Research On The Ecological Characteristic And Soil Conservation Of Four Dwarf Bamboos

The ecological characteristic and water conservation function of four dwarf bamboos Arundinaria argenteostriata, Arundinaria fortunei, Shibataea chinensis, Sasaella masamuneana f.aureostriata were researched. The law of bamboo shoots emerging, photosynthesis and transpiration changing, physiological indexes changing under stress tolerances, the relation between the roots and soil characteristic and conservation function of these four dwarf bamboos were discussed, the results shown:(1) The four dwarf bamboos presented"less-more-less"on the quantity of bamboo shoots, and the quantity of shoot degradation increased after the climax of bamboo shoot. The height growth showed"s"pattern. The time for the height growth of each species was different. The quantity of bamboo shoots increased after clear-cut, but the height growth reduced and the velocity of growth was slower.(2) The diurnal variation of net photosynthetic rate and transpiration were bimodality in April and August, while it was a single peak curve in November. The transpiration rate of these four dwarf bamboos was highest in August, and the net photosynthetic rate of Shibataea chinensis was highest in August, and that of the rest was highest in July.(3) The permeability membrane and the contents of MDA of these four dwarf bamboos increased under the stress tolerance. The contents of chlorophyll decreased, the POD and SOD showed the same changes, which increased firstly, then deceased.(4) Water and soil conservation function of Arundinaria fortunei was the best, and that of the rest was Shibataea chinensis, Sasaella masamuneana f.aureostriata and Arundinaria argenteostriata in turn. The water conservation ability of Shibataea chinensis was the best, and Sasaella masamuneana f.aureostriata was the worst.(5) The root distribution of the four species had the same rule. The root content below 0.5mm was the biggest, and beyond 1.0mm was the least. With the enhancement of soil depth, the roots content was descending gradually. The soil amelioration of 3-3.5mm was the most obvious in the roots of different diameter.(6) The litter fall of the investigated bamboo was bigger in June and Aug. The dynamic course of water-holding capacity and water absorption rate were similar. With the immersion time extending, the water-holding capacity was increasing. At last, the increasing range became small. The evaporation rate of leaves and culms had positive relativity with illumination and temperature, and negative relativity with relative humidity.(7) With the depth of soil increasing, the shear strength descended obviously. The action of 0.5mm-1.0mm roots was the biggest in enhancing the shear strength of soil.(8) The antiscour index of Arundinaria fortunei was 2.632, which was the biggest in these four bamboos. The rests were Arundinaria argenteostriata, Shibataea chinensis, Sasaella masamuneana in turn. In the different diameter of roots, the action of 0.3-0.35mm was the biggest. With the increasing of depth of soil, the water-stable index was descending gradually.