Monaci F.,University of Siena |
Leidi E.O.,IRNAS |
Mingorance M.D.,Andalusian Institute of Earth Science |
Valdes B.,University of Seville |
And 2 more authors.
Journal of Environmental Sciences | Year: 2011
To assess the ecophysiological traits and the phytoremediation potential of the endemic heather Erica andevalensis, we determined the concentrations of major and trace elements in different plant parts and in rizosphere soils from Riotinto mining district (Huelva, Spain). The results showed that E. andevalensis may grow on substrates with very high As, Cu, Fe and Pb concentrations (up to 4114, 1050, 71900 and 15614 μg/g dry weight, respectively), very low availability of macro- and micronutrients and with pH values ranging from 3.3 to 4.9. In these harsh edaphic conditions E. andevalensis selectively absorbed and translocated essential nutrients and excludes potentially phytotoxic elements, which were accumulated in the root epidermis. The concentrations of major and trace elements in E. andevalensis aerial parts from the Riotinto mining district were in the normal range for plants; likewise other Erica species it accumulated Mn and only in a very polluted site we measured leaf concentrations of As and Pb within the excessive or toxic limits for plants. Differently from previous studies, which emphasized the soil pH and bioavailability of phytotoxic elements as the main stress factors, this study showed that in the Riotinto region, E. andevalensis can tolerate wide range of pH and toxic element concentrations; the harshest environments colonized by monospecific patches of this species were characterized above all by very low availability of nutrients. The extraordinary capability to adapt to these extreme habitats made E. andevalensis a priority species to promote the phytostabilization and the development of a self-sustaining vegetative cover on Riotinto mine tailings. © 2011 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences.
Munoz-Rojas M.,University of Western Australia |
Ibanez B.,IRNAS |
Ecosystem Services | Year: 2016
An ecosystem services approach entails the development of a set of evaluation tools in order to quantify the benefits and vulnerabilities of each ecosystem. In this context, the current research explores the conceptualization of different evaluation tools for representative forest ecosystem services in Mediterranean areas.Mediterranean forests provide a wide range of ecosystem services, nevertheless they have to confront various threats such as deforestation, fires, and urban/industrial development. The Mediterranean region has suffered intense changes in land use over the past several decades such as intensification of agricultural and urban development, while marginal croplands have been abandoned and reforested. Thus, the dynamics of land use change have become an important driving force for the potential impact on ecosystem services. Quantifying the magnitude of land use change is therefore essential to estimate its consequences on ecosystem services.Taking this into account, the general aims of this research are (a) to evaluate the state and trends of forest ecosystem services at regional scale in Andalusia (South Spain), (b) to contribute to the methodology for accounting three main forest ecosystem services: carbon storage, protection of soil erosion, and cork oak provisioning, and (c) to assess how theses ecosystem services are affected by drivers of change, such as land use change. In this sense, the main results are the methodologies for the standardization and harmonization of the types of forest ecosystems using the mappings of land use (LULCMA), obtaining an objective quantification of the balance of surface supplying forest ecosystem services, and monitoring over time. © 2016 Elsevier B.V.
Perez-Ramos I.M.,IRNAS |
Urbieta I.R.,University of Castilla - La Mancha |
Zavala M.A.,CIFOR INIA |
Zavala M.A.,University of Alcalá |
Journal of Ecology | Year: 2012
In heterogeneous environments, species segregate spatially in response to selective abiotic and biotic filters occurring throughout plant ontogeny. Ontogenetic conflicts in recruitment may lead to spatially discordant patterns of regeneration among microhabitats with different plant cover. In addition, species differing in seed size may be subjected to opposing ecological and evolutionary pressures throughout the life cycle of the plant. We used a multi-stage demographic approach aimed at characterizing the main stage-specific probabilities of recruitment (seed survival, seed germination, seedling emergence and survival during the first 3years of life) in two Mediterranean oak species coexisting at southern Spain. We calibrated linear and nonlinear likelihood models for each of these consecutive life history stages and calculated overall probabilities of recruitment along a wide range of plant cover and seed size variation. Seed predation and seedling mortality over the dry season were the most limiting processes for the two studied oak species. However, species ranking diverged substantially through the life history stages considered in this study due to different ontogenetic trends among species. At the intraspecific level, recruitment-driving processes during the seed and the seedling stages showed opposing tendencies along the explored range of plant cover and seed size. Thus, small-sized acorns and open areas were favoured for the seed stage, whereas large acorns and dense microhabitats did for the seedling stage. The existence of opposing selective pressures on seed mass and their differential influence on the two studied oak species determined the occurrence of species-specific optimal seed sizes (small acorns for Quercus canariensis vs. acorns of large or intermediate size for Quercus suber). The spatial patterns predicted by our overall-recruitment models provided some evidence of regeneration niche partitioning in the two coexisting oak species, supporting their current distribution patterns as saplings and adults at the study area. Synthesis. We conclude that within- and among-species differences through plant ontogeny, arising from species differential response to microhabitat heterogeneity and seed size variation, could be of great importance for oak species niche segregation, driving stand dynamics and spatial pattern distribution along the landscape. The information provided by this study could be also applied to optimize management and restoration programmes since it has enabled us to identify the most favourable conditions and traits for recruitment in oak species that exhibit serious constraints for natural regeneration. © 2011 The Authors. Journal of Ecology © 2011 British Ecological Society.
Grubb P.J.,University of Cambridge |
Maranon T.,IRNAS |
Pugnaire F.I.,EEZA |
Sack L.,University of California at Los Angeles
Journal of Arid Environments | Year: 2015
Much attention has been paid to differences in leaf form and composition among vegetation types, but less to the frequently substantial variation within vegetation types. We focused on the extent to which correlations between variables are the same in both succulent-poor and succulent-rich vegetation in semi-arid SE Spain. Mean foliar [N] of perennials varied among species over a 5-fold range. Across species, [N] was positively correlated with specific leaf area (i.e., leaf area divided by dry mass; SLA) and with water concentration at saturation (WCS) in the grasslands, excluding the one succulent species. In succulent-rich vegetation on marl, SLA was correlated with [N] but not WCS, and there was a wedge-shaped relationship between [N] and WCS. Foliar [N] and [P] were positively correlated in the grasslands, but not in succulent-rich vegetation on marl. The N/P quotient varied from 8 to 29, with mean 14 in grassland on limestone and mean 26 in grassland on deep soil over gypsum. Our chief finding is that most correlations among SLA, WCS, [N] and [P] found in the non-succulent vegetation are not found in the succulent-rich vegetation. The results are discussed in relation to global patterns and the problems of defining succulence. © 2015 Elsevier Ltd.
Gonzalez-Perez J.A.,IRNAS |
Gonzalez-Vila F.J.,IRNAS |
Arias M.E.,University of Alcalá |
Rodriguez J.,University of Alcalá |
And 3 more authors.
Environmental Chemistry Letters | Year: 2011
The bio-geographical significance of Rhododendron ponticum spp. baeticum (Ericaceae) as a relict species is well recognized. However, out of its native habitat it is an invasive exotic considered a major threat to natural ecosystems in areas of Atlantic Western Europe. The studies on the impact of Rhododendron influence on soil organic matter composition and associated ecological implications, i. e. presence of bioactive compounds with ecological significance, are limited. This work describes the soil lipid assemblage in three sites under Rhododendron stands and adjacent sites with deciduous oak (Quercus canariensis), both in their native habitats in Southern Spain (Sierra de Luna, Cádiz). The results are discussed in terms of organic matter dynamics and the presence of molecules that may be associated with Rhododendron invasive success. The soils are acid Xerochrepts formed on siliceous sands. Composite soil samples were taken at two depths (0-10 cm and 10-20 cm) and soxhlet extracted with a dichloromethane-methanol mixture (3:1). Soil lipid assemblage was studied by GC/MS after fractionation and appropriate derivatization of extracts. The qualitative chemical composition of soil extractable lipids under Rhododendron is reported here for the first time. Our results show that soil n-alkane and fatty acid distributions are compatible with an input from plant epicuticular waxes, as well as with the occurrence of selective preservation of long-chain fatty acids with depth. The pattern of short-chain n-alkanes found in surface samples indicates an anthropogenic contamination threat from nearby industrialized areas of "Campo de Gibraltar". The presence of branched iso and anteiso C15 and C17, β-hydroxy fatty acids and the sterol brassicasterol points to high microbial soil activity. Finally, the pentacyclic triterpenes taraxerone and taraxerol were detected in soils with Rhododendron but not with Quercus. These are known bio-active plant compounds and could be related with the effectiveness of Rhododendron as an invasive exotic species. © 2010 Springer-Verlag.
Martinez A.T.,CIB |
Ruiz-Duenas F.J.,CIB |
Gutierrez A.,IRNAS |
del Rio J.C.,IRNAS |
And 8 more authors.
Biofuels, Bioproducts and Biorefining | Year: 2010
Most industrial enzymes are hydrolases, such as glycosidases and esterases. However, oxidoreductases have an unexploited potential for substituting harsh (and scarcely selective) chemical processes. A group of basidiomycetes are the only organisms degrading the aromatic lignin polymer, enabling the subsequent use of plant polysaccharides. Therefore, these fungi and their ligninolytic peroxidases are the biocatalysts of choice for industrial delignification and oxidative biotransformations of aromatic and other organic compounds. The latter also include oxygenation reactions, which are catalyzed with high regio/stereo selectivity by fungal peroxygenases. In search for novel and more robust peroxidases/peroxygenases, basidiomycetes from unexplored habitats were screened, and hundreds of genes identified in basidiomycete genomes (in collaboration with the DOE JGI). The most interesting genes were heterologously expressed, and the corresponding enzymes structurally-functionally characterized. The information obtained enabled us to improve the enzyme operational and catalytic properties by directed mutagenesis. However, the structural-functional relationships explaining some desirable properties are not established yet and, therefore, their introduction was addressed by 'non-rational' directed evolution. Then, over 100 oxidative biotransformations were analyzed. Among them, it is noteworthy to mention the regio/stereo selective hydroxylation of long/short-chain alkanes (a chemically challenging reaction), epoxidation of alkenes, and production of hydroxy-fatty acids. Concerning aromatic oxygenations, the regioselective hydroxylation of flavonoids, and stereoselective hydroxylation/epoxidation of alkyl/alkenyl-benzenes were among the most remarkable reactions, together with enzymatic hydroxylation of benzene (as an alternative for harsh chemical process). Finally, peroxidases and peroxygenases also showed a potential as delignification biocatalysts and in the decolorization of contaminant dyes from textile industries. © 2014 The Authors. Biofuels, Bioproducts and Biorefi ning published by Society of Chemical Industry and John Wiley & Sons, Ltd.
Perez-Ramos I.M.,IRNAS |
Rodriguez-Calcerrada J.,French National Center for Scientific Research |
Ourcival J.M.,French National Center for Scientific Research |
Rambal S.,French National Center for Scientific Research
Perspectives in Plant Ecology, Evolution and Systematics | Year: 2013
There is a growing interest in understanding and forecasting the responses of plant communities to projected changes of environmental conditions. Multi-stage demographic approaches, where plant recruitment is explored across multiple and consecutive stages, are essential to obtain a whole overview of the consequences of increasing aridity on tree recruitment and forest dynamics, but they are still rarely used. In this study, we present the results of an experimental rainfall exclusion aimed to evaluate the impact of projected increasing drought on multiple stage-specific probabilities of recruitment in a key tree species typical of late-successional Mediterranean woodlands (Quercus ilex L.). We calibrated linear and nonlinear likelihood models for the different demographic processes and calculated overall probabilities of recruitment along a wide range of microhabitat conditions. Rainfall exclusion altered Q. ilex recruitment throughout ontogeny. Seed maturation, seedling emergence and survival and, to a lesser extent, post-dispersal seed survival were the most sensitive demographic processes to decreased rainfall. Interestingly, both the identity of the most critical stages for recruitment and their specific sensitivity to rainfall manipulation depended largely on the yearly pattern of precipitation. The microhabitat heterogeneity strongly determined the success of recruitment in the study species. The experimental increase in drought displaced the peak of maximum overall recruitment towards the low end of the light gradient, suggesting that the dependence on shrubs for an effective recruitment in Q. ilex could be intensified under future environmental scenarios. In terms of phenotypic plasticity, Q. ilex seedlings responded more strongly to light availability than to experimentally increased drought, which could reduce its ability to persist under on-going environmental conditions due to climate change. Results from this study provide a full picture of the ecological and functional consequences of the projected rainfall reduction on tree recruitment and forest dynamics in two years of contrasting precipitation. © 2013 Perspectives in Plant Ecology, Evolution and Systematics.
PubMed | EBD, University of Barcelona, IRNAS and University of Cordoba, Spain
Type: Journal Article | Journal: Oecologia | Year: 2016
Extreme climatic episodes, likely associated with climate change, often result in profound alterations of ecosystems and, particularly, in drastic events of vegetation die-off. Species attributes are expected to explain different biological responses to these environmental alterations. Here we explored how changes in plant cover and recruitment in response to an extreme climatic episode of drought and low temperatures were related to a set of functional traits (of leaves, roots and seeds) in Mediterranean shrubland species of south-west Spain. Remaining aerial green cover 2 years after the climatic event was positively related to specific leaf area (SLA), and negatively to leaf water potential, stable carbon isotope ratio and leaf proline content. However, plant cover resilience, i.e. the ability to attain pre-event values, was positively related to a syndrome of traits distinguished by a higher efficiency of water use and uptake. Thus, higher SLA and lower water-use efficiency characterized species that were able to maintain green biomass for a longer period of time but were less resilient in the medium term. There was a negative relationship between such syndromes and the number of emerging seedlings. Species with small seeds produced more seedlings per adult. Overall, recruitment was positively correlated with species die-off. This study demonstrates the relationship between plant traits and strong environmental pulses related to climate change, providing a functional interpretation of the recently reported episodes of climate-induced vegetation die-off. Our findings reveal the importance of selecting meaningful traits to interpret post-event resilience processes, particularly when combined with demographic attributes.
Perez-Ramos I.M.,IRNAS |
Journal of Vegetation Science | Year: 2012
Questions: Based on comparisons between canopy and seedling layers, which woody species of a Mediterranean forest community, if any, are recruitment-limited? What abiotic and biotic factors predominantly affect seedling density and survival for each species? How spatially consistent are the two demographic processes? What are the ecological implications of these findings for forest stand dynamics and species co-existence? Location: Mediterranean oak forests in southern Spain. Methods: We present the results of a community-level study conducted over 4 yr in three Mediterranean forest sites in order to determine species-specific recruitment patterns. We analyse the most influential factors for seedling dynamics in the main co-occurring woody plant species. Results: We found a strong uncoupling between the canopy and the seedling layer, irrespective of the structural characteristics of the forest site. Some of the most dominant species in the overstorey, such as Quercus suber, Arbutus unedo or Pistacia lenticus, were scarcely represented as seedlings in the understorey, suggesting problems of recruitment limitation. In contrast, other shrub species, such as Viburnum tinus or Phillyrea latifolia, showed large seedling densities with a high probability of survival despite their low frequencies as adults in the canopy. Species composition and abundance in the seedling layer were the result of the combined effect of different mechanisms involving both seed dispersal and the environmental filtering of seedling establishment. However, the factors that determined seedling spatial patterns were inconsistent with those that influenced seedling survival, probably as a consequence of different habitat associations through subsequent recruitment life stages. Conclusions: The community-wide approach enabled us to detect substantial differences among species in their spatial and temporal recruitment patterns, as well as in the relative importance of factors affecting seedling dynamics. The differential effect that spatial micro-heterogeneity exerted for each of the studied species suggests the existence of multiple species-specific regeneration niches, favouring species co-existence and the maintenance of these diverse forest communities. However, the observed recruitment limitation for some dominant forest species will probably result in future shifts in species composition. © 2011 International Association for Vegetation Science.