Effects of a large irrigation reservoir on aquatic and riparian plants: a history of survival and loss

Dammed rivers have unnatural stream flows, disrupted sediment dynamics, and rearranged geomorphologic settings. Consequently, fluvial biota experiences disturbed functioning in the novel ecosystems. The case study is the large irrigation reservoir Alqueva in Guadiana River, Southern Iberia. The study area was divided into three zones: upstream and downstream of the dam and reservoir. For each zone, species composition and land use and land cover (LULC) were compared before and after the Alqueva Dam implementation. Data consist of aquatic and riparian flora composition obtained from 46 surveys and the area (%) of 12 classes of LULC obtained in 90 riverine sampling units through the analysis of historical and contemporary imagery. There was an overall decrease of several endemic species and on the riparian shrublands and aquatic stands, although di erences in the proportion of functional groups were not significant. Nevertheless, compositional diversity shows a significant decline in the upstream zone while landscape diversity shows an accentuated reduction in the reservoir area and downstream of the dam, which is likely related to the loss of the rocky habitats of the ‘old’ Guadiana River and the homogenization of the riverscape due to the irrigation intensification. The mitigation of these critical changes should be site-specific and should rely on the knowledge of the interactions between surrounding lands, ecological, biogeomorphologic, and hydrological components of the fluvial ecosystemsinfo:eu-repo/semantics/publishedVersio

Riparian and aquatic vegetation in Mediterranean-type streams (western Iberia)

Floral composition and structural patterns displayed by the aquatic and riparian vegetation in Mediterranean-type streams show distinctive features when compared to mesic fluvial systems. In this paper we sum up two decades of studies on the ecology of riparian and aquatic vegetation in western Iberia (Portugal). We present results concerning the structural patterns of the riparian woody vegetation, its variation in space and time, and its role in fluvial processes. We give an overall description and ecological appraisal of the riparian and aquatic flora and its complex relationships with abiotic drivers from both the river corridor and the drainage basin. We also describe our observations of floral disturbances derived both from natural and human causes. We have taken various approaches to assessing ecological quality using river plants, and these are also reviewed. The overall results obtained in these last twenty years are discussed as a contribution to future research needs.La composición florística y los patrones estructurales de la vegetación acuática y riparia en ríos mediterráneos muestran características diferenciales cuando son comparados con sistemas fluviales templados. En este trabajo, intentamos reunir dos décadas de estudios sobre la ecología de la vegetación riparia y acuática en Iberia Occidental (Portugal). Presentamos resultados acerca de los patrones estructurales de la vegetación leñosa riparia, su variación espacio-temporal, y su papel en los procesos fluviales. Hacemos una descripción global y un abordaje ecológico de la flora riparia y acuática y sus complejas relaciones con los factores abióticos, desde la escala del corredor fluvial hasta la cuenca de drenaje. Describimos también las perturbaciones observadas sobre la flora, tanto derivadas de causas naturales como humanas. Hemos desarrollado algunos enfoques para evaluar la calidad ecológica utilizando plantas y estos son también revisados. Se discuten los resultados obtenidos en estos últimos veinte años con el objetivo de contribuir para la determinación de futuras necesidades en la investigación

The role of soil temperature in mediterranean vineyards in a climate change context

The wine sector faces important challenges related to sustainability issues and the impact of climate change. More frequent extreme climate conditions (high temperatures coupled with severe drought periods) have become a matter of concern for the wine sector of typically dry and warm regions, such as the Mediterranean European countries. Soil is a natural resource crucial to sustaining the equilibrium of ecosystems, economic growth and people’s prosperity worldwide. In viticulture, soils have a great influence on crop performance (growth, yield and berry composition) and wine quality, as the soil is a central component of the terroir. Soil temperature (ST) affects multiple physical, chemical and biological processes occurring in the soil as well as in plants growing on it. Moreover, the impact of ST is stronger in row crops such as grapevine, since it favors soil exposition to radiation and favors evapotranspiration. The role of ST on crop performance remains poorly described, especially under more extreme climatic conditions. Therefore, a better understanding of the impact of ST in vineyards (vine plants, weeds, microbiota) can help to better manage and predict vineyards’ performance, plant-soil relations and soil microbiome under more extreme climate conditions. In addition, soil and plant thermal data can be integrated into Decision Support Systems (DSS) to support vineyard management. In this paper, the role of ST in Mediterranean vineyards is reviewed namely in terms of its effect on vines’ ecophysiological and agronomical performance and its relation with soil properties and soil management strategies. The potential use of imaging approaches, e.g. thermography, is discussed as an alternative or complementary tool to assess ST and vertical canopy temperature profiles/ gradients in vineyards. Soil management strategies to mitigate the negative impact of climate change, optimize ST variation and crop thermal microclimate (leaf and berry) are proposed and discussed, with emphasis on Mediterranean systemsinfo:eu-repo/semantics/publishedVersio

Carbon stock estimation in a Mediterranean riparian forest: a case study combining field data and UAV imagery

This study aims to estimate the total biomass aboveground and soil carbon stocks in a Mediterranean riparian forest and identify the contribution of the different species and ecosystem compartments to the overall riparian carbon reservoir. We used a combined field and object-based image analysis (OBIA) approach, based on unmanned aerial vehicle (UAV) multispectral imagery, to assess C stock of three dominant riparian species. A linear discriminator was designed, based on a set of spectral variables previously selected in an optimal way, permitting the classification of the species corresponding to every object in the study area. This made it possible to estimate the area occupied by each species and its contribution to the tree aboveground biomass (AGB). Three uncertainty levels were considered, related to the trade-o between the number of unclassified and misclassified objects, leading to an error control associated with the estimated tree AGB.We found that riparian woodlands dominated by Acacia dealbata Link showed the highest average carbon stock per unit area (251 90 tC ha1) followed by Alnus glutinosa (L.) Gaertner (162 12 tC ha1) and by Salix salviifolia Brot. (73 17 tC ha1), which are mainly related to the stem density, vegetation development and successional stage of the different stands. The woody tree compartment showed the highest inputs (79%), followed by the understory vegetation (12%) and lastly by the soil mineral layer (9%). Spectral vegetation indices developed to suppress saturation effects were consistently selected as important variables for species classification. The total tree AGB in the study area varies from 734 to 1053 tC according to the distinct levels of uncertainty. This study provided the foundations for the assessment of the riparian carbon sequestration and the economic value of the carbon stocks provided by similar Mediterranean riparian forests, a highly relevant ecosystem service for the regulation of climate change effectsinfo:eu-repo/semantics/publishedVersio

Functional diversity of riparian woody vegetation is less affected by river regulation in the Mediterranean than Boreal

Original ResearchRiver regulation may filter out riparian plants often resulting in reduced functional diversity, i.e., in the range of functions that organisms have in communities and ecosystems. There is, however, little empirical evidence about the magnitude of such reductions in different regions. We investigated the functional diversity patterns of riparian woody vegetation to streamflow regulation in boreal Sweden and Mediterranean Portugal using nine plant functional traits and field data from 109 sampling sites. We evaluated changes in mean plant functional traits as well as in indices of multidimensional functional traits, i.e., functional richness (FRic) and functional redundancy (FRed) within regions and between free-flowing and regulated river reaches. We found that regulation significantly reduced functional diversity in Sweden but not in Portugal. In Sweden, the increased magnitude of variations in water flow and water level in summer, the prolonged duration of extreme hydrological events, the increased frequency of high-water pulses, and the rate of change in water conditions were the likely main drivers of functional diversity change. Small riparian plant species with tiny leaves, poorly lignified stems, and shallow root systems were consistently associated with regulated sites in the boreal region. In Portugal, the similar functional diversity values for free-flowing and regulated rivers likely stem from the smaller streamflow alterations by regulation combined with the species legacy adaptations to the Mediterranean natural hydrological regimes. We conclude that streamflow regulation may reduce the functional diversity of riparian woody vegetation, but the magnitude of these effects will vary depending on the adaptations of the local flora and the patterns of streamflow disturbances. Our study provides insights into functional diversity patterns of riparian woody vegetation affected by regulation in contrasting biomes and encourages further studies of the functional diversity thresholds for maintaining ecosystemsinfo:eu-repo/semantics/publishedVersio

Riparian Ecological Infrastructures: Potential for Biodiversity-Related Ecosystem Services in Mediterranean Human-Dominated Landscapes

Riparian Ecological Infrastructures are networks of natural and semi-natural riparian areas located in human-dominated landscapes, crucial in supporting processes that directly or indirectly benefit humans or enhance social welfare. In this study, we developed a novel multimetric index, termed Habitat Ecological Infrastructure’s Diversity Index (HEIDI), to quantify the potential of Riparian Ecological Infrastructures in supporting biodiversity, and related ecosystem services, in three managed landscapes: Intensive Agriculture, Extensive Agriculture, and Forest Production. Metrics describing the structure, composition, and management of riparian vegetation and associated habitats were used to derive the potential of Riparian Ecological Infrastructures in supporting three distinct biological dispersal groups: short-range dispersers (ants), medium-range dispersers (pollinators), and long-range dispersers (birds, bats, and non-flying small mammals). The composition of floristic resources, assessed by identifying trees and shrubs at the species and genus level, and herbaceous plants at the family level, was used as a proxy to evaluate the potential of Riparian Ecological Infrastructures in promoting seed dispersal and pollination ecosystem services provided by the three biological communities. Our research evidenced that Riparian Ecological Infrastructures located in the Forest Production and Intensive Agriculture landscapes exhibited the highest and lowest potential for biodiversity-related ecosystem services, respectively. The Forest Production landscape revealed higher suitability of forage resources for short- and medium-range dispersers and a higher landscape coverage by Riparian Ecological Infrastructures, resulting in more potential to create ecological corridors and to provide ecosystem services. The Riparian Ecological Infrastructures located in the Extensive Agriculture landscape seemed to be particularly relevant for supporting long-ranges dispersers, despite providing less habitat for the biological communities. Land-use systems in the proximity of Riparian Ecological Infrastructures should be sustainably managed to promote riparian vegetation composition and structural quality, as well as the riparian width, safeguarding biodiversity, and the sustainable provision of biodiversity-related ecosystem servicesinfo:eu-repo/semantics/publishedVersio

Multi-biologic group analysis for an ecosystem response to longitudinal river regulation gradients

This work assesses the effects of river regulation on the diversity of different instream and riparian biological communities along a relieve gradient of disturbance in regulated rivers. Two case studies in Portugal were used, with different river regulation typology (downstream of run-of-river and reservoir dams), where regulated and free-flowing river stretches were surveyed for riparian vegetation, macrophytes, bryophytes, macroalgae, diatoms and macroinvertebrates. The assessment of the regulation effects on biological communities was approached by both biological and functional diversity analysis. Results of this investigation endorse river regulation as a major factor differentiating fluvial biological communities through an artificial environmental filtering that governs species assemblages by accentuating species traits related to river regulation tolerance. Communities' response to regulation gradient seem to be similar and insensitive to river regulation typology. Biological communities respond to this regulation gradient with different sensibilities and rates of response, with riparian vegetation and macroinvertebrates being the most responsive to river regulation and its gradient. Richness appears to be the best indicator for general fluvial ecological quality facing river regulation. Nevertheless, there are high correlations between the biological and functional diversity indices of different biological groups, which denotes biological connections indicative of a cascade of effects leading to an indirect influence of river regulation even on non-responsive facets of communities' biological and functional diversities. These results highlight the necessary holistic perspective of the fluvial system when assessing the effects of river regulation and the proposal of restoration measures.publishe

Revisiting niche fundamentals with Tukey depth

1. The first attempts to describe species ecological niches were simple geometric procedures that depict the niche boundaries directly from environmental data. The convex hull was one of such procedures, popular for its simplicity, clear ecological rational and precise definition of the niche. However, it lacked the ability to differentiate areas of the niche with different probabilities of occurrence according to environmental suitability. 2. We incorporate the Tukey depth, a mathematical tool to measure the centrality of a point within a cloud of points on a multidimensional space, in the convex hull approach to (i) propose a new procedure (CH-Tukey) to estimate species’ environmental suitability, and (ii) estimate niche overlap coherently. In addition to a clear ecological rational and simplicity the CHTukey procedure has a number of attractive features: use of presence-only data; independence from background data; invariance to scale; robustness to outliers; and the decomposition of the niche into a finite number of isosuitability levels, permitting the computation of consistent overlap indices. We illustrate the use of CH-Tukey, using occurrence data of the main Quercus species and subspecies from Western Mediterranean Europe, comparing its outputs with BIOCLIM and MAXENT. 3. Results showed distinct niche geometries among the different approaches. BIOCLIM produced rectilinear niches reflecting the assumption that ecological variables are independent in their action on the species. CHTukey, relaxing this assumption, adjusts niche outer boundary and the inner suitability levels to the known occurrences. MAXENT produced unbounded niche geometries, showing abrupt shifts in the species response to the environmental variables. 4. The niche predictions obtained with geometric approaches, BIOCLIM and CH Tukey, are simpler but better aligned with Hutchinson’s niche concept than those obtained with MAXENT, this latter showing ecologically implausible relationships with the environmental variables. CH-Tukey and the related overlap measures provide an adequate tool to explore niche properties and species-environment relationships

Biometrical analysis reveals major differences between the two subspecies of the European rabbit

The climatic oscillations that have occurred in the last few million years have strongly affected species distribution ranges. Highly divergent genetic lineages arose, some of which correspond to recognized subspecies that currently occupy small geographical areas. Understanding the implications of the genetic differences between these subspecies is crucial for proper conservation of Evolutionarily Significant Units. We use the two European rabbit subspecies, Oryctolagus cuniculus cuniculus and O. c. algirus, in the Iberian Peninsula as a model to investigate the repercussions at the biometric level of their largely recognized genetic differentiation. To accomplish this we analysed the ear and hind foot length, and the body mass of 999 adult rabbits from 27 locations across the distribution range of both subspecies in their native range, the Iberian Peninsula. Our results show biometric differences between the two subspecies, also explained by geographical location and sex, O. c. algirus being lighter and having shorter ear and hind foot lengths. We examine these findings under an evolutionary framework, and discuss their implications for current conservation efforts. Future research should focus on the ecological implications of these biometric differences, namely potential different habitat use and anti-predatory strategies in the species' native range.This study was partially funded by Projects PAI06-170, VP-0119-07,POII09-0099-2557, CGL2009-11665, 2012-30E060, CGL2013-43197, CGL2013-43197-R, FCT research project (PTDC/BIA-EVF/111368/2009), and ‘Genomics Applied to Genetic Resources’ co-funded by North Portugal Regional Operational Programme 2007/2013 (ON.2 – O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF). C.F. was supported by a PhD grant (Ref. SFRH/BD/22084/2005) and a postdoctoral grant (Ref. SFRH/BPD/88643/2012), and J.B.-A. by a postdoctoral grant (Ref. SFRH/BPD/65464/2009) all from the Fundaçao para a Ciência e Tecnologia of the Ministêrio da Ciência, Tecnologia e Ensino Superior, Portuguese government. C.F. is currently supported by a Marie Curie Out going International Fellowship for Career Development (PIOF-GA-2013-621571) within the 7th Framework Programme of the European Union. M.D.-M. is currently funded by Consejería de Economía, Innovación, Ciencia y Empleo of Junta de Andalucía, and the European Union’s SeventhFramework Programme for research, technological development and demonstration under grant agreement 267226. C.A.R.-S. was supported by a doctoral grant from the National Council of Science and Technology of Mexico (CONACyT). P.C.A. was supportedby an FCT sabbatical grant (SFRH/BSAB/1278/2012) and by FLAD (Luso-American Foundation).Peer Reviewe

METHYLPHENIDATE: PROCONVULSANT EFFECT AND ACTION ON ACETYL CHOLINESTERASE ACTIVITY IN YOUNG AND ADULT MICE

Objective: Methylphenidate (MPH) is a derivative of piperidine, structurally related to amphetamine. It is the most widely psychostimulant used in Brazil for treating attention deficit disorder and hyperactivity. This drug was investigated in an epilepsy model induced by pilocarpine and on acetylcholinesterase (AChE) activity in young and adult mice. Methods: The control group was treated with saline. The treated groups received MPH (2.5, 5, 10 or 20 mg/kg) in single dose, followed by pilocarpine (400mg/Kg). The groups were observed for1h after treatment. Results: MPH, in all doses, was efficacious in decreasing both the latency to first seizures and the survival percentage in young and adult animals. Determination of AChE activity in the hippocampus and striatum of young and adult animals, after pilocarpine-induced status epilepticus, demonstrated that pretreatment with MPH reduced AChE activity only in the striatum. Conclusion: Our findings suggest that MPH has proconvulsant action and cholinergic neurotransmission system can play a role in this effect