Ziwuling Forest Shrub Layer Species Of Quercus Updated

It is imperative to accelerate the recovery and restoration degenerative ecosystem on the Loess Plateau. Ziwuling is a relative intact natural secondary forest region on the Loess Plateau where Quercus liaotungensis is a climax community types and wide distribution. The vegetation have an important for adjusting regional climate, maintaining ecological balance and promoting ecologically sustainable development. So research natural regeneration of Q. liaotungensis, whether improved the ecological environment or productive of ecosystem in the Northwest area has significant ecological meaning.This paper that base on many related researches both at home and abroad and investigation of plant community in Malan forest region. We surveyed the whole community through taking typical sample.30 plots of 10 m×10 m were established in 8 sample site to research the effects of shrub layer species on regeneration of Q. liaotungensi in Ziwulig forest region of Loess Plateau. The results as follow:1. With the growth of Q. liaotungensis in Malan forest region on the Loess Plateau. From seedlings to sapling, the number become little. During different growth stage of Q. liaotungensis, seedling and sapling have correlation with around shrub species which growth were affected by shrub species during regeneration of Q. liaotungensis.2. In this paper,χ2 test and association coefficients (AC) are used for testing the interspecific association of seedling and sapling with 35 main shrub species; the relationship between the distribution of main shrub species and environmental factors was analyzed by CCA. The results show that:①Theχ2 values implied that seedling had not significant association with shrub species(χ2<3.841), and the association coefficients (AC) ranging from -0.210 to 0.370, the association degree is comparatively low, it implied that seedling were inclined to coexist independent in the community; but theχ2 values implied that sapling had significant (3.841≤χ2< 6.635) or highly significant (χ2≥6.635) relationship with some shrub species, the sapling growth is greatly affected by the shrub species;②Sapling had significant positive association with Spiraea pubescens, the species pairs of significant positive association distributed together that they adaptive for similar habitats; sapling had significant negative association with Lonicera serreana,Crataegus pinnatifida,Viburnum hupehense,Litsea pungens,Lonicera fragrantissima,Toxicodendron vernicifluum,Swida bretchneideri,Cotoneaster multiflorus,Acanthopanax brachypus,Lespedeza bicolor,Cerasus tomentosa,Smilax stans, and the species pairs of significant negative association occur spaces seperation that they adaptive for different habitats.3. The analysis on the niche of Q. liaotungensis regeneration layer in the shrub layers. The result show that:①In the Q. liaotungensis regeneration layer, with the growth from seedling to sapling V, the niche breadth changed from large to small, The larger niche of seedling indicated that there was a good adaptable to environment and those abilities to use the environment resources are stranger than others, the smallest niche of adult Q. liaotungensis indicated that there was not adaptable to environment well; In the shrub layer, a larger number of shrub species which adaptable to the environment.②With the growth of Q. liaotungensis, there is a smaller niche overlap between sapling V and others sapling or seedling, others niche overlap is lager. When Q. liaotungensis become adult tree, which were inclined to indepently in the community. But there has a affect each other between seedling and sapling; Different shrub species have difference affects to growth of Q. liaotungensis, some shrub species have affects to special growth stage of Q. liaotungensis.To sum up, during regeneration of Q. liaotungensis in the shrub layer, the number become little from seedlings to sapling, the quantity of Q. liaotungensis seedling was enough and grew well in the area. During different growth stage of Q. liaotungensis, seedling and adult tree were inclined to coexist independent in the shrub layer. But sapling growth is strongly affected by around shrub species that result in number of sapling become little. The seedling have stronger ability to use the environment resources, but with growth of seedlings which ability of adapt environment become weaken. So, we should put attention to manage sapling stage in order to promote Q. liaotungensis regeneration well.