Effects of Glyphosate Application on Physiologically Integrated Clones of the Invasive Plant Carpobrotus edulis

[Abstract] Management of invasive alien species is a high priority for biodiversity conservation. Here, we studied the effects of glyphosate application, at 0.06 g/m2 concentration, on physiologically integrated basal and apical ramets of the invasive clonal plant Carpobrotus edulis. Physiological integration allows the transport of resources and other substances between connected ramets in clonal plants. We found a significant reduction of growth and photochemical efficiency both in basal and apical ramets of C. edulis after glyphosate application. Interestingly, we also observed a significant growth reduction in untreated basal ramets when they remained connected to apical ramets treated with glyphosate. This result was interpreted as a cost for basal ramets due to supporting severely stressed apical ramets. Therefore, local application of glyphosate to apical ramets of C. edulis can negatively affect not only their own growth, but also the growth of their interconnected, untreated basal ramets. Our results suggest that glyphosate effectiveness can be maintained when applied only to one part of the clone so that the amount of herbicide used in eradication programs can be greatly reduced, which can minimize the negative impact of chemical herbicides on ecosystems

Temperate Kelp Forest Collapse by Fish Herbivory: A Detailed Demographic Study

[Abstract] Kelps dominate rocky shores in temperate latitudes, acting as important foundation species. Recently, kelp forests have received growing attention for their decline around the world. Climate change is one of the main drivers of their deforestation, both through abiotic stress and/or distortion of biotic interactions. In NW Spain, golden kelp (Laminaria ochroleuca) forests have recently declined in some areas due to excessive grazing. To further investigate the mechanisms behind this decline, a thorough 1-year seasonal demographic study was carried out on eight golden kelp reefs: four healthy and four degraded by herbivory. Kelps covered the full range of size classes throughout the year on healthy reefs. By contrast, only small, newly recruited kelps were found on degraded reefs in spring-summer, because excessive herbivory in autumn-winter caused a total collapse of kelp populations on a reef-scale (i.e., all kelps reduced to inviable stubs with no blade and no growth meristem). Bite marks in kelps covering all size classes showed that fishes, instead of invertebrates, were the culprits of the excessive herbivory. Recent studies, mostly conducted in the Indo-Pacific, also found that fish herbivory, alone or in combination with abiotic stressors, can maintain a canopy-free state in kelp reefs. To the best of our knowledge, this is the first time that fish is also shown to cause the collapse of entire kelp forests on a reef scale in the temperate Atlantic. The implications of this finding for the management and potential recovery of degraded reefs are discussed.This research was funded by the “Fundación Biodiversidad y el Ministerio de Transición Ecológica y el Reto Demográfico.” BioCost Research Group acknowledges funding from Xunta de Galicia (grants ED431D 2017/2020 and ED431B 2018/49 of “Axudas para a consolidación e estructuración de unidades de investigación competitivas do SUG” program). SB received financial support from the Xunta de Galicia and the European Union (European Social Found – ESF) (grant ED481A-2018/101). CP-C received financial support from Xunta de Galicia “Axudas de apoio á etapa de formación posdoutoral “(grant ED481B-2021/095)”Xunta de Galicia; ED431D 2017/2020Xunta de Galicia; ED431B 2018/49Xunta de Galicia; ED481A-2018/101Xunta de Galicia; ED481B-2021/09

Conocimiento de la diversidad específica de algas coralinas costrosas (Corallinophycidae, Rhodophyta) asociadas a lechos de maerl de la Europa atlántica mediante la utilización de códigos de barras genéticos

DNA barcoding in combination with morpho-anatomical analysis was applied to study the diversity of crustose coralline algae associated to two maerl beds from two protected Atlantic European areas from Brittany and Galicia —France and Spain, respectively—. Given the records of gametophytes of the maerl species Phymatolithon calcareum under crustose growth-forms, and that associated crustose coralline algae appear to be involved in the recruitment of new maerl plants, we compared the species composition between the associated crustose coralline algae to Breton and Galician maerl beds with the maerl species identified in these beds in previous DNA barcoding surveys. Our molecular results revealed higher species diversity in associated crustose coralline algae than in maerl-forming species. Nine taxa of crustose coralline algae were found in both study areas: four in Brittany and five in Galicia. Three species from Brittany were identified as Phymatolithon calcareum, Phymatolithon lamii, and Lithophyllum hibernicum. The remaining six ones were assigned to the genera Phymatolithon and Mesophyllum, along with Lithothamnion and Lithophyllum. Morpho-anatomical examination of diagnostic characters corroborated our molecular identification. Our results showed that the most representative genus of crustose coralline algae in Brittany was Phymatolithon, while in Galicia was Mesophyllum. In Brittany, Phymatolithon calcareum was found under both growth-forms, maerl and crustose coralline algae, the latter assigned to the gametophyte stage by the presence of uniporate conceptacles. The recruitment of new maerl plants involving associated crustose coralline algae with maerl beds may occur, but only we can affirm it for Phymatolithon calcareum in Brittany. By contrast, the different species composition between both growth-forms in the Galician maerl beds would indicate that the fragmentation of own free-living maerl species appears to be the most common propagation mechanism.En este trabajo se han utilizado el sistema de códigos de barras genéticos y análisis morfo-anatómicos para estudiar la diversidad de algas coralinas costrosas asociadas a dos fondos de maerl localizados en dos áreas protegidas del Atlántico Europeo en Bretaña y Galicia —Francia and España, respectivamente—. Dadas las citas recientes de gametófitos de la especie típica de lechos de maerl, Phymatolithon calcareum, bajo una forma de crecimiento costrosa, y que las algas coralinas incrustantes parecen estar implicadas en el reclutamiento de nuevas plantas del maerl, en este trabajo se compara la composición entre estas algas asociadas a fondos de maerl bretones y gallegos, con las especies del maerl identificadas en estos fondos en estudios previos de códigos de barras genéticos. Los resultados moleculares del presente trabajo revelaron una diversidad más alta en las algas coralinas costrosas asociadas que en las propias especies formadoras del maerl. En las áreas estudiadas se encontraron nueve táxones de algas coralinas costrosas: cuatro en la Bretaña francesa y cinco en Galicia. Tres especies de la Bretaña fueron identificadas como Phymatolithon calcareum, Phymatolithon lamii y Lithophyllum hibernicum. Las seis especies restantes fueron asignadas a los géneros Phymatolithon y Mesophyllum, junto con Lithothamnion y Lithophyllum. El examen morfo-anatómico de caracteres diagnósticos concordó con la identificación molecular. Los resultados obtenidos evidenciaron que el género más representativo de algas coralinas costrosas en la Bretaña fue Phymatolithon, mientras que en Galicia fue Mesophyllum. En la Bretaña, Phymatolithon calcareum fue encontrado bajo ambas formas de crecimiento —maerl y morfología incrustante—, en este último caso asignada a la generación gametofítica por la presencia de conceptáculos uniporados. El reclutamiento de nuevas plantas del maerl a través de las algas coralinas costrosas asociadas a fondos de maerl puede suceder, pero solo se puede afirmar para Phymatolithon calcareum en la Bretaña. Por contra, en los fondos de maerl de Galicia la composición diferente de ambas formas de crecimiento podría indicar que la fragmentación de las propias especies del maerl podría ser el mecanismo de propagación más común

Mining microsatellite markers from public expressed sequence tags databases for the study of threatened plants

Background: Simple Sequence Repeats (SSRs) are widely used in population genetic studies but their classical development is costly and time-consuming. The ever-increasing available DNA datasets generated by high-throughput techniques offer an inexpensive alternative for SSRs discovery. Expressed Sequence Tags (ESTs) have been widely used as SSR source for plants of economic relevance but their application to non-model species is still modest. Methods: Here, we explored the use of publicly available ESTs (GenBank at the National Center for Biotechnology Information-NCBI) for SSRs development in non-model plants, focusing on genera listed by the International Union for the Conservation of Nature (IUCN). We also search two model genera with fully annotated genomes for EST-SSRs, Arabidopsis and Oryza, and used them as controls for genome distribution analyses. Overall, we downloaded 16 031 555 sequences for 258 plant genera which were mined for SSRsand their primers with the help of QDD1. Genome distribution analyses in Oryza and Arabidopsis were done by blasting the sequences with SSR against the Oryza sativa and Arabidopsis thaliana reference genomes implemented in the Basal Local Alignment Tool (BLAST) of the NCBI website. Finally, we performed an empirical test to determine the performance of our EST-SSRs in a few individuals from four species of two eudicot genera, Trifolium and Centaurea. Results: We explored a total of 14 498 726 EST sequences from the dbEST database (NCBI) in 257 plant genera from the IUCN Red List. We identify a very large number (17 102) of ready-to-test EST-SSRs in most plant genera (193) at no cost. Overall, dinucleotide and trinucleotide repeats were the prevalent types but the abundance of the various types of repeat differed between taxonomic groups. Control genomes revealed that trinucleotide repeats were mostly located in coding regions while dinucleotide repeats were largely associated with untranslated regions. Our results from the empirical test revealed considerable amplification success and transferability between congenerics. Conclusions: The present work represents the first large-scale study developing SSRs by utilizing publicly accessible EST databases in threatened plants. Here we provide a very large number of ready-to-test EST-SSR (17 102) for 193 genera. The cross-species transferability suggests that the number of possible target species would be large. Since trinucleotide repeats are abundant and mainly linked to exons they might be useful in evolutionary and conservation studies. Altogether, our study highly supports the use of EST databases as an extremely affordable and fast alternative for SSR developing in threatened plants

Could the Annual Saccorhiza Polyschides Replace a Sympatric Perennial Kelp (Laminaria Ochroleuca) When It Comes to Supporting the Holdfast-Associated Fauna?

[Abstract] Kelp forests dominate temperate rocky shores worldwide but are declining globally with consequences for organisms that depend on them. In NW Iberia, the golden kelp (Laminaria ochroleuca) commonly occurs alongside a fast-growing annual that, unlike the golden kelp, does not seem to have receded in recent times (Saccorhiza polyschides). Here, we assessed whether the bulbous holdfast of S. polyschides could replace the intricate holdfast of L. ochroleuca as epifaunal habitat provider. Richness, diversity and total abundance of epifauna was similar in both seaweeds, while colonial/encrusting fauna was more abundant in L. ochroleuca. More importantly, each host supported a distinctive assemblage structure, indicating that S. polyschides seems an unsuitable replacement for L. ochroleuca as habitat provider for holdfast epifauna. Therefore, while S. polyschides may contribute substantially to the kelp forest canopy in some seasons, a regional decline of L. ochroleuca will likely alter the patterns of biodiversity within kelp stands.This research was funded by the “Fundación Biodiversidad y el Ministerio de Transición Ecológica y el Reto Demográfico.” BioCost Research Group acknowledges funding from Xunta de Galicia (grant ED431B 2021/32 of “Axudas para a consolidación e estructuración de unidades de investigación competitivas do SUG” program). SB received financial support from the Xunta de Galicia and the European Union (European Social Found – ESF) (grant ED481A2018/101). CP-C received financial support from Xunta de Galicia “Axudas de apoio á etapa de formación posdoutoral “(grant ED481B-2021/095)”Xunta de Galicia; ED431B 2021/32Xunta de Galicia; ED481A2018/101Xunta de Galicia; ED481B-2021/09

Understanding the Local Drivers of Beta-Diversity Patterns Under Climate Change: The Case of Seaweed Communities in Galicia, North West of the Iberian Peninsula

[Abstract] Aim: To understand spatial-temporal changes (beta-diversity) in coastal communities and their drivers in the context of climate change. Coastal ecosystems are extremely exposed and dynamic, where changes in seaweed assemblages have been associated with changing water temperatures. However, at local scale, the effects of changes in the upwelling events and related stressors seek further exploration. Location: Galicia rías, North West of the Iberian Peninsula. Methods: Using data collected in 42 sampling localities in Galicia rias and over two time periods (1998 and 2014), we analysed changes in the seaweed community's composition through time and space. We calculated the temporal beta-diversity index and spatial beta-diversity as the pairwise composition differences between sampling localities. We use generalized dissimilarity models, to identify local environmental drivers of spatial and temporal beta-diversity. Results: We found a significant change in seaweed communities of Galicia rias, between 1998 and 2014 (temporal beta-diversity). They were mostly related to species loss rather than to species replacement. The dissimilarity among localities (spatial beta-diversity) was significantly higher in 2014 than in 1998. Nitrate concentration was consistently predicted as the main driver of both temporal and spatial beta-diversity patterns. Main conclusions: Unlike other studies in marine ecosystems, our results suggest that observed changes in the structure of perennial seaweed assemblages in Galicia Rias might lead to a local biotic heterogenization, indirectly linked to climate change through changes in nutrients availability and the upwelling intensity. Changes in Galicia seaweed communities call scientific attention to the importance of local stressors in climate change studies.Portugal. Fundação para a Ciência e a Tecnologia; PTDC/BIA-BMA/31893/201

Assessing the Importance of Kelp Forests for Small-Scale Fisheries Under a Global Change Scenario

[Abstract] Kelp forests are critical habitats for temperate coasts that are experiencing dramatic declines worldwide in recent decades. Yet, even though they often support wildlife populations of high socioeconomic value, the consequences of kelp forest decline for small-scale fisheries (SSFs) have received surprisingly little attention. Here, we take the first step to fill this gap through the local ecological knowledge (LEK) of SSF fishers whose fisheries are associated with this habitat in NW Spain. LEK was used to 1) estimate kelp forest loss, 2) identify the main fisheries associated with kelp forests, 3) gain insight into the changes these fisheries may have undergone in recent times, 4) evaluate the economic importance of kelp in the study area, and 5) describe the commercial chain of exploited kelps and relevant fisheries related to them. Fisher’s knowledge of kelp forests was documented through interviews with the help of a semi-structured questionnaire with open–closed questions about the small-scale fishery and its target species. Additionally, participants were asked to map the current and former (20 years ago) distribution of kelp forests in their fishing area. Results show that a range of fish, crustaceans, mollusks, echinoderms, and even the kelp itself are fished/harvested in the study area, suggesting the socioeconomic value of those species. The most intensively targeted species usually belong to fisheries with high commercial value, and first-sale data indicate that they are worth some 10 million euros to the local economy. On the other hand, compared to two decades ago, fishers reported a substantial contraction in the area occupied by kelp forests and decreases in the fisheries typically associated with this habitat. Landing data partly support this perception of a decline in catches. Altogether, this information will be useful to foster kelp forest conservation and to evaluate their socioecological and economic implications for SSFs.This research was funded by the “Fundación Biodiversidad y el Ministerio de Transición Ecológica y el Reto Demográfico.” BioCost Research Group acknowledges funding from Xunta de Galicia (grants ED431D 2017/2020 and ED431B 2018/49 of “Axudas para a consolidación e estructuración de unidades de investigación competitivas do SUG” program). CP-C received financial support from Xunta de Galicia “Axudas de apoio á etapa de formación posdoutoral “(grant ED481B-2021/095)”. SB received financial support from the Xunta de Galicia and the European Union (European Social Found – ESF) (grant ED481A2018/101). This publication has been funded by the University of la Laguna though the Vicerrectorado de Investigación, Transferencia y Campus Santa Cruz y SurXunta de Galicia; ED431D 2017/2020Xunta de Galicia; ED431B 2018/49Xunta de Galicia; ED481B-2021/095Xunta de Galicia; ED481A2018/10

Population Structure of a Widespread Species under Balancing Selection: The Case of Arbutus unedo L.

Arbutus unedo L. is an evergreen shrub with a circum-Mediterranean distribution that also reaches the Eurosiberian region in northern Iberia, Atlantic France, and a disjunct population in southern Ireland. Due to the variety of climatic conditions across its distribution range, the populations of A. unedo were expected to display local adaptation. Conversely, common garden experiments revealed that diverse genotypes from a range of provenances produce similar phenotypes through adaptive plasticity, suggesting the action of stabilizing selection across its climatically heterogeneous range. Nonetheless, since a uniform response might also result from extensive gene flow, we have inferred the population structure of A. unedo and assessed whether its extended and largely one-dimensional range influences gene flow with the help of AFLP genotypes for 491 individuals from 19 populations covering the whole range of the species. As we had anticipated, gene flow is restricted in A. unedo, providing further support to the hypothesis that stabilizing selection is the most likely explanation for the homogeneous phenotypes along the range. The Euro-Siberian populations were not particularly isolated from the Mediterranean. Instead, there was a distinct genetic divide between the populations around the Mediterranean Sea and those sampled along Atlantic coasts from northern Africa up to Ireland. This genetic structure suggests the action of historic rather than biogeographic factors as it seems consistent with a scenario of independent glacial refugia in the Atlantic and Mediterranean portions of the range of A. unedo. Genetic exchange was likewise restricted within each set of populations. Nevertheless, isolation-by-distance (IBD) was stronger, and FST increased faster with distance, along the Atlantic, suggesting that gene flow might be larger among Mediterranean populations. Genetic diversity was significantly lower in NW Iberia and Ireland than in other populations whereas Ireland was more closely related to populations in NW Iberia than to a population in Atlantic France, suggesting a postglacial stepping-stone colonization of the Atlantic coast. Altogether, our results show that stabilizing selection is able to homogenize the phenotypic response even when population structure is strong, gene flow is constrained, and the phylogeographic past is complexThis research was supported by research grant CGL2009-11356 (Ministerio de Ciencia e Innovación) and FPU fellowship AP-2009-0962 (Ministerio de Educación). This research was also supported by the European Regional Development's Fund (ERDF)S

Phylogeography of a widespread species: pre-glacial vicariance, refugia, occasional blocking straits and long-distance migrations

Phylogeographic studies give us the opportunity to reconstruct the historical migrations of species and link them with climatic and geographic variation. They are, therefore, a key tool to understanding the relationships among biology, geology and history. One of the most interesting biogeographical areas of the world is the Mediterranean region. However, in this area, the description of concordant phylogeographic patterns is quite scarce, which limits the understanding of evolutionary patterns related to climate. Species with one-dimensional distribution ranges, such as the strawberry tree ( Arbutus unedo ), are particularly useful to unravel these patterns. Here, we describe its phylogeographic structure and check for concordance with patterns seen in other Mediterranean plants: longitudinal/latitudinal clines of diversity, evidence for glacial refugia and the role of sea straits in dispersal. We also identify the most likely source for the disjunct Irish population. With this aim, we sequenced four chloroplast non-coding fragments of A. unedo from 23 populations covering its whole distribution. We determined the genetic diversity, population structure, haplotype genealogy and time to the most recent common ancestor. The genealogy revealed two clades that separated during the last 700 ky but before the last glacial maximum. One clade occupies Atlantic Iberia and North Africa, while the other occurs in the Western Mediterranean. The Eastern Mediterranean is inhabited by newer haplotypes derived from both clades, while the Irish population is closely related to Iberian demes. The straits of Sicily and Gibraltar partially restricted the gene flow. We concluded that a vicariance event during the Late Quaternary in the western end of the species' range followed by eastward migration seems a likely explanation for the observed phylogeographic pattern. The role of straits indicates an occasional communication between Europe and North Africa, suggesting that the latter was a novel refugia. The East–West genetic split in Iberia is consistent with the refugia-within-refugia model. Finally, the strawberry tree possibly reached Ireland from Iberia instead of throughout the maritime fringe of France as previously thoughtThis work was supported by the Spanish Ministry of Science and Innovation (research grant CGL2009-11356), the European Regional Development's Fund (ERDF) and also by the Spanish Ministry of Education (FPU fellowship AP-2009-0962 to X.S.)S