Study On Renewal Potential Of Oak Forests In Baotianman Nature Reserve

Natural regeneration of vegetation is a complicated ecological process,which plays important roles in the multiplication,spread and continuation of plant population and the stabilization and succession of plant community,being a hotspot in the research of vegetation dynamics.Natural regeneration to fully rely on the forces of nature to achieve forest ecological environment of the natural recovery.In line with the laws of nature to produce a high biological diversity and forests of high ecological quality,and it's only 1/4 the cost of artificial reforestation.It is a low-input and high-yield way to cultivate the forest.As a result of this traditional way of forest regeneration is more suited to modern business and the sustainability of forest biodiversity conservation principles, which concerned both at home and abroad.Research on forest plant communities of different environmental factors to update the response mechanism,not only for the understanding of forest regeneration and biodiversity to maintain the mechanism has theoretical significance,and ecological restoration of forests has important application value.Baotianman Nature Reserve in North China is the district line of China's sub-tropical and warm temperate climate,and also the line of zoning animals Gubei China and Oriental.This district is the mosaic strip of Central China and southwest,is the ecotone of Warm temperate deciduous broad-leaved forest and North sub-tropical evergreen and deciduous mixed forest. Forest in this area preserved well,forest cover of 88%,it is the sub-tropical and warm temperate regions north of natural broad-leaved forest.Special geographical location and ecological environment of complex and varied conditions,combined with a smaller human disturbance to protected areas to preserve the rich biodiversity resources.Oak is the main species in Baotianman area,accounting for the entire 70 percent of tree species,mainly Quercus variabills,Q.glandulifera and Q.variabilis,et al.This study was run in Baotianman Nature Reserve region.Q.variabills,Q.glandulifera and Q. variabilis are main in the forests in different altitudes.We studied the update of main trees in forest ecosystem with the two species:Q.glandulifera and Q.variabilis.The conclusions of study were as follows:(1) From the vertical distribution can be seen to Q.variabills community-based mainly at an altitude of 1000m below.Between 1000～1300m above sea level there are transition forest of Q. variabills.Q.glandulifera and Q.variabilis,but in most cases,dominated mainly by Q.glandulifera. Q.variabilis to community-based mainly at an altitude of over 1300m.(2) In core region Q.variabills seedlings at an altitude between 1000～1400m,Q.glandulifera seedlings exist between 1000～1500m above sea level,Q.variabilis seedlings exist more than 1200m above sea level.They were mainly seedlings not sprouts.It's a very low success rate form seedlings to saplings.Young trees were extremely rare.(3) In years of small seed-bearing,Q.glandulifera and Q.variabilis,with a small amount of seed rain and short duration.Seed rain began in late October,early November at the maximum, ended in mid-November.Seed rain intensity reached the maximum in early November,at the same time,the seeds of Q.glandulifera along an altitudinal increase in rain intensity increased gradually. Seed rain intensity of Q.variabilis reached the maximum at an altitude between 1400～1600m, gradually decreases upward and downward.(4) In the early fate of seed rain Q.glandulifera and Q.variabilis,seed-eating by insects dropped first,which was higher than the number of intact seeds.But later,the number of intact seeds should be higher than the seed-eating by insects.Dry seeds in the seed rain process had remained at a lower level and smaller fluctuations.(5) In the process of seed rain,with the passage of time,insects eat the proportion of seeds decreased,while the intact seeds in the seed firm in a high proportion over time and gradually increased.(6) In years of small seed-bearing,Q.glandulifera and Q.variabilis,the soil seed bank is almost to 0.(7) Q.glandulifera and Q.variabilis seeds have a good condition with high activity.In Baotianman Nature Reserve,oak forests have stable structure.Natural regeneration is difficult to be carried out within the oak forests.Natural regeneration of oak forests should rely on a large area of open land or bare land.Oak seeds,take advantage of its number and high activity is enable to develop rapid,and take up the space.