Mecanismes estructuradors de les metacomunitats d'ostracodes d'aigües continentals

Un dels objectius principals de l'estudi de les metacomunitats és entendre els patrons de distribució de grups d'espècies i els mecanismes ecològics que condicionen aquestos patrons. Recentment, els estudis sobre metacomunitats han estat centrats en determinar la importància relativa de l'ordenació d'espècies (i.e. l'efecte filtrador de l'ambient) i la dispersió (i.e. els efectes espacials) com a mecanismes estructuradors de les metacomunitats. En aquesta tesi hem analitzat el paper d'aquestos mecanismes estructuradors sobre diferents metacomunitats d'ostracodes i altres invertebrats en tres sistemes aquàtics diferents situats a l'est de la Península Ibèrica: llacunes temporals, basses de roca i rius. Els nostres resultats mostren que l'ordenació d'espècies és un mecanisme que afecta generalment a aquestes metacomunitats, però afegint que els processos dispersius també són importants en alguns casos. Per exemple, la limitació dispersiva explicava part de l'estructura de les comunitats de les llacunes i de les basses de roca, i els efectes de massa foren més forts que l'ordenació d'espècies en les comunitats dels rius. Per altra banda, també hem estudiat com aquesta importància relativa dels mecanismes estructuradors varia al llarg del temps en les llacunes temporals. En aquest estudi vam observar com l'ordenació d'espècies mantenia en el temps el seu paper dominant, excepte al principi de l'hidroperíode, quan els ous de moltes espècies oportunistes eclosionen ràpidament després de la inundació, provocant distribucions aleatòries independents de l'ambient i l'espai. Per tant, fenòmens estocàstics i altres mecanismes no relacionats amb l'ambient i l'espai podrien també influenciar les metacomunitats. En aquest sentit, hem utilitzat els assemblatges de restes d'ostracodes (i.e. tafocenosi) trobant una gran concordança entre les comunitats vives (i.e. biocenosi) i la tafocenosi, i determinant un possible paper dels efectes prioritaris, com un mecanisme estructurador relacionat amb la contingència històrica de les comunitats. Els estudis sobre metacomunitats ens ensenyen la relació entre la distribució de les espècies i les característiques del paisatge i els seus ecosistemes, i per tant oferixen un coneixement bàsic necessari per a una millor gestió i conservació del medi natural.One of the main aims of the study of metacommunities is to understand species distribution patterns and their ecological drivers. Recently, ecologists have focused metacommunity analysis on determining the relative importance of species sorting (i.e. environmental effects) and dispersal (i.e. spatial effects), as structuring mechanisms of metacommunities. In the present thesis, we analyzed the role of these structuring mechanisms on metacommunities of ostracods and other invertebrates in three aquatic systems located in the Eastern Iberian Peninsula: shallow lakes, rock pools and streams. We found that in general species sorting drives these metacommunities, but dispersal processes are also important in some cases. For instance, dispersal limitation explained a fraction of the community structures in the studied lakes and rock pools, whereas mass effects were stronger than species sorting in explaining stream communities. On the other hand, we also studied the relative importance of the structuring mechanisms through time in shallow lakes. In this study, we observed that species sorting was dominant through time, except at the onset of the flooding period when no mechanism significantly affected the species composition, likely because of random structures generated by an abundant hatching of opportunistic species from the egg bank. Therefore, stochastic phenomena and other mechanisms unrelated to environment and space could also influence metacommunities. In this line, we analyzed the ostracod remain assemblages (i.e. taphocoenoses), finding a significant concordance between living communities (i.e. biocoenoses) and taphocoenoses, and determining a possible role of priority effects, as a structuring mechanism related to the historical contingency of these communities. Metacommunity studies highlight the relationship between species distribution and landscape features and their ecosystems, and provide basic knowledge necessary for the management and preservation of the natural environment

Effects of the temporal scale of observation on the analysis of aquatic invertebrate metacommunities

The development of metacommunity theory has boosted the implementation of numerous empirical tests with field data, mostly focused on the role of spatial and environmental gradients on metacommunity organization. These studies showed an important dependence of the results on the observational scale considered, i.e., spatial grain, sampling spacing, and extent. However, few works deal with time per se as a component explaining metacommunity structure, even when data from periodic sampling are available. We suggest adding time explicitly to metacommunity analysis, but taking into account that the temporal scale of observation could affect the estimation of the relative influence of environment, space, and time, as previously recorded for spatial scale variation. Here, we analyze temporal scale dependence using simulated and empirical metacommunities of aquatic invertebrates. The effects of the study duration (i.e., temporal extent) were stronger when most metacommunity variation occurred along the temporal axis, so that local communities were spatially homogenized under high dispersal rates. Contrarily, dispersal limitation and niche differentiation (depending on the spatio-temporal structure of the environment) kept constant the spatial heterogeneity of the metacommunity, reducing the temporal variation and the importance of the temporal scale of observation. Our results highlight the importance of the temporal scale chosen for the analysis of metacommunity dynamics and emphasizes the temporal perspective of metacommunities, suggesting novel and interesting avenues in this research program

The use of branch piles to assist in the restoration of degraded semiarid steppes

Desertification is a major environmental problem in arid and semiarid regions. Tree plantation has been commonly employed to foster the recovery of degraded areas. However, this technique is costly, and their outcomes are often uncertain. Therefore, we evaluated an alternative method for the restoration of degraded semiarid steppes that involved the construction of branch piles to attract frugivores as potential seed-dispersing birds, promoting seed rain, and fostering the formation of woody patches. We measured the success of branch piles in terms of the number of bird visits and seed input compared to naturally occurring shrub patches. Generally, frugivorous birds visited branch piles less frequently than shrub patches. Yet, branch piles accumulated seeds of patch-forming shrub species. Seed rain was higher under patches of the dominant shrub Rhamnus lycioides than under branch piles. In contrast, woody patches and branch piles did not differ in seed input of the less abundant Pistacia lentiscus shrub. Our study demonstrates that branch piles are used by frugivorous birds and accumulate seeds of patch-forming shrubs. Branch piles may be a suitable method to promote the expansion of bird-dispersed plant species and restore semiarid wooded steppes. However, their efficiency largely depends on pile persistence and economic cost

IMOST: A database for non-marine ostracods in the Iberian Peninsula, the Balearic Islands and Macaronesia

Ostracods are common microcrustaceans in inland waters, widely used as (palaeo-) environmental indicators. Information on their species distribution worldwide is extremely fragmentary, and usually biased towards some regions, hampering attaining a general view of their biogeography. The Iberian Peninsula, the Balearic Islands and Macaronesia are considered biodiversity hotspots as part of the Mediterranean Region, whose non-marine ostracod fauna was reviewed in the 1990s accounting for 88 species. Most of these data were included in the NODE database (Non-marine Ostracod Distribution in Europe). Here, we present IMOST (Ibero-Balearic and Macaronesian OSTracod database), a non-marine ostracod database for the Iberian Peninsula and the Balearic and Macaronesian islands, incorporating data included in NODE plus many new records from recently published studies and new unpublished observations. Our database stores data in separated and standardised spreadsheets, one for each data source. Moreover, the database also offers updated, reviewed and accurate coordinates of the cited occurrence and taxonomic identification. According to the data compiled in IMOST, we updated the list of non-marine ostracods in the studied region from 88 to 118 species. Nevertheless, we expect that the actual number of species for the included regions should be higher, considering other Mediterranean countries with smaller areas but more extensive surveys (e.g. 152 species in Italy). The updated database is instrumental for our understanding of the biodiversity and biogeographic patterns of these organisms in this hotspot, as well as for analysing their species-environment relationships in a context of global change

Precision restoration: a necessary approach to foster forest recovery in the 21st century

We thank S. Tabik, E. Guirado, and Garnata Drone SL for fruitful debates about the application of remote sensing and artificial intelligence in restoration. E. McKeown looked over the English version of the manuscript. Original drawings were made by J. D. Guerrero. This work was supported by projects RESISTE (P18-RT-1927) from the Consejeria de Economia, Conocimiento, y Universidad from the Junta de Andalucia, and AVA201601.19 (NUTERA-DE I), DETECTOR (A-RNM-256-UGR18), and AVA2019.004 (NUTERA-DE II), cofinanced (80%) by the FEDER Program. F.M.-R. acknowledges the support of the Agreement 4580 between OTRI-UGR and the city council of La Zubia. We thank an anonymous reviewer for helpful comments that improved the manuscript.Forest restoration is currently a primary objective in environmental management policies at a global scale, to the extent that impressive initiatives and commitments have been launched to plant billions of trees. However, resources are limited and the success of any restoration effort should be maximized. Thus, restoration programs should seek to guarantee that what is planted today will become an adult tree in the future, a simple fact that, however, usually receives little attention. Here, we advocate for the need to focus restoration efforts on an individual plant level to increase establishment success while reducing negative side effects by using an approach that we term “precision forest restoration” (PFR). The objective of PFR will be to ensure that planted seedlings or sowed seeds will become adult trees with the appropriate landscape configuration to create functional and self-regulating forest ecosystems while reducing the negative impacts of traditional massive reforestation actions. PFR can take advantage of ecological knowledge together with technologies and methodologies from the landscape scale to the individual- plant scale, and from the more traditional, low-tech approaches to the latest high-tech ones. PFR may be more expensive at the level of individual plants, but will be more cost-effective in the long term if it allows for the creation of resilient forests able to providemultiple ecosystemservices. PFR was not feasible a few years ago due to the high cost and low precision of the available technologies, but it is currently an alternative that might reformulate a wide spectrum of ecosystem restoration activities.Junta de Andalucia P18-RT-1927European Commission AVA201601.19 A-RNM-256-UGR18 AVA2019.004OTRI-UGR 4580city council of La Zubia 458

Ahora / Ara

La cinquena edició del microrelatari per l’eradicació de la violència contra les dones de l’Institut Universitari d’Estudis Feministes i de Gènere «Purificación Escribano» de la Universitat Jaume I vol ser una declaració d’esperança. Aquest és el moment en el qual les dones (i els homes) hem de fer un pas endavant i eliminar la violència sistèmica contra les dones. Ara és el moment de denunciar el masclisme i els micromasclismes començant a construir una societat més igualitària. Cadascun dels relats del llibre és una denúncia i una declaració que ens encamina cap a un món millor

Microalgae colonization of different microplastic polymers in experimental mesocosms across an environmental gradient

A variety of organisms can colonize microplastic surfaces through biofouling processes. Heterotrophic bacteria tend to be the focus of plastisphere research; however, the presence of epiplastic microalgae within the biofilm has been repeatedly documented. Despite the relevance of biofouling in determining the fate and effects of microplastics in aquatic systems, data about this process are still scarce, especially for freshwater ecosystems. Here, our goal was to evaluate the biomass develop-ment and species composition of biofilms on different plastic polymers and to in-vestigate whether plastic substrates exert a strong enough selection to drive species sorting, overcoming other niche-defining factors. We added microplastic pellets of high- density polyethylene (HDPE), polyethylene terephthalate (PET), and a mix of the two polymers in 15 lentic mesocosms in five different locations of the Iberian Peninsula, and after one month, we evaluated species composition and biomass of microalgae developed on plastic surfaces. Our results, based on 45 samples, showed that colonization of plastic surfaces occurred in a range of lentic ecosystems covering a wide geographical gradient and different environmental conditions (e.g., nutrient concentration, conductivity, macrophyte coverage). We highlighted that total bio-mass differed based on the polymer considered, with higher biomass developed on PET substrate compared to HDPE. Microplastics supported the growth of a rich and diversified community of microalgae (242 species), with some cosmopolite species. However, we did not observe species-specificity in the colonization of the different plastic polymers. Local species pool and nutrient concentration rather than polymeric composition seemed to be the determinant factor defying the community diversity. Regardless of specific environmental conditions, we showed that many species could coexist on the surface of relatively small plastic items, highlighting how microplastics may have considerable carrying capacity, with possible consequences on the wider ecological context.This work was supported by EU H2020-INFRAIA-project No 731065 “AQUACOSM: Network of Leading European AQUAtic MesoCOSM Facilities Connecting Mountains to Oceans from the Arctic to the Mediterranean”. MGM was funded by grant RyC-2016-19348 funded by MCIN/AEI/10.13039/501100011033 and by “ESF Investing in your future.” Raman facilities were provided by the Department of Earth and Environmental Sciences (DISAT, University of Milano- Bicocca, Italy,Peer reviewe

Methane Emissions in Spanish Saline Lakes: Current Rates, Temperature and Salinity Responses, and Evolution under Different Climate Change Scenarios

Wetlands are among the most biologically active ecosystems on Earth, playing an important role in the global carbon cycle. Methane production in wetlands, resulting from anaerobic respiration of organic matter, accounts for an important part of natural sources of methane. In this work, we have evaluated the methane release rates of saline shallow lakes located in Central Spain, some of which maintain natural conditions, whereas others are hydrologically altered, with lowered salinity, or even presenting trophic alterations. We used sediment core plus water incubations to determine the release of methane from the studied lakes to the atmosphere, integrating both diffusion and ebullition processes, as well as the effects of temperature and salinity on methane production. The studied hypersaline lakes released methane at rates within the lowest range reported for temperate lakes and wetlands, whereas in hydrologically altered lakes that have dropped their salinity these rates were markedly higher. Models built with the specific response of methane release rates to temperature regarding the temperature changes expected according to the RCP climate scenarios predicted significant increases of these rates for the future, which could almost double current methane release for some of the studied lakes under the most pessimistic mitigation scenario (RCP8.5)

Ostracods from shallow lakes in Central Spain

Presentación de datos preliminares sobre la distribución de las especies de ostrácodos, su abundancia y las comunidades de 30 lagunas de la España central

Higher alpha and gamma, but not beta diversity in tropical than in Mediterranean temporary ponds : a multi‐taxon spatiotemporal approach

This study was sustained by the Spanish Ministry of Economy, Industry and Competitivity–AEI, and FEDER (EU), through project METACOM-SET (CGL2016-78260-P). Ángel Gálvez was also supported by an FPI fellowship BES-2017-080022 from the Spanish Ministry of Economy, Industry and Competitiveness.The latitudinal diversity gradient predicts that tropical regions should have higher alpha, beta, and gamma diversity than temperate areas. However, only a few studies have assessed the temporal variability of the different components of diversity across climatic regions. In this study, we compare, using a spatial and temporal approach, the diversity of multiple taxa inhabiting tropical and Mediterranean temporary ponds. We sampled the biological communities of each set of ponds on three occasions during the same hydrological year. Under a spatial framework, we analyzed, alpha, beta, and gamma diversities. With a temporal approach, we compared the coefficients of variation in alpha diversity for each local community, and temporal beta diversity. Differences between regions and sampling periods were tested using generalized linear mixed models. We found higher gamma and alpha diversity in the tropical ponds, as expected given the latitudinal differences between them. However, phytoplankton and microinvertebrates from the Mediterranean region, matched or even exceeded tropical alpha diversity on some occasions. Spatial beta diversity did not differ between regions, and it showed lower values at the middle or the end of the hydroperiod in bacteria, micro‐ and macroinvertebrates and amphibians. Thus, processes homogenizing and heterogenising pond metacommunities must be balanced in both studied regions. Temporal variation in alpha and beta diversity was similar for ponds in both regions, except for macroinvertebrates and amphibians, suggesting differential effects on community variation observable only in animals with longer life‐spans, at our temporal scale of analysis.Publisher PDFPeer reviewe