Huang Hong-Lan, Zhang Lu, Liao Cheng-Kai
College of Landscape and Art, Jiangxi Agricultural University, Nanchang 330045, China.
Ying Yong Sheng Tai Xue Bao. 2012 Apr;23(4):972-8.
Taking the natural Toona ciliata var. pubescens forest in the Jiujiangshan National Nature Reserve in Jiangxi Province of China as test object, an investigation was conducted on the seed rain, soil seed bank, and seedlings number in 2008-2011. The seed rain of the forest was dispersed from late October to the end of December. In 2010, the seed rain intensity in different sampling plots was in the order of Xiagongtang observatory (320.3 +/- 23.5 seeds x m(-2)) > Xiagongtang protection station (284.7 +/- 24.2 seeds x m(-2)) > Daqiutian protection station (251.6 +/- 24.7 seeds x m(-2)), and the quantity of the intact seeds in soil supplied for seed germination and regeneration was 222.0, 34.3, and 22.6 seeds x m(-2), respectively. The seed bank reserves was affected by the seed production amount, bird feeding, and seed viability, etc., of which, bird feeding was the prime factor for the substantial drop of the seed bank reserves. Due to the low resistance against storage and a large number of rot during storage, the seeds in soil could hardly be effectively stored beyond one month. The seedlings germinated in December were averagely less than 2 stands x m(-2), and the soil seed reserves in the next January was the least (6.7-11.8 seeds x m(-2)), with the germinated seedlings averagely 0.4-0.6 stands x m(-2), which was consistent with the rare distribution of natural seedlings in the forest. It was concluded that the small seed rain reserves, low seed vigor of soil seed bank, and low seedling establishment were the important factors impacting the natural regeneration of T. ciliata var. pubescens.
以中国江西省九江山国家级自然保护区的天然红椿林为试验对象,于2008 - 2011年对其种子雨、土壤种子库及幼苗数量进行了调查。该林分种子雨从10月下旬开始散落,至12月底结束。2010年,不同样地的种子雨强度表现为:下宫塘观测点(320.3±23.5粒·m⁻²)>下宫塘保护站(284.7±24.2粒·m⁻²)>大丘田保护站(251.6±24.7粒·m⁻²),而土壤中可供种子萌发和更新的完好种子数量分别为222.0、34.3和22.6粒·m⁻²。种子库储量受种子产量、鸟类取食及种子活力等因素影响,其中鸟类取食是导致种子库储量大幅下降的主要因素。由于种子耐贮藏性差,贮藏期间大量腐烂,土壤中的种子很难有效贮藏超过1个月。12月萌发的幼苗平均每平方米不足2株,次年1月土壤种子储量最少(6.7 - 11.8粒·m⁻²),萌发幼苗平均每平方米0.4 - 0.6株,这与该林分天然幼苗分布稀少的情况相符。研究得出结论,种子雨储量小、土壤种子库种子活力低以及幼苗建成率低是影响红椿天然更新的重要因素。