人工埋藏植物种子对鼠类采食下辽东栎坚果存活及萌发率的影响(英文)

EFFECT OF BURIAL ON ACORN SURVIVAL AND SEEDLING RECRUITMENT OF LIAODONG OAK (QUERCUS LIAOTUNGENSIS) UNDER RODENT PREDATION

辽东栎林 (Q liaotungensis)是北京东灵山地区典型地带植被。过去研究表明 ,鼠类对辽东栎更新有很大影响。本研究主要调查 3个问题 :( 1)采食辽东栎坚果的鼠类种类 ;( 2 )将坚果埋藏于土中能否减少鼠类对坚果的采食 ,并提高出苗率 ?( 3)地表植被是否影响辽东栎的出苗率 ?1996年 9月在北京东灵山地区山地选取 5个类型的样地 37块 ,每样地在地表放置 10粒坚果 ,检查地表种子消失率。使用木板夹来调查采食坚果的鼠类种类 ,诱饵分别为坚果和花生米。于 1997年 10月 ,选取 5块样地 ,间隔 2 5m ,每样地在 1m2 范围内埋 50粒坚果 ,深度 5cm ,次年 5月调查出苗情况。研究结果表明 ,大林姬鼠、社鼠和黑线姬鼠为取食坚果的主要种类 ,取食比例与其丰富度有关。 370粒坚果放在地表后 ,1d、 10d、 2 0d的消失率分别达 15 1%、 78 1%、和 10 0 %。2 50粒坚果埋入土层后 ,出苗率达11 2 % ,苗平均高度为 7 8cm ,出苗率与地表植被盖度有一定负相关。本研究认为 ,人工埋藏植物种子可以减少鼠类捕食坚果 ,并能增加其出苗率。

Liaodong oak (Q. liaotungensis) forest is the zonal typicalvegetation in maintains of Beijing, China. Prior observation indicated that rodents might be involved in acorn predation and then affected oak regeneration. This study aims to investigate three questions: (1) what kind of rodent species attributed acorn disappearance of Liaodong oak(2) can burial reduce acorn predation by rodents and improve seedling recruitment of Liaodong oak(3) will ground vegetation affect seedling recruitment rate of the oakIn September of 1996, 37 plots of 5 sites were located for acorn placement test. Ten acorns were placed on the soil surface of each plot. Acorns on soil surface were checked 1,10, 20 days later after acorn placement. Wooden snare traps baited with oak acorns and peanuts were used for identifying key rodent species of removing the acorns. Five sites were located for burying 50 acorns at 5 cm in soil within one square meters at each site. Seedling numbers and seedling height were measured next year. Three rodent species (i.e. Apodemus speciosus, Rattus confucian and A. agrarius) were found to consume the acorns, and the proportion of acorn consumed was related to their abundance. Among the 370 acorns which were placed on soil surface in 37 plots of 5 sites, 15.1% of them disappeared next day, 78.1% disappeared 10 days later and all of them disappeared 20 days later. Among 250 acorns buried in five sites, 11.2% of them sprouted out with an average height of 7.8 cm. Therefore, burial can effectively reduce acorn predation by rodents. The seedling recruitment rates in five sites tended to negatively correlate with grass cover and height. It was suggested that direct seeding can facilitate oak reforestation.