Yi-Yi Meng1,2, Wei Xiang1, Yin Wen3, Dong-Liu Huang1, Kun-Fang Cao1, Shi-Dan Zhu1. 1. State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Forest Ecology and Conservation, Guangxi University, Nanning, China. 2. Nanning Qingxiushan Tourism Development Co., Ltd, Nanning Botanical Garden, Nanning, China. 3. Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.
Abstract
BACKGROUND AND AIMS: We conducted a comprehensive analysis of the functional traits of leaves (leaflets) of cycads. The aim of this study was to clarify the functional divergence between the earlier origin Cycadaceae and the later differentiated Zamiaceae, and the differences in trait associations between cycads and angiosperms. METHODS: We selected 20 Cycadaceae species and 21 Zamiaceae species from the same cycad garden in South China, and measured their leaf structure, economic traits, mechanical resistance (Fp) and leaf water potential at the turgor loss point (πtlp). In addition, we compiled a dataset of geographical distribution along with climatic variables for these cycad species, and some leaf traits of tropical-sub-tropical angiosperm woody species from the literature for comparison. KEY RESULTS: The results showed significantly contrasting leaf trait syndromes between the two families, with Zamiaceae species exhibiting thicker leaves, higher carbon investments and greater Fp than Cycadaceae species. Leaf thickness (LT) and πtlp were correlated with mean climatic variables in their native distribution ranges, indicating their evolutionary adaptation to environmental conditions. Compared with the leaves of angiosperms, the cycad leaves were thicker and tougher, and more tolerant to desiccation. Greater Fp was associated with a higher structural investment in both angiosperms and cycads; however, cycads showed lower Fp at a given leaf mass per area or LT than angiosperms. Enhancement of Fp led to more negative πtlp in angiosperms, but the opposite trend was observed in cycads. CONCLUSIONS: Our results reveal that variations in leaf traits of cycads are mainly influenced by taxonomy and the environment of their native range. We also demonstrate similar leaf functional associations in terms of economics, but different relationships with regard to mechanics and drought tolerance between cycads and angiosperms. This study expands our understanding of the ecological strategies and likely responses of cycads to future climate change.
BACKGROUND AND AIMS: We conducted a comprehensive analysis of the functional traits of leaves (leaflets) of cycads. The aim of this study was to clarify the functional divergence between the earlier origin Cycadaceae and the later differentiated Zamiaceae, and the differences in trait associations between cycads and angiosperms. METHODS: We selected 20 Cycadaceae species and 21 Zamiaceae species from the same cycad garden in South China, and measured their leaf structure, economic traits, mechanical resistance (Fp) and leaf water potential at the turgor loss point (πtlp). In addition, we compiled a dataset of geographical distribution along with climatic variables for these cycad species, and some leaf traits of tropical-sub-tropical angiosperm woody species from the literature for comparison. KEY RESULTS: The results showed significantly contrasting leaf trait syndromes between the two families, with Zamiaceae species exhibiting thicker leaves, higher carbon investments and greater Fp than Cycadaceae species. Leaf thickness (LT) and πtlp were correlated with mean climatic variables in their native distribution ranges, indicating their evolutionary adaptation to environmental conditions. Compared with the leaves of angiosperms, the cycad leaves were thicker and tougher, and more tolerant to desiccation. Greater Fp was associated with a higher structural investment in both angiosperms and cycads; however, cycads showed lower Fp at a given leaf mass per area or LT than angiosperms. Enhancement of Fp led to more negative πtlp in angiosperms, but the opposite trend was observed in cycads. CONCLUSIONS: Our results reveal that variations in leaf traits of cycads are mainly influenced by taxonomy and the environment of their native range. We also demonstrate similar leaf functional associations in terms of economics, but different relationships with regard to mechanics and drought tolerance between cycads and angiosperms. This study expands our understanding of the ecological strategies and likely responses of cycads to future climate change.
Authors: Peter B Adler; Roberto Salguero-Gómez; Aldo Compagnoni; Joanna S Hsu; Jayanti Ray-Mukherjee; Cyril Mbeau-Ache; Miguel Franco Journal: Proc Natl Acad Sci U S A Date: 2013-12-30 Impact factor: 11.205
Authors: Dayana E Salas-Leiva; Alan W Meerow; Michael Calonje; M Patrick Griffith; Javier Francisco-Ortega; Kyoko Nakamura; Dennis W Stevenson; Carl E Lewis; Sandra Namoff Journal: Ann Bot Date: 2013-08-29 Impact factor: 4.357
Authors: Félix Forest; Justin Moat; Elisabeth Baloch; Neil A Brummitt; Steve P Bachman; Steffi Ickert-Bond; Peter M Hollingsworth; Aaron Liston; Damon P Little; Sarah Mathews; Hardeep Rai; Catarina Rydin; Dennis W Stevenson; Philip Thomas; Sven Buerki Journal: Sci Rep Date: 2018-04-16 Impact factor: 4.379