广东南澳岛植被恢复过程中的群落动态研究

COMMUNITY DYNAMICS DURING THE PROCESS OF VEGETATION RESTORATION ON NAN'AO ISLAND, GUANGDONG

以广东南澳岛的 1个草坡、4个人工林和 3个次生林群落为对象 ,采用时空互代的方法 ,将这 8个群落当作植被恢复中的不同阶段 ,研究各群落的群落结构、生物量、叶面积指数和土壤养分等 ,进而研究了南澳岛退化生态系统植被恢复的过程和机理。随着植被的恢复进程 ,群落的阳性种类逐渐减少 ,中生性种类逐渐增加。物种多样性、均匀度、生态优势度和β多样性指数分析表明南澳岛植被恢复过程群落组成结构的复杂性依退化草坡→人工林→次生林逐渐增加。南澳岛退化草坡、10年生人工林、15年生人工林和次生林的生物量分别为 4.81t· hm- 2、45 .18t· hm- 2、10 0 .39t· hm- 2和 88.34 t· hm- 2 ,叶面积指数分别为 1.0 4、3.81、5 .89和 6 .5 2 ,凋落物贮量分别为0 .42 t· hm- 2 、 3.2 0 t· hm- 2 、3.70 t· hm- 2 和 4.90 t· hm- 2 。南澳岛植被恢复过程中土壤有机质、全氮和速效磷和交换性 K含量逐渐增加。由于海岛的生境、大风和暴雨的影响 ,海岛植被恢复的格局不同于大陆 ,而其恢复速度也较慢。根据本研究结果 。

A spatial series representing the temporal sequence of vegetation restoration on Nan'ao island (Guangdong, China) was studied investigating community structure, leaf area index (LAI), biomass, and soil fertility in eight communities in an examination of the process of vegetation restoration on the island. The species richness of the communities in the spatial series proceeded from degraded grassland through artificial forests to secondary forests. The number of the heliophytes in the communities decreased gradually, while mesophytes increased with the process of vegetation restoration. The biomass of degraded grassland, ten year old artificial forest, fifteen year old artificial forest and secondary forests were 4.8 t·hm -2 , 45 t·hm -2 , 100 t·hm -2 and 88 t·hm -2 , respectively, while the LAI of this sequence was 1.04, 3.81, 5.89 and 6.52. The quantity of stand litter also increased as 0.42 t·hm -2 , 3.20 t·hm -2 , 3.70 t·hm -2 and 4.90 t·hm -2 , respectively. The soil organic matter, total N, available P and exchangeable K were gradually increasing during the process of vegetation restoration. This vegetation restoration pattern was different from that of the mainland due to varying ecological habitat of the island, windiness and storm impact on the island. Most notable was the slower speed of vegetation restoration on the island relative to mainland. In this and similar environments secondary forests represent the pool of species diversity and are very important for sustaining the biodiversity of the island. The paper presents a rational plan for vegetation restoration on the island.