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Species–area relationships (SAR) constitute a key aspect of ecological theory and are integral to other scientific disciplines, such as biogeography, which have played a crucial role in advancing biology. The theory of insular biogeography provides a clear example. This theory initially expanded from true islands to other types of systems characterized by their insularity. One such approach was linked to geoedaphic islands, as seen in gypsum outcrops. While these continental areas have been considered insular systems, only limited and mostly indirect evidence thereof has been provided. This study utilized SAR to advance the understanding of gypsum outcrops as insular continental territories. It is hereby hypothesized that gypsum outcrops are edaphic islands, although their insular nature depends on the different functional or ecological plant types, and this nature will be reflected in the potential Arrhenius model z values. The results obtained support both hypotheses and provide insight into the ecological factors that help interpret the insularity of these areas. This interpretation goes beyond their mere extent and the distance among outcrops, emphasizing the importance of environmental filters. Said filters vary in permeability depending on the degree of gypsophily, or preference for gypsum, exhibited by different species. [ABSTRACT FROM AUTHOR]

Species–area relationships (SAR) constitute a key aspect of ecological theory and are integral to other scientific disciplines, such as biogeography, which have played a crucial role in advancing biology. The theory of insular biogeography provides a clear example. This theory initially expanded from true islands to other types of systems characterized by their insularity. One such approach was linked to geoedaphic islands, as seen in gypsum outcrops. While these continental areas have been considered insular systems, only limited and mostly indirect evidence thereof has been provided. This study utilized SAR to advance the understanding of gypsum outcrops as insular continental territories. It is hereby hypothesized that gypsum outcrops are edaphic islands, although their insular nature depends on the different functional or ecological plant types, and this nature will be reflected in the potential Arrhenius model z values. The results obtained support both hypotheses and provide insight into the ecological factors that help interpret the insularity of these areas. This interpretation goes beyond their mere extent and the distance among outcrops, emphasizing the importance of environmental filters. Said filters vary in permeability depending on the degree of gypsophily, or preference for gypsum, exhibited by different species.

Plants' responses to conflicting stresses may result in physiological trade-offs due to the inter-dependent and costly nature of physiological investments. Physiological tradeoffs have been proved within species, but to what extent these trade-offs are the result of phylogenetic constraints remains poorly known. Environmental stresses can vary widely in different biomes, and therefore assessing physiological tradeoffs across species must account for this variation. One way of doing so is to assess it within a community, where the co-occurring species have faced a shared combination of filters to establish. Considering a representative sample of species in a single community, we use a macroevolutionary approach to test the hypothesis that plant physiological trade-offs are evolutionarily conserved within this community (i.e., closely-related species tend to solve the trade-offs similarly). We analyze the content of five metabolites in thirty co-occurring plant species, capturing their range of contrasting exposures to abiotic and biotic stresses (growing solitary and in vegetation patches). Our results support that species investment in response to abiotic stress (i.e., proline and abscisic acid content) is traded off against their investment to face biotic stress (i.e., jasmonic acid and salicylic acid), shown by the contrasting loadings of these two groups of metabolites in the first axes of a principal component analysis (PCA). In addition, the metabolic strategies observed in this community are evolutionarily conserved, as closely related species tend to have similar scores in this PCA, and thus resemble each other in their balance. This is shown by a significant phylogenetic signal in the species' scores along the first axes of the PCA. Incorporating the evolutionary history of plant species into physiological studies can help to understand the response of plants to multiple stresses currently acting in ecological communities. [ABSTRACT FROM AUTHOR]

Estudios recientes han demostrado que los afloramientos de yeso de la provincia de Almería (sureste de España) son los de mayor valor desde el punto de vista de la conservación de la flora gipsícola ibérica. La necesidad de conservar este patrimonio unida a la imposibilidad real de proteger todos los afloramientos existentes en la región, nos llevó a elucidar qué áreas de la provincia deberían ser consideradas como prioritarias para lograr la conservación de la flora gipsícola de estos enclaves. Para ello, se estableció como objetivo prioritario lograr la representación de todas las especies al menos una vez, a la vez que se plantearon otros escenarios posibles en los que se podría basar la elección de áreas -objetivos complementarios-. Se elaboró la cartografía de los gipsófitos, referida a celdas de 10 km de lado y se evaluó la importancia de cada enclave según diferentes criterios utilizados comúnmente en los estudios sobre selección de áreas (diversidad de especies, rareza de la flora, complementariedad) contrastando los resultados obtenidos mediante cada uno de ellos. Los resultados mostraron que la protección de los afloramientos existentes en tan sólo tres cuadrículas (Sorbas, ya protegida principalmente por sus valores geomorfológicos, Venta de los Yesos y Topares) sería suficiente para lograr la representación de todos los gipsófitos de la región y alcanzar además varios de los objetivos complementarios de conservación. Los resultados se discuten teniendo en cuenta las peculiaridades sociales y administrativas del territorioRecent studies have highlighted the gypsum outcrops of Almería (southeast Spain) as the most outstanding for the conservation of Iberian gypsophilous flora. The need of preserving this natural heritage and the impossibility to protect all the outcrops present within the territory, led us to identify which areas should be considered as of priority for conservation. To this end, we establish as a priority that the proposed conservation network of sites should include all gypsophyte species at least once. Other possible conservation goals on which to base the area selection and the associated scenarios were also taken into account. We first elaborated a cartography for the gypsophytes based on 10 km sided-cells. Next, in order to rank the importance of each locality, several commonly employed conservation criteria (diversity, rarity of the flora, complementarity) were applied to the cartographic information, and the findings obtained by each procedure contrasted. The results showed that protecting the deposits found in three cells (Sorbas, already protected because of its geomorphological singularity, Venta de los Yesos and Topares) would allow the representation of each species at least once and to achieve several complementary conservation targets. The findings are discussed within the context of the social and administrative peculiarities of the area

Background: Gypsum ecosystems are edaphic islands surrounded by a matrix that is inhospitable to gypsum soil plant specialists. These naturally fragmented landscapes are currently exacerbated due to man-made disturbances, jeopardising their valuable biodiversity. Concomitant action of other fragmentation drivers such as linear infrastructures may increase the already high threat to these specialists. Although some evidence suggest that gypsophytes are not evolutionary dead-ends and can respond to fragmentation by means of phenotypic plasticity, the simultaneous action of barriers to genetic flow can pose a severe hazard to their viability. Here, we evaluated the effect of a highway with heavy traffic on the genetic flow and diversity in the species Lepidium subulatum , a dominant Iberian shrubby gypsophyte., Methods: We tested the possible existence of bottlenecks, and estimated the genetic diversity, gene flow and genetic structure in the remnant populations, exploring in detail the effect of a highway as a possible barrier., Results: Results showed variability in genetic diversity, migrants and structure. The highway had a low impact on the species since populations can retain high levels of genetic diversity and genetic parameter, like F ST and F IS , did not seem to be affected. The presence of some level of genetic flow in both sides along the highway could explain the relatively high genetic diversity in the habitat remnants., Discussion: Natural fragmentation and their exacerbation by agriculture and linear infrastructures seem to be negligible for this species and do not limit its viability. The biological features, demographic dynamics and population structures of gypsum species seem to be a valuable, adaptive pre-requisite to be a soil specialist and to maintain its competitiveness with other species in such adverse stressful conditions., Competing Interests: The authors declare that they have no competing interests., (© 2021 Martín-Rodríguez et al.)