Results from chronosequences from the arctic to the tropics show that phosphorus (P) availability, total P, and the fraction of bedrockderived P remaining in soil diminishes as soils age. Thus we predict that ecosystems mantling old substrates are likely to have low available P. Yet there are myriad examples in the biogeochemical literature where the results from chronosequences are used to arg...

Kenyan farmers’ livelihoods are closely linked to climate conditions. Almost three-quarters of the labor force depend on agriculture for their livelihoods, and almost all farmers depend on timely and adequate rainfall for crop production and husbandry, as only 2 percent of cultivated area is equipped for irrigation. Thus, climate variability and change will have an increasing impact on agricult...

Citrus is produced commercially in over 30 countries worldwide. The major growing regions are located primarily between 40° north-south latitude where minimum temperature is generally greater than 20°F. Within these latitudes there are several important climatic areas that affect the growth and development, yields, and fruit quality of citrus. These include the low, middle, and high tropical re...

1 Universität Ulm Institut für Systematische Botanik und Ökologie [email protected] 2 Universität Hohenheim Institut für Bodenkunde und Standortslehre [email protected] and rangeland) in three different climatic regions (arid, semi-arid and humid) from Northern-Central Iran were selected. Top soil samples were incubated for 8 months at 25°C with and without maize litter addition. CO2 em...

New vegetation in barren areas offers possibilities for sequestering carbon in the soil. Arid and semi-arid areas (ASAs) are candidates for new vegetation. The possibility of agriculture in ASAs is reviewed, revealing the potential for cultivation by covering the surface with a layer of organic fibres. This layer collects more water from humidity in the air than does the uncovered mineral surfa...

The terrestrial age, or the terrestrial residence time of a meteorite, together with its exposure history provides us with useful insight into the history of the meteorite. It is easy to observe that stony meteorites can weather quickly in humid environments. However, we find that large numbers of meteorites found in semi-arid and arid environments can survive for much longer times. Meteorites ...

r a 200 .022 : +1 210 [email protected] Summary Surface representation of the root-zone soil moisture is investigated so that feasibility of using optical remote sensing techniques to indirectly map root-zone soil moisture is assessed. Specifically, covariation of root-zone soil moisture with the normalized difference of vegetation index (NDVI) from Moderate Resolution Imaging Spectroradiometer (MODIS) ...