alien species whose traits fit its characteristics and the disturbance intensity. Analysis of alien species traits, local distribution, habitat preferences and range makes it possible to reliably assess potentially successful invaders.

2

The spontaneous succession in a sand-pit: the role of life history traits and species habitat preferences

Kompała-Bąba A., Bąba W.

Polish Journal of Ecology

|

2013

|

Vol. 61, nr 1

13--22

EN

The prediction of species response to human activity is of great interest in contemporary restoration ecology. The purpose of the article was to analyse which species life history traits and species habitat preferences are important during succession after the abandonment of mining activity in a sand-pit. During a 15-year period (1996–2010), 176 phytosociological relevés were placed within vegetation patches of different ages and divided according to soil moisture, thus forming two series of chronosequences that ranged from 0 to ca. 50 years. The datasets were analysed using both DCA/CCA ordinations and regression trees. The successional gradient, apart from the theoretically predicted replacement R by C strategists, revealed the occurrence of stresstolerant ruderals and competitive ruderals in the early successional stages. However, differences were observed between the wet and dry series. On dry soils the ruderals, anemochorous and windpollinated species dominated in the early phases. In the middle successional phases, a preponderance of anemochorous species (nanophanerophytes, light or semi-shade demanding species), nitrogen-poor and competitive ruderals or species typical for nitrogen-rich soils was recorded. In the late successional stages, species with both the ability of vegetative and generative reproduction appeared. On the other hand, on wet sites in the early successional phases, species with vegetative growth, hydrophytes, chamaephytes and stresscompetitors prevailed. Later in the succession, they were replaced by insect-pollinated species in nitrogen rich habitats and stress-tolerant ruderals on less fertile habitats. Finally, competitors started to prevail. Knowledge of the environmental conditions of a given site, the ecological processes and species biology can assist in achieving the desired goals or in initiating or enhancing succession on some disturbed sites.

3

Diversity and distribution of high-mountain meadows across elevation gradient in Wutai Mts. (North China)

Zhang J., Mi X.

Polish Journal of Ecology

|

2007

|

Vol. 55, nr 3

585-593

EN

The Wutai Mountain Meadow Reserve, located at 112 [degrees] 50' - 113 [degrees] 50'E, 38 [degrees] 30' - 39 [degrees] 15'N, conserves the typical highmountain meadows in North China. Eighty one plots (quadrates 2 m x 2 m ) in 11 transects separated by 100 meters in altitude along an elevation gradient (2 000.3 058 m a.s.l.) were established. Species composition of plants, their abundance, coverage and height in each plot were measured and recorded. The environmental variable like slope, slope orientation, soil type, air temperature and humidity (yearly average values) were assessed. The multivariate analysis methods, TWINSPAN for classification, and DCA and CCA for ordination, were used to analyze the relationships between meadow communities and environmental variables. The results showed that there are eight types of mountain meadow vegetation in the reserve. The distribution of meadow communities is related to elevation, slope, slope orientation, and soil-water conditions. The changes of species diversity (H' = 1.5.2.5 ) in communities are mainly related to elevation gradient, and also related to community coverage, slope and slope orientation.