Search

Mediterranean scattered oak woodlands support relatively high biological diversity, and provide important ecosystem services. However, there is still a lack of knowledge about livestock-tree-grassland relationships, knowledge necessary for effective conservation management in these systems. To address such lacuna, we measured the effects of scattered trees and grazing animals (livestock vs. wild ungulates, mostly deer) on biomass and diversity (and their relationship) of the herbaceous layer (understory) of open holm oak woodland (known as dehesa ) in Central Spain, for two years. We located two 1-ha plots within three different grazing management schemes (cattle, sheep and wildlife only). Within each plot, we randomly selected four focal trees from which a subplot was established in two directions and three distances. In each subplot, we measured plant diversity and biomass, along with microclimatic variables across sites. We found rainfall variability affected herbaceous biomass and diversity in the dehesa system, and the effects were nuanced: in a dry year (<300 mm annual rainfall) the presence of livestock grazing correlated with higher herbaceous biomass (14%), and in moister year (>600 mm annual rainfall) the effect was enhanced, as plots under livestock grazing exhibited even higher herbaceous biomass (42%). In addition, livestock, particularly cattle, generated a more diverse community (52 species m −2 ). Microsites created by trees generated high plant diversity among herbaceous communities, where alpha diversity was higher (20%) in ecotone and inter-tree gaps than under the canopies. In addition, species turnover was higher than 50% in all cases. Biomass was higher (15%) under the canopies only under humid conditions. Legume dry matter was positively related to plant diversity. We concluded that agroforestry management practices such as promoting tree development through silvicultural techniques to create different microsites, and maintaining livestock grazing are needed to preserve these emblematic ecosystems. [ABSTRACT FROM AUTHOR]

We have studied the global risk of retinopathy in a Mediterranean population of type 2 diabetes mellitus (T2DM) patients, according to clinical, biochemical, and lifestyle biomarkers. The effects of the oral supplementation containing antioxidants/omega 3 fatty acids (A/ω3) were also evaluated. Suitable participants were distributed into two main groups: (1) T2DMG (with retinopathy (+DR) or without retinopathy (−DR)) and (2) controls (CG). Participants were randomly assigned (+A/ω3) or not (−A/ω3) to the oral supplementation with a daily pill of Nutrof Omega (R) for 18 months. Data collected including demographics, anthropometrics, characteristics/lifestyle, ophthalmic examination (best corrected visual acuity, ocular fundus photographs, and retinal thickness as assessed by optical coherence tomography), and blood parameters (glucose, glycosylated hemoglobin, triglycerides, malondialdehyde, and total antioxidant capacity) were registered, integrated, and statistically processed by the SPSS 15.0 program. Finally, 208 participants (130 diabetics (68 +DR/62 −DR) and 78 controls) completed the follow-up. Blood analyses confirmed that the T2DMG+DR patients had significantly higher oxidative stress (p<0.05), inflammatory (p<0.05), and vascular (p<0.001) risk markers than the T2DMG−DR and the CG. Furthermore, the A/ω3 oral supplementation positively changed the baseline parameters, presumptively by inducing metabolic activation and ameliorating the ocular health after 18 months of supplementation. [ABSTRACT FROM AUTHOR]

Highlights: [•] Integration of chemical, biological and ecotoxicological studies is here assessed. [•] DGTs and BCR are good tools to predict metal accumulation in macroinvertebrates. [•] Microtox is useful when chemical and biological quality tests are in disagreement. [Copyright &y& Elsevier]

This article discusses the aging of radionuclides in soil and the changes over time. The authors used drying and wetting cycles on soils contaminated with strontium and cesium radioisotopes from Chernobyl, Ukraine and Mediterranean areas. They found that aging was more relevant for cesium than for strontium. The fixed fractions were measured by an extraction test, but sorption could not be predicted from soil properties such as clay content. They concluded that the tests for aging will permit remediation design at contaminated sites to be improved.

Scattered trees are considered keystone structures and play an important role in Mediterranean sylvopastoral systems. Such systems are associated with high biodiversity and provide important natural resources and ecosystem services. In this study, we measured the contribution of scattered trees and different grazing management (cattle, sheep and wildlife only) to the diversity of the grassland sward in a dehesa (open holm oak woodland) located in Central Spain. We analyzed alpha and beta diversity through measurement of species richness, Shannon-Wiener, and Whittaker indices, respectively; and the floristic composition of the herb layer using subplots within two adjacent plots (trees present vs. trees absent) under three different grazing management regimes, including wildlife only, during a year. We found a 20–30% increment in the alpha diversity of wooded plots, compared to those without trees, regardless of grazing management. All beta indices calculated showed more than 60% species turnover. Wooded plots were occupied by different herbaceous species in different heterogeneous microsites (under the canopy, in the ecotone or on open land) created by the trees. Livestock grazing modified species composition (e.g. more nitrophilous species) compared to wildlife only plots. In addition to all their other benefits, trees are important to maintaining grassland diversity in Mediterranean dehesas. [ABSTRACT FROM AUTHOR]

Trees play a key role in the structure and function of many ecosystems worldwide. In the Mediterranean Basin, forests cover approximately 22% of the total land area hosting a large number of endemics (46 species). Despite its particularities and vulnerability, the biodiversity of Mediterranean trees is not well known at the taxonomic, spatial, functional, and genetic levels required for conservation applications. The WOODIV database fills this gap by providing reliable occurrences, four functional traits (plant height, seed mass, wood density, and specific leaf area), and sequences from three DNA-regions (rbcL, matK, and trnH-psbA), together with modelled occurrences and a phylogeny for all 210 Euro-Mediterranean tree species. We compiled, homogenized, and verified occurrence data from sparse datasets and collated them on an INSPIRE-compliant 10 × 10 km grid. We also gathered functional trait and genetic data, filling existing gaps where possible. The WOODIV database can benefit macroecological studies in the fields of conservation, biogeography, and community ecology.

The threatened conifer Abies cilicica currently persists in Lebanon in geographically isolated forest patches. The impact of demographic and evolutionary processes on population genetic diversity and structure were assessed using 10 nuclear microsatellite loci. All remnant 15 local populations revealed a low genetic variation but a high recent effective population size. FST -based measures of population genetic differentiation revealed a low spatial genetic structure, but Bayesian analysis of population structure identified a significant Northeast-Southwest population structure. Populations showed significant but weak isolation-by-distance, indicating non-equilibrium conditions between dispersal and genetic drift. Bayesian assignment tests detected an asymmetric Northeast-Southwest migration involving some long-distance dispersal events. We suggest that the persistence and Northeast-Southwest geographic structure of Abies cilicica in Lebanon is the result of at least two demographic processes during its recent evolutionary history: (1) recent migration to currently marginal populations and (2) local persistence through altitudinal shifts along a mountainous topography. These results might help us better understand the mechanisms involved in the species response to expected climate change.