Caloric Value, Nutrient And Chemical Composition Characteristics In Leaves Of Dominant Species In Wanmulin Nature Reserve, Fujian Province

Caloric value, ash content (AC), C and N concentration, chemical composition in leaves of 12 dominant species in Fujian Wanmulin Nature Reserve were investigated, and the allocation of which among tree layer, shrub layer, herbaceous layer and the seasonal dynamics were analyzed. Then discussed the relationships between them, in order to reveal the characteristics of the energy and matter distribution in mid-subtropical evergreen broad-leaved forest ecosystems.The results showed that:(1) The ash free caloric value (AFCV) in leaves of 12 dominant species (21.04 kJ·g-1 per year) were higher than the terrestrial plant of the whole world significantly (17.77 kJ-g-1 per year), compared with other evergreen broad-leaved forests in mid-subtropical areas of China, which was between Zhejiang province in high latitude and Guangdong province in low latitude. Considered from spatial distribution pattern, the AFCV had decreased with increasing latitude, proved that the caloric value of evergreen broad-leaved forest of Wanmulin under integrated protection system of land prohibition had got a higher level. C and N concentration in leaves of 12 dominant species were 47.79%(range from 44.30% to 50.70%) and 1.77%(range from 1.21% to 2.82%), respectively. Compared with the terrestrial plant of the whole world or other areas, C concentration was higher, N concentration was lower, appeared limited N. The ratio C to N was high revealed the nutrient use efficiency got a good level.(2) The gross caloric value(GCV), AC and AFCV of 12 dominant species had the same seasonal change patterns decreased in the following order:winter, autumn, summer and spring, then C and N concentration decreased from summer, spring, winter and autumn, and the ratio C to N was autumn> winter> spring> summer. Except N and the ratio C to N, others at least differed significantly. Under different layers in the forest, the GCV, AFCV and C content all showed tree layer> shrub layer> herbaceous layer at the significant level, and the distribution of AC and N content in different layers were more and more diversified.(3) Both GCV and AFCV in leaves of 12 dominant species were found to be significantly positive correlated with C concentration, and AC was significantly negative correlated with C concentration. The AFCV was significantly positive correlated with N content, the GCV and AC were not to be significantly with nitrogen. The GCV, AC and AFCV were not to be significantly with the ratio C to N.(4) Because of Lauraceae was rich in lipid and volatile aroma compounds, the results showed that the AC and AFCV of Lauraceae were higher than Fagaceae significantly, the GCV of Lauraceae was higher than Fagaceae but not siginificant,(5) The Fourier transform infrared Spectroscopy (FTIR) of 12 dominant species had some differences. The targets (1154/1220,1154/1733) by FTIR both showed that tree layer> shrub layer> herbaceous layer, the differences of the target (1154/1220) and (1154/1733) among layers had a significant and highly significant, respectively. Therefore, it was suggested that the two targets with FTIR, could distinguish plants from layers.