Macrophyte invasive alien species (IAS) fitness is often hypothesised to be associated with beneficial environmental conditions (environmental matching) or species-poor communities. However, positive correlations between macrophyte IAS abundance and native plant richness can also arise, due to habitat heterogeneity (defined here as variation in abiotic and native biotic conditions over space and time). We analysed survey and palaeoecological data for macrophytes in satellite lakes along the Upper Lough Erne (ULE) system (Northern Ireland, UK), covering a gradient of eutrophication and connectivity to partition how environmental conditions, macrophyte diversity and habitat heterogeneity explained the abundance of Elodea canadensis, a widely distributed non-native macrophyte in Europe. E. canadensis abundance positively correlated with macrophyte richness at both the within- and between-lake scales indicating coexistence of native and invasive species over time. E. canadensis was also more prolific in highly connected and macrophyte-rich lakes, but sparser in the more eutrophic-isolated ones. Partial boosted regression trees revealed that in eutrophic-isolated lakes, E. canadensis abundances correlated with water clarity (negatively), plant diversity (positively), and plant cover (negatively) whereas in diverse-connected lakes, beta diversity (both positively and negatively) related to most greatly E. canadensis abundance. Dense macrophyte cover and unfavourable environmental conditions thus appear to confer invasibility resistance and sufficient habitat heterogeneity to mask any single effect of native biodiversity or environmental matching in controlling E. canadensis abundance. Therefore, in shallow lake landscapes, habitat heterogeneity variously enables the coexistence of native macrophytes and E. canadensis, reducing the often-described homogenisation effects of invasive macrophytes.

中文翻译：

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栖息地异质性使浅湖景观中原生和入侵大型植物的空间和时间共存

大型植物外来入侵物种 (IAS) 适应性通常被假设与有益的环境条件（环境匹配）或物种贫乏的群落有关。然而，由于栖息地异质性（此处定义为非生物和天然生物条件随空间和时间的变化），大型植物 IAS 丰度与本地植物丰富度之间也可能出现正相关。我们分析了厄恩湖上游 (ULE) 系统（英国北爱尔兰）沿线卫星湖泊中大型植物的调查和古生态数据，涵盖了富营养化梯度和连通性，以划分环境条件、大型植物多样性和栖息地异质性如何解释伊洛狄亚的丰度canadensis，一种在欧洲广泛分布的非本土大型植物。加拿大大肠杆菌丰度与湖内和湖间尺度的大型植物丰富度呈正相关，表明随着时间的推移本地和入侵物种共存。E. canadensis在高度连通和大型植物丰富的湖泊中也较多产，但在富营养化程度较高的孤立湖泊中较少。部分增强回归树显示，在富营养化孤立的湖泊中，加拿大桉树的丰度与水的透明度（负）、植物多样性（正）和植物覆盖（负）相关，而在多样化连接的湖泊中，β 多样性（正和负） ) 与最大的E. canadensis相关丰富。因此，密集的大型植物覆盖和不利的环境条件似乎赋予了抗入侵性和足够的栖息地异质性，以掩盖本地生物多样性或环境匹配在控制E. canadensis丰度方面的任何单一影响。因此，在浅湖景观中，栖息地异质性不同地使本地大型植物和加拿大 E. canadensis共存，减少了入侵大型植物经常描述的均质化效应。