Germination Characteristic Of Quercus Wutaishanica Seeds In The Ziwuling Mountains

The Quercus wutaishanica is one of the typical vegetation types in Northwest and North of China. It distributes in steep slope and ridge zone. The Quercus wutaishanica's developed roots have noticeable effects on holding water and soil. And it has significant effect in soil and water conservation, the conservation of headwaters and ecological balance, and maintenance forest environment.Through the field investigation, we found that the regeneration of Quercus wutaishanica population depended mainly on sprouting of seed tree. Seedling trees were seldom. But the sprouting might result in the decline of entire population. Therefore, revealing the characteristics of Quercus wutaishanica seedling stand renewal was one of the key to promote species conservation. We chose the Quercus wutaishanica seed which was gathered in the Ziwuling Mountains, as the experimental objects. According to the study of germination in the laboratory experiment and field experiments, we analyzed the effects of temperature, lighting, soil moisture and mulching conditions on the germination and seedling of Quercus wutaishanica seeds. The results were following:(1) Under the different temperature condition,the germination of Quercus wutaishanica seeds showed that the temperature was one of leading factors which influenced germination of Quercus wutaishanica seed.①The mature Quercus wutaishanica seed could germinated so long as the temperature and humidity condition being suitable, and the germination concentrated in 1～5d of the initial stage;②Under 5℃~25℃the constant temperature condition, the germination rate of Quercus wutaishanica seed increased along with the increasing of temperature. The seed's germination rate in 5℃is only 33%, but its may reach to 80% in 25℃;③In 15℃~25℃, the germination rate of Quercus wutaishanica seed is higher, and it was highest in 25℃. But the germination rate decreased significantly when the temperature was lower than 15℃and higher than 35℃;④Temperature influence in radicle growth and germinations were basically identical. It manifested as radicle growth is quick under the temperature which germination speed are quick;⑤In 15℃/25℃variable temperature condition, the germination rate of Quercus wutaishanica seed was obviously higher than 15℃/30℃.(2) Under the same temperature (25℃) condition, the Quercus wutaishanica seed's Germination rate and Germination power were significant differences in the 24h illumination and the 10h light, dark treatment. The germination rate and germination power can respectively reach 97% and 80% in 24h illumination. Its indicated that the illumination were beneficial to the germination of Quercus wutaishanica seed, but its radicle growth is slowest under the 24h illumination.(3) The germination rate and seedling emergence rate was various under the different soil moisture content condition;①The germination rate of Quercus wutaishanica seed was high in 10%~40% soil moisture. And germination rate was 90% which is highest under 20% soil moisture. The germination power differs little from germination index on different soil moisture. But the germination rate was lowest in 45% soil moisture;②When soil moisture was 25%, the Quercus wutaishanica radicle growth was longest; and when 45% soil moisture was contented, the radicle growth was shortest;③The suitable soil moisture to seedling emergence of Quercus wutaishanica seed is 15%~25%.And in this range, the optimum soil moisture was 20%.When soil moisture higher than 30%,the seedling emergence was inhibition, and the seedling emergence was zero in 40% soil moisture completely.(4) The wild experiment of germination indicated that the stand microenvironment effects the germination of Quercus wutaishanica seed. In the gap, the germination of Quercus wutaishanica seed was better than undergrowth. It had the direct relationship with full light and high temperature in the gap.(5) The mulching method had effects in germination and seedling emergence of Quercus wutaishanica seed;①I n the gap, the germination rate of Quercus wutaishanica seed under soil mulching higher than litter coverage about 6.4%.But there were not obvious difference each other;②In the gap, radicle length under soil mulching was higher than litter coverage about 0.87cm. But there only had the small difference in the undergrowth;③Whatever soil mulching or litter coverage, germinate and the root of Quercus wutaishanica seed were all concentration, and the germination rate was not obvious difference;④The soil mulching is beneficial to maintain water balance of seeds, and promote germination. So, the germination rate of Quercus wutaishanica seed under soil mulching was better than under litter coverage.(6)The seeds fate of Quercus wutaishanica under ground-cover had obvious difference.①U nder the soil mulching, the germination rate of Quercus wutaishanica seed can respectively reach 56% and 63.2%.This indicated that the soil mulching was suitable environment to germination of Quercus wutaishanica seed;②T he Quercus wutaishanica seed lost severely under non-cover condition. And even if it was reserved, there were only few seed which would germinate and survive due to decay and died;③Even though under soil mulching, the decay and mortality rate still reached 21.2%.