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Morfología del cariotipo de Luma apiculata (DC.) Burret (Myrtaceae)
No full textLuma apiculata (DC.) Burret, had a symmetric karyotype, with 2n = 22 small sized chromosomes, ranging between 2.2 μηι and 0.8 μηι. The haploid karyotype formula was 9m + 2sm = 11. These karyotype characteristics of L. apiculata are a common character within Myrtaceae
Incomplete trimorphic incompatibility expression in Oxalis compacta Gill. ex Hook. et Arn. subsp. compacta in the central Chilean Andes
No full textThe expression of trimorphic incompatibility was investigated in a high altitude population of Oxalis compacta subsp. compacta distributed in the upper alpine belt (3100-3470 m) of the central Chile Andes. Stigma-anther reciprocity (2 populations), morph representation (7 populations), unassisted selfing capacity and open-pollination fruit set (6 populations) were determined. O. compacta ssp. compacta es highly dependent on external pollinators. Although it has typical tristylous flowers, considerable seed set is possible following illegitimate intermorph and intramorph cross pollination. Open pollination fruit set varied from 9-83% and on average was lower in the higher-elevation populations. The possibility of seed set following two kinds of illegitimate cross pollination is seen as a means of enhancing reproductive output by enabling more effective use of the limited pollinator resource in the high alpine environment, where fruit set shows high inter-annual variability and there is some evidence for pollination limitation in Oxalis compacta subsp. compacta
Compositional patterns of ruderal herbs in Santiago, Chile
No full textFragmentation of the natural environment is a consequence of urbanisation. It impacts the biodiversity of native flora that characterises a region. This study focused on characterising the diversity, composition and distribution of native and alien ruderal species present in different suburbs of Santiago de Chile. We found that plant assemblages of ruderal species were characterised by a higher proportion of alien species (69 taxa), whose original distribution corresponds to the Mediterranean Basin (46 taxa), and a low representation of native species (14 taxa). The results show that the spatial distribution of weeds within Santiago was not random, because two clusters were found based on patterns of compositional similarity. Further research should be undertaken to determine the cause of this phenomenon that probably obeys historical and ecological factors such as the past use of soils or urban landscape ornamentation programs
CINCO NUEVOS REGISTROS DE LIQUENES MARINOS PARA CHILE
No full textCinco especies de líquenes marinos son documentadas por primera vez en Chile: Arthopyrenia saxicola Massal., Caloplaca carphinea (Fr.) Jatta, C. thallincola (Wedd.) Du Rietz, Pertusaria rupicola (Fr.) Harm. y Xanthoria ectaneoides (Nyl.) Zahlbr. Dichos taxones fueron hallados en la Bahía de Constitución, Chile Central. Para cada taxón, se entrega una descripción basada en el material estudiado consistente en la morfología externa del talo y las características morfológicas internas de las estructuras reproductoras de cada especie. También se incluyen las reacciones químicas del talo y de algunas estructuras reproductoras, cuando el taxón lo amerita. Además se adjuntan fotografías a color de los talos de las especies estudiada
Using hyperspectral plant traits linked to photosynthetic efficiency to assess N and P partition
No full textSpatial prediction of photosynthesis requires an understanding of how foliage nitrogen (N) and phosphorus (P) regulate this process and the relationship between these elements and scalable spectral proxies. Hyperspectral imagery has been used to predict important photosynthetic variables such as the maximum rate of carboxylation (V-cmax) and electron transport (J(max)). However, our understanding of how generally applicable these relationships are for plants that are limited by N and P, characterised by respective mass based ratios of N/P 10, is still incomplete as most studies assume N and P co-limit photosynthesis.
Hyperspectral imagery and measurements of photosynthesis were obtained from one-year old Pinus radiata D. Don, grown under a factorial combination of N and P treatments. Using these data, the objectives of this study were to (i) identify whether trees were co-limited or independently limited by N and P, and then use hyperspectral imagery to (ii) partition N and P limited trees, (iii) build models of N and P from a range of hyperspectral indices and (iv) explore links between key plant traits and both V-cmax and J(max).
Compared to the use of all data, which assumes co-limitation, markedly stronger relationships between N and P and photosynthetic capacity were obtained through splitting data at N/P = 10 (independent limitation) for both V-cmax (R-2 = 0.40 vs. 0.59) and J(max) (R-2 = 0.38 vs. 0.64). A random forest model was used to accurately partition N from P limited trees and the two main variables used within this model were Photochemical Reflectance Index (PRI) and Solar-Induced Chlorophyll Fluorescence (SIF). Using data from the P limiting phase, the most precise models of P were created using PRI (R-2 = 0.75) and SIF (R-2 = 0.52). Indices that were proxies for chlorophyll were the most precise predictors of N within the N limiting phase but strong positive relationships were also evident between N and both PRI (R-2 = 0.83) and SIF (R-2 = 0.57). Through their correlations with N and P, there were strong positive relationships between both SIF, PRI and V-cmax (R-2 = 0.78 and 0.83, respectively) and J(max) (R-2 = 0.80 and 0.83, respectively) that were generalisable across both N and P limiting ranges. These results suggest that quantified SIF and PRI from hyperspectral images may have greater precision and generality for predicting both foliage nutrition and biochemical limitations to photosynthesis than other widely used hyperspectral indices
Antecedentes poblacionales de Chaptalia exscapa (Pers.) Baker var. chilensis (DC.) Burkart en la provincia de Talca, Chile central
No full textWe examine the distribution and ecology of Chaptalia exscapa (Pers.) Baker var. chilensis (DC.) Burkart in the Talca Province, Maule Region. It is reports new data related to the morphology of the plant and the presence of Chaptalia in four new localities in the Maule Region. The populations present a high vulnerability due low population size and disturbed habitat. Flowering and fructification of individuals is scanty
Estudio de la relación polen-vegetación actual en el Norte de Chile, en el transecto Pozo Almonte-Salar de Huasco (20º15’S/69º06’O)
No full textLa diversidad vegetal de la zona andina del Norte Grande de Chile ha sido estudiada desde diversos puntos de vista (florísticos, fisonómicos, etnobotánicos, conservacionistas, etc.); sin embargo, hasta ahora no se ha estudiado desde un punto de vista palinológico. Así, este trabajo tiene como objetivo aportar al conocimiento de la vegetación y su señal polínica en los distintos pisos altitudinales del Norte Grande de Chile, aportando además a la identificación de los principales tipos polínicos presentes. Este estudio presenta la relación entre lluvia de polen y vegetación actual en un transecto altitudinal entre Pozo Almonte y el Salar de Huasco, en el norte de Chile, junto con fotografías y descripciones de 12 morfotipos polínicos representativos de la zona. Los resultados de los muestreos de vegetación corroboran las tendencias descritas en trabajos previos identificándose los principales pisos de vegetación descritos anteriormente (piso prepuneño, puneño, altoandino y subnival). De igual manera los resultados de la lluvia de polen muestran una clara relación con los ensambles de vegetación que la produce, siendo posible diferenciar cada uno de los pisos de vegetación a partir de su señal polínica. Así, los resultados pueden ser de gran interés para la interpretación de registros polínicos fósiles o para estudios de carácter ecológico
Karyotypic studies in the Chilean genus Placea (Amaryllidaceae)
No full textChromosome numbers and karyotypes of seven specific taxa of the Chilean endemic genus Placea were determined. Chromosome numbers of P. lutea, P. ornata, P grandiflora, P germainii andP. aff davidii are described for the first time. All taxa are diploid with 2«=2x=16 and karyotypes are composed of four metacentric (4 m), ten submetacentric (10 sm), and two subtelocentric (2 st) chromosomes. The most symmetrical karyotype was observed in P. lutea (AI: 6.84) while the most asymmetrical karyotype was shown by P. arzae (AI: 9.72). The constancy in karyotype formulae and high similarity in asymmetry indexes suggest that some orthoselection mechanism might be involved in Placea's chromosomal evolution. In spite that no significant karyotypic differences were observed, the species may be differentiated by their chromosomal sizes. Moreover, the tribal position of Placea and its likely relationships with other hippeastroid genera are discussed
Productos de Ingeniería en madera
Get PDF27 páginasEl propósito de este documento es aportar al sector forestal-maderero información de valor estratégico que pueda contribuir de forma positiva a los diversos actores que hoy desarrollan sus trabajos e investigaciones en el área de productos de madera para la construcción en el país.
En el documento se presenta una revisión y descripción de los productos de ingeniería en madera (EWP-Engineered Wood Products) que han desempeñado un papel importante en la innovación de materiales de construcción durante las últimas tres décadas y que son el resultado de la aplicación de la ciencia e ingeniería de materiales en el proceso de utilización óptima de componentes de madera
Validación de Alstroemeria parvula Phil. (Alstroemeriaceae)
No full textAlstroemeria parvula Phil., is validated according to new recollections and observations in the Central Chilean Andes. It is redescribed and new localities are included confirming that it is solely protected in the private reserve and RAMSAR Site "Parque Andino Juncal"