A Study On Relationship Between The Main Chemical Comositions And Caloric Value Of Robinia Pseudoacacia And Other Tree Species

Robinia pseudoacacia is a widely planted tree species which had strong adaptability, fast growth and other characteristics in our country, and it was widely used as a type of fuel energy tree species in recent years. Caragana korshinskii, Hippophae rhamnoides, and Elaeagnus angustifolia L. were also important shrub type fuel energy tree species. In order to do further research on these energy tree species, mainly studies the research object in this paper, Ash, holocellulose, crude protein, crude fat, tannins, starch and soluble sugar contents of the branch, leaves,bark,trunk, as well as the relationships between these chemical compositions and calorific values were studied in this paper. What we concluded provide important basis for the cultivation and selection of the energy tree species in the future.The main results were as follows:(1) Gross calorric values and ash contents of different organs in different densities were significantly different(P<0.01).The caloric values of leaves,bark were significantly higher than the branch and trunk. The order of ash contents amount of Robinia species were leaves>bark>branch> trunk and leaves> root> branch> trunk> bark of the korshinskii et al.(2) Linear relationships and LOWESS regressions between holocellulose, crude protein, crude fat contents and gross calorric values had small fitting R2values,but better effect with ash-free calorific values.The linear relationships and LOWESS regressions between tannins, starch, soluble sugar contents and gross calorric values, ash-free calorific values were not satisfying. The chemical compositions and calorific values had no obvious changing laws of these tree species.(3) Ash-free calorific values were very significant positive correlated with ash contents of these tree species,and significant negative with holocelluIose(P<0.01). Its crude protein, crude fat contents were significant positive correlated with ash-free calorific values.The correlations between tannins, starch, soluble sugar contents and ash-free calorific values were not significant.(4) The regression equations between the caloric values and chemical compositions were very significant of Tetraploid Robinia, Robinia pseudoacacia cv.idaho and Caragana Korshinskii (P<0.01).Fittings of multiple regression equation were significant of Rapid growing Robinia and Robinia (P<0.05).The regression equation of Hippophae rhamnoides was not significant.There was no relevant regression equation of Elaeagnus angustifolia because of insufficient determining datas.(5)We take ash-free calorific value as the ash sample space, ash content and other six chemical compositions as the variables used for principal component analysis.Then principal component expressions of higher contribution rates are got, and the comprehensive factors which reflecting are in accordance with the above conclusions.