Epiphytic succession on tree trunks in a mixed oak-cedar forest,Kumaun Himalaya

The epiphytes present at about breast height on trunks of different size were studied for three major tree species in a seasonally wet forest at 2050 m altitude in the Kumaun Himalaya: Cedrus deodora, Quercus floribunda and Q. leucotrichophora. The total biomass and species number per unit trunk area, were found to increase with trunk size. It was supposed that the results indicated a succession in the type of epiphytic cover from young trunks to older trunks.The amount of loose material (plant remains and soil) per unit area of trunk increased with increasing girth. The C:N ratio in this material was initially very high on the oaks (129–197) and declined with increasing trunk size (to 73–78); the ratio was constant across girth classes in the cedar (86–87).Bryophytes produced most biomass on most trunks; next to them were lichens on the smallest trunks, and flowering plants on the largest. The number of species of epiphytes was similar on all three host species. The results are discussed in relation to contemporary ideas on diversity and strategies.Nomenclature follows: Ganguli (1972, 1977 & 1980); Kashyap (1929); Nayar (1970); Osmaston (1927).Financial support from the Council of Scientific and Industrial Research, Delhi and University Grants Commission, New Delhi is gratefully acknowledged.