Herbarium collections constitute permanent and often well-documented records of the distribution of taxa through space and time. Since their creation, their uses have dramatically expanded and with many new uses being proposed, including some for which herbaria were not initially intended for. In this paper we assess the potential of these collections on conservation biology, by providing exemplary studies that use herbarium specimens, grouped into four categories: (1) based on occurrence data, such as studies about plant extinction or introduction, or those focused on modelling their ecological niche; (2) based on the specimens themselves, such as morphological or phenological studies to evaluate the impact of climate change; (3) based in genetic data, such as phylogeographic or taxonomical studies; and (4), other applied studies. Resumen Las colecciones de herbario constituyen un registro permanente y a menudo bien documentado de la distribución de los taxones a lo largo del espacio y el tiempo. Desde su creación, sus aplicaciones se han diversificado de forma considerable, y recientemente han emergido nuevos usos, algunos no contemplados originalmente. En este trabajo evaluamos el potencial de estas colecciones para la biología de la conservación, a partir de algunos ejemplos de estudios que usan especímenes de herbario, agrupados en cuatro categorías: (1) basados en datos de presencia, como por ejemplo estudios sobre extinciones o introducciones de plantas, o modelizaciones del nicho ecológico; (2) basados en los propios especímenes, tales como estudios morfológicos o fenológicos para evaluar el impacto del cambio climático; (3) basados en datos genéticos, como por ejemplo estudios filogeográficos o taxonómicos y (4) otros estudios aplicados.

Dediquem aquest treball al professor Salvador Rivas-Martínez, pal de paller i animador incansable de la fitocenologia ibèrica Abstract. We present a review of the main trends of vegetation zonation in the entire Pyrenean mountain system, including previous overviews and a great many papers on flora and vegetation. The main floristic territories are roughly set as parallel zones along the main axis. The high mountain zone forms a central core, characterized by the dominant Boreo-Alpine element. The Atlantic mid altitudes and lowlands (mainly on the north face of the chain) and the mid altitudes of the Iberian side bear Medioeuropean flora as their dominant element, but include a good representation of the transitional Submediterranean element. Lower down, the Iberian lowlands harbour dominant Mediterranean flora. This landscape zonation may be understood in terms of the Alpine model, by which high mountains include three belts (subnival, alpine, subalpine), the mid altitudes show one belt on the Atlantic face (montane) and two on the Iberian face (montane, submontane), and the low altitudes form a basal belt with two contrasting faces (Atlantic and Mediterranean). The vegetation belts are briefly defined in terms of the main potential communities, since these are the most closely related to bioclimate. Thus, the boundaries between belts mostly coincide with boundaries of potential domains, but a few vegetation domains occur in two neighbouring belts. Then, substrata properties and regional climatic variation within the same belt produce noticeable shifts in the potential domains. This makes the basal and montane belts more diverse throughout the Pyrenean range than the high mountain belts. The boundaries between belts run a bit higher on south-facing slopes than on north-facing slopes, reflecting the effect played by topographic thermal and hydric drivers on vegetation. Also, the somewhat higher location of the boundaries in the central sector than towards the edges of the chain is connected with the continental character of the inner Pyrenean area.

The Bernades herbarium in the Botanic Institute of Barcelona (BC).-The BC-Bernades herbarium is one of the oldest collections conserved in the Botanical Institute of Barcelona. It contains part of the fi eld collections of Miquel Bernades i Mainader and Miquel Bernades i Clarís, doctors of medicine and botanists of Catalonian origin living in Madrid in the 18 th century. The collection consists of 817 sheets, the complete list provided in the annexe. We also present information concerning the localities of certain specifi c recollections, the taxonomic groups and families, as well as a list of sheets of special interest. This list contains witness of cornfi eld weed now very rare or extinct in Iberian lands, such as Hymenocarpos circinatus (L.) Savi or Securigera securidaca (L.) Degen & Dörfl , and also some of the fi rst witness known from Spain of introduced plants, such as Aster cordifolius L. or Bidens bipinnata L.

The Achillea millefolium aggregate is one of the most diverse polyploid complexes of the Northern hemisphere and has its western Eurasian boundary in the Iberian Peninsula. Four ploidy levels have been detected in A. millefolium, three of which have already been found in Iberia (diploid, hexaploid and octoploid), and a fourth (tetraploid) reported during the preparation of this paper. We collected a sample from 26 Iberian populations comprising all ploidy levels, and we used microsatellite markers analyzed as dominant in view of the high ploidy levels. Our goals were to quantify the genetic diversity of A. millefolium in the Iberian Peninsula, to elucidate its genetic structure, to investigate the differences in ploidy levels, and to analyse the dispersal of the species. The lack of spatial genetic structure recovered is linked to both high levels of gene flow between populations and to the fact that most genetic variability occurs within populations. This in turn suggests the existence of a huge panmictic yarrow population in the Iberian Peninsula. This is consistent with the assumption that recent colonization and rapid expansion occurred throughout this area. Likewise, the low levels of genetic variability recovered suggest that bottlenecks and/or founder events may have been involved in this process, and clonal reproduction may have played an important role in maintaining this genetic impoverishment. Indeed, the ecological and phenologic uniformity present in the A. millefolium agg. in Iberia compared to Eurasia and North America may be responsible for the low number of representatives of this complex of species present in the Iberian Peninsula. The low levels of genetic differentiation between ploidy levels recovered in our work suggest the absence of barriers between them.

El herbario BC-Trèmols fue creado durante la segunda mitad del siglo XIX por el químico y botánico catalán Frederic Trèmols i Borrell. Entre 1930 y 1960, el técnico Antoni Marcos llevó a cabo una profunda revisión. La colección actual consta aproximadamente de unos 9000 pliegos; está formada por 58 volúmenes reordenados por Marcos, más otros dos con la estructura original, cuatro cajas de Hieracium y 85 cajas de material adicional. Hasta la fecha se han informatizado 22 de los volúmenes y las cuatro cajas de Hieracium (3695 especímenes), se ha llevado a cabo un inventario a nivel de género de todos los volúmenes y se ha informatizado el catálogo original del herbario y el fichero taxonómico existente. También se ha elaborado un inventario preliminar del contenido de las cajas adicionales. El análisis de los 3695 especímenes revela que el herbario está formado mayoritariamente (67,1%) por pliegos de intercambio obtenidos principalmente a través de la Société Helvétique pour l’Échange des Plantes y la Societat Botànica Barcelonesa. Entre los materiales estudiados se han localizado dos pliegos que consideramos interesantes desde un punto de vista taxonómico y/o nomenclatural (isótipos de Silene holzmanii Heldr. ex Boiss. y de Arenaria minutiflora Loscos). El interés principal del herbario radica, pues, en la gran diversidad de procedencias geográficas de las plantas, que hacen de esta colección uno de los primeros «herbarios europeos» de Cataluña. [ca] L’herbari BC-Trèmols fou creat durant la segona meitat del segle XIX pel químic i botànic català Frederic Trèmols i Borrell. Entre 1930 i 1960, el tècnic Antoni Marcos va fer-ne una profunda revisió. La col·lecció actual consta aproximadament d’uns 9000 plecs; està formada per 58 volums reordenats per Marcos, dos volums amb l’estructura original, quatre capses de Hieracium i 85 capses de material addicional. Fins ara s’han informatitzat 22 dels volums i les quatre capses de Hieracium (3695 espècimens), s’ha realitzat un inventari a nivell de gènere de tots els volums i s’ha informatitzat el catàleg original de l’herbari i el fitxer taxonòmic existent. També s’ha elaborat un inventari preliminar del contingut de les capses addicionals. L’anàlisi dels 3695 espècimens fa evident que l’herbari està format majoritàriament (67,1%) per plecs d’intercanvi obtinguts sobretot mitjançant la Société Helvétique pour l’Échange des i la Societat Botànica Barcelonesa. Entre els materials estudiats s’han trobat dos plecs que considerem interessants des d’un punt de vista taxonòmic i/o nomenclatural (isotipus de Silene holzmanii Heldr. ex Boiss. i d’Arenaria minutiflora Loscos). L’interès principal de l’herbari, doncs, rau en la gran diversitat de procedències geogràfiques de les plantes, que fan d’aquesta col·lecció un dels primers «herbaris europeus» de Catalunya.