Are Chilean coastal forests pre‐Pleistocene relicts? Evidence from foliar physiognomy,palaeoclimate, and phytogeography

Aim We ask whether contemporary forests of the Chilean Coastal Range can be considered to be direct and conservative descendants of pre‐Pleistocene palaeofloras that occurred in southern South America from the Palaeogene to early Neogene periods (65–10 Ma), maintaining foliar physiognomies that do not match their present‐day climate. We also identify the most likely ancestors of present‐day coastal forests. Location Coastal Range of south‐central Chile (33–40° S). Methods We compared leaf morphology between five representative modern floras from mid‐latitude forests of the Chilean Coastal Range, and 14 Palaeogene–early Neogene palaeofloras from southern South America. We also compared the composition of biogeographical elements (defined by the modern distribution of plant genera) between fossil and present‐day assemblages. Palaeoclimatic reconstructions were based on a canonical correspondence analysis between leaf morphology of modern assemblages and eight climatic variables, and tested by a Monte Carlo permutation test. We compared the relative positions of fossil and modern floras on the environmental vector space defined by Canoco, and on axes defined by instrumental and estimated temperature and precipitation data. Results According to foliar characters, Palaeogene palaeofloras were strikingly divergent from present‐day coastal forests of central Chile. In contrast, two extant forest floras of the Chilean Coastal Range have a foliar morphology that resembles some late Eocene to early Miocene mixed palaeofloras, at least 23 Myr older. These two modern sites are representative of an area of the Coastal Range (36–37° S) that has been highlighted for its relictual character. None of the 14 fossil floras corresponded exactly to the modern composition of phytogeographic elements, although correspondence analyses showed that mixed and Neogene subtropical fossil floras were compositionally close to the extant woody floras of coastal forests in central Chile. Main Conclusions Contemporary forests of the Chilean Coastal Range exhibit strong physiognomic resemblance to the mixed palaeofloras from 33°57′ to 41°15′ S, which may be the closest ancestor of the deciduous and endemic‐rich Maulino forest, presently restricted to coastal areas between 36° and 38° S. In turn, the Neogene subtropical palaeoflora that occurred in the Proto‐Andean foothills of central Chile is the likely predecessor of Mediterranean‐type sclerophyllous forests of central Chile (32–33° S). Despite foliar resemblance between the late pre‐Pleistocene and extant forest floras, our palaeoclimatic reconstructions suggest that modern assemblages exist under climatic conditions that do not match their foliar physiognomy. We attribute this convergence in foliar morphology to the ‘evolutionary inertia’ of surviving lineages, favoured by the buffering effect of the coastal environment on climatic variability.     

Do leaf margins of the temperate forest flora of southern South America reflect a warmer past?

Aim   Our aims were: (1) to characterize the linear relationship between the proportion of woody dicotyledonous species with entire-margined leaves ( E ) and mean annual temperature (MAT) from a southern temperate flora that still harbours many lineages that originated under warmer climates; (2) to compare this relationship with those developed from floras of different regions of the world; and (3) to contrast temperature predictions based on leaf margins of the native southern flora versus the naturalized alien flora, mostly of boreal origin.
Location   The temperate forest of southern South America (TFSA).
Methods   At each 1° latitudinal band, we estimated E based on species latitudinal ranges and MAT from both an isotherm map and a global temperature grid. We also calculated E from five local floras located between 40 and 43° S, and from the naturalized alien flora of Nahuel Huapi National Park in southern Argentina.
Results   We found a close relationship between E and MAT for the TFSA. Equations developed from floras of the Northern Hemisphere overestimated extant temperatures of this biome by 6–10 °C at both geographical and local spatial scales. On the other hand, MAT predictions from leaf margins of the alien flora were similar to the actual MAT. A published regression between E and MAT from tropical South America was remarkably similar to the one we estimated from the TFSA. This tropical equation predicted accurately the temperatures observed for this temperate biome based on leaf margins of the native flora.
Main conclusions   Despite massive plant extinction due to environmental cooling and biogeographical isolation during the Tertiary, leaf-margin analysis reveals that the flora of the TFSA still reflects its original development under the warmer conditions of western Gondwana and its past connections with low-latitude forest floras of tropical South America.     

Review of plant biogeographic studies in Brazil

Molecular phylogenetic studies have become a major area of interest in plant systematics, and their impacts on historical biogeographic hypotheses are not to be disregarded. In Brazil, most historical biogeographic studies have relied on animal phylogenies, whereas plant biogeographic studies have largely lacked a phylogenetic component, having a limited utility for historical biogeography. That country, however, is of great importance for most biogeographic studies of lowland tropical South America, and it includes areas from a number of biogeographic regions of the continent. Important biogeographic reports have been published as part of phylogenetic studies, taxonomic monographs, and regional accounts for small areas or phytogeographic domains, but the available information is subsequently scattered and sometimes hard to find. In this paper we review some relevant angiosperm biogeographic studies in Brazil. Initially we briefly discuss the importance of other continents as source areas for the South American flora. Then we present a subdivision of Brazil into phytogeographic domains, and we cite studies that have explored the detection of biogeographic units （areas of endemism） and how they are historically related among those domains. Examples of plant taxa that could be used to test some biogeographic hypotheses are provided throughout, as well as taxa that exemplify several patterns of endemism and disjunction in the Brazilian angiosperm flora.     

Sensitivity of leaf size and shape to climate: global patterns and paleoclimatic applications

? Paleobotanists have long used models based on leaf size and shape to reconstruct paleoclimate. However, most models incorporate a single variable or use traits that are not physiologically or functionally linked to climate, limiting their predictive power. Further, they often underestimate paleotemperature relative to other proxies. ? Here we quantify leaf-climate correlations from 92 globally distributed, climatically diverse sites, and explore potential confounding factors. Multiple linear regression models for mean annual temperature (MAT) and mean annual precipitation (MAP) are developed and applied to nine well-studied fossil floras. ? We find that leaves in cold climates typically have larger, more numerous teeth, and are more highly dissected. Leaf habit (deciduous vs evergreen), local water availability, and phylogenetic history all affect these relationships. Leaves in wet climates are larger and have fewer, smaller teeth. Our multivariate MAT and MAP models offer moderate improvements in precision over univariate approaches (± 4.0 vs 4.8°C for MAT) and strong improvements in accuracy. For example, our provisional MAT estimates for most North American fossil floras are considerably warmer and in better agreement with independent paleoclimate evidence. ? Our study demonstrates that the inclusion of additional leaf traits that are functionally linked to climate improves paleoclimate reconstructions. This work also illustrates the need for better understanding of the impact of phylogeny and leaf habit on leaf-climate relationships.     

Biogeographic constraints on the world‐wide leaf economics spectrum

Aim The world‐wide leaf economic spectrum (LES) describes tight coordination of leaf traits across global floras, reported to date as being largely independent of phylogeny and biogeography. Here, we present and test an alternative, historical perspective that predicts that biogeography places significant constraints on global trait evolution. These hypothesized constraints could lead to important deviations in leaf trait relationships between isolated floras that were influenced by different magnitudes of genetic constraint and selection. Location Global, including floristic regions of the Northern and Southern Hemispheres, eastern North America, East Asia (EAS), the Hawaiian Islands and tropical mainland floras. Methods We use a large leaf‐trait database (GLOPNET) and species native distribution data to test for variation in leaf trait relationships modulated by floristic region, controlling for climatic differences. Standardized major axis analyses were used to evaluate biogeographic effects on bivariate relationships between LES traits, including relationships of photosynthetic capacity and dark respiration rate (A_mass–R_d‐mass), leaf lifespan and mass per area ratio (LL–LMA), and photosynthetic capacity and nitrogen content (A_mass–N_mass). Results Independent of climate or biome, floras of different evolutionary histories exhibited different leaf trait allometries. Floras of the Northern Hemisphere exhibited greater rates of return on resource investment (steeper slopes for the trait relationships analysed), and the more diverse temperate EAS flora exhibited greater slopes or intercepts in leaf trait relationships, with the exception of the A_mass–N_mass relationship. In contrast to our hypothesis, plants of the floristically isolated Hawaiian Islands exhibited a similar A_mass–N_mass relationship to those of mainland tropical regions. Main conclusions Differences in leaf trait allometries among global floristic regions support a historical perspective in understanding leaf trait relationships and suggest that independent floras can exhibit different tradeoffs in resource capture strategies.     

Biogeographic diversification in Nolana （Solanaceae）, a ubiquitous member of the Atacama and Peruvian Deserts along the western coast of South America

The present paper reconstructs the biogeographic diversification for Nolana L.f. （Solanaceae）, a genus of 89 endemic species largely restricted to fog-dependent desert lomas formations of coastal Peru and Chile. Previous efforts have reconstructed a phylogenetic estimate for Nolana using a combination of molecular markers. Herein, we expand on those results to examine hypotheses of biogeographic origins and diversification patterns. Nolana occupies habitats within a continuous coastal desert and forms a terrestrial archipelago of discrete ＂islands＂ unique in size, topography, and species composition. Each locality contains at least one Nolana species and many contain multiple species in sympatry. The genus has a Chilean origin, with the basal clades confined to Chile with wide geographic and ecological distributions. Peru contains two strongly supported clades, suggesting two introductions with subsequent radiation. A Chilean clade of shrubby, small-flowered species appears to have had its origins from the same ancestors of the second line that radiated in Peru and northern Chile. Nolana galapagensis is endemic to the Islas Galapagos, with origins traced to Peruvian taxa with a divergence time of 0.35 mya. Rates of diversification over the past 4.02 mya in Nolana, in one of the driest habitats on Earth, suggest rapid adaptive radiation in several clades. Success in Nolana may be attributed to characters that confer a competitive advantage in unpredictable and water-dependent environments, such as succulent leaf anatomy and ecophysiology, and the reproductive mericarp unique to Nolana. The processes affecting or shaping the biota of western South America are discussed.     

DNA from herbarium specimens settles a controversy about origins of the European potato

Landrace potato cultivars are native to two areas in South America: the high Andes from eastern Venezuela to northern Argentina and the lowlands of south-central Chile. Potato first appeared outside of South America in Europe in 1567 and rapidly diffused worldwide. Two competing hypotheses suggested the origin of the "European" potato from the Andes or from lowland Chile, but the Andean origin has been widely accepted over the last 60 years. All modern potato cultivars predominantly have Chilean germplasm, explained as originating from breeding with Chilean landraces subsequent to the late blight epidemics beginning in 1845 in the UK. The Andean origin has been questioned recently through examination of landraces in India and the Canary Islands, but this evidence is inferential. Through a plastid DNA deletion marker from historical herbarium specimens, we report that the Andean potato predominated in the 1700s, but the Chilean potato was introduced into Europe as early as 1811 and became predominant long before the late blight epidemics in the UK. Our results provide the first direct evidence of these events and change the history of introduction of the European potato. They shed new light on the value of past breeding efforts to recreate the European potato from Andean forms and highlight the value of herbarium specimens in investigating origins of crop plants.     

Paleogene Land Mammal Faunas of South America; a Response to Global Climatic Changes and Indigenous Floral Diversity

An appraisal of Paleogene floral and land mammal faunal dynamics in South America suggests that both biotic elements responded at rate and extent generally comparable to that portrayed by the global climate pattern of the interval. A major difference in the South American record is the initial as well as subsequent much greater diversity of both Neotropical and Austral floras relative to North American counterparts. Conversely, the concurrent mammal faunas in South America did not match, much less exceed, the diversity seen to the north. It appears unlikely that this difference is solely due to the virtual absence of immigrants subsequent to the initial dispersal of mammals to South America, and cannot be explained solely by the different collecting histories of the two regions. Possible roles played by non-mammalian vertebrates in niche exploitation remain to be explored. The Paleogene floras of Patagonia and Chile show a climatic pattern that approximates that of North America, with an increase in both Mean Annual Temperature (MAT) and Mean Annual Precipitation (MAP) from the Paleocene into the Early Eocene Climatic Optimum (EECO), although the Paleocene-Eocene Thermal Maximum (PETM) is not recognized in the available data set. Post-EECO temperatures declined in both regions, but more so in the north than the south, which also retained a higher rate of precipitation. The South American Paleogene mammal faunas developed gradual, but distinct, changes in composition and diversity as the EECO was approached, but actually declined somewhat during its peak, contrary to the record in North America. At about 40 Ma, a post-EECO decline was recovered in both hemispheres, but the South American record achieved its greatest diversity then, rather than at the peak of the EECO as in the north. This post-EECO faunal turnover apparently was a response to the changing conditions when global climate was deteriorating toward the Oligocene. Under the progressively more temperate to seasonally arid conditions in South America, this turnover reflected a major change from the more archaic, and more tropical to subtropical-adapted mammals, to the beginning of the ultimately modern South American fauna, achieved completely by the Eocene-Oligocene transition. Interestingly, hypsodonty was achieved by South American cursorial mammals about 15–20 m.y. earlier than in North America. In addition to being composed of essentially different groups of mammals, those of the South American continent seem to have responded to the climatic changes associated with the ECCO and subsequent conditions in a pattern that was initially comparable to, but subsequently different from, their North American counterparts.     

Phylogenetic relationships in Myrceugenia (Myrtaceae) based on plastid and nuclear DNA sequences

Myrceugenia is a genus endemic to South America with a disjunct distribution: 12 species occurring mainly in central Chile and approximately 25 in southeastern Brazil. Relationships are reconstructed within Myrceugenia from four plastid markers (partial trnK-matK, rpl32-trnL, trnQ-5'rps16 and rpl16) and two ribosomal nuclear regions (ETS and ITS) using maximum parsimony and Bayesian analyses. Relationships inferred previously from morphological data are not completely consistent with those from molecular data. All molecular analyses support the hypothesis that Myrceugenia is monophyletic, except for M. fernadeziana that falls outside the genus. Chilean species and Brazilian species form two separate lineages. Chilean species form three early diverging clades, whereas Brazilian species are a strongly supported monophyletic group in a terminal position. Least average evolutionary divergence, low resolution, short branches, and high species diversity found in the Brazilian clade suggest rapid radiation. Geographical distributions and phylogenetic reconstructions suggest that extant Myrceugenia species arose in northern Chile followed by colonization southward and finally to the Juan Fernández Islands and southeastern Brazil.     

Effects of plant-soil feedback on tree seedling growth under arid conditions

Aims Plants are able to influence their growing environment by changing biotic and abiotic soil conditions. These soil conditions in turn can influence plant growth conditions, which is called plant–soil feedback. Plant–soil feedback is known to be operative in a wide variety of ecosystems ranging from temperate grasslands to tropical rain forests. However, little is known about how it operates in arid environments. We examined the role of plant–soil feedbacks on tree seedling growth in relation to water availability as occurring in arid ecosystems along the west coast of South America.Methods In a two-phased greenhouse experiment, we compared plant–soil feedback effects under three water levels (no water, 10% gravimetric moisture and 15% gravimetric moisture). We used sterilized soil inoculated with soil collected from northwest Peru (Prosopis pallida forests) and from two sites in north-central Chile (Prosopis chilensis forest and scrublands without P. chilensis).Important findings Plant–soil feedbacks differed between plant species and soil origins, but water availability did not influence the feedback effects. Plant–soil feedbacks differed in direction and strength in the three soil origins studied. Plant–soil feedbacks of plants grown in Peruvian forest soil were negative for leaf biomass and positive for root length. In contrast, feedbacks were neutral for plants growing in Chilean scrubland soil and positive for leaf biomass for those growing in Chilean forest soil. Our results show that under arid conditions, effects of plant–soil feedback depend upon context. Moreover, the results suggest that plant–soil feedback can influence trade-offs between root growth and leaf biomass investment and as such that feedback interactions between plants and soil biota can make plants either more tolerant or vulnerable to droughts. Based on dissecting plant–soil feedbacks into aboveground and belowground tissue responses, we conclude that plant–soil feedback can enhance plant colonization in some arid ecosystems by promoting root growth.     

An inverse latitudinal gradient of diversity of peracarid crustaceans along the Pacific Coast of South America: out of the deep south

Aim To understand the ecological and historical/evolutionary processes underlying an inverse latitudinal gradient of richness (LGR) using crustacean peracarid species as a model group. Location The Pacific coast of South America, along the Chilean coast between 18° S and 56° S. Methods The LGR was evaluated using a dataset including 320 marine peracarid species reported for the coasts of Chile. Five ecological hypotheses invoking a relationship between species richness and present‐day conditions were tested: species–energy, species–area, Rapoport rescue effect, mid‐domain geometric constraint and niche breadth. Historical/evolutionary hypotheses (i.e. biogeographic conservatism, and diversification rates) were indirectly tested by analysing the latitudinal variation in the taxonomic distinctness, the taxonomic conservatism of the midpoint of the latitudinal range and the degree of nestedness at different taxonomic levels. Results Richness increased poleward, varying approximately eightfold, following an inverse LGR coupled with an increase in bathymetric distribution. Overall this inverse LGR seems robust to uncertainties in the completeness of the species inventory. We found support for only two of the five ecological hypotheses tested: species–area and Rapoport rescue effect. Historical/evolutionary hypotheses seemed important in structuring the richness pattern, as indicated by the higher taxonomic distinctness in the southern region, the strong taxonomic inertia in the mean range size and the high degree of nestedness of assemblages at different taxonomic levels. Conclusions When combined, these results underscore the importance of long‐term processes and historical/evolutionary explanations for the inverse LGR, conceptualized in what we term the ‘out of the deep south’ hypothesis that involves the effects of both biogeographic niche conservatism and evolutionary rates. We propose that the southern region may be a source of evolutionary novelties and/or exhibit higher diversification rates (i.e. higher speciation/lower extinction rates). Furthermore, phylogenetic conservatism of latitudinal range may limit the geographic expansion of these new taxa towards the depauperated northern region.     

Bat rabies in urban centers in Chile

One hundred and five rabies isolates obtained from domestic animals and insectivorous bats in Chile between 1977 and 1998 were molecularly characterized by limited sequence analysis of their nucleoprotein genes. These isolates were compared with viruses isolated from known domestic and wildlife rabies reservoirs in the Americas to identify potential reservoirs of rabies in Chile. The phylogenetic analyses showed that none of the Chilean isolates segregated with viruses from the terrestrial reservoirs. No non-rabies lyssaviruses were found in this study. The Chilean samples were not related to viruses of the sylvatic cycle maintained by the common vampire bat (Desmodus rotundus) in Latin America. Five genetic variants were identified from insectivorous bats in Chile. The Brazilian free-tailed bat (Tadarida brasiliensis) was identified as the reservoir for the rabies genetic variant most frequently isolated in the country between 1977 and 1998. The close association of a group of viruses obtained from a domestic dog (Canis familiaris), Brazilian free-tailed bats, and a red bat (Lasiurus borealis) with viruses maintained by Lasiurus spp. in North America implicated species of this genus as the possible reservoirs of this particular genetic variant in Chile. Reservoirs for the other three variants remain unknown.     

Multi-scale phylogenetic structure in coastal dune plant communities across the globe

Aims Studies integrating phylogenetic history and large-scale community assembly are few, and many questions remain unanswered. Here, we use a global coastal dune plant data set to uncover the important factors in community assembly across scales from the local filtering processes to the global long-term diversification and dispersal dynamics. Coastal dune plant communities occur worldwide under a wide range of climatic and geologic conditions as well as in all biogeographic regions. However, global patterns in the phylogenetic composition of coastal dune plant communities have not previously been studied.Methods The data set comprised vegetation data from 18463 plots in New Zealand, South Africa, South America, North America and Europe. The phylogenetic tree comprised 2241 plant species from 149 families. We calculated phylogenetic clustering (Net Relatedness Index, NRI, and Nearest Taxon Index, NTI) of regional dune floras to estimate the amount of in situ diversification relative to the global dune species pool and evaluated the relative importance of land and climate barriers for these diversification patterns by geographic analyses of phylogenetic similarity. We then tested whether dune plant communities exhibit similar patterns of phylogenetic structure within regions. Finally, we calculated NRI for local communities relative to the regional species pool and tested for an association with functional traits (plant height and seed mass) thought to vary along sea–inland gradients.Important findings Regional species pools were phylogenetically clustered relative to the global pool, indicating regional diversification. NTI showed stronger clustering than NRI pointing to the importance of especially recent diversifications within regions. The species pools grouped phylogenetically into two clusters on either side of the tropics suggesting greater dispersal rates within hemispheres than between hemispheres. Local NRI plot values confirmed that most communities were also phylogenetically clustered within regions. NRI values decreased with increasing plant height and seed mass, indicating greater phylogenetic clustering in communities with short maximum height and good dispersers prone to wind and tidal disturbance as well as salt spray, consistent with environmental filtering along sea–inland gradients. Height and seed mass both showed significant phylogenetic signal, and NRI tended to correlate negatively with both at the plot level. Low NRI plots tended to represent coastal scrub and forest, whereas high NRI plots tended to represent herb-dominated vegetation. We conclude that regional diversification processes play a role in dune plant community assembly, with convergence in local phylogenetic community structure and local variation in community structure probably reflecting consistent coastal-inland gradients. Our study contributes to a better understanding of the globally distributed dynamic coastal ecosystems and the structuring factors working on dune plant communities across spatial scales and regions.     

The evolutionary origin of a second radiation of annual Castilleja (Orobanchaceae) species in South America: The role of long distance dispersal and allopolyploidy

Considerable attention has been directed toward understanding the wide gaps in range that are common among many groups of closely related organisms. By placing their biology and geography in a phylogenetic context, we may gain a broader knowledge of the series of historical events that have led to present species distributions. In addition to the North American annuals, a second radiation of annual Castilleja species is in Andean Peru and central Chile. Phylogenetic analyses of chloroplast and nuclear DNA regions revealed a complex history for the origin and diversification of annual Castilleja species in South America. In addition to at least three independent long-distance dispersal events from North America, allopolyploidy has played a significant role in this disjunct radiation. Only C. attenuata occurs in both California and South America, and these results support its recent arrival to central Chile. Two Peruvian species are inferred to be allopolyploids; hybridization between annual lineages derived from independent long-distance dispersal events from North America gave rise to C. profunda, and hybridization between South American annual and perennial species gave rise to C. cerroana. The relative importance these events are discussed with reference to the observed morphological, ecological, and distributional patterns.     

Origins and colonization history of pandemic Vibrio parahaemolyticus in South America

The dynamics of dissemination of the environmental human pathogen Vibrio parahaemolyticus are uncertain. The O3:K6 clone was restricted to Asia until its detection along the Peruvian coasts and in northern Chile in 1997 in phase with the arrival of El Niño waters. A subsequent emergence of O3:K6 strains was detected in austral Chile in 2004. The origin of these 1997 and 2004 population radiations has not yet been conclusively determined. Multiple loci VNTR analysis using seven polymorphic loci was carried out with a number of representative strains from Asia, Peru and Chile to determine their genetic characteristics and population structure. Asian and Chilean subpopulations were the most genetically distant groups with an intermediate subpopulation in Peru. Population structure inferred from a minimum‐spanning tree and Bayesian analysis divided the populations into two genetically distinct groups, consistent with the epidemic dynamics of the O3:K6 clone in South America. One group comprised strains from the original Asiatic population and strains arriving in Peru and Chile in 1997. The second group included the remaining Peruvian Strains and Chilean strains obtained from Puerto Montt in 2004. The analysis of the arrival of the O3:K6 clone at the Pacific coasts of South America has provided novel insights linking the origin of the invasion in 1997 to Asian populations and describing the successful establishment of the O3:K6 populations, first in Peru and subsequently in the South of Chile owing to a possible radiation of Peruvian populations.     

Heterozostera tasmanica (Martens ex aschers.) den Hartog in Chile

A 1.2 km² meadow of Heterozostera tasmanica (Martens ex Aschers.) den Hartog was found at Pto. Aldea, Bahia Tongoy, 60 km south of Coquimbo, 30°S on the coast of Chile. This provides documented evidence of seagrass occurrence on the west coast of South America. Since H. tasmanica is widespread throughout southern Australia, the Chilean stock represents a highly disjunct population. It appears from several growth parameters (density, leaf biomass, leaf area index, specific leaf area, δ ¹³C) that the H. tasmanica meadow at Pto. Aldea is very similar to those found in other parts of the world.     

History of canids in Chile and impacts on prey adaptations

Artiodactyl prey species of Chile, especially guanacos (Lama guanicoe), are reported to be very susceptible to predation by pack‐hunting feral dogs. It has been previously suggested that guanacos and endemic South American deer may have evolved in the absence of pack‐hunting cursorial predators. However, the paleoecology of canid presence in southern South America and Chile is unclear. Here, we review the literature on South American and Chilean canids, their distributions, ecologies, and hunting behavior. We consider both wild and domestic canids, including Canis familiaris breeds. We establish two known antipredator defense behaviors of guanacos: predator inspection of ambush predators, for example, Puma concolor, and rushing at and kicking smaller cursorial predators, for example, Lycalopex culpaeus. We propose that since the late Pleistocene extinction of hypercarnivorous group‐hunting canids east of the Andes, there were no native species creating group‐hunting predation pressures on guanacos. Endemic deer of Chile may have never experienced group‐hunting selection pressure from native predators. Even hunting dogs (or other canids) used by indigenous groups in the far north and extreme south of Chile (and presumably the center as well) appear to have been used primarily within ambush hunting strategies. This may account for the susceptibility of guanacos and other prey species to feral dog attacks. We detail seven separate hypotheses that require further investigation in order to assess how best to respond to the threat posed by feral dogs to the conservation of native deer and camelids in Chile and other parts of South America.     

Phylogenetics of Puya (Bromeliaceae): Placement, major lineages, and evolution of Chilean species

Puya (Bromeliaceae), a large genus of terrestrial bromeliads found throughout a range of elevations in the Andes and central Chile, is of great systematic, evolutionary, and biogeographical interest. This first molecular phylogenetic study of Puya and related bromeliads employs matK, trnS-trnG, rps16, and PHYC sequences. Chloroplast DNA, nuclear DNA, and combined DNA data all place Puya closest to subfamily Bromelioideae. Nuclear and combined data support Puya as monophyletic, and the two subgenera are nonmonophyletic. All data indicate that the Chilean species of Puya are early diverging within the genus, consistent with Chilean genera as the first-diverging members of subfamily Bromelioideae. Central Chile is identified as a key region for understanding the biogeographical history of Bromeliaceae, as is true with other South American plant groups. A complicated history involving early chloroplast capture and later secondary hybridization and/or introgression is seen in Chilean lineages. These events help explain the occurrence of sterile inflorescence tips, floral color and shape, and leaf indument. The ecological radiation of Puya appears coincident with the final, recent rise of the Andes and subsequent high-elevation habitat diversification. Additionally, geographical distribution, rather than moisture or elevational adaptations, correlates to species relationships. Evolution of CAM photosynthesis has occurred multiple times.     

From East Gondwana to Central America: historical biogeography of the Alstroemeriaceae

Aim The Alstroemeriaceae is among 28 angiosperm families shared between South America, New Zealand and/or Australia; here, we examine the biogeography of Alstroemeriaceae to better understand the climatic and geological settings for its diversification in the Neotropics. We also compare Alstroemeriaceae with the four other Southern Hemisphere families that expanded from Patagonia to the equator, to infer what factors may have permitted such expansions across biomes. Location South America, Central America, Australia and New Zealand. Methods Three chloroplast genes, one mitochondrial gene and one nuclear DNA region were sequenced for 153 accessions representing 125 of the 200 species of Alstroemeriaceae from throughout the distribution range; 25 outgroup taxa were included to securely infer evolutionary directions and be able to use both ingroup and outgroup fossil constraints. A relaxed‐clock model relied on up to three fossil calibrations, and ancestral ranges were inferred using statistical dispersal–vicariance analysis (S‐DIVA). Southern Hemisphere disjunctions in the flowering plants were reviewed for key biological traits, divergence times, migration directions and habitats occupied. Results The obtained chronogram and ancestral area reconstruction imply that the most recent common ancestor of Colchicaceae and Alstroemeriaceae lived in the Late Cretaceous in southern South America/Australasia, the ancestral region of Alstroemeriaceae may have been South America/Antarctica, and a single New Zealand species is due to recent dispersal from South America. Chilean Alstroemeria diversified with the uplift of the Patagonian Andes c. 18 Ma, and a hummingbird‐pollinated clade (Bomarea) reached the northern Andes at 11–13 Ma. The South American Arid Diagonal (SAAD), a belt of arid vegetation caused by the onset of the Andean rain shadow 14–15 Ma, isolated a Brazilian clade of Alstroemeria from a basal Chilean/Argentinean grade. Main conclusions Only Alstroemeriaceae, Calceolariaceae, Cunoniaceae, Escalloniaceae and Proteaceae have expanded and diversified from Patagonia far into tropical latitudes. All migrated northwards along the Andes, but also reached south‐eastern Brazil, in most cases after the origin of the SAAD. Our results from Alstroemeria now suggest that the SAAD may have been a major ecological barrier in southern South America.