Wyniki wyszukiwania

1

Temperature and nutrient dynamics in eutrophic freshwater ecosystems

100%

Zalewski M., Wagner I.

Geographia Polonica

|

1998

|

tom 71

2

Bamboo: potential resource for eco-restoration of degraded lands

84%

Mishra G., Giri K., Panday S., Kumar R., Bisht N. S.

Journal of Biology and Earth Sciences

|

2014

|

tom 04

|

nr 2

3

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Seasonal influence of physico-chemical parameters on phytoplankton diversity, community structure and abundance at Parangipettai coastal waters, Bay of Bengal, South East Coast of India

84%

Vajravelu M., Martin Y., Ayyappan S., Mayakrishnan M.

Oceanologia

|

2018

|

tom 60

|

nr 2

4

Water- and N-induced changes in soil C:N:P stoichiometry and its implications for N limitation of a desert steppe species, Glycyrrhiza uralensis

84%

Huang J., Yu H., Zhang F., Li M., Lin H.

Polish Journal of Ecology

|

2016

|

tom 64

|

nr 2

Changes in precipitation patterns and the deposition of atmospheric nitrogen (N) increase the possibility of altering soil carbon (C):N:phosphorus (P) stoichiometry through their effects on soil C and nutrient dynamics, especially in water- and N-limited ecosystems. We conducted separate 2-year watering and N addition experiments, and examined soil C:N:P stoichiometry, relative growth rate, and leaf N resorption traits of Glycyrrhiza uralensis Fisch in a desert steppe of northwestern China. Our objectives were to determine how soil C:N:P stoichiometry responded to climate change, and its indications for plant growth and N resorption. The results showed that additional water increased N loss and thus decreased N availability, resulting in high N resorption from senescing leaves of G. uralensis. N addition increased N availability, consequently reducing plant N dependence on leaf resorption. High relative growth rates occurred with intermediate N:P and C:N ratios, while high N resorption occurred with a low N:P ratio but a high C:N ratio. Our results indicate that soil C:N:P stoichiometry also could be a good indicator of N limitation for desert steppe species. Altered soil C:N:P stoichiometry affects the N strategy of plants, and will be expected to further influence the structure and function of the desert steppe community in the near future.

5

Effects of grass carp introduction on macrophyte communities in a shallow lake

67%

Krupska J., Pelechaty M., Pukacz A., Ossowski P.

Oceanological and Hydrobiological Studies

|

2012

|

tom 41

|

nr 1

6

Effects of freezing and freeze-thaw cycles on soil microbial biomass and nutrient dynamics under different snow gradients in an Alpine meadow (Tibetan Plateau)

67%

Liu L., Wu Y., Wu N., Xu J., Mao Y., Luo P., Zhang L.

Polish Journal of Ecology

|

2010

|

tom 58

|

nr 4

In alpine zones, cold season processes, particularly those associated with snow accumulation and ablation, have a central role in ecosystem functioning. However, we know very little about soil carbon and nitrogen processes under the snowpack in these ecosystems, including the Tibetan Plateau. We conducted an experiment comparing three snow regimes (11 m × 1 m plots) of different snow depths and durations at an altitude of 4,100 m in the Minshan Range on the eastern Tibetan Plateau. The three snow regimes included a shallow and short duration snowpack (SS; depth <10 cm), a moderate snow depth and medium duration snowpack (MS; depth <20 cm), as well as a deep and long duration snowpack (DS; depth > 30 cm). This study explores the effects of different snow conditions on soil temperature, and further describes the sequence and timing of dissolved nutrients and microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) in soils under different snow regimes during the autumn-winter transition (i.e. November 7, 2008 – March 7, 2009). Three successive phases of temperature change were distinguished: I – initial decline – soil temperatures dropped steadily from 4°C to about 0°C at the same rate for all three snow regimes; II – moderate freezing – soil temperatures fluctuated between 0°C and –7°C under all three snow regimes; III – multiple freeze-thaw cycles took place in the SS and MS regimes, but permanent freezing occurred in the DS regime. Under moderate freezing, we found that soil temperature fluctuation was an essential factor for the transformation of soil C and N. Our results indicate that larger temperature fluctuations correlate with a greater increase in dissolved organic nitrogen (DON) content. Dissolved organic carbon (DOC) content increased markedly only under the most drastic temperature fluctuations. In contrast, MBC content increased significantly only when soil temperatures were relatively steady. Under the permanent freezing, only a large number of freeze-thaw cycles caused a significant decline of NO₃⁻–N and DOC concentrations. DON content declined markedly under permanent freezing and multiple freeze-thaw cycles. However, MBC content declined significantly only under permanent freezing. Ultimately, multiple freeze-thaw cycles resulted in the export of dissolved nutrients (organic and inorganic nitrogen) from the alpine ecosystem which had previously accumulated in the moderate freezing phase of the soil.

7

High resolution 3D-ecosystem model for the Neva Bay and Estuary - model validation and future scenarios

67%

Korpinen P., Kiirikki M., Rantanen P., Inkala A., Sarkkula J.

Oceanologia

|

2003

|

tom 45

|

nr 1

We have used a simple 3D-ecosystem model to describe nutrient dynamics and biomass production in the Neva Bay off St.Petersburg. The River Neva is responsible for carrying the waste waters of St. Petersburg to the Gulf of Finland. Literature values of chlorophyll-a concentrations and satellite images have been used for model validation. The results indicate that our model can reproduce both the temporal and spatial variation in the phytoplankton biomass with reasonable accuracy. The model was used to analyse scenarios describing the ecological effects of planned water protection measures. More efficient phosphorus purification was found to be the most effective measure for improving the water quality off St.Petersburg.

Ograniczanie wyników

Temperature and nutrient dynamics in eutrophic freshwater ecosystems

Bamboo: potential resource for eco-restoration of degraded lands

Seasonal influence of physico-chemical parameters on phytoplankton diversity, community structure and abundance at Parangipettai coastal waters, Bay of Bengal, South East Coast of India

Water- and N-induced changes in soil C:N:P stoichiometry and its implications for N limitation of a desert steppe species, Glycyrrhiza uralensis

Effects of grass carp introduction on macrophyte communities in a shallow lake

Effects of freezing and freeze-thaw cycles on soil microbial biomass and nutrient dynamics under different snow gradients in an Alpine meadow (Tibetan Plateau)

High resolution 3D-ecosystem model for the Neva Bay and Estuary - model validation and future scenarios