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DANTHONIA DECUMBENS(DANTHONIAE, POACEAE), NUEVA ESPECIE ADVENTICIA PARA LA FLORA DE CHILE CONTINENTAL
No full textThis article reports the finding of Danthonia decumbens (L.) DC. in the surrounding of Puerto Montt(41°26' S;73°05' W) in the south of Chile, which also constitutes the first register of this European grass in South America
Evidencia de ADN ribosomal y del cloroplasto para la diversificaciOn de las PortulacAceas de AmErica occidental en la regiOn andina
No full textSe determinaron las secuencias del espaciador interno (ITS) del ADN ribosomal y del espaciador intergénico de ycf3-trnS del ADN del cloroplasto para 183 muestras de taxas, chilenos y no chilenos, de Portulacaceae de América occidental, y sus grupos externos. Los datos permiten refinar previas inferencias sobre la circunscripción e interrelaciones de los géneros estudiados. En particular estos datos revelan que una circunscripción anteriormente publicada de Cistanthe Spach es polifilética y también revelan la existencia de un clado norteamericano compuesto por Claytonia L., Lewisia Pursh, Lewisiopsis R. Govaerts, and Montia L. De los datos de los géneros sudamericanos surgieron dos patrones: (1) en algunos casos la divergencia interespecífica es notablemente baja dado los marcadores empleados y el número estimado de especies; y (2) en cuanto la divergencia de uno o de los dos marcadores ofrecen resolución filogenética, existen conflictos entre ellos y/o entre la morfología. Estos patrones pueden ser interpretados en términos de dos fenómenos: diversificación morfológica/ecológica siguiendo más rápida que la divergencia en las secuencias; y (2) frecuente hibridación. Este alto grado de hibridación sugiere que el árbol filogenético molecular puede representar mal el patrón temporal, morfológico y ecológico de diversificación de estas especies. Al presente no es claro si la hibridación es una regla o una excepción entre las Portulacaceae chilenas. No obstante, en Chile las condiciones ecológicas, espaciales y temporales, son en general favorables para la formación y persistencia de híbrido
Leaf litter hides post-dispersed seeds from invasive alien removers in a sclerophyll forest in central Chile
No full textAim of study: Seed removal may be a determining filter for regeneration. Factors such as leaf litter, tree cover and seed density affect seed removal. This aims to assess three aspects involving on post dispersal seed removal of four woody species (Lithraea caustica, Maytenus boaria, Quillaja saponaria and Retanilla ephedra) of a sclerophyll forest.
Area of study: Andean Mediterranean sclerophyll forest of Quillaja saponaria and Lithraea caustica located in the Rio de Los Cipreses National Reserve, Chile.
Material and methods: Seven experimental plots were set up, in which seeds were offered in an experiment with variations in leaf litter, tree cover and seed density. Generalized Linear Mixed Models (GLMM) were used for the statistical analysis. Camera traps were installed to identify the seed removers.
Main results: Q. saponaria seeds were more removed than the seeds of the other species (0.84, observed mean). Whereas that M. boaria and R. ephedra did not show significant differences on the removal of their seeds (0.77 and 0.67 respectively), both were more removed than L. caustica (0.59). The removal of M. boaria, Q. saponaria and R. ephedra seeds was lower in the presence of leaf litter. No factor influenced the removal of L. caustica seeds. Seed removers were identified as invasive alien species such as Rattus sp. and Oryctolagus cuniculus and native species such as Lycalopex culpaeus.
Research highlights: Three woody species of this forest suffer severe seed removal by invasive alien fauna with major implications for the resilience of these forests. The coverage of leaf litter is key to hide away the seeds, increasing survival and could promote germination
CYCLOTELLA OCELLATA PANTOCSEK (BACILLARIOPHYCEAE): PRIMERA CITA EN CHILE Y COMENTARIOS SOBRE SU VARIABILIDAD MORFOLOGICA
No full textCyclotella ocellata Pantocsek es señalada por primera vez para las aguas continentales de Chile, encontrada en una muestra recolectada en el embalse Rapel (34º02'S, 71º35'W). Se entrega una descripción de la especie y comentarios relacionados con su variabilidad morfológic
Valor sistemático de la epidermis abaxial de la lámina foliar en especies americanas del género Trisetum Pers. (Poaceae: Pooideae: Aveninae)
No full textSe estudió la epidermis abaxial de la lámina foliar en 29 especies y 3 variedades del género Trisetum s.s. Adicionalmente, se incluyó a Deschampsia brasiliensis (Louis-Marie) Valencia (= Trisetum brasiliense Louis-Marie), Helictotrichon bulbosum (Hitchc.) Parodi (= T. bulbosum Hitchc.) y Peyritschia deyeuxioides (Kunth) Finot (= T. deyeuxioides Kunth). Además, se realizaron observaciones de la epidermis adaxial en algunas especies sudamericanas, utilizando microscopio electrónico de barrido (MEB). Se confeccionó una matriz básica de datos (35 OTUs x 17 caracteres de la epidermis abaxial), a la que se aplicó análisis de agrupamientos (UPGMA) y análisis de componentes principales (ACP). Se reconoció cuatro grupos de especies: 1. Deschampsia brasiliensis. 2. Helictotrichon bulbosum. 3. Subg. Deschampsioideum (Louis-Marie) Finot (T. durangense Finot & P.M.Peterson, T. filifolium Scribn. ex Beal, T. palmeri Hitchc., T. tonduzii Hitchc., T. viride (Kunth) Kunth y T. virletii E.Fourn.), T. pringlei (Scribn. ex Beal) Hitchc. y T. rosei Scribn. & Merr. (Subg. Trisetum) . 4. Subg. Trisetum. Las secciones Trisetum y Trisaetera Asch. & Graebn., no pueden distinguirse, así como no es posible distinguir Trisetum de Peyritschia E.Fourn. sobre la base de los caracteres estudiados
The effect of chilling on seed germination of placea species (Asparagales: Amaryllidaceae), an endemic genus to central Chile
No full textThe effect of chilling on germination was examined for six Placea species, a genus in the Amaryllidaceae endemic to the Andes and Coastal Range of central Chile. Based on their natural environment, we hypothesized that low temperatures would be important for germination in theses species. We addressed two questions (i) do Placea seeds require chilling for seed germination? (ii) if they required chilling, does thermal history before chilling affect their responsivity to chilling? At 4ºC seeds of all species germinated faster and to a higher level than at 25ºC. After 28 days, when seeds held at 25ºC were moved to 4ºC, germination increased significantly, however at the end of the assay, their germination was still lower than those seeds initially at 4ºC. Thus, Placea seeds required chilling for germinate. Seeds of Placea species might have physiological dormancy or might be non-dormant but with narrow and low range of temperature that are optimal for germinatio
COMPARATIVE FOLIAR EPIDERMAL MORPHOLOGY OF THE WEST AFRICAN SPECIES OF THE GENUS AFZELIA SMITH (LEGUMINOSAE: AESALPINIOIDEAE)
No full textThe epidermal features of the leaves of the six West African species of Afzelia were examined and compared using light and scanning electron microscopy. The leaves are hypostomatic in all species and stomatal type is paracytic. Anticlinal walls may be undulate or straight-curved and stomatal index ranges from 17.48% in A. bella var. gracilior to 25.20% in A. bipindensis. Porrect and flattened scales distinguish the infra-specific taxa of A. bella while presence of unicellular trichomes separates A. pachyloba from other species. The leaf surface is entirely covered by epicuticular wax deposits and the stomata are either raised or sunken in the genus. Using these foliar epidermal characters, an artificial key has been prepared to facilitate identification of the species
FRUIT (PERICARP AND SEED) ONTOGENY OF SIDA SPECIES
No full textFruits (pericarps and seeds) of the weedy species Sida rhombifolia L., S. urens L. and S. regnellii R. E. Fr. were analyzed structurally using light and scanning electron microscopy. The yellowish brown calyx is persistent on the mature fruit and consists of a crystalliferous hypodermis with U-shaped wall thickenings and homogeneous mesophyll. Fruits are schizocarpic, of the subtype coccarium, with a fibrous endocarp. Seeds are exotegmic and the embryos are clearly bent, with folded cotyledons. Structural features that are potentially significant to species' characterization are the structure of the ovary, the morphology of the mericarp apex, the pattern of the reticulate sclerenchymatous endocarp and the presence or absence of nonglandular trichomes in the hilum and funiculus of the seed
Incorporando la multifuncionalidad en la evaluación económica de proyectos de restauración de bosques nativos siempreverdes en el sur de Chile
Get PDFpáginas 23-40Se evaluó la factibilidad económica de implementar iniciativas de restauración de bosques del Tipo Forestal Siempreverde, incorporando un análisis de costos y beneficios asociados a la ejecución de las actividades de manejo forestal y los retornos económicos potenciales por la comercialización de madera y de los servicios ecosistémicos secuestro de carbono y producción de miel