Another way to collect a stool sample is to loosely place plastic wrap across the rim of the toilet, under the seat. Then place the stool sample in a clean, sealable container before taking to the laboratory. Plastic wrap can also be used to line the diaper of an infant or toddler who is not yet using the toilet. The stool should be collected into clean, dry plastic jars with screw-cap lids.
The potential variations in the properties of agricul-. tural soils are less well known. Diaz et al. (1994) have. reported that under a climate change scenario the soil. organic matter content and erosion rate would de-. crease with regard to current values in the Arrecifes. River basin.
Global warming affects evapotranspirationâthe movement of water into the atmosphere from land and water surfaces and plants due to evaporation and transpirationâ which is expected to lead to: Increased drought in dry areas. In drier regions, evapotranspiration may produce periods of droughtâdefined as below-normal levels of rivers, lakes, and groundwater, and lack of enough soil moisture in agricultural areas. Precipitation has declined in the tropics and subtropics since 1970.