Our aim is to determine the population dynamics of Fagus sylvatica L. during the last 4,000 cal. BP in NW Iberia and the causes of its spatial and temporal patterns, previous palaeoecological studies having shown that between the Upper Pleistocene and the recent Holocene Fagus survived in this region.
The coastal lagoon‐beach complex at the Cíes Islands located at the opening of the Ría de Vigo (NW Iberia) is an important ecosystem currently threatened by anthropogenic impacts and climate variations. We used multiproxy marine sediment analyses to reconstruct the millennial environmental dynamics of this insular system and, in particular, the recent history of its coastal lagoon. Geophysical surveys were used to obtain bathymetry and identify the major sedimentary units of its closest submarine basin as well as their sediment sources. Core samples were taken in the middle and distal parts of the sedimentary body, where several prograding sedimentary units are thinner, allowing continuous sampling of the facies. Lithological, textural, elemental and chronological analyses were carried out on two cores. The detailed palynological studies on one of the cores included the analyses of the pollen, non‐pollen palynomorphs and dinocysts dating back three millennia. Our results revealed noticeable environmental changes affecting this area during the last 3000 years, due mainly to changing climate and oceanic conditions but also to the impact of historic human occupation of the islands. Several cold events (the 2.8 ka BP event and the Little Ice Age) characterized by enhanced upwelling alternated with warmer stormy periods of prevailing downwelling conditions in the ria. These circumstances altered the balance amongst the lacustrine, marsh, dune and lagoon systems, opening ephemeral inlets and modifying the trophic stage of the shallow waters surrounding the archipelago. Here we provide a background of the human and climatic impacts affecting these highly sensitive habitats, which may serve to improve their future management strategies.
Natural habitats are continuing to deteriorate in Europe with an increasing number of wild species which are also seriously threatened. Consequently, a coherent European ecological network (Natura 2000) for conservation of natural habitats and the wild fauna and flora (Council Directive 92/43/EEC) was created. Even so, there is currently no standardized methodology for surveillance and assessment of habitats, a lack that it is particularly problematic for those habitats occupying large areas (heathlands, forests, dunes, wetlands) and which require a great deal of effort to be monitored. In this paper we evaluate the changes affecting the European dry heaths (Nat-2000 4030) from the SCI Os Ancares-O Courel (Galicia, NW Spain) during the past decade. High-resolution aerial imagery analyses and Geographic Information Systems (GIS) were used. Losses of more than 7,000 ha (20.3%) of European dry heaths were computed during the 2003-2011 period in the SCI Os Ancares-O Courel, and also an increase of the degree of fragmentation was demonstrated for this habitat. Paradoxically, major impacts (afforestations, pasturelands) were financed by agri-environmental funds from the EU. Rather than promote biodiversity, these activities have provoked serious damages in this habitat of community interest, which is in complete opposition to the objectives of protection involved in the declaration of the SCI Os Ancares-O Courel.
OPEN ACCESSDiversity 2013, 5 558
Se presenta un estudo detallado dos tipos de bosques existentes na Devesa da Rogueira (Folgoso doCourel, Lugo, España) elaborado a partir da información previamente publicada e da realización de novos traballos de inventariación en campo. En total, recoñécense 21 comunidades diferentes de bosques, para as que se describe a súa ecoloxía, caracterización florística e distribución dentro da área de estudio. Tendo en conta a reducida extensión da superficie arborada estudiada (310 ha) e a súa elevada riqueza fitocenótica, a Devesa da Rogueira confírmase como un lugar de excepcional valorambiental, non só dentro do contexto local ou autonómico, senón dentro da área temperada do NW Ibérico.
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