Assessment of the Accuracy of a Multi-Beam LED Scanner Sensor for Measuring Olive Canopies

MDPI. CC BYCanopy characterization has become important when trying to optimize any kind of agricultural operation in high-growing crops, such as olive. Many sensors and techniques have reported satisfactory results in these approaches and in this work a 2D laser scanner was explored for measuring canopy trees in real-time conditions. The sensor was tested in both laboratory and field conditions to check its accuracy, its cone width, and its ability to characterize olive canopies in situ. The sensor was mounted on a mast and tested in laboratory conditions to check: (i) its accuracy at different measurement distances; (ii) its measurement cone width with different reflectivity targets; and (iii) the influence of the target’s density on its accuracy. The field tests involved both isolated and hedgerow orchards, in which the measurements were taken manually and with the sensor. The canopy volume was estimated with a methodology consisting of revolving or extruding the canopy contour. The sensor showed high accuracy in the laboratory test, except for the measurements performed at 1.0 m distance, with 60 mm error (6%). Otherwise, error remained below 20 mm (1% relative error). The cone width depended on the target reflectivity. The accuracy decreased with the target density

Spatial priorities for freshwater fish conservation in relation to protected areas

Abstract1. Freshwater habitats are vital for both humans and nature owing to theirexceptional biodiversity and valuable ecosystem services, but they are currentlyfacing serious threats. The designation and management of protected areas havebeen proposed as the most feasible way to ensure conservation objectives for thefuture. However, traditional approaches have not protected freshwater faunaeffectively, especially freshwater fish.2. Previous studies have identified the most irreplaceable terrestrial places toachieve conservation goals. Here, the aim was to investigate how the presentnetwork of protected areas preserves irreplaceable rivers for freshwater fish.3. The irreplaceability of the world's river basins was calculated using InternationalUnion for the Conservation of Nature Red List distribution maps, considering therarity, richness, and conservation status of their freshwater fish fauna. Theoverlap between irreplaceable basins and the present network of protected areaswas also calculated.4. The results highlight the conservation significance of tropical rivers, particularlythose in the Neotropics. The subset of the basins covering 30% of the mostirreplaceable land surface (in line with the United Nations 30by30 target)encompasses 99% of freshwater fish species. However, protected areas do notseem to provide sufficient protection to these basins, as 89% of their surface arealies outside protected areas. Only 7% of freshwater ecoregions meet the UnitedNations 30by30 target.5. Given the context of climate change, allocating new protected areas becomescrucial in providing better survival opportunities for freshwater fish species.Despite the limitations inherent to the absence of total knowledge of freshwaterfish biogeography and the irreplaceability index itself, this study identifies prioritysites for their conservation that may help inform decision-making in the future toestablish more effective protected areas

From expert to data-driven biodiversity knowledge: assessing ecosystem irreplaceability with IUCN red list data for freshwater fish

Critical as they are for humans and nature, freshwater ecosystems are threatened-but the extent and depth of these threats are not well understood, especially if essential biodiversity data are lacking. Any policy aimed at protecting such ecosystems must first assess the threat factors and the potential harm, well before proposing conservation measures such as the creation and development of Protected Areas (PAs). These assessments must be done using a deep and sound knowledge of the actual and potential biodiversity variables. Freshwater ecosystems have been largely neglected in traditional PA design and management (Abell et al. 2007), be it for scarcity of biodiversity data, or for more perception-related reasons such as visibility and accessibility driving the allocation of conservation resources to more data-rich environments

Ecology and conservation of freshwater fishes biodiversity: we need more knowledge to develop conservation strategies

Freshwater fish represent one-fourth of all vertebrate species, despite freshwater occupying less than 1% of the Earth’s surface [...

Analysing freshwater fish biodiversity records and respective conservation areas in Spain

The number of threatened freshwater fish species in Spain is among the highest recorded in Europe and includes a high percentage of endemic taxa. We investigated the distribution of Spanish freshwater fish to identify priority areas for conservation and assess the extent to which freshwater fish are included in the existing network of protected areas. We considered those threatened species recorded in the Spanish National inventories. From these data, several biodiversity indices were calculated and analysed. Our results reveal important discrepancies between the national and international assessments of conservation status. The current Spanish national catalogue requires updating to reconcile these inconsistencies. Several important areas for the conservation of freshwater fish lie outside protected areas. Our results encourage the establishment of protected areas specifically for freshwater environments. An extensive database of Spanish freshwater fish species is needed to redefine priority areas and to maintain freshwater biodiversity

Radiales time series: 25 years building monitoring and analytical capacities in the Iberian shelf

The RADIALES program has been monitoring shelf waters in Spain for the last 25 years. This is the oldest field program for multidisciplinary marine research addressing long term variability issues at ecosystem level. Core observations include ship-based hydrographic, biogeochemical and plankton observations at monthly frequency in several oceanographic sections along the Iberian shelf. These observations are complemented with buoy and satellite observations and all these data are used to validate hydrographic and ecological models of plankton at local and regional scales. From the first series initiated in the northwestern shelf other programs extended the observations to the Mediterranean and off shelf waters using the same approach. The success of RADIALES extends beyond pure scientific knowledge, as the expertise gathered with the program has been applied to solve multiple environmental issues, from fisheries and pollution to global change. The program is also instrumental for educational purposes, allowing the specialization of students and technicians. Thanks to a basal funding provided by the Instituto Español de Oceanografía, the program currently obtains more than 60% of its annual budget from competitive calls, as it offers an unique platform for coastal research. Among the results of this program are 400 publications, including peer-review papers, 24 Thesis and 54 scientific reports. The RADIALES data are freely distributed to national and international users as a contribution to the development of cost-effective ocean research and marine servicesIEO (RADIALES

Diagnosing stream ecosystem integrity in the Ordesa-Viñamala Biosphere Reserve, central Spanish Pyrenees

This work studied the ecological integrity of river ecosystems inside the Ordesa-Viñamala Biosphere Reserve, in the central Spanish Pyrenees. Despite its protected status, the Ordesa-Viñamala Biosphere Reserve endures a considerable number of human stresses, so we aimed to evaluate the conservation status of the two river basins inside the protected area: The Gállego River Basin, located inside the transition zone of the protected area, allowing a wide range of human activities; and the Ara River Basin, inside the buffer zone, where only sound ecological practices are authorised. The environmental status of river ecosystems was analysed by studying fish and macroinvertebrate communities, hydrochemical and habitat characteristics and by calculating environmental quality indices. From August to September 2011 a total of 14 sites were sampled. Fish sampling was conducted using an electrofishing gear and macroinvertebrate was sampling by applying the IBMWP and IASPT procedures. Our results showed that, while the Ara River Basin keeps a good ecological integrity, the Gállego River Basin endures important habitat alteration. Trout, the dominant and exclusive species in the Ara River, were absent and replaced by translocated native cyprinids in the Gállego River Basin. This colonisation was explained by the alteration of the stream ecosystems and their homogenisation. The study of macroinvertebrate communities and the diagnosis obtained with the environmental quality indices also enhanced the deficient ecological integrity of some sites in the Gállego River. Our results suggest that the figure of the Biosphere Reserve is not providing an adequate protection to streams inside its boundaries leading to a major degradation of their biological integrity