Ficus Species Resources In Xiamen, And Energy Ecology Of Some Species

Based on the investigation of status of Ficus species resources in Xiamen city, some representative species were selected to be studied respectively on the Dynamics of caloric values during leaf development and senescence, dynamics of matter and energy during the decomposition of leaves, and relationship between cold resistance and conductance rate in this paper. The results will be beneficial for the conservation, management and introduction of Ficus species resources.1. There were 69 species at Xiamen City (including introduced species).2. Ten Ficus species had the high ash contents, with the ash contents of over 10% for F. benjamina, F. laco, F. concinna, F. microcarpa cv. golden leaves and F. carica; F. virens, F. elastica and F. auriculata had the high gross caloric values (over 20.20 kJ/g), F. laco, F. benjamina, F. microcarpa cv. golden leaves, F. religiosa and F. carica had the low gross caloric values (<19.00 kJ/g); meanwhile, seven species had the higher gross caloric values in spring than in autumn, but three species had opposite results; Gross caloric values were correlated remarkably with ash contents both in Spring (P<0.01) and Autumn (P<0.05); F. virens, F. elastica and F. benjamina had the high ash free caloric values (over 22.00 kJ/g), F. carica, F. religiosa and F. laco had the low ash free caloric values (<21.0 kJ/g).3. Caloric values and ash contents in the leaves at the different development stages of Ficus species (Ficus religiosa, Ficus elastica, Ficus laco, Ficus microcarpa cv. golden leaves, Ficus microcarpa) showed that ash content increased with the development of leaves from young to old, old leaves had the relatively high ash contents, indicating that the leaves had a mechanism to maintain the balance of mineral elements; Young leaves had relatively higher gross caloric values than mature and old leaves, gross caloric values in the leaves at the different development stages varied with species; gross caloric values were correlated remarkably with ash contents (P<0.05) for the leaves at the different development stages; ash free caloric values in the leaves at the different development stages also varied with species.4. By litterbag method, elemental, caloric, and nutritive changes in decomposing Ficus microcarpa leaves were discussed in this paper. The half-time of leaf decomposition was 101d; an increase in N concentration, and a decrease in the ratio of C/N; a rapid decrease in tannin content at the beginning of decomposition with the decrease of 59.9% and 88.9% at the first month and 4th month followed by the relative stabilization, the decrease trend in soluble sugar contents opposite to the increase in crude protein contents; somewhat decrease in gross caloric value at the beginning of decomposition followed by the increase at the third and 4th month, and then decrease; the increase in ash free caloric value with increasing degree of decomposition and then decrease.5. The relative conductance rate increased with the decline of temperature. The cold resistance of ten Ficus species followed the order was F. virens var. sublanceolata> F. lyrata>F. auriculata>F. virens>F. concinna>F. benjamina>F. elastica var. variegate>F. elastica cv.'Decora Burgundy'>F. sp. >F. benjaminai"Golden Princess",namely, F. virens var. sublanceolata,F. lyrata,F. auriculata,F. virens had the stronger ability for cold resistance than F. benjamina,F. elastica var. variegate,F. elastica cv.'Decora Burgundy',F. sp.,F. benjaminai"Golden Princess".