LiDAR Scan Density and Spatial Resolution Effects on Vegetation Fuel Type Mapping

This article presents the performance of a vegetation fuel type (FT) classification based on conditional rules according to the Prometheus system, including an analysis of the effect of cell size and scan density on mapping vertical structural types, exemplified as FT, using exclusively LiDAR data. Since the Prometheus system does not specify any criterion for the minimum extension where those methodologies can be applied, we searched for the optimal classification cell size by gridding the study area at 20 and 40 m cell sizes. We also included a study of the effects of varying the scan density from 2 to 0.5 pulses·m-2. To validate the classification method, we used a stratified random sampling without replacement of 15 cells per FT and made an independent visual assessment of FTs. The best results in terms of precision were obtained for the combination of 0.5 pulses·m-2 and 20 m-resolution dataset, with an overall accuracy of 84.13%. It was also showed that an increase in scan density would not improve the global accuracy of the classification, but it would be desirable for a better detection of the shrub stratum

Synthetic seed production from encapsulated somatic embryos of cork oak (Quercus suber L.) and automated growth monitoring.

Cork oak (Quercus suber) somatic embryos were coatedwith alginate for the production of synthetic seeds and their storability for commercialization was investigated. Also, the automatic monitoring of somatic embryo growth with a digital system of image capture was tested.Apower regressionmodelwasfitted between size and fresh weight (Adjusted R-squared = 0.96). This method permitted growth assessment without contamination risk and opens the possibility of an automated control of culture growth for the future up scaling of plant production. Conversion rate of synthetic seedswas higher onmediumsupplementedwithmineral nutrients than onmediumwithout nutrients. Also, when the somatic embryos were coated without mineral nutrients added to the capsule, conversion rate was significantly lower. The addition of sucrose to the capsule had no significant effect on the conversion rate. No differences were recorded between 50 and 100 mM CaCl2 for capsule complexation. Synthetic seeds were cold stored at 4_C for two months without significant loss of conversion capacity. The present study reports the first attempts to determine optimal storage time and conditions for conversion of encapsulated somatic embryos of cork oak

De la cartographie a la géo-information: trois décennies de service publique à l’administration régionale andalouse

Treinta años de gestión autonómica en torno a una materia como la cartografía, que al calor de las nuevas tecnologías ha evolucionado tanto en los últimos tiempos, aportan en el caso andaluz, una dilatada experiencia que es la que el presente trabajo pretende recoger. Este artículo muestra como, partiendo de una situación precaria en cuanto a la disponibilidad de cartografía, para la gestión de competencias vinculadas al planeamiento y la ordenación del territorio, se pasa a una producción propia que, con el tiempo, en atención a las nuevas demandas de la administración y la sociedad, se va diversificando, dejando atrás el sesgo sectorial con el que la labor cartográfica fue concebida, para convertirse en una actividad horizontal en el seno de la administración, papel que se refuerza a raíz de la confluencia, en un mismo organismo, el Instituto de Estadística y Cartografía de Andalucía, de las competencias en materia cartográfica y estadística.Thirty years of regional management about a subject such as cartography, which in the heat of new technology has evolved so much in recent years, contributing in the Andalusian case, an extensive experience which is what this paper aims to demonstrate. This article shows how, starting from a precarious situation regarding the availability of cartography, competency management related to planning and land use, and passed to a self-production which, over time , in response to the administration and society demands, is becoming more diversified. It is behind the character with which the sector of cartographic work was conceived, to become a horizontal activity within the administration, a role that is reinforced because of the confluence, in same office, the Institute of Statistics and Cartography of Andalusia, to skills in cartography and statistics.Trente ans de gestion régionale sur un sujet tel que la cartographie, qui dans la chaleur de nouvelles technologies a tellement évolué au cours des dernières années, contribuant dans le cas andalouse, il y a une vaste expérience qui est ce que ce document vise à recueillir. Cet article montre comment, à partir d’une situation précaire en ce qui concerne la disponibilité de la cartographie pour la gestion des compétences en matière de planification et d’ aménagement du territoire, est passé à une production qui, au fil du temps, en réponse aux nouvelles exigences administration et de la société, sont de plus en plus diversifiée. Laissant derrière le caractère sectoriel avec lequel le travail de cartographie a été conçu, l’information geographique devient a une activité horizontale au sein de l’administration , un rôle qui est renforcée en raison de la confluence, une même corps, l’Institut de la Statistique et de la Cartographie de l’Andalousie, des compétences en matière de cartographie et des statistiques

Sap flow, leaf-level gas exchange and spectral responses to drought in Pinus sylvestris, Pinus pinea and Pinus halepensis

In a climate change scenario, Mediterranean forest species such as pines may be endangered by rising temperatures and reduced precipitation, thus calling for studies on the transpiration and water balance in pines. In this paper, the response of young plants of Pinus sylvestris L., Pinus pinea L. and Pinus halepensis Mill. to different irrigation treatments has been studied. Significant differences were found in water potential, sap flow, leaf-level gas exchange and spectral variables. P. sylvestris had higher pre-dawn and midday water potentials, sap flow rates and leaf-level gas exchange rates compared to the other two species in well-watered conditions. Vapor pressure gradient correlated with stomatal conductance, net assimilation and transpiration, but the association between stomatal conductance and sap flow was weak. The environmental variables more strongly associated with sap flow were solar radiation and reference evapo-transpiration, especially in the well-watered plants, but those associations were weaker in the stressed plants. All three pine species showed the isohydric, drought-avoiding strategy common in the genus Pinus, maintaining relatively high water potentials in dry conditions. Nevertheless, P. halepensis showed a water-saving strategy, with a stomatal closure behavior under drought. Stomatal regulation was less strict in P. sylvestris, closer to a water-spending pattern, while P. pinea showed an intermediate behavior. Significant differences were recorded among species in spectral reflectance in the visible and infra-red regions. Photochemical Reflectance Index, Normalized Difference Vegetation Index and combinations of other ratios permitted the discrimination among the three pine species. These spectral variables showed association with sap flow rate, water potential and leaflevel gas exchange variables. Both cluster analysis and k-means classification discriminated Scots pine and Aleppo pine in two different groups. On the other hand, Stone pine showed differences in spectral behavior depending on the hydric status of the plants. Well-watered Stone pine plants had the same spectral behavior as Scots pine, while the plants subjected to drought stress were closer to Aleppo pine plants in spectral response. These findings may help to quantify the impacts of early and mid-summer water deficit on Mediterranean pines in future climate regimes

Mean height and variability of height derived from Lidar data and Landsat images relationship

The mean height and standard deviat ion of the height of the forest canopy, derived from lidar data show to be important variables to summarize forest st ructure. However lidar data has a limited spat ial extent and very high economic cost . Landsat data provide useful st ructural informat ion in the horizontal plane and have easy access. The integrat ion of both data sources is an interest ing goal for sustainable forest management. Different spect ral indices (NDVI and Tasseled Cap) were obtained from 3 Landsat scenes (March 2000, June 2001 and September 2001). In addit ion, mean and standard deviat ion of lidar height werecalculated in 30x30m blocks. Correlat ion and forward stepwise regression analysis was applied between these two variables sets. Best correlat ion coefficients are achieved among mean lidar height versus NDVI and wetness for the three dates (range between 0.65 to -0.73). Others authors indicate that wetness is one of the best spectral indices to characterize forest st ructure. Best regression models include NDVI and wetness of June and September as dependent variables (adjusted r2: 0.55 – 0.62). These results show that lidar data can be useful for training Landsat to map forest st ructure but it should be interest ing to opt imize this approach

Lidar and true-orthorectification of infrared aerial imagery of high Pinus sylvestris forest in mountainous relief

Combination of various data sources has been demonstrated more effective than using them separately. Information retrieval is significantly improved by synergies between laser scanner and optical imagery. Digital photography relies on traditional methods for orthorectification in order to accomplish an accurate correspondence with Lidar. We investigated combinatorial techniques in a high pine forest situated in mountainous relief in the Guadarrama Range (Spain). Results have shown critical inaccuracies in the integration of these data, even when obtained simultaneously. We propose the use of Lidar-derived Digital Surface Model in the process of orthorectification of aerial imagery. We hypothesised that the use of true-orthophoto techniques for improving the planimetric accuracy of VHR can be reliable for forestry applications. The methodology slightly improved the geometrical results obtained, though radiometric results might be meaningless. Consequently, other possible solutions are also discussed

LINHE Project: Development of new protocols for the integration of digital cameras and LiDAR, NIR and Hyperspectral sensors.

The LINHE project aims to develop applications for forest management based on the combined use of LiDAR data, images from spaceborne (multi and hyperspectral) and airborne sensors (panchromatic, colour, near infrared), and NIR field data from a portable sensor. The integration of the different types of data should be performed in a rapid, intuitive, cost-effective and dynamic way. In order to achieve this objective, new algorithms were developed and existing ones were tested, for the correlation of data collected in the field and those gathered by the different sensors. Specific software (LINHE prototype viewer) was developed to support data gathering and consultations, and it was tested in three different forest ecosystems, so as to validate the tool for forest management purposes. The optimisation of the synergic capabilities derived from the combined use of the different sensors will allow the enhancement of their efficiency and provide accurate information for operational forestry

Role of synthetic plant extracts on the production of silver-derived nanoparticles

The main antioxidants present in plant extracts—quercetin, β-carotene, gallic acid, ascorbic acid, hydroxybenzoic acid, caffeic acid, catechin and scopoletin—are able to synthesize silver nanoparticles when reacting with a Ag NO3 solution. The UV-visible absorption spectrum recorded with most of the antioxidants shows the characteristic surface plasmon resonance band of silver nanoparticles. Nanoparticles synthesised with ascorbic, hydroxybenzoic, caffeic, and gallic acids and scopoletin are spherical. Nanoparticles synthesised with quercetin are grouped together to form micellar structures. Nanoparticles synthesised by β-carotene, were triangular and polyhedral forms with truncated corners. Pentagonal nanoparticles were synthesized with catechin. We used Fourier-transform infrared spectroscopy to check that the biomolecules coat the synthesised silver nanoparticles. X-ray powder diffractograms showed the presence of silver, AgO, Ag2O, Ag3O4 and Ag2O3 . Rod-like structures were obtained with quercetin and gallic acid and cookie-like structures in the nanoparticles obtained with scopoletin, as a consequence of their reactivity with cyanide. This analysis explained the role played by the various agents responsible for the bio-reduction triggered by nanoparticle synthesis in their shape, size and activity. This will facilitate targeted synthesis and the application of biotechnological techniques to optimise the green synthesis of nanoparticles