fungal ecology 11 (2014) 50e59 available at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/funeco What factors influence the occurrence of the genus Degelia (a threatened lichen) in central Spain? I. MARTINEZ*, T. FLORES, G. ARAGON, M.A.G. OTALORA, M. RUBIO-SALCEDO Area de Biodiversidad y Conservacion, ESCET, Universidad Rey Juan Carlos, c/ Tulipan s/n, 289337 Mostoles, Madrid, Spain article info abstract Article history: The main factors determining the occurrence, abundance, growth and reproductive Received 29 July 2013 capacity of threatened lichens need to be known in order to implement conservation ini- Revision received 3 March 2014 tiatives. The main objective of the present study was to evaluate which factors affect the Accepted 6 March 2014 conservation status of Degelia species-complex in central Spain. We undertook a non- Available online parametric analysis to evaluate whether population sizes are larger in protected areas. Corresponding editors: Peter Crittenden We fitted generalized linear models (GLM) and mixed models (GLMMs) to analyze which and Darwyn Coxson variables are driving occurrence and abundance of Degelia, the thallus size and repro- duction capacity. Results show that population sizes of Degelia are very variable, being Keywords: larger in broad-leaved evergreen forests and inside protected areas. Tree characteristics Conservation play an important role in its local dynamics. Lichen ª 2014 Elsevier Ltd and The British Mycological Society. All rights reserved. Protected areas Reproduction Thallus size Introduction One of the major threats to biodiversity is forest frag- mentation and forest degradation. It affects the survival and Biodiversity conservation is a way to generate a holistic view conservation of species worldwide (Debinski and Holt, 2000; of nature and so stop perceiving it as a set of individual Fahrig, 2003), and therefore nowadays is a priority for Con- components (Primack and Ros, 2002). Currently, numerous servation Biology (Young and Clarke, 2000). Lichen-rich hab- threats are affecting biodiversity worldwide, but most con- itats, such as forests are being destroyed and the number of servation programs have been directed at birds, mammals or rare and extinct species has increased in recent decades plants, while other organisms are being overlooked (IUCN, (Martınez et al., 2012; Scheidegger and Werth, 2009). 2012). Despite the importance and value of epiphytic lichens Degelia is a threatened genus of epiphytic lichen species in in many forest ecosystems (Carroll, 1979; Hayward and central Spain (Martınez et al., 2003; Otalora et al., 2013). The Rosentreter, 1994; Petterson et al., 1995), both in terms of current taxonomic treatment of Degelia species-complex in species diversity and of ecological function (Longton, 1992; Dix Europe recognizes four species (Blom and Lindblom, 2010): and Webster, 1995), they are often overlooked in determining Degelia atlantica, D. cyanoloma, D. ligulata and D. plumbea.In conservation biology priorities. Spain, D. atlantica and D. plumbea are the two species of this * Corresponding author. Tel.: þ34 914887183; fax: þ34916647490. E-mail address: [email protected] (I. Martınez). 1754-5048/$ e see front matter ª 2014 Elsevier Ltd and The British Mycological Society. All rights reserved. http://dx.doi.org/10.1016/j.funeco.2014.03.005 Occurrence of the genus Degelia 51 genus which are better represented (Martınez et al., 2003; Castilla-La Mancha, www.jccm.es), although in mountainous Otalora et al., 2013), although D. cyanoloma has been recently places climate conditions are characterized by lower tem- recorded in some western localities (Blom and Lindblom, perature and higher precipitation. We have studied the dis- 2010). D. plumbea populations are distributed primarily in tribution of Degelia in this region for more than a decade. All Mediterranean-Atlantic regions of Africa, Europe (Portugal to previously reported localities of Degelia were visited to Norway and the Crimea), the Macaronesian islands and North delimitate its populations. In addition, some areas with high Eastern America (COSEWIC, 2010). D. plumbea produces probability that Degelia might be present were also visited numerous sexual structures (apothecia) while D. atlantica (well-preserved broad-leaved evergreen forests and deciduous seldom forms these structures but forms isidia. In central and semideciduous forests located in mountainous places), Spain, the genus Degelia is found in a very limited number of although there were not previous records. However, only in localities, specifically in humid valleys and ravines, and two of them did we find Degelia individuals. within well-preserved forests ranging from 750 to 1 280 m A total of 15 forest patches were included in this study altitude (Carballal et al., 2010). The species are listed as vul- (Fig 1) between 734 and 1 622 m altitude, most being situated nerable in the central Iberian Peninsula (Martınez et al., 2003). within protected areas such as National Park, Natural Parks The main threats are forest fragmentation, logging and other and habitat/species management areas (Table 1). Finally, 8 forest management activities, drought, overgrazing, agricul- forests of Q. pyrenaica, 4 forests of Q. ilex subsp. ballota, 1 forest tural, recreational and environmental pollution (Martınez of Arbutus unedo, and 2 mixed forests, one of Q. pyrenaica and F. et al., 2003). This genus occurs typically in Lobarion pulmonar- sylvatica, and one with Q. pyrenaica and Q. faginea (Table 1). Q. iae Oschner (Barkman, 1958; Rose, 1988) communities, and it is pyrenaica is a semideciduous oak almost entirely restricted to highly susceptible to high incidence of light (Gauslaa and the Iberian Peninsula with some isolated populations in Solhaug, 1996) and the frequency and duration of dehy- northern Morocco and on the southwestern tip of France. Q. dration events. In addition, Degelia distribution can also be ilex subsp. ballota is a large evergreen oak native to the Medi- limited by the availability of appropriate substrate, pollution terranean region. A. unedo is also a broad-leaved evergreen and others factors related to dispersal (Gauslaa and Solhaug, tree native to the Mediterranean region and Western Europe. 1998; Richardson and Cameron, 2004; COSEWIC, 2010). F. sylvatica is a deciduous tree widespread throughout West- In a previous population genetics study in central Spain, ern Europe, reaching in central Spain its southern distribution Otalora et al. (2013) found high levels of genetic similarity limit in Europe. And Q. faginea is a native semideciduous between D. plumbea and the inland D. atlantica, suggesting that species of Mediterranean forest, growing in areas with Medi- probably D. atlantica and D. plumbea do not correspond to two terranean climate of North Africa and the Iberian Peninsula. distinct species and an urgent study of species boundaries of this species-complex was needed (Otalora et al. in prep.). Experimental design and data collection Thus, the main objective of the present study was to assess the conservation status of populations of the Degelia species- In every forest a plot of 3 000 m2 (30  100 m) was established complex (named “Degelia” elsewhere in the document) and to to determine the abundance of species. Each plot was located study the factors affecting its population size as the per- at least 100 m from the forest edge to avoid possible effects formance of individuals in central Spain. Our hypothesis was caused by microclimatic changes associated with edge- that the occurrence and abundance of Degelia would be higher interior gradient (Belinchon et al., 2007). To facilitate the inside protected areas and in more humid places and that the field work, the plots were subdivided into 20 small rectangles reproductive capacity would be related to thallus size and of 10 m  15 m. Within each plot, all trees were sampled and microclimatic conditions. We examined: (1) which environ- all individuals of Degelia growing at a maximum height of 2 m mental variables determine occurrence and abundance of tree were considered. Above this height, it is very rare to find Degelia; (2) which microhabitat factors are affecting size and individuals of this genus in the study area. A range of abiotic reproductive capacity of Degelia; and (3) differences among and biotic variables were measured at four levels: stand, plot, population sizes within and outside protected areas in the tree and lichen. study area. Variables at the stand level were: (1) Climate variables obtained from climate model estimates for Spain CLIMOEST (Sanchez-Palomares et al., 1999) e total precipitation (mm), Methods winter precipitation (mm), summer precipitation (mm), mean annual temperature (C), mean maximum temperature of the Study area warmest month (C), mean minimum temperature of the coldest month (C), relationship between total precipitation/ The study area was located in central Spain and comprised a mean annual temperature (P/T). (2) Geographic and topo- vast and mountainous region covered with different types of graphic variables, taken in situ with GPS e latitude and longi- Mediterranean forests (Quercus faginea, Q. ilex subsp. ballota, Q. tude of each locality in UTM, altitude of each locality (m). (3) pyrenaica, Fagus sylvatica, Pinus spp. are the tree species which Structural variables e Forest type: deciduous (Q. pyrenaica, Q. mainly constitute forests in Central Spain) and scrublands faginea, F. sylvatica) and broad-leaved