机构地区:[1]西北农林科技大学林学院,杨凌712100 [2]西北农林科技大学西部环境与生态教育部重点实验室,杨凌712100
出 处:《生态学报》2010年第23期6512-6520,共9页Acta Ecologica Sinica
基 金:国家自然科学基金项目(30872018);陕西省科学技术研究发展重点基础研究项目(2009JZ005);国家林业局国家级重大林业科学技术推广项目(2009)
摘 要:栓皮栎(Quercus variabilis)是中国暖温带和亚热带林区的主要建群种,也是重要的栲胶、软木资源树种。为了阐明栓皮栎在不同生境条件下的种子成苗、实生苗生长及其与环境因素的关系,采用典型样地调查的方法,对秦岭北坡栓皮栎林3种生境中(林窗、林缘、林下)的栓皮栎种子库中种子数量、实生苗的存活数量、生长情况及生物量分配进行了研究,对影响实生苗生长发育的环境因素进行了相关分析。结果表明:林下、林窗和林缘的种子库中种子数量差异显著(P<0.05),3种生境中能够萌发形成1a苗的种子数量少,种子能否萌发明显受枯枝落叶层厚度、光照强度和空气湿度的影响;栓皮栎种群有充足的苗库,其中较大年龄实生苗数量是种群能否持续更新的关键,林下、林窗和林缘中8a苗分别占该年龄实生苗总量的22.53%、45.60%和31.87%,林窗中较大年龄实生苗的数量比林下和林缘多,林窗为栓皮栎实生苗的定居提供了有利条件;栓皮栎实生苗的生长与光照强度和空气温度显著正相关,与土壤含水量显著负相关,林窗中实生苗的生长状况和生物量积累均优于林缘、林下。林窗对栓皮栎种群更新有利。在今后的栓皮栎林的经营过程中,可以适当间伐,增加林窗数量,为种群可持续发育提供有利条件。Quercus variabilis distributed widely in the warm temperate and the subtropical area of China is not only an important constructive species of local forest but also a resource for tannin extracts and cork production.In order to understand the characteristics of seed bank,seed germination,seedling development and their influencing factors,15 sampling plots belonging to 3 classes of habitats(understory,forest gap and forest edge) in Q.variabilis forests on the north slopes of Qinling Mountains where was the core distribution area of this species were studied.The number of Q.variabilis seeds in soil seed bank was investigated in 2008,the age structure,survival number of young seedlings,and the growth and biomass in relation to age development were investigated during the following year.Meanwhile,7 environmental factors which might affect the germination of seeds and the growth of seedlings were also measured and analyzed.The main results were as follows:The number of intact seeds in seed banks,being different significantly(P 0.05),were 3.60 × 103,1.94 × 103 and 2.80 × 103 per 100 m2 respectively among plots for understory,forest gap and forest edge.They were resulted from that the processes of remove and predation,mildewing and immaturity affected the number of seeds to different extent among the 3 kinds of habitats.While remove and predation were the main way for the loss of seeds in the 3 kinds of habitats.Few seeds were able to germinate and develop to one-year-old seedlings,and the germinating process was observably influenced by the thickness of litter,radiation condition and air humidity according to the result of the correlation analysis.Q.variabilis population had plenty of young seedlings,however,the number of seedlings decreased dramatically with the age increase.The elder seedlings might play a key role in sustained regeneration of the population.The eight-yearold seedlings in understory,forest gap and forest edge accounted for 22.53%,45.60% and 31.87% of the total number of the seedlings res
分 类 号:S792.18[农业科学—林木遗传育种]
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