Conservation strategies for endangered arable plant Euphorbia gaditana

Fragmentation and habitat loss are considered among the most important threats to biodiversity. More precisely, transformation of natural habitats into farmlands has been identified as one of the primary causes of plant species extinction. Therefore, understanding the effects of habitat fragmentation is crucial to the successful conservation of threatened species. Metapopulation modeling is one of the prospective tools used in conservation biology to evaluate long-term survival in fragmented landscapes. In this work, we applied a metapopulation approach to the conservation of the rare plant Euphorbia gaditana Coss., an endangered species growing on the margins of crops in southern Spain. The species is threatened due to herbicide application and intensification of cultivation, which results in a highly patchy distribution, with more than 50 patches of habitat across three separate networks of patches. We used IFM (Incidence Function Modeling) to compare the relative effectiveness of four conservation management scenarios and the effect of three threat scenarios on the risk of extinction of the species. The results of our simulations of population dynamics under plausible management scenarios will aid conservation decision-making, for example, allowing priority conservation areas to be identified or assessing the effect of future reintroductions

Etnobotánica "apprehendere et iocari"

Depto. de Biodiversidad, Ecología y EvoluciónFac. de Ciencias BiológicasFALSEsubmitte

Vertical structure of Erica umbellata, a representative species of European Ibero-Atlantic dry heaths

The canopy structure of Erica umbellata was studied in order to (a) quantify biomass allocation among several organ types, (b) analyse the possible changes in vertical structure related to season and plant size, and (c) evaluate the effectiveness of non-destructive measures to estimate biomass for a species that is declining in some areas, due to fire and other human disturbances. The study was conducted in NW Spain, sampling E. umbellata plants belonging to three size groups. Destructive (biomass) and non-destructive (frequency, height, diameter) measures were used to characterise the vertical distribution and abundance of photosynthetic, woody, reproductive and dead organs. Allometric equations were calculated to estimate total mass using non-destructive measurements. As E. umbellata increases in size, those organs with a higher renewal rate (leaves, new stems, flowers) increase in the upper strata. Seasonal differences are recorded for the reproductive organs and new stems. A sharp decrease in the green/total phytomass ratio (from 0.51 to 0.17) is observed as plant size increases. Organ biomass can be accurately predicted from total weight and it is also possible to estimate the total weight from non-destructive measures, which provides an easier way of recording data in the field

Coordination between water uptake depth and the leaf economic spectrum in a Mediterranean shrubland

Water is the most limiting resource for plant survival and growth in arid environments, but the diversity of water- use strategies among coexisting species in dryland communities is not well understood. There is also growing interest in assessing whether a whole- plant coordination exists between traits related to water- use and the leaf economic spectrum (LES). 2. We used water stable isotopes (δ2H, δ18O) to quantify water uptake proportions from different soil depths by 24 species in a Mediterranean shrubland. Leaf traits associated with water- use efficiency, stomatal regulation (δ13C, δ18O) and the LES (SLA, N, P, K concentrations) were also measured. We assessed potential trade- offs between the above- mentioned leaf traits, water uptake depth and their relationship with species abundance. 3. We found distinct ecohydrological niche segregation among coexisting species. Bayesian models showed that our shrubland species used a median of 37% of shallow soil water (0– 30 cm) and 63% of deep water (30– 100 cm). Still, water source proportions varied considerably among species, as shallow soil water- use ranged from a minimum of 6.4% to a maximum of 68%. Interspecific variability in foliar carbon investment (SLA) and nutrient concentrations was remarkably high, indicating diverse nutrient- use strategies along the LES. Leaf δ18O, δ13C and δ15N values also differed widely among species, revealing differences in stomatal regulation, water- use efficiency and nitrogen acquisition mechanisms. After accounting for evolutionary history effects, water uptake depth was coordinated with the LES: species using shallower soil water from fertile topsoil layers exhibited a more acquisitive carbon- and nutrient- use strategy, whereas water uptake from deeper but less fertile soil layers was linked to a more conservative nutrient- use strategy. Leaf- level water- use traits significantly influenced species abundance, as water- savers with tight stomatal regulation and high water- use efficiency were dominant. 4. Synthesis. Greater utilisation of water stored in nutrient- rich topsoil layers favoured a more acquisitive nutrient- use strategy, whereas a deeper water uptake pattern appeared to constrain access to nutrients. Our findings thus suggest a largely inescapable trade- off and coordination between soil water uptake depth and carbon- and nutrient- use strategies in low- fertility drylands.Ministerio de Economía y CompetitividadComunidad de MadridDepto. de Biodiversidad, Ecología y EvoluciónFac. de Ciencias BiológicasTRUEpu

La flora de la ciudad de Madrid como modelo para la integración de la conservación de la biodiversidad en el diseño urbanístico

La flora de las ciudades no ha sido objeto de demasiada atención conservacionista en el pasado. En este trabajo se ofrece un análisis de las posibilidades de conservación de la biodiversidad vegetal en el medio urbano valorando algunas herramientas desarrolladas por la Biología de la Conservación: áreas protegidas, reintroducciones, hábitats artificiales, arboricultura y jardinería. Después, se utiliza la flora de la ciudad de Madrid como posible modelo de aplicación de las medidas conservacionistas generales expuestas. Se mencionan algunas de las extinciones locales mejor documentadas en la ciudad y se propone el uso de distintos tipos de microrreservas (estratégicas, potenciales o de novo, y de extrarradio) para intentar evitar extinciones adicionales en el futuro. Se concluye con una propuesta novedosa de estrategia de gestión de la biodiversidad consistente en el encaje biótico dentro del planeamiento urbanístico general de las ciudades. El encaje biótico persigue, entre otros objetivos, incorporar a técnicos en biodiversidad en las plantillas locales de las ciudades para alcanzar una gestión más completa de las áreas verdes urbanas

The colonization of abandoned land by Spanish juniper: Linking biotic and abiotic factors at different spatial scales

Colonization of abandoned lands by woody vegetation may be a great opportunity for ecosystem recovery given the current and future trend of land abandonment. This may help to reverse the generalized condition of ecosystem degradation of developed countries which is an urgent need. However, ecosystem recovery in abandoned lands can be seriously limited by biotic and abiotic factors. Indentify such factors and determine the relevant spatial scales at which they operate will help to understand natural patterns of colonization of abandoned lands and may be useful to guide restoration activities. We used Spanish juniper remnant woodlands and old fields recently colonized by the species to assess the variation in post-dispersal seed predation and environmental suitability to plant recruitment. These biotic and abiotic factors are two of the most limiting for vegetation recovery in abandoned lands, at the regional and local spatial scale. We found that recruitment was controlled by factors operating at different spatial scales in a hierarchical manner along different stages of the process. The regional scale was determinant for postdispersal seed predation and seedling abundance which was, in turn, controlled by environmental suitability at the local spatial scale. Post-dispersal seed removal was higher in old fields than in mature woodlands, hence increasing seed limitation, a pervasive constraint for plant recruitment in abandoned lands. Environmental suitability for plant recruitment did not decrease as a result of previous farming uses at the regional scale, a common pattern in areas not subjected to intensive farming practices. Abandoned lands in Mediterranean areas seem to have a strong potential for ecosystem recovery being the biotic factors (e.g. seed availability) more limiting than the abiotic ones when non-intensive farming practices have been performed. This together with predictions of increase in land abandonment in low productive areas makes old fields especially relevant from an ecosystem recovery perspective

Phylogeography of a gypsum endemic plant across its entire distribution range in the western Mediterranean

PREMISE: Gypsum soils in the Mediterranean Basin house large numbers of edaphic specialists that are adapted to stressful environments. The evolutionary history and standing genetic variation of these taxa have been influenced by the geological and paleoclimatic complexity of this area and the long-standing effect of human activities. However, little is known about the origin of Mediterranean gypsophiles and the factors affecting their genetic diversity and population structure. METHODS: Using phylogenetic and phylogeographic approaches based on microsatellites and sequence data from nuclear and chloroplast regions, we evaluated the divergence time, genetic diversity, and population structure of 27 different populations of the widespread Iberian gypsophile Lepidium subulatum throughout its entire geographic range. RESULTS: Lepidium subulatum diverged from its nearest relatives ~3 million years ago, and ITS and psbA/matK trees supported the monophyly of the species. These results suggest that both geological and climatic changes in the region around the Plio-Pleistocene promoted its origin, compared to other evolutionary processes. We found high genetic diversity in both nuclear and chloroplast markers, but a greater population structure in the chloroplast data. These results suggest that while seed dispersal is limited, pollen flow may be favored by the presence of numerous habitat patches that enhance the movement of pollinators. CONCLUSIONS: Despite being an edaphic endemic, L. subulatum possesses high genetic diversity probably related to its relatively old age and high population sizes across its range. Our study highlights the value of using different markers to fully understand the phylogeographic history of plant species.Unión Europea. H2020Ministerio de Economía y Competitividad (MINECO)Comunidad de MadridDepto. de Biodiversidad, Ecología y EvoluciónFac. de Ciencias BiológicasTRUEpu

The role of root community attributes in predicting soil fungal and bacterial community patterns

Roots are assumed to play a major role in structuring soil microbial communities, but most studies exploring the relationships between microbes and plants at the community level have only used aboveground plant distribution as a proxy. However, a decoupling between belowground and aboveground plant components may occur due to differential spreading of plant canopies and root systems. Thus, soil microbe–plant links are not completely understood. Using a combination of DNA metabarcoding and spatially explicit sampling at the plant neighbourhood scale, we assessed the influence of the plant root community on soil bacterial and fungal diversity (species richness, composition and b-diversity) in a dry Mediterranean scrubland. We found that root composition and biomass, but not richness, predict unique fractions of variation in microbial richness and composition. Moreover, bacterial b-diversity was related to root b-diversity, while fungal b-diversity was related to aboveground plant b-diversity, suggesting that plants differently influence both microbial groups. Our study highlights the role of plant distribution both belowground and aboveground, soil properties and other spatially structured factors in explaining the heterogeneity in soil microbial diversity. These results also show that incorporating data on both plant community compartments will further our understanding of the relationships between soil microbial and plant communities

Larger aboveground neighbourhood scales maximise similarity but do not eliminate discrepancies with belowground plant diversity in a Mediterranean shrubland

Aims: An unresolved question in plant ecology is whether diversity of the aboveground and belowground compartments of a plant community is similar at different neighbourhood scales. We investigated how the similarity between both compartments varies with the aboveground sampling grain and if significant discrepancies exist between aboveground and belowground plant diversity at the maximum similarity scale. Methods We fully mapped the aboveground perennial plant community of a 64 m2 plot in a Mediterranean shrubland and analysed this compartment by assessing diversity in 5 to 50 cm radii circles centred in soil cores. We sampled 2.5 cm radius root cores at two different depths and identified plant species by using DNA metabarcoding to characterise the belowground compartment. We quantified differences in species richness, composition and species’ spatial distribution above- and belowground. Results: The differences between aboveground and belowground communities were affected by the size of the aboveground sampling grain and were minimised when considering a circle of 20 cm radius in the aboveground. We found a significant dissimilarity in richness and composition between the two compartments, with larger differences when considering the deeper soil layer only. Conclusions: Our results showed that the spatial grain selected to sample a plant community aboveground and belowground is critical to characterise them in a comparable manner. Although their composition is related, species distribution patterns strongly differ, suggesting the simultaneous action of different assembly mechanisms. Our results call for caution when studying community assembly considering only the standing vegetation, since total plant diversity can be underappreciated

Estimating belowground plant abundance with DNA metabarcoding

Most work on plant community ecology has been performed above ground, neglecting the processes that occur in the soil. DNA metabarcoding, in which multiple species are computationally identified in bulk samples, can help to overcome the logistical limitations involved in sampling plant communities belowground. However, a major limitation of this methodology is the quantification of species’ abundances based on the percentage of sequences assigned to each taxon. Using root tissues of five dominant species in a semi‐arid Mediterranean shrubland (Bupleurum fruticescens, Helianthemum cinereum, Linum suffruticosum, Stipa pennata and Thymus vulgaris), we built pairwise mixtures of relative abundance (20%, 50% and 80% biomass), and implemented two methods (linear model fits and correction indices) to improve estimates of root biomass. We validated both methods with multispecies mixtures that simulate field‐collected samples. For all species, we found a positive and highly significant relationship between the percentage of sequences and biomass in the mixtures (R2 = .44–.66), but the equations for each species (slope and intercept) differed among them, and two species were consistently over‐ and under‐estimated. The correction indices greatly improved the estimates of biomass percentage for all five species in the multispecies mixtures, and reduced the overall error from 17% to 6%. Our results show that, through the use of post‐sequencing quantification methods on mock communities, DNA metabarcoding can be effectively used to determine not only species’ presence but also their relative abundance in field samples of root mixtures. Importantly, knowledge of these aspects will allow us to study key, yet poorly understood, belowground processes