Statistical analysis and simulation modelling of the belowground food webs of two winter wheat management practices.

Abstract

Soil food webs from conventional and integrated management practices at an experimental site (Netherlands) were analysed using multivariate statistical procedures and simulation modelling, so as to identify patterns in species interactions and material transfers. Cluster analysis, canonical discriminant analysis and canonical correspondence analysis of the dynamics of biomass-N of functional groups within the food webs indicated that the webs could be compartmented into functional groups based on food choice and trophic level. The degree of compartmentalization depended on management practice. Consumers of fungi were separated in time from consumers of bacteria under the integrated management practice whereas little separation was observed under conventional practice. Simulation modelling was used to estimate the flux rates of nitrogen among functional groups within the food webs. The modelling demonstrated that more flow occurred in the integrated plot than in the conventional plot. More material flow occurred in the upper 10 cm of the integrated plot than in the 10-25 cm layer, whereas there was no such difference in the conventional plot. The effect may be due to the differences in the tillage practice on each plot. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Biomass, composition and temporal dynamics of soil organisms of a silt loam soil under conventional and integrated management.

“…Not only when nutrients become available (synchronization of supply by the soil and demand by the plant) but also where they become available is important (synlocalization of supply by the soil and rooting by the plant). Simulation modelling has shown that disproportionally more material flow occurred in the upper 10 cm than in the 10-25 cm layer in IF, whereas no such difference occurred in CF (Moore et al, 1990).…”

“…Statistical analysis of the biomass dynamics of functional groups of the microflora, defined according to their ability to decompose a range of chemicals, showed that the characteristics of the microfloral populations changed considerably in time in both CF and IF, the differences within plots generally being greater than between plots (Hassink et al, submitted). Taking bacteria and fungi as two functional groups, Moore et al (1990) designed food webs of CF and IF plots on the basis of the functional groups defined in this paper and they statistically ana lysed the food webs to identify patterns in the way species interact. The food web in CF differs from that in IF by the absence of predaceous collembola and by the near non-existence of the phytophagous nematodes.…”

“…The food web in CF differs from that in IF by the absence of predaceous collembola and by the near non-existence of the phytophagous nematodes. The analysis showed that the webs can be compartmented into a bacterial and a fungal channel, the degree of compartmentalisation depending on farm management: under integrated manage ment consumers of fungi were separated in time from consumers of bacteria, as were fungi and bacteria themselves, whereas little separation was observed under conventional management (Moore et al, 1990).…”

Energetic food webs: an analysis of real and model ecosystems

“…Coauthors John C. Moore and Peter C. de Ruiter have a long history of joint publications, their first (to my knowledge) dating back to 1990 and also focused on food webs (Moore et al 1990 Energetic Food Webs targets both graduate-level students and professional researchers and strives to "advocate an integrative approach" to the study of food webs, which uses aspects of both "an individualistic community-based approach and a holistic ecosystem-based approach" (pp. 3-5).…”