Impact of land management on soil macrofauna in the upper reaches of the Guames Lake, Pasto, Colombia

The following investigation was carried out in order to evaluate the biomass, abundance, vertical distribution and diversity of the species it compared the results in three sites: a secondary forest, a field kikuyu and an onion crop field all at the Refugio Cristalino Natural Reserve, Pasto, Narino. The investigation followed the recommendations of the tropical soil biology and fertility program at the some way samples were taken to evaluate the physical and chemical characteristics of the sites. The results showed that the greatest abundance of organisms were found in the litter and 0-10 cm layer of soil in the secondary forest; of this abundance the Myriapodans formed the greatest part in number and in biomass. These was greater species diversity here than in the others sites, possibly due to the prime feeding and habitat conditions, notable in the organic matter in different stages of decomposition. In the Kikuyu and onion fields earthworms found in the first 10 cm profile principally represented the abundance and biomass. in general the use of the land affects the presence or absence of organisms that are fundamental in the process of soil evolution