科尔沁沙地刺榆局域成林机制

刺榆(Hemiptelea davidii)林是科尔沁沙地独特的森林类型,以往尚无文献记载.通过对林缘和林下种子散布及幼苗分布特征的样线断面取样、果实形态及脱落特性的调查,分析了刺榆林地更新与扩展的生物学和生态学机理.结果表明,刺榆林的种子多数沉降在林下和林缘附近,林缘3 m以外显著减少.在郁闭度较大的林分内,刺榆种群主要以根蘖苗补充更新.实生苗不受地形的限制,林地主要是以实生苗扩展空间.提出果实形态及脱落特性是刺榆在科尔沁沙地局域能形成优势种林,而在其他地理分布区仅为伴生种的生物学根源.

Local formation mechanisms of Hemiptelea davidii forest in Keerqin Sandy Land of North China

Hemiptelea davidii forest is a peculiar forest type in Keerqin Sandy Land not recorded in references so far.Aimed to understand the biological and ecological mechanisms of the regeneration and expansion of H.davidii,a sampling line transect survey was conducted on the seed dispersal and seedling recruitment of H.davidii in its forest edges and forest understory,and an observation was made on the fruit shape and fruit-shedding characteristics of the plant.A majority of H.davidii seeds were found in the under...