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1

Distribution of vegetation type according to edaphic properties and topography in Iran

100%
Zare Chahouki M. A., Khojasteh F., Tavili A.
Polish Journal of Environmental Studies
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2012
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tom 21
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nr 4
The current research was carried out to find the most effective environmental factors in plant species distribution. For this purpose, a study was conducted in the Taleghan rangelands of Tehran province. Based on a vegetation map and field surveys, indicator vegetation types were identified. Within each type, 3 parallel transects with 150 m length, each containing 15 quadrates (according to vegetation variations) were established. The sampling method was randomized systematic. Quadrat size was determined for each vegetation type using the minimal area method. The floristic list and canopy cover percentage were determined in each quadrat. The topographic conditions (elevation from sea, aspect, and slope) were recorded in quadrat locations. Soil samples were taken from 0-30 cm in starting and ending points of each transect. Measured soil properties included depth, texture, organic matter, lime, pH, electrical conductivity, nitrogen, and potassium. To determine the most environmentally effective factors on plant distribution, multivariate techniques, including the principal component analysis (PCA) and canonical correspondence analysis (CCA) methods were applied. The results indicated that edaphically factors such as texture, potassium, and organic matter play a main role in the distribution of plant species.
2

Effects of urbanization on the plant cover of Warsaw

100%
Chojnacki J., Sudnik-Wojcikowska B.
Memorabilia Zoologica
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1994
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tom 49
3

Impacts of vegetation type on soil phosphorus availability and fractions near the Alpine timberline of the Tibetan Plateau

80%
Zhang L., Wu Y., Wu N., Luo P., Liu L., Hu H. Y.
Polish Journal of Ecology
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2011
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tom 59
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nr 2
Soil phosphorus (P) availability and fractions are influenced to a large extent by land use and cover changes. Inorganic P (IP) and organic P (OP) fractions in surface soils (0–20 cm) under typical vegetation types, including subalpine coniferous forests, alpine shrubs, and alpine shrub-meadows, near the alpine timberline of the eastern Tibetan Plateau of China, were measured by a modified Hedley fraction method. The results showed that OP is the dominant soil P fraction and the main source of available P in alpine soils near the timberline. Soil organic carbon, total nitrogen, and total P contents were higher in subalpine coniferous forests than in alpine shrubs and alpine shrub-meadows. Concentrations of soil labile P (the sums of Resin–IP, NaHCO3–IP, and NaHCO3–OP) were higher in subalpine coniferous forests than in alpine shrubs and alpine shrub-meadows, an observation that may be partially ascribed to the presence of deep litter layers generated by trees. Concentrations of soil labile and moderately organic P (NaHCO3–OP and NaOH–OP) in subalpine coniferous forests were also greater than in alpine shrubs and alpine shrub-meadows. Greater amounts of soil stable OP (extracted by concentrated HCl and cHCl–OP) were accumulated in alpine shrub-meadows compared to alpine shrubs or subalpine coniferous forests. The reduced availability of OP may be attributed mainly to increasing recalcitrant soil organic matter input in alpine shrub-meadows and alpine shrubs. Concentrations of IP associated with Ca minerals and parent materials (extracted by diluted HCl and HCl–IP, and extracted by concentrated HCl and cHCl–IP, respectively) were lower in subalpine coniferous forests, indicating that coniferous forests are more likely to use recalcitrant IP than alpine shrubs and alpine shrub-meadows. In this alpine region, land cover changes from subalpine coniferous forests to alpine shrubs and alpine shrub-meadows near the alpine timberline could decrease soil P conservation, availability, and supplementation.
4
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Nutrients availability and hydrological conditions of selected wetland ecosystems in the Biebrza river valley

80%
Stelmaszczyk M., Okruszko T., Meire P.
Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation
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2015
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tom 47
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nr 1
Nutrients availability and hydrological conditions of selected wetland ecosystems in the Biebrza river valley. Paper presents results of investigation of hydrological conditions and nutrients limitation and availability for wetland vegetation in selected sites within Biebrza river valley. Analysed sites were overgrown by tall sedge Magnocaricion vegetation (Caricetum gracilis and Caricetum elatae), wet meadow Molinio-Arrhenatheretea vegetation (Molinietum caeruleae), and sedge-moss Scheuchzerio-Caricetea nigrae vegetation (Caricetum lasiocarpae). There were noted a close relationship between vegetation types, hydrological regimes and kind of nutrient limitation. Low productive Molinio-Arrhenatheretea and Scheuchzerio-Caricetea nigrae vegetations fed mainly by groundwater were limited by phosphorus, while highly productive Magnocaricion vegetation, fed by river water, was subjected to nitrogen limitation. We have found big diversifi cation of groundwater and surface water levels within habitats of different vegetation types along the Biebrza river valley. Magnocaricion vegetation present on fl ooded areas is characterized by signifi cant water level fl uctuations and long-lasting inundations. On areas covered by Molinio- -Arrhenatheretea vegetation we noted majority of water levels not exceeding the level of the ground surface. Whereas Scheuchzerio-Caricetea nigrae vegetation, fed by groundwater, is characterized by low variation of groundwater levels.
5

Tentative list of endemic vascular plants of the Zeravshan Mts in Tajikistan: distribution, habitat preferences and conservation status of species

61%
Nowak A., Nobis M.
Biodiversity: Research and Conservation
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2010
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tom 19
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