Spatiotemporal patterns of seed dispersal in a wind-dispersed Mediterranean tree (Acer opalus subsp. granatense): implications for regeneration
Spatiotemporal patterns of seed dispersal in a wind-dispersed Mediterranean tree (Acer opalus subsp. granatense): implications for regeneration
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DOI：
10.1111/j.0906-7590.2007.04658.x
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发表时间：
2007-02
期刊：
影响因子：
5.9
通讯作者：
L. Gómez‐Aparicio;J. Gómez;R. Zamora
中科院分区：
文献类型：
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作者：
L. Gómez‐Aparicio;J. Gómez;R. Zamora
种子传播严重限制了植物补充的数量和空间分布。然而，我们的理解是有限的，缺乏知识的空间和时间的种子沉积模式的更新动力学中的扩散的作用。在本文中，我们分析了种子传播模式的时空变异在地中海枫树，槭opalus subsp。granatense，通过监测种子雨沿着两年在广泛的空间尺度（2个山脉，2个种群，4个微生境每个种群）。我们量化的种子限制和它的组成部分（源和扩散限制），并探讨在空间上的扩散限制，通过分析扩散距离，种子聚集，和微生境种子分布。乳白槭granatense是强烈的种子限制在整个梯度探索，总是远高于源限制的扩散限制。种子与成年个体的距离的分布是leptokurtic和右偏在所有人群中，都是峰度和偏度较高的一年的最高种子产量。在四个种群中，扩散距离均短于随机预期，这表明距离有限的扩散。扩散模式高度聚集，并表现出优先方向周围的成年人。在微生境尺度上，大多数种子积累在成年枫树下。然而，有没有更多的种子下的树木和灌木比其他枫树在开放的间隙，这意味着建立植被不会破坏物理捕获种子的种子沉积模式。与幼苗建立模式相比，有限的传播能力和年际空间一致性的种子雨模式表明，几个潜在的安全网站招聘有一个非常低的概率在大多数枫树种群接收种子。这些发现与稀有物种特别相关，例如蛋白石槭亚种。granatense，并说明如何扩散的研究不仅是至关重要的，我们了解植物种群动态，但也提供保护方向。
Seed dispersal can severely limit the quantity of plant recruits and their spatial distribution. However, our understanding of the role of dispersal in regeneration dynamics is limited by the lack of knowledge of seed deposition patterns in space and time. In this paper, we analyse the spatiotemporal variability of seed dispersal patterns in the Mediterranean maple, Acer opalus subsp. granatense, by monitoring seed rain along two years at a broad spatial scale (2 mountain ranges, 2 populations per range, 4 microhabitats per population). We quantified seed limitation and its components (source and dispersal limitation), and explored dispersal limitation in space by analysing dispersal distances, seed aggregation, and microhabitat seed distribution. Acer opalus subsp. granatense was strongly seed-limited throughout the gradients explored, being always dispersal limitation much higher than source limitation. The distribution of seeds with distance from adult individuals was leptokurtic and right-skewed in all populations, being both kurtosis and skewness higher the year of the highest seed production. Dispersal distances were shorter than expected by random in the four populations, which suggests distance-limited dispersal. Dispersal patterns were highly aggregated and showed a preferential direction around adults. At the microhabitat scale, most seeds accumulated under adult maples. However, there were no more seeds under trees and shrubs other than maple than in open interspaces, implying that established vegetation does not disrupt patterns of seed deposition by physically trapping seeds. When compared with patterns of seedling establishment, limited dispersal ability and inter-annual spatial concordance in seed rain patterns suggest that several potentially safe sites for recruitment have a very low probability of receiving seeds in most maple populations. These findings are especially relevant for rare species such as Acer opalus subsp. granatense, and illustrate how dispersal studies are not only crucial for our understanding of plant population dynamics but also to provide conservation directions.