نتایج جستجو برای: have variable ecosystems

تعداد نتایج: 3135311  

2015
Daniel E Schindler Jonathan B Armstrong Thomas E Reed

© The Ecological Society of America www.frontiersinecology.org T greatest challenges in ecology and evolution are in understanding how physical and biological processes that play out over extensive spatial, temporal, and taxonomic scales interact to affect the dynamics of genes, phenotypes, populations, and ecosystems. The fact that many biological properties are “scale-dependent” has been reco...

Journal: :Journal of Systems and Software 2014
Sami Hyrynsalmi Marko Seppänen Arho Suominen

Mobile application stores have revolutionised the dynamics of mobile ecosystems. Research on mobile application ecosystems has been significantly driven by data that is focused on the visualisation of an ecosystem’s dynamics. This is a valuable step towards understanding the nature of the ecosystems, but it is limited in its explanatory power. Thus, a theory-driven approach is needed to underst...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2005
Val H Smith Bryan L Foster James P Grover Robert D Holt Mathew A Leibold Frank Denoyelles

Species-area relationships have been observed for virtually all major groups of macroorganisms that have been studied to date but have not been explored for microscopic phytoplankton algae, which are the dominant producers in many freshwater and marine ecosystems. Our analyses of data from 142 different natural ponds, lakes, and oceans and 239 experimental ecosystems reveal a strong species-are...

2005

The dC values of atmospheric carbon dioxide (CO2) can be used to partition global patterns of CO2 source/sink relationships among terrestrial and oceanic ecosystems using the inversion technique. This approach is very sensitive to estimates of photosynthetic C discrimination by terrestrial vegetation (DA), and depends on d C values of respired CO2 fluxes (d CR). Here we show that by combining t...

2005

The dC values of atmospheric carbon dioxide (CO2) can be used to partition global patterns of CO2 source/sink relationships among terrestrial and oceanic ecosystems using the inversion technique. This approach is very sensitive to estimates of photosynthetic C discrimination by terrestrial vegetation (DA), and depends on d C values of respired CO2 fluxes (d CR). Here we show that by combining t...

2003
Gerhard Schmiedl Angelika Mitschele Stefan Beck Kay-Christian Emeis Christoph Hemleben Hartmut Schulz Michael Sperling

High-resolution benthic foraminiferal and geochemical investigations were carried out across sapropels S5 and S6 from two sediment cores in the Levantine Sea to evaluate the impact of climatic and environmental changes on benthic ecosystems during times of sapropel formation. The faunal successions indicate that eutrophication and/or oxygen reduction started several thousand years prior to the ...

Journal: :Current Biology 2009
Andrew S. Brierley Michael J. Kingsford

Human activities are releasing gigatonnes of carbon to the Earth's atmosphere annually. Direct consequences of cumulative post-industrial emissions include increasing global temperature, perturbed regional weather patterns, rising sea levels, acidifying oceans, changed nutrient loads and altered ocean circulation. These and other physical consequences are affecting marine biological processes f...

Journal: :international journal of advanced biological and biomedical research 2014
mehdi hassanshahian

changes in the microbial community in response to catastrophic oil spills in marine and fresh water environments have been well documented. molecular methods provide tools for analyzing the entire bacterial community, covering also those bacteria that have not been cultured in the laboratory. in this study, four different microcosms were set up containing sediments collected from the persian gu...

Journal: :Small Business Economics 2022

Abstract Despite the emerging body of literature on entrepreneurial ecosystems (EEs), theoretical development is still in its infancy. In this article, we explicitly draw upon analogy forest (FEs) with an EE to extrapolate regional ecosystem (REE) as alternate conceptual framework. The REE considers a region’s socioeconomic activity and stability performance whole, influenced by partitioned int...

Journal: :Science 2003
Ramakrishna R Nemani Charles D Keeling Hirofumi Hashimoto William M Jolly Stephen C Piper Compton J Tucker Ranga B Myneni Steven W Running

Recent climatic changes have enhanced plant growth in northern mid-latitudes and high latitudes. However, a comprehensive analysis of the impact of global climatic changes on vegetation productivity has not before been expressed in the context of variable limiting factors to plant growth. We present a global investigation of vegetation responses to climatic changes by analyzing 18 years (1982 t...

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