a borítólapra  Súgó epa Copyright 
Applied Ecology and Environmental ResearchVol. 3. No. 2 (2005.)


  • Borítóen [68.87 kB - PDF]EPA-02583-00005-0010
  • S. K. Dubey :

    Abstract: Methane has profound impact on the physico-chemical properties in atmosphere leading to global climate change. Out of the various sources of CH4, rice fields are the most significant contributors. The processes involved in the emission of CH4 from rice fields to the atmosphere include CH4 production (methanogenesis) in the soil by methanogens, methane oxidation (methanotrophy) by methanotrophs and vertical transfer of CH4 via plant transport and diffusion or ebullition. In the overall methane dynamics rice plants act as : a) source of methanogenic substrate, b) conduit for CH4 through well developed system of inter cellular air space (aerenchyma), and c) potential methane oxidizing micro-habitat in the rhizosphere by diffusing oxygen which favour the growth and multiplication of methanotrophs. Apart from mechanistic uncertainties, there are several other uncertainties in the estimation of CH4 flux. Methane dynamics in the paddy field is controlled by a complex set of parameters linking the biological and physical characteristics of soil environment like temperature, carbon source, Eh, pH, soil microbes and properties of rice plants, etc. It has now become possible to isolate, detect and characterize the methanogens and methanotrophs by using molecular biological tools like PCR, FISH, etc. techniques. The apparent half saturation constant (Km) and maximum oxidation rate (Vmax) are distinctive parameters which determine the ability of bacteria to survive on atmospheric methane.

    Keywords: methane; methanotrophs; methanotrophy; methanogens; molecular tools

  • A. Jakubska ,
    D. Przado ,
    M. Steninger ,
    J. Aniol-Kwiatkowska ,
    M. Kadej :

    Abstract: Eight populations of Epipactis helleborine (L.) Crantz originating from the area of Lower Silesia in Poland (Central Europe) were examined in respect to composition of their nectar and its influence on the insect attraction in field conditions. The chemical composition of Epipactis helleborine (L.) Crantz nectar was studied by means of GC/MS SIM. A number of compounds with potential narcotic properties were identified in the nectar, namely 3-{2-{3-{3-(benzyloxy)propyl}-3-indol, 7,8-didehydro- 4,5-epoxy-3,6-d-morphinan and oxycodone. Pollinator and visitor insects were identified. The key role of ethanol in the process of alluring and stunning of the insects was discussed. A scheme of the influence of the identified compounds on the pollinators was proposed.

    Keywords: Epipactis helleborine, toxic nectar, morphinan derivatives, indol derivatives, ethanol

  • X. Chen ,
    B. L. Li :

    Abstract: Studying the spatial variability of plant functional types at large scale is important to understand the effects of environmental change on ecosystems. Here we classified the tree species in the forest area of Northeast China Transect (a middle-latitude transect and its environmental gradient was mainly driven by moisture) into three plant functional types (PFTs): drought tolerant, drought intolerant and middle type PFTs. We found that the average percentage of the drought intolerant and middle type of PFTs both increased significantly from 1986 to 1994. The drought tolerant and middle type of PFTs increased their covered areas at the western part of transect, but the covered area of the drought intolerant PFTs decreased about 48% at the western part. The dominance of the drought intolerant PFTs decreased while the dominance of the other PFTs increased. The net increments of these three PFTs were higher at 0–220 km than at 220–400 km. The negative net increments concentrated mainly at 150–350 km. The spatial autocorrelation of the drought intolerant and middle type of PFTs changed slightly from 1986 to 1994. The information entropy of the drought intolerant PFT increased across all scales and it indicated that impact from local disturbances was limited. All these indicate that the drought intolerant PFTs is vulnerable to the current environmental change. The spatial variations of different PFTs at large scales were mainly caused by the fluctuations of gradient of annual precipitation along this transect.

    Keywords: Northeast China Transect, plant functional type, precipitation gradient, spatial variation,

  • V. K. Garg ,
    S. Chand ,
    A. Chhillar ,
    A. Yadav :

    Abstract: The effect of various animal wastes on growth and reproduction of an epigeic earthworm Eisenia foetida was studied under identical laboratory conditions. For each waste, viz., cow, buffalo, horse, donkey, sheep, goat and camel, five hatchlings per 100 g of waste were inoculated and monitored for biomass gain, mortality, sexual maturity, cocoons production periodically for 15 weeks. No mortality was observed in any waste. The earthworms grew rapidly in cow, sheep, and goat wastes. Maximum weight gain and highest growth rate were attained in sheep waste. Net biomass gain/earthworm in different animal wastes was in the order of: sheep > donkey > buffalo > goat ≈ cow ≈ horse > camel. The number of cocoons produced per earthworm per day in different wastes was in the order: sheep > cow ≈ horse ≈ goat > camel > donkey > buffalo. Increase in the number of earthworms was 39.5-fold in horse waste and 26-fold in cow waste.

    Keywords: Eisenia foetida, animal waste, physicochemical characteristics, biomass, cocoon

  • D. Pešić-Mikulec ,
    L. Stojanović ,
    L. Jovanović :

    Abstract: Moulds can be found in milk as contaminants from the environment. The specific qualities of climate, vegetation and land are the important factors affecting the quality of moulds and determinators of genus and species in connection with a certain geographical location. The study was carried out in 297 milk samples taken from different geographical location: A. lowlands, B. hilly-mountainous, C. alluvial plains by the river, D. submountainous and part of basin by the river in course of four seasons. The following media were used for growing moulds in laboratory conditions as: Sabouroud dextrosa agar, Czapek agar, Potato dextrosa agar. Moulds determination was carried out according to their micromorphological properties using moulds determination keys. According to the result of study it was conclude that moulds count in raw milk samples were as follows: A. region: Fusarium genus (44.1%) in spring, Aspergillus genus (30.8%) in summer, Penicillium genus (30.2%) in autumn and the same (32.1%) in winter; B. region: Fusarium genus (55%) in spring, Penicillium genus (34.8%) in summer, Penicillium genus (23.1%) in autumn and Cladosporium + Penicillium genera (28.6%) in winter; C. region: Penicillium genus (69.3%) in spring and the same (31.8%) in summer, Geotrichum genus (24.6%) in autumn and Aspergillus genus (20.9%) in winter; D. region: Penicillium genus (42.9%) in spring and the same (50.73%) in summer, Cladosporium genus (43.2%) in autumn and Penicillium genus (45.21%) in winter. Finally we concluded that different genus of moulds which were found, are in dependence of geographical locations and seasons.

    Keywords: moulds, raw milk, contamination, ecology

  • M. Ghosh ,
    S. P. Singh :

    Abstract: Plant species have been recently used for heavy metal accumulation and most of the studies have been done on hyperaccumulator tolerant species. Metal hyperaccumulator plants though useful to phytoextract metal contaminant from soil, have many shortcomings such as low biomass, edible nature and difficult to harvest. This study is part of a series of studies that attempt to evaluate the phytoextraction potential of commonly found high biomass weed species that are harmless, non-edible in nature. We have investigated and compared five weed species (Ipomoea carnea, Dhatura innoxia, Phragmytes karka Cassia tora and Lantana camara), with two accumulator plants (Brassica juncea and Brassica campestris), in a pot study to assess Cr uptake in the range of 5 to 200 mg kg-1 soil. The results indicated that P. karka showed much greater tolerance to metals than other plants, though the uptake was low. It was more effective at translocating Cr from soil to plant shoot. The order of Cr extraction was I. carnea > D. innoxia > C. tora > P. karka > B. juncea > L. camara > B. campestris. Among the studied plants I.carnea showed maximum chromium extraction and biomass growth, but the difference of shoot by root chromium concentration was least. Other than Lantana camara, all the tested weeds were better for chromium extraction than the accumulator Brassica species. To save the Brassica species infested by army moth, pesticide application was required, whereas weeds required no care.

    Keywords: phytoremediation, weeds, bioconcentration factor, transportation index

  • J. M. Mironga :
    Effect of farming practices on wetlands of Kisii District, Kenya81-91en [434.59 kB - PDF]EPA-02583-00005-0080

    Abstract: Effect of farming practices on wetlands in Kisii District was determined through assessment of farmers’ environmental awareness. Effective conservation of wetlands in the district cannot depend on prohibitions but should be based on users’ knowledge and attitudes of wetlands. The present study examined farmers’ knowledge of the environmental effect of agricultural expansion to wetlands; absence of knowledge of characteristics of farming activities and the attitudes of farmers with respect to planning mechanisms that might be used to support wetland protection in the area. The majority of farmers ignored the effect of agriculture on wetlands. Those who occupied wetland areas practiced intensive agriculture and were ignorant of the effect of this on water quality, soil and landscape. The government should implement training programmes for all wetland users in Kisii District to make them more environmentally aware of the impacts of farming practices on wetlands. This is meant to make them become more environmentally aware of the effects of farming practices on these ecosystems and eventually change their behavior. There is a need to build a conservation ethic among wetland users by educating them to sustainably utilize wetland resources and training them to practise sustainable agriculture.

    Keywords: farming, wetlands, agriculture, environmental awareness, attitudes

  • A. H. Bu-Olayan ,
    B. V. Thomas :

    Abstract: Benthic organisms diversity were observed in the sequence of Annelida > Mollusca > Crustacea > “Diversa” group. Levels of trace metals in benthic organisms were in the range 0.12–96.86 μg/g during winter and 0.98–54.13 μg/g in summer. Species diversity index (H’), evenness index (J) and index of dominance (λ) were in the range 0.951–1.368 bits/unit, 0.475–0.684, and 0.19–0.33 respectively, for benthic organisms sampled in Kuwait Bay sites. Evenness index (–) was found to increase with increasing H’. Seasonally, an inverse correlation was observed between species richness (R1 and R2). Comparative studies revealed low diversity indices correspondingly to the increase in trace metal level in benthic species collected from four sites except Doha wherein high abundance of certain benthic species and high trace metal levels due to manmade perturbations were observed altering the diversity indices. Furthermore, these indices will validate benthic organisms as an indicator to trace metal pollution in Kuwait marine ecosystem.

    Keywords: benthic organisms; trace metals; species diversity

  • A. Ciolac ,
    N. Patriche :

    Abstract: Marine migratory sturgeons form one of the most valuable fish population of the Lower Danube River ecosystem and are also extremely important for the economy of Romania and some other riverside countries and freshwater fisheries. Decreasing sturgeon presence in the last several decades has been a true concern either for commercial fishermen and biologists. This paper is trying to analyze some biological aspects of three sturgeon species: beluga (Huso huso Linnaeus, 1758), Russian sturgeon (Acipenser gueldenstaedti Brand, 1833) and stellate sturgeon (Acipenser stellatus, Brandt, 1833) and to compare them with formerly registered data and scientific information. This paper also tries to reveal some ecological particularities concerning their migration and natural reproduction process that could help scientists and other people to find the most probable causes of the tendency why stocks are decreasing and suggesting some pertinent actions to be done on the necessary mitigation and protection activities concerning actual and further presence of these very interesting sturgeon species in Danube River.

    Keywords: Danube River, migratory sturgeons, biology, migration, biometric data

  • Cs. Sipkay ,
    L. Hufnagel ,
    M. Gaál :

    Abstract: In the years 2002, 2003 and 2004 we collected samples of macroinvertebrates on a total of 36 occasions in Badacsony bay, in areas of open water (in the years 2003 and 2004 reed-grassy) as well as populated by reed (Phragmites australis) and cattail (Typha angustifolia). Samples were taken using a stiff hand net. The sampling site includes three microhabitats differentiated only by the aquatic plants inhabiting these areas. Our data was gathered from processing 208 individual samples. The quantity of macroinvertebrates is represented by biovolume value based on volume estimates. We can identify taxa in abundant numbers found in all water types and ooze; as well as groups associated with individual microhabitats with various aquatic plants. We can observe a notable difference between the years in the volume of invertebrate macrofauna caused by the drop of water level, and the multiplication of submerged macrophytes. There are smaller differences between the samples taken in reeds and cattail stands. In the second half of 2003 – which was a year of drought – the Najas marina appeared in open waters and allowed to support larger quantities of macroinvertebrates. In 2004 with higher water levels, the Potamogeton perfoliatus occurring in the same area has had an even more significant effect. This type of reed-grass may support the most macroinvertebrates during the summer. From the aspect of diversity relations we may suspect different characteristics. The reeds sampling site proved to be the richest, while the cattail microhabitat is close behind, open water (with submerged macrophytes) is the least diverse microhabitat.

    Keywords: biovolume, reed, cattail, macrophyte, macrofauna, bootstrap, Tukey-test

  • P. Chandra Mouli ,
    S. Venkata Mohan ,
    Reddy S. Jayarama :

    Abstract: In the present study, outdoor airborne microflora (bacteria) at different locations, viz; institutional, health care, commercial, traffic, industrial and agricultural areas of Tirupati  a semi-arid urban region, southern peninsular India was investigated during winter season, 2004. Concentrations of airborne viable bacteria averaged between 19 ± 5 CFU/m3 (IE) and 3 ± 5 CFU/m3 (SVU) and observed the following trend among the locations: IE > TG > CBS > TUDA > RUYA > SVU. Airborne Grampositive bacteria were most abundant, with more than 60 to 90% of the measured population at each location. Developed regression models have been explained about 50% (or greater) variation in bacteria concentration at each location (except RUYA), due to the effect of meteorological factors – temperature, RH, and wind speed. Among these factors, wind speed had the most pronounced influence on bacterial concentration, with the regression coefficient (β) varied between 0.225 and 2.092, followed by the temperature. The overall air quality index (ABQI) with respect to bacterial composition of aerosol is found to be 22.33 which signifies that the quality of air is good. The results reveal that the airborne bacteria are contributed from terrestrial (soil) sources greatly followed by the little contribution from point sources.

    Keywords: Bioaerosol, airborne bacteria, meteorological factors, multiple linear regression, quality index, India.