The Study On Young Cyclobalanopsis Gilva Nutrient Characteristic

Cyclobalanopsis gilva is an excellent kind of local tree species from subtropical region, but also of commercial tree species. It has broad prospects, but human activities on disafforestation have destroyed the natural forest, even the natural lonely trees are in danger of extinction. This research mainly from the young forest of the Cyclobalanopsis gilva of different provenance nutrient characteristics of each organ, in combination with the study area soil nutrient, discusses different provenance Cyclobalanopsis gilva nutrient element content distribution and accumulation characteristics and utilization efficiency of nutrient elements and their relations, etcThis study first tentatively tries to screening the suitable provenance for popularization and utilization in Hunan province, based on the nutrient content of four kinds of young growth Cyclobalanopsis gilva in Huuan Dongkou, Yongding, Jingzhou and Zhejiang Zhoushan,also the content of soil nutrient in Miluo Yuchi Woodland and varies indexes of young growth Cyclobalanopsis gilva. Second, through the analysis of soil nutrients and plant nutrients, and the correlation analysis of the results, we can learn the desired elements and the nutrients accumulation of young growth Cyclobalanopsis gilva, which may provide technical support and theoretical basis to rational application of fertilizer and fine quality high yielding. The main findings are as follows:(1) Cyclobalanopsis gilva of Zhoushan provenance have reached an average height of 2.42m after it had been planted 2 years, the highest of them reached 3m. And it has a 0.61m of annual increment, which is much taller than 0.5m of other provenances. It also has a much larger ground diameter of 3.0cm than the others (Yongding 2.5cm, Jingzhou 2.0cm, Dongkou 2.1 cm). Therefore is the most optimum provenance in Hunan.(2) Miluo Yuchi Woodland has a generally higher amount of the microelement K, N, Ca in local soil, but is still in a state of deficiency. Element K have showed an extremely significant differences in multiple sampling points, while Ca, Mg, P, N are only showed in a few. Microelement Fe has an over high amount, due to the abundance of Fe ion in local red soil. Other microelements remain within a proper range for plant growth.(3) Of Cyclobalanopsis gilva’s all different organs, leaves were the one contains the highest nutrient elements amount, while the trunk contains the lowest amount. K was the highest in macro elements, then N, and the lowest turns to be Mg. Micro-element Fe has the highest amount in every organs of all provenances, the reason may due to the over high content of Fe in the local soil have led to high levels of Fe in the plant. Cu and Zn were of the lowest amount. The total accumulation amount of macro elements of young growth Cyclobalanopsis gilva in different provenances are, Zhejiang Zhoushan (32688.90 kg/hm2)> Hunan Yongding (20223.40kg/hm2)> Hunan Dongkou (12539.64kg/hm2)> Hunan Jingzhou (11540.06kg/hm2), and in the case of the micro-elements are Zhoushan (42698.65g/hm2)> Hunan Jingzhou (10667.04g/hm2)> Hunan Yongding (7092.35g/hm2)> Hunan Dongkou (4157.67g/hm2). From above all, we can tell that the leaf still is the organ which has the most accumulation amount of microelement, and the trunk is the one that has the least. In the situation of nutrient use efficiency, Hunan Yongding is 6.23 kg/t, Zhejiang Zhoushan is 5.08 kg/t, Hunan Dongkou is 5.47 kg/t, and Hunan Jingzhou is 8.37kg/t. Turns that Zhejiang Zhoushan has the highest and Hunan Jingzhou has lowest in nutrient utilization.(4) The amount of Cyclobalanopsis gilva leafs N nutrient elements was in the range of 2.40-4.40g/kg. The results of stoichiometry have showed that different provenances of Cyclobalanopsis gilva has an N/P ratio between 6.0-11.1, body<14, this inferred that Cyclobalanopsis gilva was stressed by N. And form the nutrition diagnostic, we can tell that N element has a critical diagnosis result of 4.31g/kg, which the upper limit is at 5.105g/kg and the lower limit is at 3.528g/kg. This shows that N-element is in a state of deficiency if it’s lower than 3.528g/kg, excessive if it’s higher than 5.105g/kg, high if it’s above the upper limit, and low if it’s under the lower limit.