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Fine Root Anatomical Structure, C and N Concentrations of Seven Tree Species in Maoershan

Author: ZhaoZuoLi
Tutor: WangZhengQuan
School: Northeast Forestry University
Course: Forest cultivation
Keywords: TNC Soluble nitrogen Anatomical structures Correlation Full carbon Total nitrogen Seasonal changes Fine roots
CLC: S718.4
Type: Master's thesis
Year: 2011
Downloads: 113
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Abstract

The fine roots of trees the most important physiological function is to absorb nutrients and water to support the growth of trees. ,1-2 root root branching structure is typical of the absorbing roots, life expectancies, which play an important role in the absorption of resources and ecosystem C and nutrient cycling. Study two root anatomical structure and the concentration of nutrients (carbon and nitrogen), an understanding of the relationship between the structure and function of the fine roots, predict root of life as well as evaluating the 1-2 grade root contribution to the carbon and nitrogen cycles in forest ecosystems of great significance . Therefore, this study to the northeast region of seven major afforestation tree species Manchurian ash (Fraxinus mandshurica), yellow Polo (Phellodendron amurense), walnut the Catalpa (Juglans mandshurica), larch (Larix gmelinii), Korean pine (Pinus koraiensis) Scotch Pine (Pinus sylvestris var mongolica in the) and spruce (Picea koraiensis) for the study measured 1-2 grade root anatomical structure and total carbon, total nitrogen, the TNC (non-structural carbohydrates Total non-structural Carbohydrates) soluble nitrogen concentration seasonal changes, the analysis of total carbon, total nitrogen, TNC and soluble nitrogen concentration and the anatomical structure of the concentration of nutrients (carbon and nitrogen), and reference data analysis of carbon and nitrogen concentration of fine roots of fine roots of life seasonal variation. The results are as follows: (1) seven species level 1-2 root anatomical structure has obvious seasonal variation. In the spring, the root diameter and vascular diameter minimum Wigan than the lowest, the highest proportion of cortical thin cortex, and multi-prototype lowest proportion of root; autumn is the opposite. Thus the the the Spring root absorption function may be stronger, and autumn root transport more powerful. (2) 1-2 grade root of the seven species, the TNC concentration of 26% to 43% of the total carbon concentration, the total soluble nitrogen nitrogen concentration of 6% to 28%. The lowest and the highest concentration of total nitrogen, summer carbon concentration highest autumn total nitrogen concentration minimum; spring fine root carbon concentration TNC and soluble nitrogen concentrations were lowest in summer. Correlation analysis showed that the total carbon and total nitrogen concentration of each species were significantly negatively correlated (P lt; 0.01), and the TNC soluble nitrogen concentration was a significant positive correlation (P lt; 0.01). Full carbon concentration significantly reduced the TNC and soluble nitrogen concentration, total nitrogen concentration increased significantly improves the TNC and soluble nitrogen concentration. These findings confirm: fine root soluble carbon, nitrogen concentration and total carbon, total nitrogen concentration closely. (3) Seven Species of the first two levels of root anatomical structure with the carbon and nitrogen concentration is closely related. Correlation analysis showed that fine root TNC and soluble nitrogen concentration with increasing cortical thickness and cortical ratio increased significantly (P lt; 0.01), decreases with increased vascular diameter and Wigan; total nitrogen concentration changes with soluble nitrogen concentration; total carbon concentration with the four factors are positively correlated. That cortical tissue changes caused by significant changes in nitrogen (total nitrogen and soluble nitrogen) and TNC concentration, changes in the cortical tissue and vascular tissue combined effect of the variation of the total carbon concentration. (4) seven species, the average life expectancy of most of the fine roots lowest in spring. Correlation analysis showed that fine roots born in the spring, the average life expectancy with the TNC / soluble nitrogen was significantly positively correlated (R2 = 0.715, P lt; 0.01). Show that in the fine root carbon, nitrogen concentration, the TNC / soluble nitrogen may predict the seasonal variation of the root system life the role of important instructions.

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