Spatial pattern of regeneration of two woody species in a logged area in Paranaense Forest

Los patrones de regeneración de las especies vegetales determinan la estructura de la comunidad madura y brindan información que posibilita el aprovechamiento racional de las especies más valiosas. En este trabajo se analizó el patrón espacial de la regeneración de Cabralea canjerana (Vell.) Mart. y Balfourodendron riedelianum (Eng.) Eng. en un área aprovechada de la Selva Paranaense en la provincia de Misiones, Argentina. De manera específica se evaluó la aparición eventual de agrupamientos en la regeneración, la manifestación de patrones atribuibles a potenciales procesos denso-dependientes en relación a los individuos conespecíficos adultos y patrones compatibles con la existencia de procesos de facilitación por parte de individuos adultos del resto de las especies. Los renovales de ambas especies presentaron patrones agregados hasta los 15 m. La regeneración y los individuos adultos conespecíficos de C. canjerana mostraron relaciones positivas a distancias entre los 5 y 10 m, mientras que la regeneración de B. riedelianum presentó un patrón al azar a corta distancia y asociación positiva a partir de los 5 m respecto a los individuos conespecíficos adultos. La relación de los renovales respecto a los individuos adultos de todas las especies presentó relaciones positivas en C. canjerana hasta los 10 m, mientras que B. riedelianum se asoció a partir de los 10 m de distancia. Los patrones de la regeneración de C. canjerana podrían ser atribuidos a los mecanismos de dispersión primaria y secundaria de la especie. En el caso de B. riedelianum, los patrones encontrados podrían originarse por la limitación en la dispersión de las semillas, lo cual pone en evidencia su dependencia de la presencia de individuos adultos para la regeneración.The regeneration patterns of plants determine the structure of mature communities and provide usefull information to ensure the rational use of valuables species. In this study, the spatial regeneration pattern of Cabralea canjerana (Vell.) Mart. and Balfourodendron riedelianum (Eng.) Eng. was studied in a remnant sector of Paranaense Forest in Misiones province, Argentine. We evaluated the regeneration clustering, also the related patterns with conspecific adults trees potentially linked to density dependent process; and the existence of facilitation process related to the adult trees from all species. All trees were mapped in 4 replications of 100 x 100 m plots. Univariate and bivariate point pattern analysis were carried out using Wiegand & Moloney "O" ring index. Both species have showed a regeneration in aggregated pattern for distances up to 15 m. A positive relationship was verified for distances between 5 and 10 m for C. canjerana regeneration and conespecific adult trees; and the regeneration of B. riedelianum showed a random pattern in short distances (<5 m) and a positive association for larger distances of 10 m with their conspecific adult trees. The relationship between C. canjerana regeneration and adult trees from all species was positive at distances of 10 m, whereas B. riedelianum showed association at 10 m onward. The observed regeneration patterns of C. canjerana could be due to the primary and secondary dispersal mechanism of the species. On the other side, the observed patterns of B. riedelianum may represent a seed dispersal limitation, but the regeneration depends on the presence of adult trees of this species

La arquitectura foliar de las especies de Lauraceae Nativas de Misiones, Argentina.

Leaf architecture of native Lauraceae species from Misiones, Argentina. The leaf architecture of 12 woody species of Lauraceae family that grows in Province of Misiones (Argentina) was studied with the aim of contributing to knowledge of them. The species are characterized by simple leaves, petioles, apex usually acuminate and with or without domatia. Venation patterns first, second, third, fourth and fifth order were described and illustrated for the species studied; these one presents the secondary venation from several types: brochidodromous (Nectandra megapotamica, Cryptocarya aschersoniana, Ocotea diospyrifolia, Endlicheria paniculata, Ocotea puberula and Ocotea sp.) acrodromous suprabasal imperfect -brochidrodromous (Cinnamomum amoenum, Ocotea pulchella), craspedodromous (Ocotea acutifolia) and eucamtodromous-brochidodromous (Nectandra lanceolata, Nectandra angustifolia,  Ocotea lancifolia). Areoles density was observed as an important diagnostic character; not being the case on the number of sides they have. All species showed paracytic stomata. The characters analyzed, together with morphologic and epidermal, allowed differentiation of the 12 tested species, demonstrating the importance of leaf architecture in vegetative state recognition. First time for the Argentinian flora, Endlicheria paniculata is mentioned in this contribution.La arquitectura foliar de 12 especies leñosas de la familia Lauraceae que crecen en la Provincia de Misiones (Argentina) fueron estudiadas con el objetivo de contribuir al conocimiento de las acuminado y con o sin domacios. Los patrones de venación de primero, segundo, tercero, cuarto y quinto orden fueron descriptos e ilustrados para las especies estudiadas; éstas presentan una venación secundaria de varios tipos: broquidódroma (Nectandra megapotamica, Cryptocarya aschersoniana, Ocotea diospyrifolia, Endlicheria paniculata, Ocotea puberula y Ocotea sp.), acródroma suprabasal imperfecta-broquidódroma (Cinnamomum amoenum, Ocotea pulchella), craspedódroma (Ocotea acutifolia) y eucantódromo-broquidódroma (Nectandra lanceolata, Nectandra angustifolia, Ocotea lancifolia). La densidad de areolas fue observada como un carácter diagnóstico importante; no siendo el caso del número de lados que éstas poseen. Todas las especies presentaron estomas paracíticos. Los caracteres analizados, junto con los morfológicos y epidérmicos, permitieron la diferenciación de las 12 especies estudiadas, evidenciando la importancia de la arquitectura foliar en el reconocimiento en estadovegetativo. Por primera vez para la flora Argentina, Endlicheria paniculata es citada en esta contribución.

Phyllosticta citricarpa and sister species of global importance to Citrus.

Several Phyllosticta species are known as pathogens of Citrus spp., and are responsible for various disease symptoms including leaf and fruit spots. One of the most important species is P. citricarpa, which causes a foliar and fruit disease called citrus black spot. The Phyllosticta species occurring on citrus can most effectively be distinguished from P. citricarpa by means of multilocus DNA sequence data. Recent studies also demonstrated P. citricarpa to be heterothallic, and reported successful mating in the laboratory. Since the domestication of citrus, different clones of P. citricarpa have escaped Asia to other continents via trade routes, with obvious disease management consequences. This pathogen profile represents a comprehensive literature review of this pathogen and allied taxa associated with citrus, focusing on identification, distribution, genomics, epidemiology and disease management. This review also considers the knowledge emerging from seven genomes of Phyllosticta spp., demonstrating unknown aspects of these species, including their mating behaviour.TaxonomyPhyllosticta citricarpa (McAlpine) Aa, 1973. Kingdom Fungi, Phylum Ascomycota, Class Dothideomycetes, Order Botryosphaeriales, Family Phyllostictaceae, Genus Phyllosticta, Species citricarpa.Host rangeConfirmed on more than 12 Citrus species, Phyllosticta citricarpa has only been found on plant species in the Rutaceae.Disease symptomsP. citricarpa causes diverse symptoms such as hard spot, virulent spot, false melanose and freckle spot on fruit, and necrotic lesions on leaves and twigs.Useful websitesDOE Joint Genome Institute MycoCosm portals for the Phyllosticta capitalensis (https://genome.jgi.doe.gov/Phycap1), P. citriasiana (https://genome.jgi.doe.gov/Phycit1), P. citribraziliensis (https://genome.jgi.doe.gov/Phcit1), P. citrichinaensis (https://genome.jgi.doe.gov/Phcitr1), P. citricarpa (https://genome.jgi.doe.gov/Phycitr1, https://genome.jgi.doe.gov/Phycpc1), P. paracitricarpa (https://genome.jgi.doe.gov/Phy27169) genomes. All available Phyllosticta genomes on MycoCosm can be viewed at https://genome.jgi.doe.gov/Phyllosticta

The spectral (UV, VIS, NIR) optical properties of 17 materials similar to lunar and asteroidal regoliths in terms of the parameters of Hapke's photometric function

Modern multispectral remote sensing techniques provide information about the spectral and the angle dependency of the reflected solar radiation of planetary surfaces. With the DLR-Goniospectrometer it is possible to simulate the remote sensing scenario and to investi- gate the spectral and optical scattering properties of materials similar to planetary regoliths. Comparison of such laboratory data with remote sensing data is then performed in terms of the spectral parameters of Hapke's photometric function. The analysis of the spectral Hapke-parameters of 17 materials in the UV, VIS and NIR and comparison of these datasets with remote sensing data of the lunar surface and the asteroid Gaspra gives insights intoscattering mechanisms. It thus shows that scattering depends on the microstructure of the different materials and that the Hapke-functionallows to compare spectrophotometric remote sensing data with laboratory data quantitatively

Berechnung der Beleuchtungsgeometrien für die Untersuchung von spektralen Eigenschaften an der Mars-Pathfinder-Landestelle

Unter Verwendung der IMP (Imager for Mars Patahfinder) Stereo-Bilddaten wurde im Nahbereich (ca 50 m) des Länder in einem 360° Radius ein digitales Geländemodell erstellt. Mit diesem und dem Sonnenstandsvektor, bestimmt durch den Bildaufnahmezeitpunkt auf dem Mars und den Marslander Koordinaten, wurden die Oberflächennormalen sowie die Einfalls-, und Ausfalls- und Phasenwinkel berechnet. Um Korrelationen zwischen spektralen Eigenschaften und Beleuchtungsgeometrien festzustellen, wurde eine unüberwachte Klassifikation mit mindestens 4 Spektralkanälen durchgeführt. Die so berechneten Cluster wurden nun direkt den Beleuchtungsgeometrien zugeordnet und verglichen