Impact of pine invasion on the taxonomic and phylogenetic diversity of a relict Mediterranean forest ecosystem

FOREST ECOLOGY AND MANAGEMENT

卷:367

Article

Selvi, Federico¹  Carrari, Elisa¹  Coppi, Andrea² 

[1] Univ Florence, Dept AgriFood Prod & Environm Sci, Labs Appl & Environm Bot, Ple Cascine 28, I-50144 Florence, Italy

[2] Univ Firenze, Dept Biol, Bot Labs, Via G La Pira 4, I-50121 Florence, Italy

关键词: Invasive species;    Mediterranean forests;    Pine tree;    Phylogenetic diversity;    Soil acidification;    Species richness;   

DOI  :  10.1016/j.foreco.2016.02.013

来源: Elsevier

【 摘 要 】

Invasion by non-native tree species is a major driver of reduction and fragmentation of forest ecosystems, also altering biodiversity components. However, the effects of this process on the phylogenetic structure and diversity of Mediterranean woodlands are still unknown. Accordingly, we used cork oak (Quercus suber) stands invaded by self-sowing populations of maritime pine locally introduced ca. 70 years ago as a model system to assess the impact on the taxonomic and phylogenetic diversity of the native seed plant community. We performed vegetation sampling of the two forest types in sites of central Italy with similar conditions. Taxonomic diversity was negatively affected by the pine at three levels (gamma, alpha, beta). Indicator species were significantly less numerous than in cork oak stands, and did not include two growth-forms such as herbs and vines. Phylogenetic diversity metrics were inferred from an evolutionary tree of seed plants based on a ITS-5.8S nuclear DNA dataset including original sequences from local plant material. Phylogenetic diversity (PD) was positively related to species and genus richness, showing a marked decrease in the pine stands. Seven major clades (orders) of angiosperm dicots were only represented in the cork oak community. Both the NRI and NTI indices showed a significant reduction of phylogenetic evenness in the pine forest. Here, the proportional increase of related taxa with acid-tolerance specialization suggests that soil acidification is a major driver for a habitat filtering effect causing the exclusion of several understorey species and genera of cork oak forests. Progressive thinning of the pine stands is advocated to avoid further acidification and promote the re-conversion to oak woodlands by natural regeneration. This will ultimately favor the recovery of the associated plant diversity and the restoration of a vanishing forest ecosystem of the ancient Mediterranean landscape. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

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