植物生态学报 ›› 2012, Vol. 36 ›› Issue (8): 717-718.DOI: 10.3724/SP.J.1258.2012.00717

• 研究论文 • 上一篇    下一篇

浙江古田山自然保护区常绿阔叶林种子雨的时空变异

杜彦君, 马克平*()   

  1. 中国科学院植物研究所植被与环境变化国家重点实验室, 北京 100093
  • 收稿日期:2012-01-28 接受日期:2012-06-28 出版日期:2012-01-28 发布日期:2012-08-21
  • 通讯作者: 马克平
  • 作者简介:* (E-mail: kpma@ibcas.ac.cn)

Temporal and spatial variation of seedfall in a broad-leaved evergreen forest in Gutianshan Nature Reserve of Zhejiang Province, China

DU Yan-Jun, MA Ke-Ping*()   

  1. State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
  • Received:2012-01-28 Accepted:2012-06-28 Online:2012-01-28 Published:2012-08-21
  • Contact: MA Ke-Ping

摘要:

木本植物种子产量的时间和空间变化格局对植物更新以及群落组成和结构有着重要影响, 是种子雨研究的一个重要方面。2006年6月在古田山亚热带常绿阔叶林24 hm2样地布置了130个面积为0.5 m2的种子雨收集器, 每周收集一次。利用4年的种子雨数据, 研究了种子雨的时间和空间变异。主要结果如下: (1)共收集到124227粒成熟种子, 属于29科51属63种, 每月降水量与平均每月种子数、物种数均呈显著负相关; (2)种子产量在每年干季(秋季)有明显的高峰, 有10个物种在湿季扩散种子, 不同物种结实物候起始和终止时间有差异; (3)基于4年的种子雨数据, 几乎所有物种的种子雨均存在很大的年际变异, 收集到的所有物种的种子产量年际变异系数的中位数为1.72; (4)种子雨在不同收集器之间有很大的变异, 变异系数的中位数为8.06; 几乎所有物种的空间变异都远远大于时间变异, 这可能是由于母树的稀有性、种子传播距离的差异, 以及地形等因素造成。通过与巴拿马Barro Colorado Island 50 hm 2样地108个物种种子产量的年际变异系数相比较, 古田山种子雨数据支持了高纬度地区种子产量变异高于低纬度地区的假说。

关键词: 年际变异, 季节变异, 种子产量, 空间变异, 亚热带树种

Abstract:

Aims Seedfall of woody plants often fluctuates considerably from year to year and from site to site. These variations may have strong effects not only on the recruitment of the plant populations themselves, but also on the community composition and structure. Our objective was to elucidate seasonal, annual and spatial variations of seedfall in broad-leaved evergreen forest in Gutianshan Nature Reserve of Zhejiang Province over four years.
Methods Seed rain was censused weekly since June 2006, using 130 seed traps set along 2.3 km of trails within the Gutianshan 24 hm2 subtropical evergreen forest plot. Each seed trap consisted of a square, 0.5 m2 Poly Vinyl Chloride (PVC) frame supporting a shallow, open-topped, 1-mm nylon mesh bag suspended 0.8 m above the ground. Because of heavy snowfall in February 2008, seed traps were damaged, and all seed traps were reset. Therefore, seed rain data were absent from February to April 2008. We summarized four years of seed rain data from June 2006 to August 2010.
Important findings There were a total of 124 227 seeds over the four years, belonging to 63 species, 51 genera and 29 families, and the Pearson correlation between adult tree basal area and seed production was significant. There was a marked peak in the number of seeds and species in each year in the dry season (autumn), but there were also ten species that dispersed their seeds in the wet season. Different species had different fruiting dates. Based on four years of seed rain data, annual variation in seedfall (CVyears) on Gutianshan was substantial (CVyears > 75% for almost all species), and the median coefficient of variation of annual seedfall was 1.72. Spatial variation was also great, and the median coefficient of spatial variation in seedfall among traps was 8.06. Spatial variation in seedfall density was greater than annual variation for almost all species. The rarity of seed-bearing adults, variation in seed deposition with distance, and different topography might be the most important sources of this spatial variation. Comparing with Barro Colorado Island tropical forest seed rain, Gutianshan data supported the hypothesis that annual variation in seedfall is lower in the tropics than at higher latitudes.

Key words: annual variation, seasonal variation, seed production, spatial variation, subtropical trees