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PubMedDate not supplied

[The antibiotic-aided separation of fungal and bacterial substrate-induced respiration in various soil ecosystems].

Fungal and bacterial substrate-induced respiratory activities have been distinguished in gray forest and chestnut soils in various ecosystems (forest, grassland, tillage, unused land, and shelterbelt) using the antibiotics cycloheximide and streptomycin. The optimal inhibitory concentrations of the antibiotics, added separately and in combination; the preincubation time of the antibiotics with the soil before glucose addition; and the mass of added inert material (talc) have been determined. Based on the results obtained, the inhibitor additivity ratio (IAR) has been calculated for the antibiotics. With the IAR differing from 1.0 by a value of more than 5%, the fungal and bacterial substrate-induced respiratory activities can not be distinguished reliably. Respiration measurements show that the microbial communities of natural ecosystems are dominated by fungi (81-95% on average). The smallest amount of fungi (54-59%) is found in the tillage ecosystem.

Anti-Bacterial Agents↗

PubMed2005

[Measurement of terrestrial ecosystem service value in China].

With the measurement of net primary productivity and vegetation coverage fraction based on remote sensing data,the terrestrial ecosystem service value of China in 2000 was quantitatively estimated as 9.17 x 10(12) yuan (RMB). The spatial distribution of the ecological service value showed a decreasing trend from southeast China to northwest China, which was consistent with the regional distribution of vegetation types. The service value varied with different vegetations, e. g., forests had the highest service value of 18 789 yuan x hm(-2), accounting for 40.80% of the total terrestrial ecosystem service value, and bushes and farmlands had a higher service value of 13 789 yuan x hm(-2) and 13054 yuan x hm(-2), which was 10.79% and 24.23% of total value, respectively. The service value was also varied with different ecosystem functions, i.e., gas regulation contributed the highest value of 45.16% to the total service value, and the contribution of soil conservation and water conservation was 28.83% and 14.44%, respectively. The integrated approach coupling ecology and remote sensing data provided a new method to measure the ecological service value, which could estimate the value objectively and spatial-explicitly. However, some uncertainties still existed in this approach, which should be improved in the future studies.

China↗

PubMed2002

[Parasites as a natural element of any ecosystem].

The article presents some ideas upon the functioning of the parasite populations and communities in relation to the whole ecosystem. The author underlines that the parasites are one of the natural elements of every biocenosis and their existence submittes to similar ecological rules as the populations and communities of free-living organisms. Colonization of their particular environment (living organism) demands some adaptations allowing to resist immunological defense of the host, and to coexist with other parasite species harboured by the same host, not exploiting the supplies over the host "carying capacity", what could provoke the strong pathogenic effects, including host death. The mechanims maintaning the state of relative stability in host-parasite system are similar as in the case of free-living organisms, and are of both parasite- and host origin. They can confine the number of parasites (elimination of some specimens) or their biomass (growth restraint), limit their fecundity (maturation restraint), or make particular species to use different supply (niches separation). On the other hand parasite can regulate the demography of host population: restrict their fecundity, or kill their host directly or indirectly (making them an easier prey for predators). The author presents and discusses some examples illustrating the activity of the regulating mechanisms in host-parasite relationship, as well as the role of parasites in energetic ballance of ecosystem and in "engineering of ecosystem".

Animals↗

PubMed2006

[Construction of urban green space ecosystem by using corridor network: a case study in west urban area of Dongying City, Shandong Province].

This paper discussed the ecological significance of urban green corridors network in urban green space ecosystem, analyzed the present status of green space ecosystem in the west urban area of Dongying in Shangdong Province, and figured out the ways of constructing urban green corridors network in this area to strengthen the linkage between its fragmented greenbelts, and between these greenbelts and rural natural environment. Through the construction of this network, the greenbelt area in the west urban area of Dongying would increase 1400 hm2, greenbelt area per capita would increase to 66 m2, and urban and rural greenbelts would be integrated into a whole system to serve the whole city, giving a powerful support to enhance the life quality of local people and the stability of urban ecosystem.

China↗

PubMedDate not supplied

[Comparative analysis of the energy flows in the ecosystem of a small eutrophic lake during three vegetation seasons (balance model)].

Seasonal energy flows were calculated, based on a simulation balance model, from unique data collected during three vegatation seasons, 1986-1988, in the ecosystem of the Lake Bolshoy Okunyonok, Leningrad province. The model is based on principles developed by G.G. Winberg's school of production hydrobiology and was described in detail in an earlier work (Kazantseva, 2003). Analysis and comparison of the results showed that certain regularities of energy transformation processes in any lake ecosystem are apparent in spite of natural differences determined by differences in the environment properties and the levels of development of the ecosystem components. For instance, the extreme importance of the bacteriadetritus element in the food chains of water-body was confirmed. Broad spectrum of food and considerable changes in food composition during a vegetation season were clearly shown for most hydrobionts. The degree of consumption was estimated for the production of the organisms at each trophic level. It was shown that all the consumers eat away ca. 50-60 per cent of the production of the forage phytoplankton, 90 per cent of the production of non-predatory benthos, and 20-50 per cent of the production of the other trophic groups during a season. The proposed coefficient of energy transformation, CET(s, k) = Ps(k)/Pk, where Ps(k) in the production of the consumer s created by consuming the source k, and Pk is the production of the source itself, proved to be more stable than the generally accepted coefficient q = Ps/Ps -1.

Ecosystem↗

PubMed2006

[Degradation of main ecosystems in South China Sea and corresponding conservation countermeasures].

South China Sea is a significant area of global biological diversity. Due to the long-term unreasonable exploitation and utilization, the habitat there degenerates obviously, and the biodiversity loses seriously. The estimated annual loss of mangrove area ranges from 0.5% to 3.5% , and that of seaweed area is from 20% to 50%. A total of 82% of coral reefs in the Sea display evident degradation. In this paper, a trans-boundary diagnostic analysis of ecosystem degradation in South China Sea was conducted, with the focus on mangrove, seaweed and coral reef. Based on the analysis of the destruction state of the existing ecosystems as well as the main causes of habitat degradation and its trans-boundary impacts, some countermeasures on habitat conservation and management were put forward, aimed to promote the cooperation both at national and at regional levels to implement appropriate approach to reverse the ecosystem degradation trend in South China Sea.

China↗

PubMed1995

Biodiversity of lactic acid bacteria from food-related ecosystems.

The diversity of lactic acid bacteria within a variety of food-related ecosystems was assessed and the strain as well as environment specific characteristics were investigated. The strains (108 in toto) were isolated from plant material, traditional fermented foods, dried marine algae, sea food, fungi as well as spoiled foods and beverages, and all were characterized to genus level. Lactobacillus strains dominated all ecosystems and contributed to 65% of the isolates while a further 13% consisted of Lactococcus strains, 12% of Leuconostoc strains, 5% of Pediococcus strains, and 5% of unidentified strains. Plant material was the most diverse ecosystem containing representatives from each of the genera as well as the majority of dextran and tyramine producers. Those strains able to grow at 45 degrees C as well as acid tolerant strains were predominantly isolated from traditional fermented beverages while halotolerant strains occurred mainly in sea food. Two bacteriocin producers but no histamine producers were isolated.

Bacteria↗

PubMed1995

[Causes and consequences of an unbalanced vaginal ecosystem].

The vaginal microflora of a healthy asymptomatic woman is part of a dynamic ecosystem which is easily disturbed by known and unknown factors. The normal vaginal microflora consists of a broad spectrum of aerobic and anaerobic germs. The anaerobic microaerophilic Doederlin's bacillus (lactobacillus) plays a major role in the microflora, but is only one of the many factors controlling and tuning a well-balanced ecosystem. Although our understanding is still insufficient, basic knowledge of the ecosystem and new results lead to a successful therapeutic approach.

Bacterial Adhesion↗

PubMed1997

Ecosystem health as a clinical rotation for senior students in Canadian veterinary schools.

We describe 4 years of an experimental rotation in ecosystem health offered to senior veterinary students in Canada. Faculty from the 4 Canadian veterinary colleges collaborated in offering the rotation once annually at 1 of the colleges. The 1st rotation was held in Guelph in 1993, followed in successive years by rotations at Saskatoon, Saint-Hyacinthe, and Charlottetown. The rotation is a predominantly field-based experience that allows students to work with veterinary and other role models who are actively engaged in clinical research related to ecosystem health. Five specific field studies that worked particularly well during the rotations are presented. These studies involved investigating mortality in wildlife due to botulism, designing an environmental surveillance system around herds of beef cattle, using belugas to evaluate the health of the St. Lawrence River, dealing with competition for water use by aquaculture and agriculture, and exploring the role of veterinarians during major coastal oil spills. The experience has resulted in our developing the subject matter, field examples, teaching approach, and confidence necessary to make ecosystem health the focus of a productive clinical rotation for senior year veterinary students.

Agriculture↗

PubMed1997

Health impacts of large releases of radionuclides. The radioecological significance of semi-natural ecosystems.

The transfer of radiocaesium to many food products either produced in or harvested from semi-natural ecosystems is high compared with intensive agricultural areas. Radiocaesium contamination levels in semi-natural foods are highly variable and difficult to predict. Spatial analysis may help to explain some of the variability and give improved estimates of the total output of radiocaesium in food products produced or harvested from semi-natural ecosystems. Consumption of foodstuffs from semi-natural ecosystems can contribute significantly to radiocaesium ingestion by humans. The long effective half-lives that occur for some semi-natural products lead to an increase with time in their importance compared with agricultural products. In determining the importance of semi-natural food products, the diet needs to be considered for both the average population and for special groups who utilize these environments to a greater extent than normal. Effective countermeasures have been developed to reduce radiocaesium levels in some semi-natural products.

Agriculture↗

PubMedDate not supplied

The dyslexia ecosystem.

It is all too easy, in everyday interactions in dyslexia, to see the interactions in a semi-adversarial fashion--parents competing to get more support for children, researchers competing to get more support for their theories, schools trying to get more money for their programmes. Such a set of analyses may be described as 'zero-sum'. If one party gains, the other one loses. If, by contrast, one views the dyslexia community as a complex, inter-dependent 'ecosystem', a much more positive view emerges. It becomes clear that there are solutions for the system as a whole that are in a sense optimal for the system as a whole, solutions that are 'win-win', that is, all parties gain and none lose. In this article I develop this concept of the 'dyslexia ecosystem', and outline targets that would lead to progress for the ecosystem as a whole.

Cooperative Behavior↗

PubMed1996

Ecosystem Management to Achieve Ecological Sustainability: The Case of South Florida

The ecosystems of South Florida are unique in the world. The defining features of the natural Everglades (large spatial scale, temporal patterns of water storage and sheetflow, and low nutrient levels) historically allowed a mosaic of habitats with characteristic animals. Massive hydrological alterations have halved the Everglades, and ecological sustainability requires fundamental changes in management.The US Man and the Biosphere Human-Dominated Systems Directorate is conducting a case study of South Florida using ecosystem management as a framework for exploring options for mutually dependent sustainability of society and the environment. A new methodology was developed to specify sustainability goals, characterize human factors affecting the ecosystem, and conduct scenario/consequence analyses to examine ecological and societal implications. South Florida has sufficient water for urban, agricultural, and ecological needs, but most water drains to the sea through the system of canals; thus, the issue is not competition for resources but storage and management of water. The goal is to reestablish the natural system for water quantity, timing, and distribution over a sufficient area to restore the essence of the Everglades.The societal sustainability in the Everglades Agricultural Area (EAA) is at risk because of soil degradation, vulnerability of sugar price supports, policies affecting Cuban sugar imports, and political/economic forces aligned against sugar production. One scenario suggested using the EAA for water storage while under private sugar production, thereby linking sustainability of the ecological system with societal sustainability. Further analyses are needed, but the US MAB project suggests achieving ecological sustainability consistent with societal sustainability may be feasible.

Journal Article↗

PubMed2000

Aerobic Denitrifiers Isolated from Diverse Natural and Managed Ecosystems.

Twenty-eight bacterial strains were isolated from an ecosystem adapted to fluctuating oxic-anoxic conditions. This ecosystem comprised a mixture of different natural and wastewater treatment environments. Among the 28 strains isolated, 10 exhibited aerobic denitrifying activity, i.e., co-respiration of oxygen and nitrate and simultaneous production of nitrite by 4 of them and of nitrogen gas by the remaining 6. Comparisons between the 16S rDNA sequences of the 10 strains showed that 3 of them were identical to M. aerodenitrificans, whereas RAPD profiles showed that the 3 strains were identical to each other but that they were different from M. aerodenitrificans. This implies that alternating aerobic-anoxic conditions allowed the isolation of a new strain of this aerobic denitrifier. Moreover, other denitrifying bacteria belonging to the genera Paracoccus, Thiobacillus, Enterobacter, Comamonas, and Sphingomonas were isolated in this way. These data imply that a wide variety of bacteria are able to carry out this type of metabolism. M. aerodenitrificans was also detected in methanogenic, denitrifying, nitrifying, phosphate removal, and activated sludge ecosystems by two-step PCR amplification. After 4 months of acclimation to oxic-anoxic phases, the strain was also detected in a canal and in a pond. This suggests that there is no specific natural ecological niche for aerobic denitrifiers but, as soon as selective pressure such as alternating aeration conditions is applied, this metabolism is amplified.

Journal Article↗

PubMed2000

Assessing major ecosystem types and the challenge of sustainability in Turkey.

In recent years, Turkey has experienced rapid economic and population growth coupled with both an equally rapid increase in energy consumption and a vast disparity in welfare between socioeconomic groups and regions. In turn, these pressures have accelerated the destruction of productive, assimilative, and regenerative capacities of the ecosystems, which are essential for the well-being of the people and the economy. This paper describes the structure and function of major ecosystem types in Turkey and discusses the underlying causes of environmental degradation in the framework of economy, energy, environment, and ethics. From a national perspective, this paper suggests three sustainability-based policies necessary for Turkey's long-term interests that balance economic, environmental, and energy goals: (1) decoupling economic growth from energy consumption growth through the development of energy-efficient and renewable energy technologies; (2) linking economic efficiency and distributive justice of wealth and power through distributive and participatory public policies; and (3) integrating the economic and ecological systems through the internalization of externalities and ecosystem rehabilitation.

Journal Article↗

PubMed1999

ENVIRONMENTAL AUDITING: Change in Fish Fauna as Indication of Aquatic Ecosystem Condition in Río Grande de Morelia-Lago de Cuitzeo Basin, Mexico.

/ The Río Grande de Morelia-Lago de Cuitzeo basin in west central Mexico has experienced major increases in water pollution from a rapidly growing human population. We examined changes in the long-term distribution of fishes in relation to water quality and quantity in order to assess the condition and health of aquatic ecosystems inthe basin. Sampling between 1985 and 1993 revealed that five (26%) of the 19 native fish species known from the basin had been extirpated. Two of these were endemics, Chirostoma charari and C. compressum, and they are presumed extinct. Twelve (63%) of the remaining species had declines in distribution. Sixteen (80%) of the 20 localities sampled had lost species. The greatest declines occurred in Lago de Cuitzeo proper and in the lower portion of the Río Grande de Morelia watershed. Species losses from the lake were attributable to drying and hypereutrophication of the lake because of substantial reductions in the amount and quality of tributary inputs, whereas losses from the Río Grande de Morelia watershed were the result of pollution from agricultural, municipal, and industrial sources, especially in the region around the city of Morelia. Three localities in the upper portion of the Río Grande de Morelia watershed-Cointzio reservoir, La Mintzita spring, and Insurgente Morelos stream-contained most of the remaining fish species diversity in the basin and deserve additional protection. Fish faunal changes indicated major declines in the health of aquatic ecosystems in the Morelia-Cuitzeo basin.KEY WORDS: Fish distribution; Río Lerma; Ecosystem health; Water quality; Chirostoma; Threatened and endangered specieshttp://link.springer-ny.com/link/service/journals/00267/bibs/24n1p133.html

Journal Article↗

PubMed1999

Using Stakeholders' Values to Apply Ecosystem Management in an Upper Midwest Landscape.

/ How people impact the environment is driven by how they value it; therefore, it is important to understand what these values are and who holds them. This study's objectives were to understand how community members in a rural area of the Upper Midwest value the landscape in which they live and to identify the kinds of management practices they support. The Red River Basin, in northwestern Minnesota and eastern North Dakota, served as the study area. University of Minnesota researchers used a two-phase approach to gather data. First, information attained from focus group meetings was used to help develop a questionnaire. Second, this questionnaire was sent to Red River Basin residents who were identified as stakeholders in the landscape. Data analysis examined the entire sample as a whole and divided the sample into rural and urban groups. Results show stakeholders value the landscape for a variety of noneconomic and economic reasons. They see the landscape as something that not only can help them attain an income, but also as something that affects their overall quality of life. Their preferences for management centered around education and cooperative planning efforts. Implications for management include: identify and manage for benefit opportunities dependent upon healthy ecosystems, acknowledge key ecosystem components in planning and management, increase education and cooperative planning with local residents, and stress mutual goals between land managers and constituents as well as between different interest groups.KEY WORDS: Landscape values; Ecosystem management; Benefits-based management; Agriculture; Cooperative planninghttp://link.springer-ny.com/link/service/journals/00267/bibs/24n3p399.html

Journal Article↗

PubMed2006

Northern Rivers Ecosystem Initiative: nutrients and dissolved oxygen - issues and impacts.

Anthropogenic inputs of nitrogen (N), phosphorus (P) and oxygen-consuming material to aquatic ecosystems can change nutrient dynamics, deplete oxygen, and change abundance and diversity of aquatic plants and animals. The Northern Rivers Ecosystem Initiative required a research and assessment program to establish the contribution of pulp mill and sewage discharges to eutrophication and depressions in dissolved oxygen (DO) in the Athabasca and Wapiti rivers of northern Alberta, Canada and examine the adequacy of existing guidelines for protecting these systems. Analysis of long-term data showed that total N (TN) and total P (TP) concentrations in exposed river reaches exceeded concentrations in reference reaches by < or = 2 times for the Athabasca River, and by 9.6 (TP) and 2.6 (TN) times for the Wapiti River. Results from nutrient limitation experiments conducted in situ and in mesocosms showed that benthic algal production was nutrient sufficient downstream of pulp mill discharges but constrained in upper river reaches by insufficient P (Athabasca River) or N + P (Wapiti River). Dissolved oxygen (DO) concentrations in both rivers declined during winter such that median concentrations in the Athabasca River 945 km downstream of the headwaters were approximately 8 mg L(-1) in mid-February. Although water column DO rarely approached the guideline of 6.5 mg L(-1), DO studies undertaken in the Wapiti River showed that pore water DO often failed to meet this guideline and could not be predicted from water column DO. Results from this integrated program of monitoring and experimentation have improved understanding of the interactions between nutrients, DO and aquatic ecosystem productivity and resulted in recommendations for revisions to nutrient and DO guidelines for these northern rivers.

Alberta↗

PubMed2006

PCB levels and trends within the Detroit River-Western Lake Erie basin: a historical perspective of ecosystem monitoring.

An international workshop held in the spring of 2002 convened a group of technical experts to address monitoring, modeling, and management of PCBs within the Detroit River-Western Lake Erie basin. Participants shared and discussed a diverse set of research data bases pertaining to PCB levels within the region, discussed observed changes within different components of the local ecosystem, and identified several primary issues impacting future PCB management strategies. Results presented at the workshop indicate dramatic reductions in PCB contamination levels have been observed in much of study area between the late 1970s and mid-1990s. Estimates of loadings attributable to water and atmospheric sources have generally declined, as have PCB concentrations in herring gull eggs, smelt and walleye. Nevertheless, additional improvements have not been observed during recent years and elevated contamination levels remain a concern within local hot spots, particularly in the lower Detroit River and Trenton Channel. A primary recommendation broadly supported by workshop participants is the need to maintain, support, and coordinate a comprehensive ecosystem monitoring program for the Detroit River-Western Lake Erie basin, one that incorporates both near-field and far-field monitoring elements. Such a program is crucial to provide necessary data in support of understanding ecosystem trends, calculating annual mass loadings to the system, assessing impacts of remediation actions, developing improved modeling frameworks, and formulating cost-effective management strategies for the future.

Animals↗