Temporal And Spatial Variation Of Tannin Content In Staple Food Bamboo (Bashania Fargesii) Of Giant Pandas In Foping National Nature Reserve

The giant panda(Ailuropoda melanoleuca), as the image ambassador of the world natural fund, distributed only in China and called "living fossil", has been a flagship of endangered and rare species in the world and highly concerned by the international community. In the wild, giant pandas are mainly distributed in China’s Qinling, Minshan, Qionglai mountains, Large phase ridge, Small phase ridge and Liangshan six mountains, which have different degrees of habitat and foraging environment. Bamboo is the main food source and food for pandas, and the tannic acid which is one of the secondary metabolism, will change along with the change of altitude gradient and seasons. Meanwhile, the phenomenon of vertical migration would appear in the foraging strategy of giant pandas along with seasonal and altitude gradient changes in the wild, so we speculate that the secondary metabolites of plants in bamboo may be one of the main reasons that affect the foraging strategy. As a result, we put the Three Officer Temple Station in Foping National Nature Reserve of Shaanxi provenance as an example, and analysed of the changes of tannin content in various nutritional parts of Bashania fargesii which is the staple food bamboo for giant panda. The aim was to explore the effect of plant secondary metabolites tannic acid on foraging strategy of giant pandas in the wild, and the results of the study are as follows:1. Comparison of methods(UV and HPLC) for determination of tannin content in bambooSingle and orthogonal experiments, were used to evaluate the two methods on L: N N-, two methyl amide concentration was 75%, solid-liquid ratio was 1:40, extraction time was 60 min and temperature was 50℃, and the tannin(tannic acid) as the standard, the detection wavelength was 525 nm after color. Optimization of analysis condition in high performance liquid chromatography, and we established the condition of HPLC detection: Detection wavelength 280 nm, column temperature 30 degrees, mobile phase: methanol and water(volume ratio: 80: 20), flow rate 1.0ml/min. The results found: Determination of content of bamboo in tannic acid by UV spectrophotometry method for the determination of tannin content was significantly higher than that of HPLC; and determination of ultraviolet spectrophotometry the content of tannic acid, a large range of volatility. The stability of HPLC method for the determination of tannin content of bamboo in the high, high accuracy, strong single. A comprehensive analysis of the content of the study on the determination of bamboo in tannic acid by HPLC method.2.Temporal and spatial variation of tannin content of bamboo Bashania fargesii in Foping giant panda’s staple foodThrough the research on changes of tannin content at the elevation of 1200-1900 m range, we found tannin content of bamboo leaf reached the maximum at 1700 m, 1800 m and 1900 m altitude for four reasons of a year, 1500 m to 1600 m has a significant increase, but the minimum content of tannin acid at the elevation of 1200 m. In the whole altitude range, Bamboo leaf tannin content roughly(1700-1900m) > 1600 m > 1500 m > 1400 m > 1300m/1200 m,The stem bark and stem core tannin content is roughly(1600-1900m) > 1500 m > 1400 m > 1300m/1200 m. At the same altitude,In January, the altitude 1200 m annual leaves the tannin content was the lowest(1.29 g / kg), in the summer of July 1800 m perennial bamboo tannic acid content is highest(907 g / kg),With the end of winter began in the spring of the beginning of February present tannins content of leaves with the month increased tannic acid content increased gradually and in in the summer of July or August reached maximum value and with the increase in the month shows a decreased significantly in the process, until February of tannic acid content reached the minimum.At the same time, the skin stem core stalk Bashan wood and bamboo leaf showed the same change trend. In the summer of July the stem bark and stem core tannic acid reached the maximum value, minimum content of tannic acid in winter of January. On the whole of the whole year, the perennial leaves are more than two years old bamboo leaves. Perennial stem bark, biennial between bark, and annual stem bark was not significantly different, but between the stem core content of tannic acid were significantly strong, perennial stem core > biennial stem core > annual stem core.3. A moderate range of tannin content in each part of Foping giant panda’s staple food nutrition field.According to the seasonal movement of Foping giant panda, combined with spatial and temporal variations in all parts of the nutrition content of tannic acid in Bashan bamboo, and we extracted thus conclusion: the moderate range of tannin content in leaf was 1.29g/kg-6.64g/kg, the moderate scope of stem bark was 0.93g/kg-2.15g/kg, and the moderate range of stem core was 0.36g/kg-1.98g/kg.