Contrasting Impacts of Cultivated Exotics on the Functional Diversity of Domestic Gardens in Three Regions with Different Aridity
Contrasting Impacts of Cultivated Exotics on the Functional Diversity of Domestic Gardens in Three Regions with Different Aridity
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DOI：
10.1007/s10021-020-00556-x
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发表时间：
2020-09-19
期刊：
影响因子：
3.7
通讯作者：
Swan, Christopher
中科院分区：
文献类型：
--
作者：
Padulles Cubino, Josep;Borowy, Dorothy;Swan, Christopher
栽培的外来植物通常因其美学价值而被引入，并且今天包括城市家庭花园的植物群的相当大的一部分。然而，它们对家庭花园功能多样性的相对贡献以及它在不同气候区的变化方式还没有得到充分的了解。在这里，我们调查了是否种植外来植物的功能多样性的植物美学（即，植物艳丽，株高和叶面积）相关的三个植物性状的影响不同的郊区家庭花园在三个地区（明尼苏达州，美国; Alt Emporda，西班牙;和南非中部），不同的干旱。对于每个花园，我们计算了每个植物性状的平均值和方差，考虑到所有共同出现的物种，并将它们分为共同出现的栽培外来种和本地种。我们的研究结果表明，平均植物艳丽的比例呈线性增加的栽培外来跨和研究区域内。此外，共同发生的栽培异国情调，平均而言，比本地人在所有地区，但在他们的性状差异的差异是上下文相关的。栽培外来种和干旱之间的相互作用解释的平均株高和叶面积的变化比单独的预测，栽培外来种的影响更强，在更干旱的地区。因此，在温暖和干燥的地区，共同发生的栽培外来种比本地人更高，叶子更大，而在凉爽和潮湿的地区，情况正好相反。我们的研究强调了在未来的城市生态学研究中需要考虑外来物种和气候的综合影响。
Cultivated exotic plants are often introduced for their aesthetic value and today comprise a substantial fraction of the flora of urban domestic gardens. Yet, their relative contribution to the functional diversity of domestic gardens and how it changes across different climate zones is insufficiently understood. Here, we investigated whether the effects of cultivated exotics on functional diversity of three plant traits related to plant aesthetics (that is, plant showiness, plant height, and leaf area) varied in suburban domestic gardens in three regions (Minnesota, USA; Alt Emporda, Spain; and central South Africa) that differ in aridity. For each garden, we calculated the mean and variance of each plant trait considering all co-occurring species and also splitting them into co-occurring cultivated exotics and natives. Our results revealed that mean plant showiness increased linearly with the proportion of cultivated exotics both across and within studied regions. Moreover, co-occurring cultivated exotics were, on average, showier than natives in all regions, but differences in their trait variances were context-dependent. The interaction between cultivated exotics and aridity explained variation in mean plant height and leaf area better than either predictor alone, with the effect of cultivated exotics being stronger in more arid regions. Accordingly, co-occurring cultivated exotics were taller and had larger leaves than natives in warmer and drier regions, while the opposite was true in cooler and wetter regions. Our study highlights the need to consider the combined effects of exotic species and climate in future studies of urban ecology.