194 Y.H. CHEUNG, K.Y. TAI, S.W. TSAO AND L.B. THROWER
kei wai, there would be an input of 146.5 kg. per year or 39.6 kg. per hectare of open water.
Thus, the total annual input of organic litter from these two species alone can be estimated as about 3,100 kg. dry weight per hectare or 850 per hectare of open water.
c) Colonization of Litter by Microorganisms
The occurrence of fungi in leaf litter after various periods of immersion is shown in Table 3; these fungi had been isolated from surface-sterilized tissue and therefore were present within the leaf itself. They may have infected the leaves while still on the parent bush or invaded them during immersion. Venturia sp. and Phyllosticta sp. probably represented the former group. Pythium spp. became an important component of the mycoflora after 3 days immersion and remained so until day 64. Chaetomium sp. and Trichoderma viride were also important by day 64. Representatives of an additional 9 genera of fungi were isolated from leaves after immersion but before surface sterilization, but these were considered as contaminants.
Table 3. Frequency (%) of fungal species isolated from leaves of Kandelia candel after various periods of immersion in kei wei
Period of immersion (days) 0 3-8 21-32 64 Isolates* Venturia sp. (conidial form) 31 Colletotrichum sp. 8 Phyllosticta sp. 11 Nigrospora sp. 4 Pythium spp. 90 33 33 Fusarium spp. 2 Chaetomium globosum 33 Trichoderma viride 44 Hormiscium sp. 11 O. Melanconiales 11 * from surface-sterilized leaf tissue.