Wild arable plants - diversity and function

The ecology and biology of wild arable plants are poorly understood. Of the more than 250 plant species to be found on arable farmland, typically five to 10, among which are wild oat, blackgrass, barren brome and cleavers, constitute the main weed burden of arable cropping. Many of the rest, particularly the broadleaf (dicotyledonous) species, support an arable food web that includes insect groups, mammals and birds. Despite the economic, ecological and aesthetic importance of wild arable plants, embarrassingly little is known about their ecology and genetic diversity.

Our first research paper in this new topic demonstrated the lack of basic information for even the common species (Hawes et al., 2005). If arable cropping systems are to be sustainable, then co-existence between crops and weeds must be managed with minimum or no herbicide application. To achieve this, fundamental and strategic research is necessary into the way wild arable plants respond to crops, weather and field management.

Individuals, traits and functional types

Most studies of weeds and other wild plants have used the species as the main accounting unit, as in our general work on the arable seedbank.  Species-level descriptions ignore the large within-species variation of arable plants and are unable to express directly those properties of plant development, structure and nutrition that mediate ecological processes. Questions arise as to how much of this variation is genetic, and whether it is modified by locality, management and climate and in turn whether the particular individuals at a site give a clue to its history. Our research described here using the individual as the ecological accounting unit aims to address some of these questions.

At present, we are developing and testing what is hoped will be a generic approach to quantifying within-species variation and assessing its ecological role. Capsella bursa-pastoris - shepherd's purse -  is used as a model for the following reasons: its widespread occurrence as the commonest broadleaf in the arable seedbank; persistence since the last ice age, evidence of resilience to change; minimal to moderate competitive ability against crops; valuable contribution to the food web; great architectural and physiological variation; and genetic synteny with Arabidopsis. Much attention is therefore given in this project to quantifying and assessing the role of genetic and functional variation in accessions of Capsella from arable-grass systems before extending the approach to other species. Research is described in the following studies:

  • functional and genetic variation in the model species Capsella
  • seed ecology
  • arable plants as novel cash crops
  • arable plants and crop pathogens.

Contact: Pietro Iannetta

The following government report provides more background to this topic:

Recent papers and reports

Karley, A.J., Hawes, C., Iannetta, P.P.M., Squire, G.R. 2008. Intraspecific variation in Capsella bursa-pastoris in plant quality traits for insect herbivores. Weed Research 48, 147-156.

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