Suchergebnisse

Biodiversity loss, including the decrease of diversity of ecological interactions, is known to reduce the capacity of ecosystems to cope with the effects of global change. Here we assessed whether the distribution and survival of two declining relict plant species, Daphne rodriguezii and Cneorum tricoccon, were affected by the mutualism disruption with their only seed-disperser and by climatic and habitat conditions. Due to the lack of data on demographic rates, we used an indirect approach to test these hypotheses. We used presence-absence data as response variables and took two distinct sets of predictors (i.e. habitat and topoclimatic conditions), which were hypothesized to be the main determinants of the demographic rates under question. With these two datasets we fitted species distribution models by means of MaxEnt. Such models were later used to build Combined Species Distributions Models (CM). For each plant species, these CM allowed evaluating the role of both climatic and non-climatic factors, such as the mutualism disruption. Results showed that both climate and habitat conditions determined the current distribution of the two species at a landscape scale. Additionally, the mutualism disruption between C. tricoccon and its native seed-disperser affected plant distribution, moving it to areas where a new alien disperser was present. This alien disperser modified the pattern of habitat selection by plants in terms of habitat quality, reducing their presence in suboptimal areas, which might be the determinant for their survival. Our findings highlight the need of a better understanding of the role of mutualisms within natural communities in order to undertake appropriate conservation actions on threatened plant populations. Furthermore, acting on key factors affecting plant-disperser disruptions (e.g. controlling invasive species) might help to mitigate the effects of global change on declining relict plants. ; The study is framed within projects GAEM financed by the Balearic Government and CGL2013-44386-P financed by the Ministerio de Economía y Competitividad ; Peer Reviewed

Two important biological differences between oceanic and continental islands are that the former usually have lower species richness and a higher degree of taxonomic disharmony than the latter. Although there is some evidence of less complex interaction networks on oceanic islands, only a few studies have compared island communities with each other or with mainland communities. Here, we analyse the species composition and structural properties of quantitative flower visitation networks in two communities of each of two different island systems: the Canary Islands (oceanic origin) and the Balearic Islands (continental origin). We compared different network parameters to inform us about their vulnerability in the face of different types of disturbance. The number of species was greater in the Balearic than in the Canarian networks but, contrary to expectations, the total number and diversity of interactions did not differ between them. Moreover, a greater number of opportunistic species and the presence of super-generalist species on the oceanic island led to significantly higher values of quantitative connectance and nestedness relative to those on the continental island. Given that these two parameters are associated with network stability, our findings support the hypothesis that oceanic island communities are less vulnerable to perturbations than are those of continental islands, although further studies with a network approach are needed to determine whether this is a general pattern. © 2014 The Linnean Society of London. ; This study is framed within projects CGL2007-61165/BOS and CGL2010-18759/BOS financed by the Spanish Ministry of Science and Innovation. RC-U received an FPI grant from the Spanish Government (Ministry of Economy and Competitiveness and Ministry of Education, Culture and Sport) ; Peer Reviewed

Limonium barceloi (Plumbaginaceae) is a narrow endemic seasonal halophytic plant, uniquely found in a highly degraded urban wetland in the Bay of Palma Mallorca, located in the northwest Mediterranean. It was awarded critically endangered status in 2004 and is the subject of a recovery plan administered by local government. Despite this, the last ten years have seen a dramatic decline in the population from ca. 3,000 individuals to just ca. 300; reasons for this decline are principally anthropogenic disturbance. Here we present the results of an investigation into some aspects of the reproductive biology of this species in the last remaining in situ population, in order to gain insight into its limited distribution and abundance, and to guide further development of management strategies. Findings indicate that although it provides important floral resources to a number of insect visitors, the plant is an autonomous apomictic that may also be functioning as an obligate asexual reproducer, and low genetic variation is suspected. Germinability is observed to be at ca. 70% and was positively correlated with maternal plant size characteristics. Two seed predators, the moth Goniodoma limoniella (Coleophoridae) and the ant Messor bouvieri (Myrmicinae), were discovered affecting both pre- and post-dispersal seeds. Rate of removal was high, although it is hypothesised that at this time species recruitment is not seed limited, but rather restricted by lack of suitable microsites. The results of this study are used to make recommendations for the species recovery. © 2012 Springer-Verlag. ; The Consortium Playa de Palma financed the project through an IMEDEA interdisciplinary study. ; Peer Reviewed

Background and Aims: Variation in inbreeding depression (δ) among individual plants is considered to play a central role in mating system evolution and population genetics. Moreover, such variation could be linked to individual susceptibility to pollen limitation (PL) because those individuals strongly affected by δ for seed production will require more outcross pollen for setting a given number of fruits or seeds. However, no study has tested explicitly for associations between PL and δ at the individual plant level. This study assesses the extent of among-individual variation in PL and δ, the consistency of δ across life stages, and the relationships between individual PL and δ in the mixed-mating shrub Myrtus communis. Methods Controlled hand-pollinations were performed in a natural M. communis population. Marked flowers were monitored until fruit production and a greenhouse experiment was conducted with the seeds produced.Key Results Compared with selfing, outcross-pollination enhanced seed number per fruit, germination rate and seedling growth, but did not enhance fruit-set. Only seed number per fruit was pollen limited and, thus, cumulative pollen limitation depended more on pollen quality (outcross pollen) than on quantity. The effects of δ varied considerably across life stages and individual plants. Cumulative δ was high across individuals (mean δ = 0·65), although there were no positive correlations between δ values at different life stages. Interestingly, maternal plants showing stronger δ for seed production were more pollen limited, but they were also less affected by δ for seedling growth because of a seed size/number trade-off. Conclusions Results show a general inconsistency in δ across life stages and individuals, suggesting that different deleterious loci are acting at different stages. The association between δ and PL at the individual level corroborates the idea that pollen limitation may be 'genotype-dependent' regardless of other factors. © The Author 2010. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. ; This study was supported by grants from the Spanish Ministerio de Educación y Ciencia (grant number CGL2008-000938/BOS) and the Andalusian Regional Government (grant number P07-RNM-02869). ; Peer Reviewed

[Premise] The endangered shrub Daphne rodriguezii (Thymelaeaceae) is endemic to the Balearic island of Menorca, where fragmentation and severe population decline are ongoing threats to this taxon. We developed a set of microsatellite markers to analyze the fine-scale genetics of its few extant populations. ; [Methods and Results] Fifteen microsatellite markers were obtained through Illumina high-throughput sequencing and tested in two populations. Twelve of these loci showed no evidence of null alleles and were highly polymorphic, with a mean number of 8.3 alleles per locus. Levels of observed and expected heterozygosity ranged from 0.100 to 0.952 and from 0.095 to 0.854, respectively. Seven to nine of these loci were successfully amplified in five other Daphne species. ; [Conclusions] This set of markers provides a useful tool for investigating the factors driving fine-scale population structure in this threatened species, and it represents a novel genetic resource for other European Daphne species. ; J.C.I. was funded by a GRUPIN research grant from the Regional Government of Asturias (Ref.: IDI/2018/000151), and C.G.‐V. was supported by a Vicenç Mut postdoctoral fellowship awarded by the Govern de les Illes Balears–Conselleria d'Innovació, Recerca i Turisme. The study was funded by the Ministerio de Economía, Industria y Competitividad (project Islet‐Foodwebs CGL2017‐88122‐P).

Aim Although biological invasions represent a major cause of biodiversity loss, the actual mechanisms driving species extinctions remain insufficiently understood. Here we investigate the role of three processes as drivers of phylogenetic loss in invaded local plant communities, namely the 'biotic resistance', 'environmental filtering' and 'functional equivalence' hypotheses. Location Balearic Islands (western Mediterranean). Methods We quantified the phylogenetic diversity and structure of 109 pairs of invaded and non-invaded local plant communities from two Mediterranean islands. Each pair contained one control plot and one plot invaded either by the deciduous tree Ailanthus altissima, the succulent subshrubs Carpobrotus spp. or the pseudoannual geophyte Oxalis pes-caprae. We combined generalized linear models, analyses of phylogenetic community structure and generalized linear mixed models using a Markov chain Monte Carlo technique (MCMCglmm) to contrast the 'biotic resistance', 'environmental filtering' and 'functional equivalence' hypotheses. Results While the phylogenetic structure of the non-invaded communities was not more clustered or overdispersed than expected by chance, minimum phylogenetic distance to the invasive species increased in invaded assemblages, in which the magnitude of phylogenetic diversity loss ranged from 6 to 37% depending on the invader's identity. Invader or island identity did not explain the probabilities of native species becoming locally extinct. Rather, the likelihood of extinction was mainly explained by species abundance, with scarcer species exhibiting a higher chance of becoming locally extinct. Species identity explained a small fraction of the variation in extinction risk (12%), independently of each species' evolutionary history. Main conclusions The most relevant driver of local extinction is a stochastic process where less abundant species tend to disappear more frequently irrespective of their evolutionary history. This has strong implications for conservation because it suggests that in the study region the invaders are unlikely to drive regional and global extinctions except in cases where the native species is already rare. ; Research was partially founded by the 5th EU Framework project EPIDEMIE (Contract no. EVK2-CT-2000-00074), the Spanish Ministry of Science and Innovation project Consolider-Ingenio MONTES (CSD2008-00040), and through the Severo Ochoa Program for Centres of Excellence in R+D+I (SEV-2012-0262). D.S. was supported by a Proyecto de Investigación (ref. CGL2013-47448-P) from the Spanish Government ; Peer reviewed

J.C.I. was funded by a GRUPIN research grant from the Regional Government of Asturias (Ref.: IDI/2018/000151), and C.G.‐V. was supported by a Vicenç Mut postdoctoral fellowship awarded by the Govern de les Illes Balears–Conselleria d'Innovació, Recerca i Turisme. The study was funded by the Ministerio de Economía, Industria y Competitividad (project Islet‐Foodwebs CGL2017‐88122‐P).

Although climate-driven phenological shifts have been documented for many taxa across the globe, we still lack knowledge of the consequences they have on populations. Here, we used a comprehensive database comprising 553 populations of 51 species of north-western Mediterranean butterflies to investigate the relationship between phenology and population trends in a 26-year period. Phenological trends and sensitivity to climate, along with various species traits, were used to predict abundance trends. Key ecological traits accounted for a general decline of more than half of the species, most of which, surprisingly, did not change their phenology under a climate warming scenario. However, this was related to the regional cooling in a short temporal window that includes late winter and early spring, during which most species concentrate their development. Finally, we demonstrate that phenological sensitivity-but not phenological trends-predicted population trends, and argue that species that best adjust their phenology to inter-annual climate variability are more likely to maintain a synchronization with trophic resources, thereby mitigating possible negative effects of climate change. Our results reflect the importance of assessing not only species' trends over time but also species' abilities to respond to a changing climate based on their sensitivity to temperature. ; The CBMS is funded by the Departament d'Acció Climàtica, Alimentació i Agenda Rural de la Generalitat de Catalunya and the Diputació de Barcelona, and the BMSAnd by the Andorran Government. P.C. is funded by a PhD fellowship financed by the Govern de les Illes Balears (grant no. FPI-CAIB-2018). This study was partially funded by the Catalan Government under grant no. SGR2017-1690 to X.P., by the Spanish MCIU Ministry through the NEWFORLAND research project (grant no. RTI2018-099397-B-C21 MCIU/AEI/ERDF, EU) to X.P. and the DEPICT research project (grant no. PID2020-114324GB-C2) to A.T. ; Peer reviewed

© The Authors 2015. Oceanic archipelagos are threatened by the introduction of alien species which can severely disrupt the structure, function and stability of native communities. Here we investigated the pollination interactions in the two most disturbed Galápagos Islands, comparing the three main habitats and the two seasons, and assessing the impacts of alien plant invasions on network structure.We found that the pollination network structure was rather consistent between the two islands, but differed across habitats and seasons. Overall, the arid zone had the largest networks and highest species generalization levels whereas either the transition between habitats or the humid habitat showed lower values. Our data suggest that alien plants integrate easily into the communities, but with low impact on overall network structure, except for an increase in network selectiveness. The humid zone showed the highest nestedness and the lowest modularity, which might be explained by the low species diversity and the higher incidence of alien plants in this habitat. Both pollinators and plants were alsomore generalized in the hot season, when networks showed to bemore nested. Alien species (both plants and pollinators) represented a high fraction (~56 %) of the total number of interactions in the networks. It is thus likely that, in spite of the overall weak effect we found of alien plant invasion on pollination network structure, these introduced species influence the reproductive success of native ones, and by doing so, they affect the functioning of the community. This certainly deserves further investigation. ; This research is part of a larger project funded by BBVA Foundation and is also framed within project CGL-2013-44386-P financed by the Spanish Government. R.H. was supported by the Portuguese grant FCT-IF/00441/2013, and by the Marie Curie action FP7-2012-CIG-321794 ; Peer Reviewed

Many fleshy-fruited plants from the Mediterranean and Macaronesian islands are dispersed through endozoochory. In mainland Mediterranean areas, reciprocal adaptations have been found between plants and animals, although evidence is scarce. On small isolated oceanic islands, such reciprocal adaptations might well be more prevalent due to intrinsic island traits. Here we evaluate the existence of selective pressures exerted by two different disperser guilds (lizards and birds) on two seed traits (seed coat thickness and seed germination pattern) of two congeneric species present on Mediterranean and Macaronesian islands. In the continental Balearic Islands, Rubia peregrina has evolved mostly with birds, although frugivorous lizards are present in some of these islands and are known to eventually consume its fruits. By contrast, R. fruticosa, endemic to the Macaronesian archipelago, has evolved mostly interacting with lizards and only recently with birds. We hypothesized that R. fruticosa would be especially adapted to saurochory, with thicker seed coats and higher germination proportion, whereas R. peregrina would be more adapted to ornithocory, with thinner seed coats and showing a lower germination percentage after being ingested by lizards. Captivity experiments of seed ingestions by natural and non-natural dispersers (i.e., frugivores that have not evolved with those plants) were conducted. Results suggest that dispersers did not exert any strong enough selective pressure to induce changes in germination patterns. We attribute this to the fact that the Rubiaceae is an ancestral family in the Mediterranean (both on continent and islands) and thus probably interacted with lizards in the past. Lastly, although we hold that the seed coat structure of R. fruticosa is probably associated with its evolutionary success after a long interaction with insular lizards, our findings support the idea that the relationship between endozoochorous plants and the guild of dispersers with whom they evolved is rather unspecific. © 2013 Nogales et al. ; A. Gonzalez-Castro (JAE-pre) and E. Bonnaud (JAE-doc) were funded by two grants from the Spanish National Research Council. P. Marrero has a postdoctoral fellowship from the Spanish Ministry of Education. This paper is framed within projects CGL2007-61165/BOS and CGL2010-18759/BOS financed by the Ministry of Education and Science of the Spanish Government and partially funded by the European Union. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. ; Peer reviewed ; Peer Reviewed

© The Authors 2017 ; Summit areas of oceanic islands constitute some of the most isolated ecosystems on earth, highly vulnerable to climate change and introduced species. Within the unique high-elevation communities of Tenerife (Canary Islands), reproductive success and thus the long-term survival of the species may depend on environmental suitability as well as threat by introduced herbivores. By experimentally modifying the endemic and vulnerable species Viola cheiranthifolia along its entire altitudinal occurrence range, we studied plant performance, autofertility, pollen limitation and visitation rate and the interactive effect of grazing by non-native rabbits on them. We assessed the grazing effects by recording (i) the proportion of consumed plants and flowers along the gradient, (ii) comparing fitness traits of herbivore-excluded plants along the gradient, and (iii) comparing fitness traits, autofertility and pollen limitation between plants excluded from herbivores with unexcluded plants at the same locality. Our results showed that V. cheiranthifolia performance is mainly affected by inter-annual and microhabitat variability along the gradient, especially in the lowest edge. Despite the increasingly adverse environmental conditions, the plant showed no pollen limitation with elevation, which is attributed to the increase in autofertility levels (≥ 50% of reproductive output) and decrease in competition for pollinators at higher elevations. Plant fitness is, however, extremely reduced owing to the presence of non-native rabbits in the area (consuming more than 75% of the individuals in some localities), which in turn change plant trait-environment interactions along the gradient. Taken together, these findings indicate that the elevational variation found on plant performance results from the combined action of non-native rabbits with the microhabitat variability, exerting intricate ecological influences that threaten the survival of this violet species. ; Our work was funded by a project of the "Organismo Autónomo de Parques Nacionales" (785/2012). Jaume Seguí was supported by the Graduate Fellowship Program co-funded by the European Social Fund (ESF) and the Government of the Balearic Islands (Conselleria d'Educació, Cultura i Universitats), and Marta López-Darias by a JAE Doc programme of the Spanish National Research Council. ; Peer Reviewed

Mutualistic interactions between plants and animals promote integration of invasive species into native communities. In turn, the integrated invaders may alter existing patterns of mutualistic interactions. Here we simultaneously map in detail effects of invaders on parameters describing the topology of both plant-pollinator (bi-modal) and plant-plant (uni-modal) networks. We focus on the invader Opuntia spp., a cosmopolitan alien cactus. We compare two island systems: Tenerife (Canary Islands) and Menorca (Balearic Islands). Opuntia was found to modify the number of links between plants and pollinators, and was integrated into the new communities via the most generalist pollinators, but did not affect the general network pattern. The plant uni-modal networks showed disassortative linkage, i.e. species with many links tended to connect to species with few links. Thus, by linking to generalist natives, Opuntia remained peripheral to network topology, and this is probably why native network properties were not affected at least in one of the islands. We conclude that the network analytical approach is indeed a valuable tool to evaluate the effect of invaders on native communities. ; Funding to AT and MN by the Spanish Ministry of Science and Education and FEDER funds of the European Union (CGL2004-0161BOS and CGL2007-61165BOS projects) is gratefully acknowledged. BP received a FPI grant by the Spanish Ministry of Science and Education and TB and JMO were supported by the Danish Science Research Council. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. ; Peer reviewed

© 2015 Macmillan Publishers Limited. Owing to food scarcity and to the high densities that vertebrates often reach on islands, typical insect-and seed-eaters widen their feeding niche and interact with a greater fraction of species than their mainland counterparts. This phenomenon, coined here 'interaction release', has been previously reported for single species but never for an entire community. During 4 years, we gathered data on bird-flower visitation on 12 Galápagos islands. We show that all sampled land birds exploit floral resources and act as potential pollinators across the entire archipelago, in all major habitats and all year round. Although species and link composition varies among islands, strong interaction release takes place on all islands, making their bird-flower network highly generalized. Interaction release is crucial to the survival of native birds but simultaneously threatens the unique biodiversity of this archipelago, as the birds also visit invading plants, likely facilitating their integration into pristine native communities. ; We thank the BBVA foundation for financing the expeditions and research in Galápagos as well as the Charles Darwin Foundation and Galápagos National Park for logistic support. This manuscript is part of the project CGL2013-44386-P financed by the Ministerio de Hacienda y Competitividad of the Spanish Government ; Peer Reviewed

Scientific and grey literature on invasive alien species (IAS) is conditioned by social, economic and political priorities, editorial preferences and species and ecosystem characteristics. This leads to knowledge gaps and mismatches between scientific research interests and management needs. We reviewed the literature on IAS management in Spain found in Scopus, Web of Science, Google Scholar and Dialnet to identify key deficiencies and priority research areas. The collected literature was classified, employing features describing formal aspects and content. We used bibliometric and keyword co-occurrence network analyses to assess the relationship between features and reveal the existence of additional topics. Most of the compiled documents (n = 388) were focused on terrestrial ecosystems and inland waters, whereas marine and urban ecosystems were under-represented. The literature was largely generic and not species-specific, focusing on raising awareness and proposing changes on current regulation as prominent approaches to prevent further introductions. The compiled authors exhibited many clear publishing preferences (e.g. language or document type), but less regarding target taxa. In addition, there was a strong association between species and the different features considered, especially between the methodological approach (e.g. review, field experiment) and the primary emphasis of study (i.e. basic/theoretical, applied or interdisciplinary). This indicates that research on IAS has had a strong species-specific focus. References about terrestrial species focused mainly on vascular plants, whereas references about inland waters were mostly on fishes and the giant reed (Arundo donax), which has been managed with partial success. Animal culling and plant removal were the most frequent eradication and small-scale control treatments, whereas the documents addressing wider spatial scales were largely theoretical. Consequently, the success of described treatments was largely uncertain. Spanish invasion science ...

Este artículo contiene 28 páginas, 7 figuras, 2 tablas. ; Scientific and grey literature on invasive alien species (IAS) is conditioned by social, economic and political priorities, editorial preferences and species and ecosystem characteristics. This leads to knowledge gaps and mismatches between scientific research interests and management needs. We reviewed the literature on IAS management in Spain found in Scopus, Web of Science, Google Scholar and Dialnet to identify key deficiencies and priority research areas. The collected literature was classified, employing features describing formal aspects and content. We used bibliometric and keyword co-occurrence network analyses to assess the relationship between features and reveal the existence of additional topics. Most of the compiled documents (n = 388) were focused on terrestrial ecosystems and inland waters, whereas marine and urban ecosystems were under-represented. The literature was largely generic and not species-specific, focusing on raising awareness and proposing changes on current regulation as prominent approaches to prevent further introductions. The compiled authors exhibited many clear publishing preferences (e.g. language or document type), but less regarding target taxa. In addition, there was a strong association between species and the different features considered, especially between the methodological approach (e.g. review, field experiment) and the primary emphasis of study (i.e. basic/theoretical, applied or interdisciplinary). This indicates that research on IAS has had a strong species-specific focus. References about terrestrial species focused mainly on vascular plants, whereas references about inland waters were mostly on fishes and the giant reed (Arundo donax), which has been managed with partial success. Animal culling and plant removal were the most frequent eradication and small-scale control treatments, whereas the documents addressing wider spatial scales were largely theoretical. Consequently, the success of described treatments was largely uncertain. Spanish invasion science research has been occasionally innovative, incorporating novel technologies (e.g. species distribution modelling) and engaging society with citizenscience approaches. However, the ratio between basic/theoretical and applied studies indicates that more applied research/management is needed, especially in inland waters and marine ecosystems. We call for increasing effort in the effective dissemination of experience in IAS management to enhance current practical knowledge, including that of schemes undertaken by public agencies. ; This research was funded by the Spanish Ministry of Science and Innovation (InvaNET network, RED2018‐102571‐T). Additional financial support was provided by the Spanish Ministry of Science and Innovation, Spanish State Research Agency (AEI) and European Regional Development Fund (FEDER, UE) (grants PID2020- 118550RB, PID2019-103936GB-C21, RTI2018-093504-B-I00) and the Government of Catalonia (ref. 2017 SGR 548). RMM benefitted from a postdoctoral Juan de la Cierva Fellowship from the Spanish Ministry of Science and Innovation (FJCI2016-30829). ; Peer reviewed