Search

We thank C. Díaz Palomo for his technical assistance in this work, M. de la Cruz for his useful suggestions on R language, L. De Hond for her linguistic assistance and the Staff of the Parque Nacional de la Sierra de Guadarrama for permission to work in the field area. We are also grateful to two anonymous reviewers for their thorough revision of the manuscript., Aims Harsh environmental conditions in alpine ecosystems shape vegetation structure into patches, where many different plant species cluster and grow together. Yet, which factors are important for the structure and dynamics of such plant–patch networks remains poorly understood. We aim to assess which and how environmental and biotic factors predict the assembly of plant–patch networks along a mountain range. Methods We examined the distribution of plant species in more than 5500 vegetation patches in 37 Mediterranean alpine grasslands distributed along a 500 m altitudinal gradient (National Park of Sierra Guadarrama, Spain). We established a plant–patch network for each grassland community and analyzed how nestedness and modularity vary with environmental (altitude, insolation and soil conditions) and biotic factors (number of species per plot, mean patch area and total pasture area). Important Findings Plant–patch networks showed consistent, non-random patterns characterized by a nested, but not modular, structure, which suggests that positive associations among co-occurring specialists promote their growth within patches as subsets of a pool with more generalist species. Both nestedness and modularity of plant–patch networks varied among grasslands. Specifically, nestedness decreased with increasing species per plot and increased with mean patch area, while it was independent of environmental variables; modularity increased with increasing pasture area and species per plot. The negative relationship between species per plot and nested patterns may be linked to the restricted number of species that can coexist within the same patch at a given size. Moreover, the positive relationship between patch size and nestedness indicates that the growth of rare plant species within vegetation patches occupied by more abundant species is facilitated in bigger rather than smaller patches. Furthermore, these results indicate that the nested assembly of vegetation patches may be, Ministry of Economy and Competitiveness of Spain, Madrid Regional Government, Swiss National Science Foundation, Depto. de Farmacología, Farmacognosia y Botánica, Fac. de Farmacia, TRUE, pub

The outcome of many ecological interactions lies somewhere along a continuum between pure positive and pure negative effects. Although the popularity of this idea has notoriously risen in the last decades, with the occurrence of continua in interaction outcomes invoked for a wide variety of interactions, the absence of a precise theoretical treatment has led to considerable inaccuracy and ambiguity in its treatment. We develop here a consumer-resource model to explore the occurrence of continua. This model is based on the assumption that the distribution of individual interaction events includes both negative and positive immediate outcomes, with variable frequencies, for at least one of the interacting species. Our study shows that continua in interaction outcomes happen just by varying the sign and impact of individual events. The exact shape of the continua depends on the proportion of positive versus negative events and the relative magnitude of per-capita interaction strengths. Our model shows that continua in interaction outcomes are a key property of most pairwise interactions and are originated from the variable roles played by the interacting partners. It constitutes a step forward in the paradigm change from discrete categorization of ecological interactions to a new perspective over a continuous space.

Background and aims Within-population genetic and phenotypic variation play a key role in the development of adaptive responses to environmental change. Between-population variation is also an essential element in assessing the evolutionary potential of species in response to changes in environmental conditions. In this context, common garden experiments are a useful tool to separate the genetic and environmental components of phenotypic variation. We aimed to assess within- and between-population phenotypic variation of Lupinus angustifolius L. in terms of its evolutionary potential to adapt to ongoing climate change. Methods We evaluated populations’ phenotypic variation of foliar, phenological and reproductive traits with a common garden experiment. Patterns of functional trait variation were assessed with (1) mixed model analyses and coefficients of variation (CVs) with confidence intervals, (2) principal component analyses (PCAs) and (3) correlations between pairs of traits. Analyses were performed at the population level (four populations) and at the latitude level (grouping pairs of populations located in two latitudinal ranges). Key Results Phenotypic variation had a significant genetic component associated with a latitudinal pattern. (1) Mixed models found lower specific leaf area, advanced flowering phenology and lower seed production of heavier seeds in southern populations, whereas CV analyses showed lower within-latitude variation especially in phenological and reproductive traits in southern populations. (2) PCAs showed a clearer differentiation of phenotypic variation between latitudes than between populations. (3) Correlation analyses showed a greater number of significant correlations between traits in southern populations (25 vs. 13). Conclusions Between-population phenotypic variation was determined by contrasting temperature and drought at different latitude and elevation. Southern populations had differential trait values compatible with adaptat

Landraces are key plant genetic resources because of their adaptation to the local environment, which makes them likely to contain alleles or gene complexes that confer local adaptation. After massive loss of landraces in the past century, the diversity that persists in farms is currently threatened and, thus, it must be safeguarded with the highest priority. On-farm conservation is an important management approach that allows landraces to evolve according to environmental changes. A methodological approach to systematic identification of the most appropriate areas (MAPAs) for on-farm conservation of landraces is presented, using Spanish tomato (Solanum lycopersicum L.) landraces as a case study. Among a set of potential factors that might condition the selection of the MAPAs, a panel of experts determined that the most important criteria in the assessment of the MAPAs were related to agrobiodiversity and to ecogeographical parameters. For each important criterion, a specific 5- by 5-km resolution GIS layer was created, and six different prioritization strategies were applied on the area of study to obtain a final priority value per cell and then an average priority value per county. The MAPAs were assigned to the counties with the highest average priority values according to the selected strategy. They were widely distributed in rural areas across the Iberian Peninsula mainly in the autonomous communities of Valencia, the Basque Country, Extremadura, northern Andalusia, Catalonia, northern Aragon, and western Castilla-La Mancha. The methodological approach and priority counties identified could be used by governmental agencies to allocate in situ conservation projects.

In the present framework of global warming, it is unclear whether evolutionary adaptation can happen quick enough to preserve the persistence of many species. Specifically, we lack knowledge about the adaptive potential of the different populations in relation to the various constraints that may hamper particular adaptations. There is evidence indicating that early flowering often provides an adaptive advantage to plants in temperate zones in response to global warming. Thus, the objective of this study was to assess the adaptive potential for advancing flowering onset in Lupinus angustifolius L. (Fabaceae). Seeds from four populations from two contrasting latitudes in Spain were collected and sown in a common garden environment. Selecting the 25% of the individuals that flowered earlier in the first generation, over three generations, three different early flowering selection lines were established, involving both self-crosses and outcrosses. All artificial selection lines advanced their flowering significantly with respect to the control line in the northernmost populations, but not in the southern ones. Selection lines obtained from outcrossing had a greater advancement in flowering than those from self-crossing. No differences were found in the number or weight of the seeds produced between control and artificial selection lines, probably because plants in the common garden were drip irrigated. These results suggest that northern populations may have a greater adaptive potential and that southern populations may be more vulnerable in the context of climate warming. However, earlier flowering was also associated with changes in other traits (height, biomass, shoot growth, specific leaflet area, and leaflet dry matter content), and the effects of these changes varied greatly depending on the latitude of the population and selection line. Assessments of the ability of populations to cope with climate change through this and other approaches are essential to manage

Crop wild relatives (CWR) have recently received significant attention due to their value as plant genetic resources and their contribution to world food security. We present a prioritized checklist of CWR in Spain in which the criteria of crossability with crops of economic importance, endemicity and threat status have been taken into account. First, we selected a list of genera corresponding to the most relevant crops for Spain and at the international level. These crops were classified into use categories (Food, Forage & Fodder, Ornamental, and Industrial & Other uses) depending on their main use. The wild plant species native to Spain belonging to these genera were then listed. After evaluation by national experts in plant breeding, the resulting checklist contained 929 species. Further selection based on crossability, endemicity and threat status led to the generation of the Prioritized Spanish Checklist of crop wild relatives containing 578 species. Thirty-two percent of these species belong to the Forage & Fodder use category, 28% to the Ornamental category, 24% to the Food category and 16% to the Industrial & Other uses category. Thirty-five percent of the prioritized species are endemic to Spain, and over one-fourth are classified under some category of threat according to the International Union for Conservation of Nature. Endemicity and threat status rates in the Prioritized Spanish Checklist of CWR were higher than those found in the prioritized CWR inventories of other countries. A ex situ assessment reporting number of accessions showed that 70% of the prioritized Spanish CWR have accessions preserved in genebanks.

We thank C. Díaz Palomo for his technical assistance in this work, M. de la Cruz for his useful suggestions on R language, L. De Hond for her linguistic assistance and the Staff of the Parque Nacional de la Sierra de Guadarrama for permission to work in the field area. We are also grateful to two anonymous reviewers for their thorough revision of the manuscript., Aims Harsh environmental conditions in alpine ecosystems shape vegetation structure into patches, where many different plant species cluster and grow together. Yet, which factors are important for the structure and dynamics of such plant–patch networks remains poorly understood. We aim to assess which and how environmental and biotic factors predict the assembly of plant–patch networks along a mountain range. Methods We examined the distribution of plant species in more than 5500 vegetation patches in 37 Mediterranean alpine grasslands distributed along a 500 m altitudinal gradient (National Park of Sierra Guadarrama, Spain). We established a plant–patch network for each grassland community and analyzed how nestedness and modularity vary with environmental (altitude, insolation and soil conditions) and biotic factors (number of species per plot, mean patch area and total pasture area). Important Findings Plant–patch networks showed consistent, non-random patterns characterized by a nested, but not modular, structure, which suggests that positive associations among co-occurring specialists promote their growth within patches as subsets of a pool with more generalist species. Both nestedness and modularity of plant–patch networks varied among grasslands. Specifically, nestedness decreased with increasing species per plot and increased with mean patch area, while it was independent of environmental variables; modularity increased with increasing pasture area and species per plot. The negative relationship between species per plot and nested patterns may be linked to the restricted number of species that can coexist within the same patch at a given size. Moreover, the positive relationship between patch size and nestedness indicates that the growth of rare plant species within vegetation patches occupied by more abundant species is facilitated in bigger rather than smaller patches. Furthermore, these results indicate that the nested assembly of vegetation patches may be, Ministry of Economy and Competitiveness of Spain, Madrid Regional Government, Swiss National Science Foundation, Depto. de Farmacología, Farmacognosia y Botánica, Fac. de Farmacia, TRUE, pub

Amidst the general concern about the need to conserve crop wild relatives (CWR) as a source of genetic diversity potentially useful in crop breeding, recent studies have assessed global gaps in CWR conservation using predictive distribution approaches. However, few options are available to downscale such studies and conduct efficient seed-collecting expeditions in specific target areas for ex situ conservation. A new type of optimized collecting design (OCD) to determine priority areas for collecting CWR is presented to fit this purpose. The new approach is based on the principles of complementarity and ecogeographical representativeness of ex situ collections, using ecogeographical variation as a proxy for genetic diversity of adaptive value. It aims to offer a collecting strategy that captures the maximum genetic diversity of adaptive value at a minimum cost. Ninety-eight priority species related to cereal and legume crops, selected by the Spanish National Strategy for CWR Conservation, were targeted to illustrate this approach. The analysis resulted in a ranking of 10- × 10-km areas containing decreasing richness of complementary ecogeographical gaps of selected CWR taxa. The top 10 complementary areas were overlapped with the Spanish Sites of Community Importance of the Natura 2000 network to prioritize collection in areas not covered by the network, which would be more exposed to habitat destruction and other anthropic risks. This new kind of OCD allows collectors to efficiently sample nonrepresented populations of many species growing in adaptive scenarios within a relatively reduced area at the same time. © Crop Science Society of America.

Drought, one of the most important abiotic stress factors limiting biomass, significantly reduces crop productivity. Salinization also affects the productivity of both irrigated and rain-fed wheat crops. Species of genus Aegilops can be considered crop wild relatives (CWR) of wheat and have been widely used as gene sources in wheat breeding, especially in providing resistance to pests and diseases. Five species (Ae. biuncialis, Ae. geniculata, Ae. neglecta, Ae. triuncialis and Ae. ventricosa) are included in the Spanish National Inventory of CWRs. This study aimed to identify ecogeographic gaps in the Spanish Network on Plant Genetic Resources for Food and Agriculture (PGRFA) with potential tolerance to drought and salinity. Data on the Spanish populations of the target species collected and conserved in genebanks of the Spanish Network on PGRFA and data on other population occurrences in Spain were compiled and assessed for their geo_x0002_referencing quality. The records with the best geo-referencing quality values were used to identify the ecogeographical variables that might be important for Aegilops distribution in Spain. These variables were then used to produce ecogeographic land characterization maps for each species, allowing us to identify populations from low and non-represented ecogeographical categories in ex situ collections. Predictive character_x0002_ization strategy was used to identify 45 Aegilops populations in these ecogeographical gaps with potential tolerance to drought and salinity conditions. Further efforts are being made to collect and evaluate these populations.

Fine-scale genetic structure (FSGS) can vary among populations within species depending on multiple demographic and environmental factors. Theoretical models predict that FSGS should decrease in high-density populations and increase in populations where individuals are spatially aggregated. However, few empirical studies have compared FSGS between populations with different degrees of individual spatial aggregation and microhabitat heterogeneity. In this work, we studied the relationship between spatial and genetic structure in five populations of alpine specialist Silene ciliata Poiret (Caryophyllaceae). We mapped all individuals in each population and genotyped 96 of them using 10 microsatellite markers. We found significant FSGS consistent with an isolation-by-distance process in three of the five populations. The intensity of FSGS was positively associated with individual spatial aggregation. However, no association was found between FSGS and global population density or microhabitat heterogeneity. Overall, our results support theoretical studies indicating that stronger spatial aggregation tends to increase the magnitude of FSGS. They also highlight the relevance of characterizing local plant distribution and microhabitat to better understand the mechanisms that generate intraspecific variation in FSGS across landscapes. © 2016 Macmillan Publishers Limited.

This study evaluated the phenotypic representativeness of core collections generated independently with ecogeographical data or with morphological data. The Spanish Phaseolus vulgaris L. collection was the target germplasm collection, and one map of ecogeographical categories and 15 morphological variables were used to create core collections. Three ecogeographical and 12 morphological core collections were produced combining different grouping methods (categories from ecogeographical land characterization map [CEM], two-step clustering [TSC], Ward-modified location model clustering [WM], and unweighted pair-group method using arithmetic average [UPGMA]) and allocation strategies (constant [C], proportional [P], logarithmic [L], and Gower's distance [D]). An additional morphological core collection was created using a modified least distance stepwise sampling (LDSSm) method. Core collections were evaluated with morphological data using parameters for qualitative and quantitative variables that were summarized in a new synthetic evaluation parameter (SEP). Synthetic evaluation parameter results showed that the ecogeographical core collections had high phenotypic representativeness, similar to that of morphological core collections generated by the combination of WM and TSC grouping methods and P allocation strategy. A graphical evaluation of core collections supported these results. In conclusion, ecogeographical information was confirmed as a good alternative or complement to other types of data to create reliable and representative core collections.

Background and Aims In mountain plant populations, local adaptation has been described as one of the main responses to climate warming, allowing plants to persist under stressful conditions. This is especially the case for marginal populations at their lowest elevation, as they are highly vulnerable. Adequate levels of genetic diversity are required for selection to take place, while high levels of altitudinal gene flow are seen as a major limiting factor potentially precluding local adaptation processes. Thus, a compromise between genetic diversity and gene flow seems necessary to guarantee persistence under oncoming conditions. It is therefore critical to determine if gene flow occurs preferentially between mountains at similar altitudinal belts, promoting local adaptation at the lowest populations, or conversely along altitude within each mountain. Methods Microsatellite markers were used to unravel genetic diversity and population structure, inbreeding and gene flow of populations at two nearby altitudinal gradients of Silene ciliata, a Mediterranean high-mountain cushion plant. Key Results Genetic diversity and inbreeding coefficients were similar in all populations. Substantial gene flow was found both along altitudinal gradients and horizontally within each elevation belt, although greater values were obtained along altitudinal gradients. Gene flow may be responsible for the homogeneous levels of genetic diversity found among populations. Bayesian cluster analyses also suggested that shifts along altitudinal gradients are the most plausible scenario. Conclusions Past population shifts associated with glaciations and interglacial periods in temperate mountains may partially explain current distributions of genetic diversity and population structure. In spite of the predominance of gene flow along the altitudinal gradients, local genetic differentiation of one of the lower populations together with the detection of one outlier locus might support the existence