The role of phylogenetic scale in Darwin's naturalization conundrum in the critically imperilled pine rockland ecosystem

Abstract

Aim We expand on community phylogenetic approaches to Darwin's Naturalization Conundrum by considering phylogenetic scale, comprised of phylogenetic grain and extent. We assess relatedness between invasive, non‐native and native plant species at multiple depths in the phylogeny (i.e. phylogenetic grain) and across multiple clades (i.e. phylogenetic extents) at regional and local spatial scales in the highly fragmented, critically imperilled pine rockland ecosystem. Location Miami‐Dade County, Florida, USA. Methods We used two metrics differing in phylogenetic grain to determine whether invasive or non‐native species were more closely related to native species in the regional pool and at 33 habitat fragments. At both spatial scales, we altered phylogenetic extent from all vascular plants to four smaller phylogenetic domains (Monilophyte, Gymnosperm, Monocotyledon and Dicotyledon) and assessed whether the interpretation of relatedness changed. Results For the regional pool and at a broad phylogenetic grain, non‐native species were more closely related to the native community than invasive species were for all phylogenetic extents (i.e. support for Darwin's Naturalization Hypothesis, DNH), and at a fine phylogenetic grain for only two phylogenetic extents. At the local scale, there was limited support for DNH across all phylogenetic extents. In Monocotyledons, support for DNH was more prevalent at the fine phylogenetic grain, while Dicotyledons showed support for DNH at the broad phylogenetic grain. Main conclusions In the pine rockland flora, we found either support for DNH or no difference in relatedness between non‐native‐to‐native and invasive‐to‐native species. However, patterns of relatedness varied across spatial and phylogenetic grain and, critically, this variability is highly dependent on the phylogenetic extent considered. By explicitly assessing the interactions between spatial scale and phylogenetic scale, we show that support for DNH was context dependent, and findings at smaller phylogenetic extents rarely agreed with findings at the larger phylogenic extent.

Patterns of Non-Native Species Introduction, Spread, and Ecological Impact in South Florida, the World's Most Invaded Continental Ecoregion

“…There is also strong evidence that human disturbance has created even more open niche space, as across taxonomic groups non-natives achieve higher biodiversity in urban environments than in the Everglades (Clements et al 2019, Hill & Yanong 2002, Howell et al 2021. There are also multiple lines of evidence that non-native species more dissimilar to the native community are more likely to establish and spread, again arguing for the importance of occupying an open niche and thereby minimizing biotic competition (Allen 2006, Trotta et al 2021, Van Wilgen & Richardson 2011. Among South Florida's numerous non-natives, those with the greatest ecological impact tend to either be relatively large-bodied generalist predators, a pattern seen in both terrestrial [e.g., Burmese python, feral cats (Dorcas et al 2012, Forys & Humphrey 1999] and aquatic environments [e.g., Asian swamp eel, Mayan cichlid (Pintar et al 2023, Trexler et al 2000], or plants that are able to reach incredible densities, thereby altering the physical environment [e.g., Australian pine, Paperbark melaleuca (Mazzotti et al 1981].…”

“…Among reptiles, establishment success increases with mean phylogenetic distance to the native community (Van Wilgen & Richardson 2012). Among Pine Rocklands plants, the plant community originally found in much of what is now urban Miami, mean phylogenetic distance to the native community was positively associated with proclivity of non-native species to spread from their point of introduction (Trotta et al 2021). Thus, all results, except for phylogenetic distance in birds, favor Darwin's naturalization hypothesis, indicating that biotic interactions, specifically minimizing interspecific competition, are more important for facilitating non-native species establishment and spread than is abiotic filtering.…”

Darwin’s naturalization conundrum: an unsolved paradox in invasion ecology

“…Park等人 [46] 在小尺度(样方尺 度)和大尺度(县级尺度)研究了美国外来和本地植物的 亲缘关系, 发现随着空间尺度增加, 外来种和本地种的 亲缘距离显著减小, 因此在大尺度上更符合预适应假 说的预测. 然而, 也有研究发现相反的结果, 即小尺度 研究结果更符合预适应假说 [34,47] , 而大尺度研究结果 更符合达尔文归化假说, 甚至发现随着空间尺度增加, 外来种和本地种的谱系距离逐渐增加 [16,48,49] . 因此, 空…”

Both source‐ and recipient‐range phylogenetic community structure can predict the outcome of avian introductions

“…To date, studies using patterns of relatedness to understand introduction success have overwhelmingly focused on testing the environmental filtering and competition‐relatedness hypotheses (reviewed in Ma et al 2016, Cadotte et al 2018), with very few tests of the evolutionary imbalance, competitive‐constraint or universal trade‐off hypotheses (reviewed in Maitner et al 2021a). Support for the environmental filtering vs competition‐relatedness hypotheses has been mixed, with some supporting the environmental filtering hypothesis (Maitner et al 2012, Park and Potter 2015a, Marx et al 2016, Pinto‐Ledezma et al 2020, Trotta et al 2021), some supporting competition‐relatedness hypothesis (Darwin 1859, Strauss et al 2006, van Wilgen and Richardson 2012, Levin et al 2020), others supporting scale dependence (Ma et al 2016, Park et al 2020) and still others supporting neither hypothesis (Ricciardi and Mottiar 2006). Studies of the three source‐range hypotheses have been very limited, with Fridley and Sax (2014) showing that asymmetries in species exchanges across canals can be predicted by the phylogenetic diversity of their source regions, as predicted by the evolutionary imbalance hypothesis and other studies documenting asymmetric species between regions as predicted by the evolutionary imbalance and competitive‐constraint hypotheses (Kalusova et al 2015, Mason Heberling et al 2017).…”