Study On Energy Ecology Of Casuarina Equisetifolia Plantation On Coastal Sandy

Casuarina equisetifolia, introduced into china in 1950s, had showed good adaptability and high productivity. It had structured a green wall and played an important role in defending wind, fixing sand, advancing ecological environment along the southeast coast in China. To some extent, it had become an irreplaceable plantation in protecting plantation, particularly on the wind gap site. However, after 1 or 2 generations, regenerating the existing plantation had become a serious problem for researchers. Coast sand belongs to degraded sandy site, vegetation was the energy origin of whole ecosystem, so, this kind of vegetation must have the ability to get their ecological site on the badly degraded sandy site, on which Casuarina equisetifolia can live well, and show great adaptation. Seniors had researched on adaptation and ecological effect of Casuarina equisetifolia. C. equisetifolia grows very fast and has a high rate of solar energy utilization. According to the fast growth of C. equisetifolia and the difficulty of regeneration, from 2002 to 2003, the paper researched on standing crop energy, returned amount of energy, fixing energy, energy conversing efficiency and energy release of protection plantation at Huian county, Fujian province. Moreover, and researched energy characters of Casuarina equisetifolia on different site, mix plantation and different sandy plantation at Dongshan. The study on the ecological characters of Casuarina equisetifolia can supply scientific evidences for management and selecting species.The characters of Huian Casuarina equisetifolia plantation were: The whole standing crop biomass was 152.60 t/hm2. The distribution of components was as follow: bole (43.94%)>root (24.14%)>branch (13.74%)>bark (9.40%)>foliage (6.42%)>dead branch (1.62%)>fruit (0.76%). Root occupied24.24%, which showed Casuarina equisetifolia was a developed system. Primary productivity was 10.17t/hm2a, which indicated it had comparable primary productivity level. Total litter was 14.17t/hm2a, the amount of foliage litter returned was 10.23 t/hm2a, which occupied 68.47%, leaf litter had remarkable relationship with weather at 0.01 level, the peak period of foliage litter was from May to September, and the amount of this term occupied 55.69%. Average caloric value of the whole sample tree was 19.70kJ/g, components gross caloric value was fruit (20.23 kJ/g)>foliage (20.01 kJ/g)>dead branch (19.83 kJ/g)>root (19.56 kJ/g)>bark (19.51 kJ/g)>branch (19.41 kJ/g)>trunk (19.29 kJ/g); ash content mean was 5.23%. Ash free caloric value of fractions was bark (22.15 kJ/g)>foliage (21.48 kJ/g)> fruit (21.40kJ/g)> dead branch (20.56 kJ/g)> root (20.47 kJ/g)>branch (20.34 kJ/g)>trunk (19.53 kJ/g), mean of them was 20.87 kJ/g. Caloric value of living foliage and litters was so as: The living foliage caloric was from 19.73 kJ/g to 21.62 kJ/g, mean of them was 20.68 kJ/g. the period from May to August was maximum caloric value time, during which Casuarina equisetifolia grows rapidly. Caloric value had remarkable relationship with weather, and reflected solar energy utilization. Caloric value of litter components was the caloric of foliage was 20.51 kJ/g ~21.68 kJ/g, and mean was 21.11 kJ/g, while that of branch and fruit was 19.63 kJ/g -20.21 kJ/g, 19.89 kJ/g; 18.27 kJ/g -20.63 kJ/g, respectively. During the first 12 months of litter withered on ground, caloric value reduced from beginning to the 10th month, especially from third to seventh month, then reducing ratio became smaller. But on the 9th month or 10th month, caloric value came to min. After this period, caloric trended to increase, and caloric value reduced 0.07kJ/g per month. Standing crop energy was 2998.92><106kJ/hm2and the distribution of components was so as: bole( 1293.15 x 106kJ/hm2)>root(720.57 x 106kJ/hm2)>branch(406.98 x106kJ/hm2)> bark ( 297.87 x106 kJ/hm2) > foliage ( 196.16x106 kJ/hm2) > dead branch (48.90x106kJ/hm2)>fruit (23.28x106kJ/hm2), root occupied 24.10% to total. Net energy production was 196.80x106kJ/hm2a, and the energy conversing efficiencywas...