Browsing by Subject "Neotropics"

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    A worldwide phylogeny of Adiantum (Pteridaceae) reveals remarkable convergent evolution in leaf blade architecture
    (Taxon, 2018-06-01) Huiet, L; Li, F; Kao, T; Prado, J; Smith, AR; Schuettpelz, E; Pryeri, KM
    © International Association for Plant Taxonomy (IAPT) 2018, All rights reserved. Adiantum is among the most distinctive and easily recognized leptosporangiate fern genera. Despite encompassing an astonishing range of leaf complexity, all species of Adiantum share a unique character state not observed in other ferns: sporangia borne directly on the reflexed leaf margin or “false indusium” (pseudoindusium). The over 200 species of Adiantum span six continents and are nearly all terrestrial. Here, we present one of the most comprehensive phylogenies for any large (200+ spp.) monophyletic, subcosmopolitan genus of ferns to date. We build upon previous datasets, providing new data from four plastid markers (rbcL, atpA, rpoA, chlN) for 146 taxa. All sampled taxa can be unequivocally assigned to one of nine robustly supported clades. Although some of these unite to form larger, well-supported lineages, the backbone of our phylogeny has several short branches and generally weak support, making it difficult to accurately assess deep relationships. Our maximum likelihood-based ancestral character state reconstructions of leaf blade architecture reveal remarkable convergent evolution across multiple clades for nearly all leaf forms. A single unique synapomorphy—leaves once-pinnate, usually with prolonged rooting tips—defines the philippense clade. Although a rare occurrence in Adiantum, simple leaves occur in three distinct clades (davidii, philippense, peruvianum). Most taxa have leaves that are more than once-pinnate, and only a few of these (in the formosum and pedatum clades) exhibit the distinct pseudopedate form. Distributional ranges for each of the terminal taxa show that most species (75%) are restricted to only one of six major biogeographical regions. Forty-eight of our sampled species (nearly one-third) are endemic to South America.
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    The global abundance of tree palms
    (Global Ecology and Biogeography, 2020-09-01) Muscarella, R; Emilio, T; Phillips, OL; Lewis, SL; Slik, F; Baker, WJ; Couvreur, TLP; Eiserhardt, WL; Svenning, JC; Affum-Baffoe, K; Aiba, SI; de Almeida, EC; de Almeida, SS; de Oliveira, EA; Álvarez-Dávila, E; Alves, LF; Alvez-Valles, CM; Carvalho, FA; Guarin, FA; Andrade, A; Aragão, LEOC; Murakami, AA; Arroyo, L; Ashton, PS; Corredor, GAA; Baker, TR; de Camargo, PB; Barlow, J; Bastin, JF; Bengone, NN; Berenguer, E; Berry, N; Blanc, L; Böhning-Gaese, K; Bonal, D; Bongers, F; Bradford, M; Brambach, F; Brearley, FQ; Brewer, SW; Camargo, JLC; Campbell, DG; Castilho, CV; Castro, W; Catchpole, D; Cerón Martínez, CE; Chen, S; Chhang, P; Cho, P; Chutipong, W; Clark, C; Collins, M; Comiskey, JA; Medina, MNC; Costa, FRC; Culmsee, H; David-Higuita, H; Davidar, P; del Aguila-Pasquel, J; Derroire, G; Di Fiore, A; Van Do, T; Doucet, JL; Dourdain, A; Drake, DR; Ensslin, A; Erwin, T; Ewango, CEN; Ewers, RM; Fauset, S; Feldpausch, TR; Ferreira, J; Ferreira, LV; Fischer, M; Franklin, J; Fredriksson, GM; Gillespie, TW; Gilpin, M; Gonmadje, C; Gunatilleke, AUN; Hakeem, KR; Hall, JS; Hamer, KC; Harris, DJ; Harrison, RD; Hector, A; Hemp, A; Herault, B; Pizango, CGH; Coronado, ENH; Hubau, W; Hussain, MS; Ibrahim, FH; Imai, N; Joly, CA; Joseph, S; Anitha, K; Kartawinata, K; Kassi, J; Killeen, TJ
    Aim: Palms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) and in terms of responses to climate change. We quantified global patterns of tree palm relative abundance to help improve understanding of tropical forests and reduce uncertainty about these ecosystems under climate change. Location: Tropical and subtropical moist forests. Time period: Current. Major taxa studied: Palms (Arecaceae). Methods: We assembled a pantropical dataset of 2,548 forest plots (covering 1,191 ha) and quantified tree palm (i.e., ≥10 cm diameter at breast height) abundance relative to co-occurring non-palm trees. We compared the relative abundance of tree palms across biogeographical realms and tested for associations with palaeoclimate stability, current climate, edaphic conditions and metrics of forest structure. Results: On average, the relative abundance of tree palms was more than five times larger between Neotropical locations and other biogeographical realms. Tree palms were absent in most locations outside the Neotropics but present in >80% of Neotropical locations. The relative abundance of tree palms was more strongly associated with local conditions (e.g., higher mean annual precipitation, lower soil fertility, shallower water table and lower plot mean wood density) than metrics of long-term climate stability. Life-form diversity also influenced the patterns; palm assemblages outside the Neotropics comprise many non-tree (e.g., climbing) palms. Finally, we show that tree palms can influence estimates of above-ground biomass, but the magnitude and direction of the effect require additional work. Conclusions: Tree palms are not only quintessentially tropical, but they are also overwhelmingly Neotropical. Future work to understand the contributions of tree palms to biomass estimates and carbon cycling will be particularly crucial in Neotropical forests.