Rosa A. Scherson

SITIO EL PLOMO Y NUEVOS REGISTROS DE CULTÍGENOS INICIALES EN CAZADORES DEL ARCAICO IV EN ALTO MAIPO, CHILE CENTRAL

Nuevas investigaciones arqueologicas en la cordillera andina de Chile central demuestran que cazadores recolectores del periodo Arcaico IV incorporaron el conocimiento y uso de cultigenos iniciales a su sistema de subsistencia. En el sitio El Plomo (3.460 a 3.340 anos cal. a.p.) localizado a 2.070 metros de altitud, se reitera el hallazgo de frutos de Chenopodium (cf. Chenopodium quinoa) carbonizados ademas de otros Chenopodium en estado desecado que tambien presentan rasgos de domesticacion. Los estudios morfologicos efectuados en estos ultimos con el apoyo de especialistas sugieren que sus tamanos, entre 0,8 a 1 mm de diametro, muestran similitudes con Chenopodium pallidicaule o canihua, o corresponderian a una variedad temprana de quinoa. La ausencia de testa, entre otras caracteristicas diagnosticas en estos frutos, hace dificil determinar su identidad con suficiente certeza. Esta problematica abre una nueva linea de discusion acerca de la domesticacion de Chenopodium en Chile central. Se plantea ademas el aprovechamiento de otros recursos vegetales, que no han sido particularmente considerados como alimentos en el registro arqueologico de ocupaciones de cazadores recolectores tardios en esta region. El sector de Alto Maipo en la cordillera de Chile central se propone como un umbral ecologico cultural donde ocurre tempranamente una importante innovacion en el sistema basico de subsistencia de cazadores recolectores del periodo Arcaico

Spatial phylogenetics of the vascular flora of Chile

Current geographic patterns of biodiversity are a consequence of the evolutionary history of the lineages that comprise them. This study was aimed at exploring how evolutionary features of the vascular flora of Chile are distributed across the landscape. Using a phylogeny at the genus level for 87% of the Chilean vascular flora, and a geographic database of sample localities, we calculated phylogenetic diversity (PD), phylogenetic endemism (PE), relative PD (RPD), and relative PE (RPE). Categorical Analyses of Neo- and Paleo-Endemism (CANAPE) were also performed, using a spatial randomization to assess statistical significance. A cluster analysis using range-weighted phylogenetic turnover was used to compare among grid cells, and with known Chilean bioclimates. PD patterns were concordant with known centers of high taxon richness and the Chilean biodiversity hotspot. In addition, several other interesting areas of concentration of evolutionary history were revealed as potential conservation targets. The south of the country shows areas of significantly high RPD and a concentration of paleo-endemism, and the north shows areas of significantly low PD and RPD, and a concentration of neo-endemism. Range-weighted phylogenetic turnover shows high congruence with the main macrobioclimates of Chile. Even though the study was done at the genus level, the outcome provides an accurate outline of phylogenetic patterns that can be filled in as more fine-scaled information becomes available.

Endemicity and evolutionary value: a study of Chilean endemic vascular plant genera

This study uses phylogeny-based measures of evolutionary potential (phylogenetic diversity and community structure) to evaluate the evolutionary value of vascular plant genera endemic to Chile. Endemicity is regarded as a very important consideration for conservation purposes. Taxa that are endemic to a single country are valuable conservation targets, as their protection depends upon a single government policy. This is especially relevant in developing countries in which conservation is not always a high resource allocation priority. Phylogeny-based measures of evolutionary potential such as phylogenetic diversity (PD) have been regarded as meaningful measures of the “value” of taxa and ecosystems, as they are able to account for the attributes that could allow taxa to recover from environmental changes. Chile is an area of remarkable endemism, harboring a flora that shows the highest number of endemic genera in South America. We studied PD and community structure of this flora using a previously available supertree at the genus level, to which we added DNA sequences of 53 genera endemic to Chile. Using discrepancy values and a null model approach, we decoupled PD from taxon richness, in order to compare their geographic distribution over a one-degree grid. An interesting pattern was observed in which areas to the southwest appear to harbor more PD than expected by their generic richness than those areas to the north of the country. In addition, some southern areas showed more PD than expected by chance, as calculated with the null model approach. Geological history as documented by the study of ancient floras as well as glacial refuges in the coastal range of southern Chile during the quaternary seem to be consistent with the observed pattern, highlighting the importance of this area for conservation purposes.

Consideraciones sobre la sistemática de las familias y los géneros de plantas vasculares endémicos de Chile

El endemismo es uno de los principales aspectos que trata la biogeografia historica y es uno de los criterios mas importantes para establecer las prioridades de conservacion de las especies. En el mundo, mas del 90% de las plantas que se encuentra en alguna categoria de amenaza son endemicas de un solo pais. En Chile, un 45% de las especies de plantas vasculares son endemicas. Actualmente este numero incluye 83 generos y 4 familias endemicas del pais; estos son valores elevados en comparacion con el resto de Latinoamerica. Sin embargo, la alta tasa de cambios producidos por los estudios de sistematica molecular en la taxonomia ha generado modificaciones en estos numeros. Este trabajo pretende discutir dichas modificaciones y asi contribuir a la correcta delimitacion de estos generos endemicos. Utilizando bases de datos y bibliografia actualizadas, se llevo a cabo una revision exhaustiva sobre estos generos. Se sustrajeron de la lista aquellos generos con registros fuera del pais y aquellos que cuentan con evidencia suficiente para cambiar su estatus taxonomico. Se entrega una revision critica de la bibliografia sistematica respecto de los generos en cuestion, discutiendo principalmente aquellos que a la luz de la literatura presentaron ambiguedades en su clasificacion.

Phylogeny-Based Measures of Biodiversity When Data Is Scarce: Examples with the Vascular Flora of Chile and California

The urgency for conserving biodiversity has elicited much research on how to determine its “value” for conservation. The use of phylogenetic diversity (PD) has provided a quantitative framework to assess biodiversity at different taxonomic levels and spatial scales. PD assessments at any spatial resolution need a reasonably well-resolved phylogeny and distribution data for the target taxa. Because of the explosive growth of phylogenetic work, it is becoming easier to get phylogenetic information for a given group. However, distribution data is much harder to obtain. Using examples from world flora, this study explores the correlation between PD-related studies and availability of distribution data. We found that most PD studies in plants have been done in a handful of countries, which correlate with the amount of available distribution information. In order to address the question of whether PD studies should be done in places where information is scarce, we took two recent studies in which PD was calculated – the flora of Chile and California – as examples of poor and good sampling efforts of herbaria data, respectively. We randomly pruned the California database to see if and how spatial patterns of PD change with data depletion. We show that if redundancy (a measure of sampling) is kept at reasonable levels, meaning using larger grid sizes, PD patterns could still be inferred even with 25% of the original data. We argue that these studies are worth doing even with poor data sets, since even coarse PD patterns can point at places where future studies, and conservation efforts, should be focused.

Domeykoa andina (Apiaceae; Azorelloideae), a New Species from Northern Chile

Abstract This study reports a new species of Domeykoa (Apiaceae; Azorelloideae) from the Andes of northern Chile. A detailed description and an illustration of the species are provided. Diagnostic morphological characters that distinguish it from similar species are its erect habit, fewer flowers per umbel, and opposite leaves. The new species is an erect annual or short-lived perennial herb, it is glabrous, up to 25 cm high, and is profusely branched close to the base. Its umbels are simple, sessile, or sub-sessile with three or four yellow flowers. DNA was obtained for molecular phylogenetic analyses. Bayesian analyses showed that the new species, D. andina, is nested within the previously recognized Clade Eremocharis-Domeykoa, as sister to D. amplexicaulis from the southern coast of Peru. This study confirms previous findings that neither of the two genera in the clade are monophyletic, raising questions about the nomenclature. The phylogeny also suggests an interesting Peru-Chile latitudinal disjunction of more than 500 km, also seen in other recently described species. However, a more complete phylogeny is needed to make conclusions on this matter. Based on IUCN criteria and categories, we suggest assigning a critically endangered (CR) category to Domeykoa andina.

Assessing floristic representativeness in the protected areas national system of Chile: are vegetation types a good surrogate for plant species?

Conservation planning relies heavily on representativeness patterns. In Chile, this has not been assessed at the species level. This study evaluates floristic representativeness in the National System of Protected Areas (SNASPE). Species rarefaction and non-parametric estimators were used to extrapolate total representativeness. Given that conservation planning in Chile is mainly based on protecting vegetation types, the effectiveness of using vegetation types as a surrogate of plant species was evaluated based on richness and complementarity. The study found available information for 42% of the 96 protected areas of continental Chile. According to this information the SNASPE protects at least 48% of the native vascular flora. The southern area protects the largest number of species, most of which are non-endemic natives. The largest number of endemic protected species was found in the central-northern area. The SNASPE in its full range is projected to protect 64% of the vascular flora of Chile. Richness and complementarity surrogacy analyses showed weak effectiveness of vegetation types as a surrogate of plant species, although complementarity performed slightly better than richness. Surrogacy effectiveness was lower for endemic species, probably due to their narrow distributions that are more easily missed when vegetation types are considered instead.