Denholm, I., Plant Ecology Division, IACR-Rothamsted, Harpenden, Herts. AL5 2JQ, United Kingdom
Gorman, K., Plant Ecology Division, IACR-Rothamsted, Harpenden, Herts. AL5 2JQ, United Kingdom
Cenis, J.L., CIDA, 30150 La Alberca (Murcia), Spain
Denholm, I., Plant Ecology Division, IACR-Rothamsted, Harpenden, Herts. AL5 2JQ, United Kingdom
Gorman, K., Plant Ecology Division, IACR-Rothamsted, Harpenden, Herts. AL5 2JQ, United Kingdom
Cenis, J.L., CIDA, 30150 La Alberca (Murcia), Spain