Abstract. Oceanic islands are cradles of endemism, contributing substantially to global biodiversity. A similarity in magmatic origin translates into high global comparability of substrates of volcanic islands on the oceanic crust. In some places, the petrography of magmatic rocks is differentiated chemically or physically. Phonolites are examples of rare localities with intermediate chemical traits between felsic and mafic and with diverse textures. They contribute to habitat heterogeneity and offer specific growth conditions in a significantly different matrix of basaltic substrates. The explicit contribution of geodiversity to island biodiversity has been little studied, despite accumulating evidence of its importance on continents. On the island of La Palma, Canary Islands, isolated phonolitic rocks are conspicuous by their light colour and specific shape. Although these outcrops only cover small areas, their unique form and composition increase within-island geodiversity. To investigate how this affects biodiversity on La Palma, we sampled all vascular plant species in 120 plots on four sets of paired sites, comparing phonolitic with basaltic rocks, to test whether phonolitic rocks increase overall plant species richness and promote the reproductive fitness of plants. We recorded species number and abundance, individual plant height, and diameter as proxies for aboveground resource allocation and tested for differences in vegetation cover and species composition between the bedrock types. We found higher species richness and abundance on phonolites than neighbouring basaltic substrates, and individuals of the same species were larger (in height and diameter) on phonolites compared to neighbouring basalt. An endemic woody species with two distinct varieties even appears almost exclusively on the small surfaces of phonolitic rock. Despite extremely limited spatial extent, phonolitic rocks can play an important role for plant biodiversity on islands.

中文翻译：

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火山岛上的地球多样性和生物多样性：分散的方沸石对植物多样性和生殖适应性的作用

摘要。海洋岛屿是地方特有的摇篮，为全球生物多样性做出了巨大贡献。岩浆成因的相似性转化为洋壳上火山岛底物的高度全球可比性。在某些地方，岩浆岩的岩石学在化学或物理上是不同的。酚醛石是稀有地区的例子，其化学性质介于长英质和镁铁质之间，质地多样。它们有助于生境异质性，并在玄武质基质的显着不同基质中提供特定的生长条件。尽管有越来越多的证据表明，地球多样性对岛屿生物多样性的明确贡献尚未得到研究。在加那利群岛的拉帕尔玛岛上，孤立的方圆岩以其浅色和特定形状而引人注目。尽管这些露头仅覆盖小片区域，但它们的独特形式和成分增加了岛内的地球多样性。为了调查这如何影响拉帕尔玛岛上的生物多样性，我们在四对配对地点的120个样地中对所有维管植物物种进行了采样，比较了方程式岩和玄武岩，以测试方程式岩是否增加了整体植物物种的丰富度并促进了植物的繁殖能力。我们记录了物种数量和丰富度，单株高度和直径作为地上资源分配的代理，并测试了植被覆盖度和基岩类型之间的物种组成差异。我们发现，与邻近的玄武质底物相比，声石上的物种丰富度和丰度更高，相较于邻近的玄武岩，相同种类的个体在语音上的体积更大（在高度和直径上）。具有两个不同变种的特有木本物种甚至几乎仅出现在回音岩的小表面上。尽管空间范围极为有限，但方解石仍可对岛屿上的植物生物多样性发挥重要作用。