Sorption of 2,4-D on Natural and Organic Amended Soils of Different Characteristics

The effect of one organic amendment consisting of an urban waste compost (UWC) was assessed on the sorption properties of the herbicide 2,4-D on four soils of different physicochemical characteristics. The soils chosen were a Typic Haphorthod (ST), a Typic Endoaquept (SR), an Entic Pelloxerert (TO), and a Typic Eutrochrept (AL). Adsorption experiments were performed on the original soils, and on mixtures of these soils with UWC at a rate of 6.25% (w/w). These mixtures were used just after preparation, and after aging for 8 and 25 weeks. 2,4-D adsorption was the highest on ST soil, whereas the lowest adsorption was for SR soil. This behavior is related to the high amount of organic matter (OM) and amorphous iron and aluminum oxides content on soil ST, whereas soil SR had the lowest OM content and specific surface area of the soils of this study. Addition of exogenous OM to soils caused an increase in the 2,4-D adsorption by three of the soils treated with UWC, with the only exception being ST soil, due to an observed decrease in its specific surface area. The adsorbed amounts of the herbicide on aged organic fertilized soils diminished in three of the amended soils, but was still greater than on unamended soils. In contrast, the ST soil showed the largest adsorption for unamended soil.     

Combating the Illegal Trade in African Elephant Ivory with DNA Forensics

Abstract:  International wildlife crime is burgeoning in this climate of global trade. We contend that the most effective way to contain this illegal trade is to determine where the wildlife is being removed. This allows authorities to direct law enforcement to poaching hot spots, potentially stops trade before the wildlife is actually killed, prevents countries from denying their poaching problems at home, and thwarts trade before it enters into an increasingly complex web of international criminal activity. Forensic tools have been limited in their ability to determine product origin because the information they can provide typically begins only at the point of shipment. DNA assignment analyses can determine product origin, but its use has been limited by the inability to assign samples to locations where reference samples do not exist. We applied new DNA assignment methods that can determine the geographic origin(s) of wildlife products from anywhere within its range. We used these methods to examine the geographic origin(s) of 2 strings of seizures involving large volumes of elephant ivory, 1 string seized in Singapore and Malawi and the other in Hong Kong and Cameroon. These ivory traffickers may comprise 2 of the largest poaching rings in Africa. In both cases all ivory seized in the string had common origins, which indicates that crime syndicates are targeting specific populations for intense exploitation. This result contradicts the dominant belief that dealers are using a decentralized plan of procuring ivory stocks as they became available across Africa. Large quantities of ivory were then moved, in multiple shipments, through an intermediate country prior to shipment to Asia, as a risk-reduction strategy that distances the dealer from the poaching locale. These smuggling strategies could not have been detected by forensic information, which typically begins only at the shipping source.