نتایج جستجو برای: natural ecosystems
تعداد نتایج: 518661 فیلتر نتایج به سال:
'Digital ecosystems' is a metaphor inspired by natural ecosystems which describes a set of distributed, adaptive, and open socio-technical systems. Being parts of such ecosystems, individual persons, public and private organisations are becoming increasingly dependent on each other. When such cooperation moves beyond simple buying and selling of goods and well-defined services, there is a need ...
The results of investigations of transuranic elements { H , , M 0 P u and 2 4 'Am) behaviour in the soil-vegetation cover of natural and semi-natural ecosystems in the regions of Belarus contaminated as a result of Chernobyl acci dent have been summarised. The parameters of plutonium and americium vertical migration have been estimated for typical soil varieties; the radionuclides accumulation...
During various surveys of Phytophthora diversity in Europe, Chile and Vietnam slow growing oomycete isolates were obtained from rhizosphere soil samples and small streams in natural and planted forest stands. Phylogenetic analyses of sequences from the nuclear ITS, LSU, β-tubulin and HSP90 loci and the mitochondrial cox1 and NADH1 genes revealed they belong to six new species of a new genus, of...
The task of modern agriculture is to safeguard the production of high quality food, in a sustainable natural environment under the precondition of pollution not exceeding accepted norms. The sustainability of current land use in agro-ecosystems can be assessed with respect to heavy metal accumulation in soils by balancing the input/ output fluxes. The objectives of this study were to model accu...
Freshwater ecosystems are important for global biodiversity and provide essential ecosystem services. There is consensus in the scientific literature that freshwater ecosystems are vulnerable to the impacts of environmental change, which may trigger irreversible regime shifts upon which biodiversity and ecosystem services may be lost. There are profound uncertainties regarding the management an...
Competition for resources has long been believed to be fundamental to the evolution of diversity. However, the difficulty of working with natural ecosystems has meant that this theory has rarely been tested. Here, we use the Avida experimental platform to demonstrate the evolution of ecosystems composed of digital organisms. We show that stable ecosystems are formed during evolution in an envir...
The natural world generates a range of valuable goods and services that support human well–being. !ese goods and services, collectively called ecosystem services, are typically provided free of charge and often have characteristics of public goods. Like other public goods, ecosystem services will not be provided optimally by aggregating the decisions of individuals motivated by self–interest. F...
There is growing evidence that terrestrial ecosystems are exporting more dissolved organic carbon (DOC) to aquatic ecosystems than they did just a few decades ago. This "browning" phenomenon will alter the chemistry, physics, and biology of inland water bodies in complex and difficult-to-predict ways. Experiments provide an opportunity to elucidate how browning will affect the stability and fun...
Many recent studies have focused on the relationship between biodiversity and ecosystem functioning, such as investigations into the productivity of experimental plant communities. One of the central issues affecting the functioning of ecosystems is the diversity of resident species richness and the composition of the plant community. However, one challenge to experimental studies is that resul...
The field of urban ecology has seen a major expansion in the last two decades. As the world rapidly urbanizes, human settlements constitute one of the few ecosystems on earth that are significantly increasing in their extent. As a result, interest from both the scientific community and society at large has turned its attention to the functioning of cities and their impacts on larger regions, gl...
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