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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 analysed the distribution patterns of the life forms of a bromeliad species in 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 A. 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: A. 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). [ABSTRACT FROM AUTHOR]

Societal Impact Statement: Understanding of tropical forests has been revolutionized by monitoring in permanent plots. Data from global plot networks have transformed our knowledge of forests' diversity, function, contribution to global biogeochemical cycles, and sensitivity to climate change. Monitoring has thus far been concentrated in rain forests. Despite increasing appreciation of their threatened status, biodiversity, and importance to the global carbon cycle, monitoring in tropical dry forests is still in its infancy. We provide a protocol for permanent monitoring plots in tropical dry forests. Expanding monitoring into dry biomes is critical for overcoming the linked challenges of climate change, land use change, and the biodiversity crisis. [ABSTRACT FROM AUTHOR]

Copyright of Boletín de la Sociedad Argentina de Botánica is the property of Sociedad Argentina de Botanica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Boletín de la Sociedad Argentina de Botánica is the property of Sociedad Argentina de Botanica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bosque (03048799) is the property of Facultad de Ciencias Forestales, Universidad Austral de Chile and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Gran Chaco is a wide ecologic-geographic region comprising northern Argentina, western Paraguay, southern Bolivia and the southwestern extreme of Brazil. This region exhibits extreme temperatures, annually regular frosts, and sedimentary soils; it has been dramatically threatened by agriculture expansion in recent decades. Therefore, increasing knowledge of plant diversity is critical for conservation purposes. We present a Legume checklist of the Gran Chaco ecoregion including conservation status of its endemic species. Leguminosae is the third most diverse plant family in the Neotropics. Assuming a rigorous spatial definition of the Gran Chaco, we recorded 98 genera, 362 species, and 404 specific and infraspecific taxa. Endemic/typical taxa were 17%, comparable to adjacent tropical plant formations, and they were found in higher percentages in Caesalpinioideae (24%) and Cercidoideae (33%) than Papilionoideae (11%) subfamily. We also analyzed the plant diversity comparing lineages and subregions. The Gran Chaco Legumes are predominantly widespread generalists, or they belong to either Chaco sensu stricto or Neotropical Seasonally Dry Tropical Forest (SDTF) lineages. Though the Humid Chaco registered the highest species richness, Dry Chaco and Sierra Chaco, the most threatrened subregions, exhibited the highest percentages of exclusive and proper Chaco-lineage species. These results suggest that diversification of Legumes has been most relevant in Dry Chaco and Sierra Chaco, probably by their more demanding and harsh environmental conditions limiting the dispersion of generalists or intrusive-invading species. This study is paramount to reach an improved delimitation of the Gran Chaco ecoregion in transitional areas with the SDTF and Cerrado formations. Conservation status is critical in genera of high economic interest, such as Arachis, Mimosa and Prosopis. At least one third of endemic taxa exhibit a critical status of conservation or are endangered, many of them being relevant to inbreeding program or exhibiting multiple economic uses. [ABSTRACT FROM AUTHOR]

Seasonally dry tropical forests are distributed across Latin America and the Caribbean and are highly threatened, with less than 10% of their original extent remaining in many countries. Using 835 inventories covering 4660 species of woody plants, we show marked floristic turnover among inventories and regions, which may be higher than in other neotropical biomes, such as savanna. Such high floristic turnover indicates that numerous conservation areas across many countries will be needed to protect the full diversity of tropical dry forests. Our results provide a scientific framework within which national decision-makers can contextualize the floristic significance of their dry forest at a regional and continental scale. [ABSTRACT FROM AUTHOR]

• Genetic data and species distribution models reveal spatio-temporal dynamics of dry forest. • Climatic changes in the quaternary cannot be regarded as the main cause for the molecular divergence amongst the haplotypes of Anadenanthera colubrina var. cebil. • The distribution of Anadenanthera colubrina var. cebil was widespread and fragmented in the Pleistocene in South America even before the LGM. • Fossil data show the occurrence of Anadenanthera colubrina var. cebil in northern Argentina since the Miocene. Neotropical seasonally dry forest (dry forest) is a fragmented biome that occurs in regions with pronounced seasonal rainfall. There are several hypotheses about the evolution of the distribution of these forests concerning the influence of climatic changes during the Quaternary. Anadenanthera colubrina var. cebil is a native tree that is considered the most paradigmatic and ecologically specialized key species of dry forest. The present work aims to test whether the current disjunct distribution of A. colubrina var. cebil is a remnant of a formerly widespread range during the cold and dry phases of the Last Glacial Maximum (LGM). Here, we take an approach that combines chloroplast DNA, palaeodistribution modelling and fossil evidence to understand the spatial and temporal dynamics of the distribution of Anadenanthera colubrina var. cebil. Seven haplotypes were detected in the two non-coding regions of cpDNA analysed and their divergence was dated to the Neogene. Maps of climatic suitability for A. colubrina var. cebil throughout South America showed that the potential distribution of the species was extensive and fragmented from the lower Pleistocene to modern times. Data from the fossil record confirm the occurrence of A. colubrina var. cebil at the southern limit of the dry forest distribution in historical times before the Quaternary. We found that climate change during the Pleistocene cannot be considered the main cause of molecular divergence of A. colubrina var. cebil haplotypes. We also found that A. colubrina var. cebil already had a widespread and fragmented distribution in South America during the Pleistocene, and that A. colubrina var. cebil was already present in northern Argentina in pre-Pleistocene. [ABSTRACT FROM AUTHOR]