Seasonal changes in populations of the orchidGoodyera repensBr. and in its mycorrhizal development

Abstract
Population dynamics of Goodyera repens Br. were investigated on permanent quadrats over a 12 month period in conjuction with a study of mycorrhizal infection. The production and death of individuals were recorded at monthly intervals. At all sites production of new individuals was greatest during summer and lowest in winter; deaths were not so markedly seasonal. Recruitment was greater than mortality and the population size increased at all sites. The turnover time of the populations was related to their size and was greater in large populations. The level of mycorrhizal infection in the roots remained constant throughout the year but in the main rhizomes infection was greater in winter when their rate of extension was least. The pattern of infection suggests that internal mycelial spread takes place throughout the year together with some re-infection from the soil.