Evaluation and propagation of Chinese wingnut, Pterocarya stenoptera, as a new bioenergy feedstock

Chinese wingnut;pterocarya Stenoptera;propagation;biomass

Miller, Robert ; Kling ; Gary J.

关键词: Chinese wingnut;    pterocarya Stenoptera;    propagation;    biomass;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/49371/Robert_Miller.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Short rotation woody crops (SRWC) as a source of biomass for energy production could play a vital role in solving the problems associated with climate change, global warming, and the rising price and diminishing supplies of carbon-based fossil fuels.In order to meet these challenges, new species will need to be assessed for use as SRWCs.Chinese wingnut, Pterocarya stenoptera, has been reported to exhibit several characteristics such as fast growth rate and suitability to a wide range of soil and moisture conditions that could make it attractive as a potential source of woody biomass.Due to lack of past work with the species, little is known regarding clonal and seed propagation, coppicing ability, biomass composition and growth rate.In order to determine the best methods of propagation for this species, hardwood and semi-hardwood cuttings were treated with a range of Indole-3-butyric acid (IBA) concentrations suspended in a mixture of 25% ethanol or suspended in talcum powder.The cuttings were subjected to wounding or non-wounding treatments and treated with liquid quick dip IBA concentrations of 1000, 2500 and 5000 ppm or mixed with talcum powder to produce concentrations of 1000, 3000, and 8000 ppm IBA.The cuttings were grown under mist conditions for 6 to 9 weeks with 14 hour photoperiods.Results were analyzed using analysis of deviance in SAS.The number of roots per cutting and rooting percentages varied with IBA concentrations but results also revealed a high degree of variability in the mist bench conditions., The results of this study indicate that the preferred method of propagation of Pterocarya stenoptera by cuttings would be to utilize wounded, semi-hardwood, subterminal cuttings treated with either liquid dip or talc powder quick dip with IBA levels ranging from 2500 to 8000 ppm under mist conditions.In order to better understand propagation of Chinese wingnut from seed, a replicated study was conducted with batches of seeds being removed from stratification at 4.5 °C in moist heat sterilized sand every 5 days for a period of 60 days.Seeds were then planted in greenhouse trays and germinated under greenhouse conditions. A logistic regression model was fit to assess the impact of stratification period on seed germination. The probability of seed germination increased with increasing days of stratification up to 30 days, with only minor changes after 30 days, indicating an optimal stratification period of 30 days.In order to better understand the coppicing ability of Chinese wingnut, a study was designed to test the effect of different cutting heights on regrowth of shoots from the main stem.The study was conducted using nine-month-old containerized wingnuts grown from seed under greenhouse conditions.Treatments consisted of removing all leaves from the plant and cutting the main stem so that 0, 5, 10, or 15 buds remained with treatments having average heights of 4.6 (± 2.5), 8.0 (± 1.7), 11.9 (± 2.5), and 15.3 (±2.3) cm, respectively.Data was collected on the number of shoots and leaves, and total leaf dry mass per plant after 33 days. Dry mass was analyzed via Analysis of Variance (ANOVA) and shoot and leaf count data were analyzed via Analysis of Deviance.Dry mass was affected (α= 0.001) by the number of buds left remaining on the stem, with the 15-bud treatment having a mean dry regrowth shoot mass of 4.37g.The number of shoots regenerated from the three treatments was significant (α= 0.001) with the 15-bud treatment producing the greatest number of shoots (10.3/plant); however, the number of leaves produced by treatments was not significant, suggesting that plants with fewer shoots had a greater density of canopy.Results suggest that a harvest system should allow some degree of above ground biomass to allow for fast coppice regrowth.When considering the suitability of a woody plant for use as a biofuel feedstock an accurate picture of the chemical composition of the biomass is necessary.To that end compositional analysis was conducted on Pterocarya stenoptera biomass.Biomass samples were collected at the University of Illinois bioenergy research farm and from locations in seven Midwestern states.The samples were collected from tree limbs during winter dormancy with samples being divided by age class to contain the most recent growing years 1-4.Samples were oven dried and ball milled.High pressure liquid chromatography analysis was used to determine structural carbohydrates such as lignin, hemicellulose, monosaccharides, and acetate content.High temperature incubation was used to determine Klason lignin content, and extractives content was determined using an ethanol and water extraction.Test procedures followed those set forth by the National Renewable Energy Laboratory.Samples collected from the fourth year of growth had the following compositional profile:cellulose 26.9 ± 2.37%, hemicellulose 16.3 ± 0.98%, lignin 24.6 ± 0.79%, ash 1.99 ± 0.52%, extractives 12.8 ± 2.32% and acetyl 3.12 ± 0.18%.Results indicate comparatively low levels of cellulose at26.9 ± 2.37% for 4 year old wood compared to common biomass production species such as Robinia pseudoacacia, Populus deltoides, and Salix alba that have cellulose values ranging from 40 - 42%.The low levels of cellulose found in the compositional analysis studies reveal that Chinese wingnut, Pterocarya stenoptera, is not an ideal candidate for biomass production.