نتایج جستجو برای: have variable ecosystems
تعداد نتایج: 3135311 فیلتر نتایج به سال:
Polypore fungi are an important group of wood-inhabiting basidiomycetes that have significant roles in biomass recycling in forests and woodland ecosystems. Figures on the polypore diversity in Iran have been partly made available through few checklists, but there have been no comparative studies on the pattern of geographic distribution of the species. The prevalence of the Mediterranean biocl...
Learning to appreciate novel ecosystems will take practice and, as we argue in this chapter, perhaps some new approaches to valuing them. The challenge is not in learning to value novel ecosystems for the first time. After all, as Jackson (Chapter 7) notes, novel ecosystems are nothing new. Significant new ecological assemblies have arisen throughout the past. What is different now is the pace ...
Background and Objectives: ?????? Methods: ?????? Findings: ?????? Conclusion: ????? Coral ecosystems, like other natural habitats, are under effect by global warming. Every year we see the bleaching of corals in different parts of the world. Since the physical parameters of seawater are affected by meteorological phenomena, so in this study using ten-year data of oceanographic buoys, the ...
The effect of biodiversity on ecosystem productivity has been a controversial issue in ecological research. species richness–productivity relationship is highly variable natural ecosystems, with positive being one the most commonly observed relationships. Previous regional studies from terrestrial ecosystems have demonstrated that environmental gradients can regulate relationship. However, how ...
background: copper is a trace element vital to life, but the toxic effect of water pollution with it on fish is now exhibited. fish blood is susceptible to contamination-induced stress and its alternation due to the hematological and immunological parameters can be utilized as toxicity indices of xenobiotics. methods: in this study, juvenile species of silver carp with average weight of 200gr w...
Hiccups are common, typically limited, and rarely present with adverse complications. In the context of persistent or intractable episodes, however, hiccups may signal a more serious underlying cause. Here, we present an unexpected and pathologic case of hiccups in a patient who was ultimately diagnosed with renal abscesses.
in this thesis our aim is to construct vector field in r3 for which the corresponding one-dimensional maps have certain discontinuities. two kinds of vector fields are considered, the first the lorenz vector field, and the second originally introced here. the latter have chaotic behavior and motivate a class of one-parameter families of maps which have positive lyapunov exponents for an open in...
Because resilience of a biological system is a product of its evolutionary history, the historical template that describes the relationships between species and their dynamic habitats is an important point of reference. Habitats used by Pacific salmon have been quite variable throughout their evolutionary history, and these habitats can be characterized by four key attributes of disturbance reg...
Global land cover is an essential climate variable and a key biophysical driver for earth system models. While remote sensing technology, particularly satellites, have played a key role in providing land cover datasets, large discrepancies have been noted among the available products. Global land use is typically more difficult to map and in many cases cannot be remotely sensed. In-situ or grou...
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