Mycorrhizae concentration and fitness of canopy orchids in the cloud forest of Monteverde, Costa Rica

Orchids require the presence of mycorrhizal fungi in their root systems to germinate, but the importance of fungi after germination is the focus of this investigation. The purpose of this study was to examine whether increasing the coverage of mycorrhizal fungi increases overall fitness and productivity of individual orchids. Orchids of two species Masdevalia chasei and Trichosalpinx memor were collected from cloud forest tree canopies and their fitness and infection levels were estimated. The fitness of each individual was measured here as number of leaves, number of inflorescences, length of longest leaf, length of longest stem. The percent coverage of mycorrhizae was determined by the amount of area on a cross section of a root sample covered by fungi divided by the total surface area of each cross section. The results showed that the amount of mycorrhizal fungi is not correlated with orchid fitness or productivity. There was no significant difference between the mean percent coverage between the two orchid species (t-test, t = 0.08, p = 0.94, df = 43). The importance of mycorrhizal fungi to epiphytic orchids in the cloud forests of Monteverde may be important and possibly even critical, but not precisely correlated with fitness. Las orquídeas requieren la presencia de hongos micorrícicos en sus raíces para germinar, pero la importancia de estos hongos después de la germinación es el enfoque de esta investigación. El propósito de este estudio fue examinar si aumentando el número de hongos micorrícicos, la salud y la productividad de las orquídeas individuales aumentan.https://digitalcommons.usf.edu/tropical_ecology/1308/thumbnail.jp