Reflections on plant and soil nematode ecology: past, present and future

Abstract

The purpose of this review is to highlight key developments in nematode ecology from its beginnings to where it stands today as a discipline within nematology. Emerging areas of research appear to be driven by crop production constraints, environmental health concerns, and advances in technology. In contrast to past ecological studies which mainly focused on management of plant-parasitic nematodes, current studies reflect differential sensitivity of nematode faunae. These differences, identified in both aquatic and terrestrial environments include response to stressors, environmental conditions, and management practices. Methodological advances will continue to influence the role nematodes have in addressing the nature of interactions between organisms, and of organisms with their environments. In particular, the C. elegans genetic model, nematode faunal analysis and nematode metagenetic analysis can be used by ecologists generally and not restricted to nematologists.

Keywords: ecology; future; history; interaction; management; molecular biology; nematology; plant; soil.

Fig. 1

Functional metabolic footprints of nematodes in depauperate and climatically constrained soil food webs of the Mojave Desert of California. Vertical axis of each footprint represents the enrichment footprint and horizontal axis the structure footprint. Larrea tridentata (creosote bush) and Chrysothamnus sp. (rabbitbrush), From Ferris (2010).

Fig. 2

Structure of attributes defining soil quality. The basic attributes were measured in the field and are in bold, while the aggregate attributes form the stages leading to soil quality. Attributes within a bold box aggregate to form a higher level attribute. Thus: Earthworms and Enchytraeids combine to give Faunal pores; Faunal pores, Water retention and Air permeability combine to give Pore structure; etc. It should be noted that Decomposition occurs twice as it contributes to both Function and Losses. The abbreviated attributes are: PNR – potential nitrification rate; PDR – potential denitrification rate; ELFA – ester linked fatty acids; TEN – total extractable nitrogen; DOC – dissolved organic carbon. Nematodes contribute to both the decomposition and biodiversity attributes of soil quality (from Griffiths et al., 2010).

Fig. 3

Score values from a soil quality multi-attribute model, for those attributes to which nematodes contributed, see Fig. 2, at field sites with added compost (PC) or slurry (PS) or in the grass phase of a grass – arable rotation (TG), sampled in May 2006 (), Oct 2006 (), April 2007 (), June 2007 () and Sept 2007 (). A score of 3 means that the attribute was unaffected by the treatment (<15% different from the control treatment) while a score >3 indicates an improvement in the attribute and <3 a deterioration in the attribute (from Griffiths et al., 2010, derivation of score values are explained within).