Wyniki wyszukiwania - BazTech

1

The effect of lake water characteristics on decomposition of aquatic macrophytes

Kufel L., Kufel I., Królikowska J.

Polish Journal of Ecology

|

2004

|

Vol. 52, nr 3

261-273

EN

In situ decomposition of the hornwort (Ceratophyllum demersum L.), the buckbean (Menyanthes trifoliata L.) and leaf blades of the yellow water lily (Nuphar lutea L.) was studied with the litter bag method in three small mid-forest lakes of different pH and nutrient content. Time course of decomposition and of nutrient release from decomposing plant material was best fitted with a logarithm approximation and not by usually used exponential fit. pH of lake waters strongly affected decomposition rates of C. demersum and M. trifoliata. No effect of nutrient concentrations in lake water or in plant tissues on decomposition was noted for any of the analysed plants. Organic carbon deficit is speculated as a possible reason for the observed pH effect on decomposition rates. Modification of particulate and soluble N:P ratios are underlined as a consequence of different N and P release from decomposing plant material.

2

Does biotic patchiness in a lake conform to chemical heterogeneity?

Kufel I., Kufel L.

Polish Journal of Ecology

|

2001

|

Vol. 49, nr 4

427-430

EN

Analyses of lake water taken in discrete sites along a c. 2 km transect from a 1 m depth in a eutrophic Lake Miko?ajskie revealed a uniform horizontal distribution of temperature and oxygen concentrations. Conductivity, soluble reactive phosphorus and particularly chlorophyll concentrations showed, however a marked variability along the transect. Significant correlation between pH and conductivity suggest that a local photosynthetically induced calcite precipitation may be responsible for the observed horizontal variability of these parameters. Biotic response (inferred from chlorophyll concentrations) was not coupled with chemical differences. Different temporal scales of chemical processes and phytoplankton growth are assumed to explain this discrepancy.

3

Spatial variability and long-term changes of the trophic parameters in the Great Masurian Lakes (Poland)

Kufel I., Kufel L.

Polish Journal of Ecology

|

1999

|

Vol. 47, no 3

323-333

EN

Hydrologic division of the Great Masurian Lakes (North-eastern Poland) into the northen and southern drainage basin was found to be reflected in different trophic status of lakes. Chlorophyll (but not nutrient) concentrations in the northern part of the system were significantly lower than those in lakes of the southern part. It has been shown that tunnel-valley lakes (numerous in the southern watershed) appear to be more eutrophied in terms of chlorophyll abundance than morainic stratified lakes. Hypolimnetic enrichment and internal loading were probably responsible for the lack of in-lake phosphorus and chlorophyll decline in spite of the evident decrease of the external nutrient loading which had taken place between 1985 and 1996. Such a positive response was observed, however, in the case of nitrogen. Only in a hypertrophic Lake Niegocin some symptoms of recovery were noted after reduction of external point source pollution.

4

Long term effects of liming in a humic lake : ecosystem processes, biodiversity, food web functioning (Lake Flosek, Masurian Lakeland, Poland)

Hillbricht-Ilkowska A., Dusoge K., Ejsmont-Karabin J., Jasser I., Kufel I., Ozimek T., Rybak J.I., Rzepecki M., Węgleńska T.

Polish Journal of Ecology

|

1998

|

Vol. 46, no 4

347-415

EN

The chemical composition of water and bottom sediments, productivity and decomposition rates as well as the biodiversity and food web functioning (organic suspension, edible algae, bacterio-detrivores, herbivores, grazers, predators) in plankton and benthos were analysed in humuc, weakly acid, mid-forest lake surrounded by peatmoss Sphagnum (Lake Flosek, Masurian Lakeland, Poland) before and 1-4 and 20-23 years after application of powdered lime. Calcium content and pH in water and sediment raised permanently. High water quality variables were main-tained after liming (low production, algal biomass, chlorophyll and nutrient concentration, low release rate of phosphorus from the sediments). Decomposition rate of organic matter increased significantly. The species richness and diversity of algae, rotifers, crustacean and benthic invertebrates increased at least twice as well as the abundance of bacterio-detrivores in plankton (small rotifers) and benthos (chironomids) and herbivores (big daphnids, diaptomids) in plankton. The distinct succession in species composition was observed in many taxa. The predators like larvae of Chaoborus, cyclopids and predatory rotifers became very abundant after 20 years since liming. No evident peatmoss mat spreading over the lake table has been observed since liming but also no detrimental effect on peatmoss surrounding the lake. It was concluded that the moderate liming affects first of all the biodiversity of lake biota then it stimulates the mobilisation of the lake which eventually lead to the greater and more stable complexity of trophic links. The species-rich and top-down controlled food web was installed in the limed lake without interfering with high quality of lake waters (low-productive, high-transparent) and unique, natural values of its surroundings.However, a slight increase in nutrient concentration after 22-23 years was observed which could be related to more efficient recycling mechanism in lake (due to abundant big components in plankton and benthos) or to eutrophication.