CAJ | 학술논문

在广西靖西土石山生态交错区调查了西南桦(Betula alnoides)生殖植株的生长状况,并研究土山和石山两种生境条件下西南桦的生殖构件及其在冠层的分布格局.结果表明:石山西南桦开始开花结实的林木胸径明显小于土山;两种立地上西南桦植株的花芽、花序数以及雄花序比率与其胸径、树高均不显著相关(P>0.05);土山和石山的西南桦雄花序数随着总花序数的增加均呈对数曲线增长趋势,在生殖投资较小的情况下植株趋向于优先发育雄花序,而在生殖投资较大时主要增加雌花序的数量;西南桦生殖构件在两种生境间存在显著差异,石山植株的雄花芽数、每个雄发芽发育出的雄花序数均显著低于土山(P<0.05),雄花序少于雌花序的植株比例远高于土山,生殖枝比率亦显著低于土山(P<0.05);尽管石山雄花序、雌花序和总花序数量以及雄花序比率低于土山,其雌花序比率高于土山,但是由于两种立地上单株间变异幅度大,独立t检验表明其差异均未达到显著水平;两种立地上西南桦花序大多着生于树冠上、中层,且90%以上的生殖枝居于树冠外层.
재엄서정서토석산생태교착구조사료서남화(Betula alnoides)생식식주적생장상황,병연구토산화석산량충생경조건하서남화적생식구건급기재관층적분포격국.결과표명:석산서남화개시개화결실적림목흉경명현소우토산;량충입지상서남화식주적화아、화서수이급웅화서비솔여기흉경、수고균불현저상관(P>0.05);토산화석산적서남화웅화서수수착총화서수적증가균정대수곡선증장추세,재생식투자교소적정황하식주추향우우선발육웅화서,이재생식투자교대시주요증가자화서적수량;서남화생식구건재량충생경간존재현저차이,석산식주적웅화아수、매개웅발아발육출적웅화서수균현저저우토산(P<0.05),웅화서소우자화서적식주비례원고우토산,생식지비솔역현저저우토산(P<0.05);진관석산웅화서、자화서화총화서수량이급웅화서비솔저우토산,기자화서비솔고우토산,단시유우량충입지상단주간변이폭도대,독립t검험표명기차이균미체도현저수평;량충입지상서남화화서대다착생우수관상、중층,차90%이상적생식지거우수관외층.
Growth status of reproductive individuals of Betula alnoides were investigated in an ecological ectone of two types of soils originated from limestone (site L) and granite (site G), respectively, at Jingxi County, Guangxi, and the relationships between reproductive modules and their allocation patterns in crown layer were discussed.The results showed that the diameter at breast height (DBH) in site L were remarkably smaller than that in site G, when plants started flowering and fruit setting.The number of flower buds, total number of inflorescences and ratio of male inflorescences were not significantly correlated with DEH and plant height (P>0.05).The number of male inflorescences increased with increment of total number of inflorescences by logarithm curve, and the trees trended to develop male inflorescences under lower reproductive investment, while mainly develop female inflorescences under larger reproductive investment.There were remarkable differences in characteristics of reproductive module between both sites, the number of male buds and number of inflorescenees developed from each male bud at site L was significantly lower than that in site G (P <0.05), the ratio of the plants with male inflorescences less than female ones was much higher than that at site G, and the ratio of reproductive branches was also significantly lower than that at site G (P<0.05).Although the number of male inflorescences, female inflorescences, total inflorescences and ratio of male inflorescences at site L were smaller than those at site G, and ratio of female inflorescences at site L was larger than that at site G, there were no significant difference between them (P>0.05) due to high level of variation among individuals at each site.The majority of inflorescences were on upper and middle layers of crown, and above 90% of reproductive branches occupied on the surface of crown at both sites.