The Influence Of Long-term High Wind To Rootsystem Distribution Of Zygophyllum Xanthoxylum (Bunge) Maxim

Zygophyllum xanthoxylum(Bunge) Maxim., which growing in the habitat withstrong wind and drought is a component species in Dabancheng natural community，and is also an pioneer species in the process of vegetation restoration. Root system asan important organ in plant fixation growth, plays an important role to maintain thestability of the whole plant. The adaptation mechanism of Zygophyllum xanthoxylumroot system to the wind in windy desert is very important for vegetation ecosystemreconstruction and windbreak and sand-fixation. In this paper, three ways has beenaccepted to observe the characteristics of rootsystem distribution in natural high windof Zygophyllum xanthoxylum:(1)In Dabancheng natural high wind environment,choose different plants of Zygophyllum xanthoxylum in young and adult agesrepresentatively, and observed their characteristics of rootsystem distribution directly;(2)In open ground of the field, choosed two sites as sample areas, set up an enclosurealternatively. Comparing the rootsystem distribution between wind-protected site andwind-exposed site;(3)The wind simulation experiment were taked in the experimentalfield of campus, analysisd the characteristics of rootsystem distribution betweendifferent wind speeds.The effects of long-term high wind to rootsystem distribution of Zygophyllumxanthoxylum was over the different growth stages. In the young stage, the effects ofwind to Zygophyllum xanthoxylum did not show asymmetry distribution in rootsystemsystem. In adult stage, the growth of lateral root number, length and diameter inleeward was larger than windward side, root system presented significant asymmetrydistribution. The influence of wind on the asymmetry of Zygophyllum xanthoxylumrootsystem was likely to be through changing the redistribution of the winter snow,which influenced the distribution of soil moisture, and affect root system distributionindirectly.The lateral root number and length at different levels were affected greatlyinlong-term high wind. Secondary lateral root length of young Zygophyllumxanthoxylum in open sites was larger than wind-protected sites, the first lateral rootnumber of wind-protected sites was significantly greater. Compared with the windspeed of7m/s, the first order lateral root and tertiary lateral root number in12m/sincreased significantly. Zygophyllum xanthoxylum increased the lateral root numberand length to adapt to the long-term high winds.In long-term high winds, the horizontal distribution and vertical distribution ofroot system are changed. Under natural high environment, root system which distances from the center of the main stem within20to30cm in horizontal has thelargest number of lateral root and lateral root length. In wind shading conditions, thevertical distribution of lateral root diameter in Long-term high wind was less affected,young Zygophyllum xanthoxylum has a bigger number of lateral root and lateral rootlength in the vertical soil profile within10to30cm. In long-term high winds, rootsystem of horizontal and vertical distribution range were increased.In conclusion, under the treatment of long term high wind, the secondary lateralroots and root range increasing. In natural wind environment, there is no asymmetryroot system distribution in young Zygophyllum xanthoxylum lateral root system. Butin adult Zygophyllum xanthoxylum, root system presented significant asymmetrydistribution. The influence of wind on the asymmetry of Zygophyllum xanthoxylumrootsystem was likely to be through changing the redistribution of the winter snow,which influenced the distribution of soil moisture, and affect root system distributionindirectly.