Area In Central Spain Research Articles

Selection of Lepidopterologically Interesting Areas in Central Spain Using UTM Distribution Maps

This paper deals with species richness and biogeographic interest of the butterfly fauna (Papilionoidea & Hesperioidea) of the Madrid province, using its one hundred and nine 100 sq. km UTM squares data. Richest species squares (80-102 species) are on the north (Sierra de Guadarrama) and the poorest ones on the centre and south. There is a slightly rich area on the southeast. Fauna’s biogeographic interest (chorological index sensu Kudrna) shows a different pattern, being maximum on the southeast squares, lightly high on the south and centre, and low on the north. In conclusion, richest species squares are not necessarily those of maximum average chorological index. This is explained by the environmental similarity (climate, vegetation, etc) between Sierra and the European generality , while plant formations on the south (typically xerophytic) are peculiar in comparison with the rest of the continent, which have been used as a biogeographic reference. Consequently, species richness appears as a limited criterion when focussing the selection of areas lepidopterologically interesting. Qualitative criteria must be also considered to establish possible zones to protect their butterfly communities, such as the biogeographic interest of the fauna, provided by UTM species distribution maps. Resumen. Este trabajo estudia el numero de especies y el valor biogeografico de la fauna de mariposas (Papilionoidea & Hesperioidea) presente en cada una de las 109 cuadriculas UTM de 100 kilometros cuadrados de la provincia de Madrid. Las cuadriculas con mayor numero de especies (entre 80 y 102) se situan al norte del territorio (Sierra de Guadarrama) y las mas pobres en el centro y sur. Al sureste hay una zona moderadamente rica. El valor biogeografico de la fauna (indice corologico de Kudrna) tiene un reparto bien distinto, ya que es maximo en las cuadriculas del sureste, moderadamente alto en el sur y centro, y bajo en el norte. Se infiere, por tanto, que las cuadriculas mas ricas en especies no son necesariamente las de mayor indice corologico medio, lo que atribuimos a la similitud ambiental (clima, vegetacion, etc) de la Sierra con la mayor parte de Europa, mientras que las formaciones vegetales del sur (encinares, coscojares y quejigares sobre todo) son mas singulares (mas xerofilas) con respecto al continente, ambito de referencia biogeografica utilizado. Concluimos con que el criterio del numero de especies es de utilidad limitada en la seleccion de areas de interes lepidopterologico, y que son necesarios tambien criterios cualitativos, como el valor biogeografico de la fauna, para establecer zonas susceptibles de proteccion por su fauna de mariposas, a partir de mapas UTM de distribucion de las especies.

Ecophysiological aspects of rapid population growth in a novel migratory blackcap (Sylvia atricapilla) population: an experimental approach.

Blackcaps (Sylvia atricapilla) that breed in central Europe have usually migrated to Mediterranean or African wintering grounds. In the past several decades, a portion of this breeding population has started migrating to the British Isles to overwinter and this population has increased dramatically. Several factors, including higher annual survivorship (due to supplemental feeding and reduced migratiry distance), assortative mating, and enhanced reproductive success may be involved in this rapid population growth. As part of an intensive, long-term study of this population, we tested the hypothesis that the differences in photoperiod experienced by British-wintering versus Mediterranean-wintering blackcaps might lead to relatively early vernal (i.e., migratory and/or reproductive) physiological condition in members of the former group. We found that birds exposed to photoperiodic conditions that simulated migration to Britain to overwinter generally initiated vernal migratory activity earlier than birds held under conditions simulating migration to traditional wintering areas in central Spain. This difference, coupled with the shorter migratory distance to the British Isles, leads to significantly earlier estimated arrival dates for blackcaps that winter in Britain compared to central Spain. Bimodality in arrival times suggests that assortative mating on central European breeding grounds might occur between members of the different wintering populations. Males exposed to British-winter photoperiods showed significantly earlier testicular development than males kept under Spanish-winter photoperiods. Early arrival on the breeding grounds, coupled with accelerated reproductive condition, should lead to a relatively early reproductive effort, perhaps increasing average reproductive success. In general, these results support the hypothesis that differences in photoperiod on the wintering grounds may play an important role in the dynamic state of this population.

Production and spatial structure of Mediterranean pastures in different stages of ecological succession

The aim of this paper is to describe the changes of Mediterranean pasture phytomass and their dependence on succession, slope geomorphology and herbivore consumption. Four neighbouring slopes of similar aspect and steepness, located in a pasture area of Central Spain, were chosen for sampling. The slopes had not been cultivated for 1, 3, 8 and 40 years respectively. On each slope both the upper, erosion zone and the lower, accumulation zone were sampled during the months of plant growth (April to July), phytomass being recorded in plots where herbivore consumption was avoided with protection cages and in unprotected plots.

Evaluation of MSS Landsat imagery over central Spain

Twenty four MSS Landsat I and II images have been selected to determine the most persistent lineaments within a given area in Central Spain. This area comprises four different geotectonic units: the Hercynian basement, an intermediate-type Alpine chain and two undeformed Tertiary basins. Lineaments appear to be well established in the Iberian Peninsula and their general pattern in good accordance with the faults system. Some of them correspond to simple or composite linears that extend over the entire peninsula, and must affect the whole crust. A generalized late-Hercynian fracture event is admitted to be the origin of these linears and their extension into the post-Hercynian areas is related to an Alpine reactivation. The main lineament directions are NS, N20, N70, N120 and N160. These trends seem to correlate well with arches and troughs inferred from gravimetric and aeromagnetic surveys carried out over both Tertiary basins. BPCG, Sn, W mineralizations within the Hercynian basement occur in relation to quartz and baryte dykes trending N20, N70, and N120.

Accuracy and precision of GPS receivers under forest canopies in a mountainous environment

Georeferencing field plots by means of GPS/GLONASS techniques is becoming compulsory for many applications concerning forest management and inventory. True coordinates obtained in a total station traverse were compared against GPS/GLONASS occupations computed from one navigation-grade and three survey-grade receivers. Records were taken under a high Pinus sylvestris L. forest canopy situated in a mountainous area in central Spain. The horizontal component of the absolute error was a better descriptor of the performance of GPS/GLONASS receivers compared to the precision computed by the proprietary software. The vertical component of absolute error also failed to show the effects revealed when the horizontal one was studied. These differences might be critical for applications involving high-demanding surveys, in which a comparison against a terrestrially surveyed ground truth is still mandatory for accuracy assessment in forested mountainous areas. Moreover, a comparison of diverse Differential GPS/GLONASS techniques showed that the effect of lengthening the baseline and lowering the logging rate was not significant in this study. Differences among methods and receivers were only observed for recording periods between 5 and 15 minutes. The hand-held receiver was inappropriate for plot establishment due to its inaccuracy and a low rate of fixed solutions, though it may be used for forest campaigns tolerating low precision or permitting the employment of periods of 20 minutes or longer for plot mensuration.