Seed dispersal to revegetated isolated rainforest patches in North Queensland
Seed dispersal to revegetated isolated rainforest patches in North Queensland
复制标题
将种子传播到北昆士兰重新植被的孤立雨林地区
DOI：
10.1016/j.foreco.2004.02.002
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发表时间：
2004
影响因子：
3.7
通讯作者：
J. Wilson
中科院分区：
文献类型：
--
作者：
E. White;N. Tucker;N. Meyers;J. Wilson
植被结构、植物区系和与种子源的距离影响种子向恢复植被的地点的扩散。这项研究调查了距离种子源的距离对种子传播到北昆士兰Atherton Tablelands上的三个恢复雨林地点(都是大约10年生)的影响。这三个地点距离最近的种子来源的距离各不相同，一个毗邻雨林保护区，两个被牧场包围，与最近的雨林相隔600米和2公里。不同地点的植物区系和植被结构(LAI、地面侧向盖度、茎密度和地被物)相似，表明这三个地点同样适合种子传播型动物使用。因此，繁殖扩散到三个地点的差异可能归因于距离种子来源的距离，而不是植被结构。自建立以来的十年里，被飞行动物、地面哺乳动物、风和各种传播剂散布到邻近地点的本土物种的数量远远高于任何一个孤立的地点(密度更高)。这两个与世隔绝的地点比邻近地点的外来新兵水平高得多(这是演替早期阶段的特征)，这是因为这些地点靠近含有外来牧草和杂草的牧场。在每个地点都有极少数被招募的物种极其丰富，而大多数新物种很少，这种模式在遥远的地点尤为明显。由于与种子来源隔绝，与邻近地点相比，这两个与世隔绝的地点招募具有中后期演替阶段的典型物种的速度要慢得多。如果没有人类的种子传播，这些遥远的地点可能不会恢复到自我维持的成熟雨林。特别是分散在哺乳动物中的物种不太可能到达这些地点，除非有人类的贡献。如果热带雨林系统的恢复集中在现有热带雨林的周边，而不是孤立的地区，则恢复可能会更快、更成功。
Vegetation structure, floristics and distance from a seed source influence dispersal of seeds to revegetated sites. This study investigates the effects of distance from a seed source on dispersal of seeds to three restored rainforest sites (all approximately 10 years old) on the Atherton Tablelands, North Queensland. The three sites were located at varying distances from the nearest seed source, one being adjacent to a rainforest reserve and two being surrounded by pasture and isolated from the nearest rainforest by distances of 600m and 2km. Floristics and vegetation structure (LAI, lateral cover at ground level, stem density and groundcover) were similar between sites, suggesting that the three sites would be equally suitable for use by seed-dispersing fauna. Differences in propagule dispersal to the three sites were therefore likely attributable to distance from seed source rather than vegetation structure. Over the decade since establishment a far higher number of native species—dispersed by flying fauna, ground-dwelling mammals, wind and varied dispersal agents—had been recruited (in higher densities) to the adjacent site than to either of the isolated sites. The two isolated sites had far higher levels of exotic recruits (characteristic of early successional stages) than did the adjacent site, owing to the proximity of these sites to pasture containing exotic grasses and forbs. A very small number of recruited species were extremely abundant at each site, while the majority of new species were rare, this pattern being particularly pronounced at the distant sites. Owing to isolation from a seed source, recruitment of species typical of intermediate and late-successional stages is occurring far more slowly at both isolated sites compared with the adjacent site. Recovery of these distant sites to self-sustaining mature rainforest may not occur without human mediated seed dispersal. Mammal-dispersed species in particular are unlikely to reach these sites unless contributed by humans. Recovery of tropical rainforest systems is likely to occur more quickly and be more successful if restoration is concentrated around the perimeter of existing rainforest rather than in isolated patches.