The element silicon (Si) is required for the growth of silicified organisms in marine
environments, such as diatoms. These organisms consume vast amounts of Si together with …

Over the past few decades, we have realized that the silica cycle is strongly intertwined with
other major biogeochemical cycles, like those of carbon and nitrogen, and as such is …

Nitrogen is a requisite and highly demanded element for living organisms on Earth.
However, increasing human activities have greatly altered the global nitrogen cycle …

Chemical weathering is an integral part of both the rock and carbon cycles and is being
affected by changes in land use, particularly as a result of agricultural practices such as …

Natural flood plains are among the most biologically productive and diverse ecosystems on
earth. Globally, riverine flood plains cover> 2× 106 km2, however, they are among the most …

TERRESTRIAL WATER CYCLE water use between 1800 and 1980, when the global
population increased by a factor of four (Haub 1994). Aggregate irretrievable water losses …

HYDROLOGICAL ALTERATIONS impoundment of water has reduced sea levels; moreover,
the concentration of water in reservoirs at high latitudes has increased, albeit minutely, the …

Cumulatively, headwater streams contribute to maintaining hydrologic connectivity and
ecosystem integrity at regional scales. Hydrologic connectivity is the water‐mediated …

Chemical weathering and the subsequent export of carbonate alkalinity (HCO3–+ CO3–2)
from soils to rivers account for significant amounts of terrestrially sequestered atmospheric …

As humans continue to influence the quantity, timing, and quality of freshwater input to
estuaries, it is becoming increasingly common for policies to be enacted that mandate the …