DOI: 10.5061/dryad.x69p8czhw
title: Biogeography of different life forms of the southernmost neotropical tank bromeliad

description: Aim: Factors affecting bromeliad distribution depend on the life forms of
 the studied species, some could grow as terrestrial, saxicolous, or
 epiphytic depending on the type of habitat. We analyzed the distribution
 patterns of the life forms of a bromeliad species on different
 biogeographic domains and associated them with environmental variables and
 vegetation types. Location: Chaquenian, Amazonian, and Seasonally
 Dry Tropical Forest domains; South America. Taxon: The tank
 bromeliad Aechmea distichantha (Bromeliaceae:
 Bromelioideae). Methods: We compiled records of the biogeographic
 distribution and the vegetation types where Aechmea distichantha occurs
 based on bibliographic data, digital datasets, herbaria, and personal
 observations. We associated the distributional records of this species
 with altitude, five selected bioclimatic variables, four soil variables,
 and with the vegetation types where it occurs. Results: Aechmea
 distichantha has been recorded as epiphytic, terrestrial, and saxicolous
 in all biogeographic domains, but showed contrasting patterns in life form
 proportions among them. In the Amazonian domain, characterized by
 evergreen tropical and subtropical forests with high precipitation, it
 mainly grows as epiphytic. In the Chaquenian domain, dominated by
 xerophytic forests with low rainfall, high soil pH, and base saturation,
 it mainly grows as terrestrial, whereas in the Seasonally Dry Tropical
 Forest domain the three life forms were recorded in similar proportions.
 In azonal plant communities of all domains, it mainly grows as
 saxicolous. Main conclusions: This tank bromeliad species can
 thrive in sites with contrasting habitat and environmental conditions. Its
 ability to survive in different environments could be associated with its
 high frost tolerance, the presence of the CAM photosynthetic pathway, a
 well-developed phytotelma, and high phenotypic plasticity. The life form
 prevailing in each domain is influenced by water availability (i.e. the
 quantity of water available during each year, the precipitation in the
 driest month, and the plant water supply relative to demand).
description: <b>Occurrences data
 survey</b> Occurrence points were obtained
 by extensively searching the Google Scholar and Scopus databases for
 literature reporting information on its appearance, as well as reports
 about the interaction of this species with animal or fungi species.
 Specimens deposited in FACEN, FCQ, PY (Paraguay), and UNR (Argentina)
 herbaria, and other specimens available in digital databases (GBIF, 2019;
 Tropicos, 2019; Flora do Brasil, 2019), as well as journal datasets (Ramos
 et al., 2019), were also explored. JStor Global Plants (JSTOR, 2019) and
 ‘Flora del Conosur’ (Zuloaga & Belgrano, 2019) websites were
 consulted to check types or synonyms. Given that most occurrences and
 literature citations mentioned only the species name ‘<i>Aechmea
 distichantha</i>’, for the present analysis we did not make any
 distinction between infraspecific
 taxa. As there could be many sources of potential errors when using large online datasets (Maldonado et al., 2015; Zizka et al., 2019, Zizka et al., 2020), the dataset was compiled and filtered by comparing recorded distributions with areas noted in the literature, as well as with the field experience of the authors. Obvious distribution outliers were checked and deleted when necessary and cultivated specimens were excluded from the analysis. For specimens lacking georeferenced data, coordinates were estimated only for records with accurate locality level spatial data (e. g. municipality or town name, station, farm, finca, estancia or mountain location, roads or rivers intersections, park, reserve or forested area, etc.). We performed manual georeferencing by meticulous interpretation of site descriptions. When available, we checked the original field notes, specimen labels, etc. to improve georeferencing precision and reduce spatial error. To assign the coordinates of each occurrence record we analyzed the site location, classified the type of locality, and then georeferenced it by using the point or point-radius methods in Google Maps and/or Google Earth respectively, following Chapman & Wieczorek (2020) Georeferencing Best Practices. Records with unambiguous life form information were classified according to the presence of this species on the canopy (epiphytic), on the soil (terrestrial), and on rocky outcrops (saxicolous; Zotz, 2016). A final dataset of 1232 occurrences of <i>A. distichantha</i> was compiled, containing information either on life form, geographic coordinates, or biogeographic regions (provided or inferred).   <b>Environmental data survey</b> For those records with vegetation description, vegetation types were identified for each biogeographic domain based on community structure description or from its floristic composition (DRYFLOR, 2016; Oliveira-Filho & Fontes, 2000; Prado, 2000). For the Amazonian domain (<i>sensu</i> Cabrera & Willink, 1980) we classified the records into wet forests, savannas, and azonal communities. For the Seasonally Dry Tropical Forest domain (<i>sensu</i> Prado, 2000; Särkinen, Iganci, Linares-Palomino, Simon, & Prado, 2011), we classified the vegetation as mesophytic forests or azonal communities. Finally, for the Chaquenian domain (<i>sensu</i> Prado, 1993a, b), we recognized the following vegetation types: tall xerophytic forests, low xerophytic forests, savannas, and azonal communities. We did not include in the vegetation dataset those records that corresponded to transitions between different domains (N=83; <i>i.e</i>. 63 transitions Chaquenian-SDTF domains, and 20 transitions SDTF-Amazonian domains). For the present contribution, we consider that other bioregionalization schemes (<i>e.g.</i> Morrone, 2014) are not suitable because they do not take into account the unique identity of the SDTF in South America (<i>sensu</i> DRYFLOR, 2016), to which the studied species shows an important association. We selected altitude and five bioclimatic variables based on the effects that they could have on the growth and survival of a facultative epiphytic bromeliad, and therefore on its distribution (Males & Griffiths, 2017; Males, 2018). Mean Annual Precipitation (MAP, mm) was considered as a proxy for the absolute quantity of water available during each year (Males, 2018). Precipitation in the driest month (<i>P<sub>dry</sub></i>, mm) was a proxy for the absolute degree of water limitation during the dry season (Males, 2018). Precipitation Seasonality (<i>P<sub>seas</sub></i>, %) was used as a proxy for the severity of the dry season relative to the remainder of the year (Males, 2018). Aridity Index (AI, mm mm<sup>-1</sup>) is measured as MAP/MAE, where MAE is Mean Annual Evapotranspiration, and hence is affected by precipitation, potential evaporation, and temperature. It was used as a proxy for the degree of dryness, where higher AI values denote lower dryness (Zomer et al., 2007). Actual Evapotranspiration/Potential Evapotranspiration (AET/PET, mm mm<sup>−1</sup>) was used as a proxy for plant water supply relative to demand (Males, 2018). As terrestrial bromeliad distribution could also be affected by soil features (Benzing, 2000; Barberis et al., 2014), we selected four soil variables (<i>i.e.</i> pH, Percentage of Clay (Clay, %), Cation Exchange Capacity (CEC, cmolc kg<sup>-1</sup>), and Base Saturation (BSAT, %)) that are known to vary widely among biomes (Rubio et al., 2019). Altitude, MAP, <i>P<sub>dry</sub></i>, and <i>P<sub>seas</sub></i>, were taken from Worldclim version 2.0 (Fick & Hijmans, 2017, available in http://www.diva-gis.org/), at 30 seconds spatial resolution (~1 km<sup>2</sup>). Aridity Index, Actual Evapotranspiration (AET), and Potential Evapotranspiration (PET) layers were obtained at the same resolution from the CGIAR-CSI portal (Zomer et al., 2007). The selected soil variables were taken from The Soil and Terrain database for Latin America and the Caribbean (SOTERLAC), version 2.0, at a scale 1:5 million (available in http://www.isric.org/). DIVA GIS v7.5 (Hijmans et al<i>.</i>, 2012) was used to extract the environmental information associated with each record.   <b>REFERENCES</b> Barberis, I. M., Torres, P. S., Batista, W. B., Magra, G., Galetti, L., & Lewis, J. P. (2014). Two bromeliad species with contrasting functional traits partition the understory space in a Southamerican xerophytic forest: correlative evidence of environmental control and limited dispersal. <i>Plant Ecology</i>, <i>215</i>, 143-153. https://doi.org/10.1007/s11258-013-0261-3 Benzing, D. H. (2000). <i>Bromeliaceae. Profile of an adaptive radiation</i>. Cambridge, England: Cambridge University Press. Cabrera, A. & Willink, A. (1980). <i>Biogeografía de América Latina</i>. Washington, USA: Secretaría General de la Organización de los Estados Americanos. Chapman, A. D., & Wieczorek, J. (2020). <i>Georeferencing best practices</i>. Copenhagen, Denmark: Global Biodiversity Information Facility. DRYFLOR, Banda, K., Delgado-Salinas, A., Dexter, K. G., Linares-Palomino, R., Oliveira-Filho, A., … Pennington, R. T. (2016). Plant diversity patterns in neotropical dry forests and their conservation implications. <i>Science</i>, <i>353</i>, 1383-1387. https://doi.org/10.1126/science.aaf5080 Fick, S. E., & Hijmans, R. J. (2017). Worldclim 2: New 1-km spatial resolution climate surfaces for global land areas. <i>International Journal of Climatology</i>, <i>37</i>, 4302–4315. https://doi.org/10.1002/joc.5086 Flora do Brasil (2019). Jardim Botânico do Rio de Janeiro. Retrieved from: http://floradobrasil.jbrj.gov.br/ (accessed 12 July 2019]. GBIF (2019). GBIF - Global Biodiversity Information Facility. Retrieved from: https://www.gbif.org (accessed 12 July 2019). Hijmans, R., Guarino, L., Bussink, C., Mathur, P., Cruz, M., Barrentes, I., & Rojas, E. (2012). DIVA-GIS: A geographic information system for the analysis of species distribution data. Version 7, 476-486. JSTOR (2019). JSTOR Global Plants. Retrieved from: http://plants.jstor.org (accessed 12 July 2019). Maldonado, C., Molina, C. I., Zizka, A., Persson, C., Taylor, C. M., Albán, J., Chilquillo, E., Rønsted, N., & Antonelli, A. (2015). Estimating species diversity and distribution in the era of Big Data: to what extent can we trust public databases? <i>Global Ecology and Biogeography</i>, 24, 973-984. https://onlinelibrary.wiley.com/doi/full/10.1111/geb.12326 Males, J. (2018). Geography, environment and organismal traits in the diversification of a major tropical herbaceous angiosperm radiation. <i>AoB Plants</i>, <i>10</i>, ply008. https://doi.org/10.1093/aobpla/ply008 Males, J., & Griffiths, H. (2017). Functional types in the Bromeliaceae: relationships with drought-resistance traits and bioclimatic distributions. <i>Functional Ecology</i>, <i>31</i>, 1868-1880. https://doi.org/10.1111/1365-2435.12900 Morrone, J. J. (2014). Biogeographical regionalisation of the Neotropical region. <i>Zootaxa</i>, <i>3782</i>, 1-110. https://doi.org/10.11646/zootaxa.3782.1.1 Oliveira-Filho, A. T., & Fontes, M. A. L. (2000). Patterns of floristic differentiation among Atlantic Forests in Southeastern Brazil and the influence of climate. <i>Biotropica</i>, <i>32</i>, 793-810. https://doi.org/10.1111/j.1744-7429.2000.tb00619.x Prado, D. E. (1993a). What is the Gran Chaco vegetation in South America? I. A review. Contribution to the study of the flora and vegetation of the Chaco. V. <i>Candollea</i>, <i>48</i>, 145-172. Prado, D. E. (1993b). What is the Gran Chaco vegetation in South America? II. A redefinition. Contribution to the study of the flora and vegetation of the Chaco. VII. <i>Candollea</i>, <i>48</i>, 615-629. Prado, D. E. (2000). Seasonally dry forests of tropical South America: from forgotten ecosystems to a new phytogeographic unit. <i>Edinburgh Journal of Botany</i>, <i>57</i>, 437-461. https://doi.org/10.1017/S096042860000041X Ramos, F. N., Mortara, S. R., Monalisa-Francisco, N., Costa, E. J. P., Neto, L. M., Freitas, L., … Ribeiro, M. C. (2019). ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest. <i>Ecology</i>, <i>100</i>, e02541. https://doi.org/10.1002/ecy.2541 Rubio, G., Lavado, R. S., & Pereyra, F. X. (2019). <i>The soils of Argentina</i>. Cham, Switzerland: Springer International Publishing. Särkinen, T., Iganci, J. R. V., Linares-Palomino, R., Simon, M., & Prado, D. (2011). Forgotten forests - issues and prospects in biome mapping using Seasonally Dry Tropical Forests as a case study. <i>BMC Ecology</i>, <i>11</i>, 27. https://doi.org/10.1186/1472-6785-11-27 Tropicos (2019). Tropicos.org. Missouri Botanical Garden, USA. Retrieved from http://www.tropicos.org (accessed 12 July 2019). Zizka, A., Silvestro, D., Andermann, T., Azevedo, J., Duarte Ritter, C., Edler, D., Farooq, H., Herdean, A., Ariza, M., & Scharn, R. (2019). CoordinateCleaner: Standardized cleaning of occurrence records from biological collection databases. <i>Methods in Ecology and Evolution, 10,</i> 744-751. https://doi.org/10.1111/2041-210X.13152 Zizka, A., Carvalho, F. A., Calvente, A., Baez-Lizarazo, M. R., Cabral, A., Coelho, J. F. R., Colli-Silva, M., Fantinati, M. R., Fernandes, M. F., Ferreira-Araujo, T., Gondim Lambert Moreira, F., Santos, N. M. C., Santos, T. A. B., dos Santos-Costa, R. C., Serrano, F. C., Alves da Silva, A. P., de Souza Soares, A., Cavalcante de Souza, P. G., Calisto Tomaz, E., Vale, V. F., Vieira, T. L., & Antonelli, A. (2020b). No one-size-fits-all solution to clean GBIF. <i>PeerJ, 9916</i>. https://doi.org/10.7717/peerj.9916 Zomer, R. J., Bossio, D. A., Trabucco, A., Yuanjie, L., Gupta, D. C, & Singh, V. P. (2007). <i>Trees and water: smallholder agroforestry on irrigated lands in Northern India</i>. Colombo, Sri Lanka: International Water Management Institute. Zotz, G. (2016). <i>Plants on plants–The biology of vascular epiphytes</i>. Switzerland: Springer. Zuloaga, F. O., & Belgrano, M. J. (2019). Catálogo de plantas vasculares del Cono Sur. Retrieved from: http://www.darwin.edu.ar/proyectos/floraargentina/fa.htm (accessed 12 July 2019).