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The characterization of suitable microsites for tree seedling establishment and growth is one of the most important tasks to achieve the restoration of native forest using natural processes in disturbed sites. For that, we assessed the natural Quercus petraea forest expansion in a 20-year-old reclaimed open-cast mine under sub-Mediterranean climate in northern Spain, monitoring seedling survival, growth, and recruitment during 5 years in three contrasting environments (undisturbed forest, mine edge, and mine center). Seedling density and proportion of dead branches decreased greatly from undisturbed forest towards the center of the mine. There was a positive effect of shrubs on Q. petraea seedling establishment in both mine environments, which increase as the environment undergoes more stress (from the mine edge to the center of the mine), and it was produced by different shrub structural features in each mine environment. Seedling survival reduction through time in three environments did not lead to a density reduction because there was a yearly recruitment of new seedlings. Seedling survival, annual growth, and height through time were greater in mine sites than in the undisturbed forest. The successful colonization patterns and positive neighbor effect of shrubs on natural seedlings establishment found in this study during the first years support the use of shrubs as ecosystem engineers to increase heterogeneity in micro-environmental conditions on reclaimed mine sites, which improves late-successional Quercus species establishment.

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Epizoochory has been less studied than other seed dispersal mechanisms, such as endozoochory, and generally only a small percentage of plant species show adaptations to this strategy. Nevertheless, epizoochorous seed dispersal can affect an appreciable number of herb species in forests and man‐made habitats. Also, few studies have dealt with temporal variation in epizoochory. In this paper, medium‐long distance epizoochory is analyzed in a hedgerow habitat for the first time, using a domestic dog in an area in northwest Spain. Special attention is paid to seasonal variation and differential traits of plant taxa involved. Approximately 30 % of available herb taxa were found attached to hair. The intermonthly difference in the frequency of the taxa involved in epizoochory was significant, and the overall peak was reached in June–October linked with diaspore ripening phenology. Ninety‐three percent of the plant taxa adhered to hair had diaspores with traits facilitating epizoochory (hooks, spines, awns, rigid hairs), in comparison with 17 % for available plant taxa not adhered to hair. The taxa involved in epizoochory had larger diaspores than the rest of the available taxa, but ranged considerably in size. Numerous hooks covered the largest, heaviest diaspores, and allowed them to attach to hair. There was no significant difference in mean plant height between taxa involved in epizoochory and the rest of the available taxa. The difference in life span between taxa involved in epizoochory and the rest of available taxa was not significant, most of them being perennials in both cases. Seventy‐three percent of all the available plant taxa were potential forest plants typically found in edges and gaps, and 64 % of the plant taxa involved in epizoochory were these kinds of potential forest plants. High or medium involuntary positive selection by the dog of diaspores of Taraxacum gr. officinale, Galium aparine, Geum urbanum, and Agrimonia eupatoria was observed. In conclusion, epizoochorous dispersal can be quantitatively and functionally important in hedgerow habitats during summer‐autumn, affecting mainly herb taxa with specialized diaspores.

We evaluated the ecological significance of the boundary form between two patches with contrasting vegetation (mine grassland and adjacent forest) on woody colonization and forest expansion in open-cast coal mines in Northern Spain. Woody colonization and browsing traces were measured on three mine sites, along 24 transects that were laid out perpendicular to the forest-mine boundary and classified according to their shape (concave, convex, straight). Mine sites were colonized from the close forest by woody species, whose colonization intensity depends on the boundary form. The overall colonization intensity decreased with increasing distance to the forest and differed depending on the boundary form. The more intense colonization was found in concave boundaries and the strongest decrease in convex boundaries close to the forest, whereas straight boundaries showed an intermediate colonization pattern. Concave boundaries reached higher woody cover in the basal strata of the mines than convex (up to 2 m) or straight boundaries (up to 1 m) from 11 m to the forest edge, mainly by the presence of dense patches of Cytisus scoparius (L.) Link, with a scattered overstory of Genista florida L. These shrubs might reduce the browsing intensity and act as nurse plants facilitating the establishment of Quercus petraea (Matt.) Liebl. in mine areas at greater distances from the forest edge. The forest-mine boundary form does not affect the forest vertical structure that is homogenous and does not help explain the woody colonization pattern in the mines. We conclude that edge characteristics have a strong potential to be used in the restoration of native forests based on natural processes. The implications of our results for sessile oak (Quercus petraea (Matt.) Liebl.) forest expansion along edges in fragmented Mediterranean forest landscapes were discussed.

The relationship between forest structure and plant diversity in Mediterranean Maritime pine stands (Pinus pinaster Ait.) in the Iberian Range (Spain) was studied. Forty eight stands were sampled. In each, a circular plot (15 m radius) and a transect (25*1 m 2 ) were established to estimate stand variables and record presence and abundance of vascular species respectively. Canonical correlation analysis (CCA), simple correlations and multiple stepwise linear regressions were used to explore the relationship between plant diversity and forest structure. Correlation between diversity measurements and stand variables is very weak, but significant correlations were found when evaluating each set of variables separately. Presence and cover of some species (for instance, Veronica arvensis L. or Micropyrum tenellum (L.) Link) is correlated with stand variables; however, determination coefficients found in step-by-step regression are not significant.Key words: Pinus pinaster Ait, Spain, Biodiversity, Stand Structure. ResumenEstructura forestal y biodiversidad en rodales de pino negral (Pinus pinaster Ait.) en el Sistema Ibérico, EspañaEn el presente trabajo se ha estudiado la relación entre la estructura forestal y la biodiversidad en rodales de pino negral (Pinus pinaster Ait.) en el Sistema Ibérico, España. En cada uno de los cuarenta ocho rodales muestreados se estableció una parcela circular de radio 15 m y un transecto de 25 por 1 m para estimar diferentes variables dasométricas y anotar la presencia y abundancia de especies de la flora vascular respectivamente. Se utilizaron técnicas de análisis de correlación canónica, correlación simple y regresión lineal múltiple paso a paso para explorar la relación entre la diversidad vascular y la estructura forestal. La correlación entre las medidas de diversidad y las variables del rodal fue débil pero cuando se analizaron cada conjunto de variables de forma independiente se encontraron correlaciones significativas. La presencia y la cobertura de ciertas especies está correlacionada con variables dasométricas pero los coeficientes de determinación de la regresión resultaron no significativos.Palabras clave: Pinus pinaster Ait, España, Biodiversidad, Estructura del rodal.

Nest-habitat selection and nest design in a Eurasian bullfinch population in the Iberian Peninsula are thoroughly addressed in this study for the first time. Hedgerows and meadows were found around all of the nests and most of them were supported by hedgerows, so bullfinches consistently used the general woody vegetation available as reproduction habitat and site. Also, poplar plantations appeared preferentially in the immediate surroundings of the nests. Partly reflecting these results, bullfinches chose zones with greater shrub and tree cover than that available. Bullfinches placed their nests on a wide variety of plant species, but showed predilection for thorny species. Overall mean height of nests above the ground was 1.43 m and large-sized shrubs/trees were preferred. The most predominant bullfinch nest orientations were S, E and centered, which arguably provided thermal benefits and protected from severe weather. In general, there were no significant temporal variations in nest-site selection. With the exception of thorny support and favourable orientation, acting jointly, there was no significant association between nest-site characteristics and nesting success, presumably because many nests were already located in the most advantageous places at each time, and because despite this, predation pressure was high. Nest external dimensions were relatively variable, whereas internal width was the least variable nest dimension. No significant monthly or interannual variations in nest weight were observed. Larger nests did not hold larger clutches. Successful nests were larger than unsuccessful ones. The bullfinch nests were of simple construction, with two clearly different regions, the outer nest and the internal cup, with no significant temporal variations in the weight of either. The outer, structural nest consisted mainly of twigs, whereas roots and herbaceous shoots were the highest fractions lining the cup. Hair was the only animal-derived material used by bullfinches.

There is very little information on the ecology of stoats Mustela erminea in the Iberian Peninsula, the southwestern limits of their Eurasian range. The aim of this study is to gain more knowledge of some ecological aspects of Iberian stoats, principally habitat and diet, by direct observation and scat collection in a valley in the Cantabrian Mountains, northwestern Spain. Stoats were observed in all the elevation range of the valley (820 – 1350 m a.s.l.) in different habitats including hedgerows-meadows, river and mountain meadows, normally close to woody vegetation. The body size of individuals killed on the road was larger than that reported for stoats in the Spanish Pyrenees, and winter whitening was complete. Stoats coexisted with common weasels Mustela nivalis, but in different habitats. According to scat analysis, stoats had a relatively varied diet of small mammals, insects, eggs/birds, fruit, reptiles and earthworms. In autumn-winter, small mammals and fruit were clearly the most abundant items in their diet, but in spring-summer it included more food categories. In the upper valley, most of the food items were fruits, and in the middle and lower valley, small mammals. Amongst the small mammals, mostly Apodemus mice were consumed, followed by Microtus voles, and to a lesser extent, Arvicola water voles, Talpa moles and Crocidura shrews. Stoats ate the fruits of at least five plant species and defecated the seeds intact, thus acting as potential dispersers via endozoochory. Presumably, this diverse diet was favoured by the biogeographical complexity of the study area, where the Eurosiberian and Mediterranean regions meet, its wide elevation range and heterogeneous landscape. However, the highest percentages of biomass ingested corresponded to small mammals in any season and at any elevation, although they were slightly lower in spring-summer and in the upper valley.