Analysing spatial correlation of weeds and harvester ants in cereal fields using point processes

Abstract

The interaction between the spatial distribution of weed richness and weed cover and the spatial location of harvester ant nets was investigated in cereal fields. The understanding of such interdependencies can be relevant to understand weed population dynamics in dryland cereal fields and may enhance management strategies for weed control. We used spatial statistical tools derived from point process theory. In particular, we compared the two spatial configurations by assuming two different point patterns. We did so by replacing the random weed fields by a related point pattern and comparing it with the point pattern of harvester ants. Our results suggest that areas with a high density of ant nests are, in this case study, in areas with low weed richness and that large nests have a greater impact than small nests. Considering that only one field was analysed, preserving and enhancing regular ant nest distributions, especially of large nests, might have an impact on depleting weeds and consequently enhancing weed control.

We wish to thank the Ministry of Education and Science of Spain (projects AGL 2007-60828 and AGL 2010-22084-C02-01) for the research funding