the stereochemistry of the actinide elements has recently undergone considerable development and a wide variety of coordination numbers and geometries have been observed. this structural versatility arises from the lack of strong crystal field effects for the 5f-electronic configurations as well as from the large ionic radii of these metal ions, which change markedly with oxidation number, or a...

Changes in the abundance of species—especially those that influence water and nutrient dynamics, trophic interactions, or disturbance regime—affect the structure and functioning of ecosystems. Diversity is also functionally important, both because it increases the probability of including species that have strong ecosystem effects and because it can increase the efficiency of resource use. Diff...

Efforts to test the hypothesised positive link between ecosystem services and functions and biodiversity are increasing in order to forecast the consequences of the present erosion of biodiversity on ecosystem functions and to provide an additional basis for the conservation of biodiversity. These efforts have been, however, modest in marine ecosystems. An examination of seagrass communities, w...

due to the notable role of different land uses in carbon sequestration and emission, four treatments including rangeland as control, haloxylon plantation area, olea plantation (olive garden), and residential lands, were selected to study the effects of land use change on soil carbon sequestration and emissions in eivanakei rangelands, semnan province. carbon stocks in vegetation and soil of eac...

Island biogeography theory (IBT) provides a basic conceptual model for understanding habitat fragmentation. Empirical studies of fragmented landscapes often reveal strong effects of fragment area and isolation on species richness, although other predictions of the theory, such as accelerated species turnover in fragments, have been tested less frequently. As predicted by IBT, biota in fragments...

BACKGROUND In recent decades the frequency and severity of natural disturbances by e.g., strong winds and insect outbreaks has increased considerably in many forest ecosystems around the world. Future climate change is expected to further intensify disturbance regimes, which makes addressing disturbances in ecosystem management a top priority. As a prerequisite a broader understanding of distur...