Agricultural development vs biodiversity conservation: the Mediterranean semiarid vegetation in El Ejido (Almería, southeastern Spain)

The development of a greenhouse agriculture in the traditionally impoverished region of Poniente de Almería, on the Mediterranean coast of Spain, has caused an enormous rise in living standards. However, the environmental impact of this badly-planned growth threatens the every dynamics of the exploitation system. A special examination must be made of the use of the three major resources responsible for the functioning of greenhouse production and its impact on the ecosystems and particularly on the vegetation. These resources are: clayey soils, sand from fossil dunes and ground water. While the use of the clayey soils and sand have negative effects on the conservation of ecologically valuable communities found nowhere else in Europe, ground water overexploitation has produced an increase in salinity in most of the aquifers. Of these, sand has been by far the best monitored resource and restoration programmes have been implemented in the extraction zones. This survey deals with the recent evolution of areas where the arto (Maytenus senegalensis subsp. europaeus) and the sabina (Juniperus phoenicea subsp. turbinata) have long been the dominant species, although the presence of the former is nowadays notoriously diminished. The study is based on aerial photographs taken in 1957, 1977 and 1985, together with our own field work. Curiously enough, all this man-made process of degradation has stimulated ornithological diversity. Finally, we propose here some measures which aim to preserve the most important enclaves of these Mediterranean shrub formations, specially those of the arto, since sabina-dominated communities already belong to existing conservation areas.     

Plasma beta-2-microglobulin in rheumatoid arthritis

The beta 2 microglobulin (beta 2m) is a low molecular weight protein, recognized on the cellular membranes of numerous nucleated cells and strictly correlated to the antigens of Major Histocompatibility Complex. Many authors have demonstrated an increase of the plasmatic beta 2m in different inflammatory diseases and, particularly in rheumatic ones, as Rheumatoid Arthritis (RA), Reiter's syndrome, Ankylosing Spondylitis, Systemic lupus erythematosus. We have also investigated the behaviour of the plasmatic beta 2m in 52 RA patients and in 17 healthy subjects. The beta 2m was measured in serum, by radioimmunoassay. We have demonstrated that the plasmatic beta 2m has moderately increased in the serum of RA patients, even if there is not a significant difference when compared to the normal subjects.     

Genomic reaction norm models exploiting genotype × environment interaction on sexual precocity indicator traits in Nellore cattle

Brazilian beef cattle are raised predominantly on pasture in a wide range of environments. In this scenario, genotype by environment (G×E) interaction is an important source of phenotypic variation in the reproductive traits. Hence, the evaluation of G×E interactions for heifer’s early pregnancy (HP) and scrotal circumference (SC) traits in Nellore cattle, belonging to three breeding programs, was carried out to determine the animal’s sensitivity to the environmental conditions (EC). The dataset consisted of 85 874 records for HP and 151 553 records for SC, from which 1800 heifers and 3343 young bulls were genotyped with the BovineHD BeadChip. Genotypic information for 826 sires was also used in the analyses. EC levels were based on the contemporary group solutions for yearling body weight. Linear reaction norm models (RNM), using pedigree information (RNM_A) or pedigree and genomic information (RNM_H), were used to infer G×E interactions. Two validation schemes were used to assess the predictive ability, with the following training populations: (a) forward scheme—dataset was split based on year of birth from 2008 for HP and from 2011 for SC; and (b) environment-specific scheme—low EC (−3.0 and −1.5) and high EC (1.5 and 3.0). The inclusion of the H matrix in RNM increased the genetic variance of the intercept and slope by 18.55 and 23.00% on average respectively, and provided genetic parameter estimates that were more accurate than those considering pedigree only. The same trend was observed for heritability estimates, which were 0.28–0.56 for SC and 0.26–0.49 for HP, using RNM_H, and 0.26–0.52 for SC and 0.22–0.45 for HP, using RNM_A. The lowest correlation observed between unfavorable (−3.0) and favorable (3.0) EC levels were 0.30 for HP and −0.12 for SC, indicating the presence of G×E interaction. The G×E interaction effect implied differences in animals’ genetic merit and re-ranking of animals on different environmental conditions. SNP marker–environment interaction was detected for Nellore sexual precocity indicator traits with changes in effect and variance across EC levels. The RNM_H captured G×E interaction effects better than RNM_A and improved the predictive ability by around 14.04% for SC and 21.31% for HP. Using the forward scheme increased the overall predictive ability for SC (20.55%) and HP (11.06%) compared with the environment-specific scheme. The results suggest that the inclusion of genomic information combined with the pedigree to assess the G×E interaction leads to more accurate variance components and genetic parameter estimates.     

Invasion of Euryops floribundus in degraded South African communal grassland: Unpacking the invasion relationship with elevation,soil properties,the quality and quantity of the herbaceous layer

Shrub invasion is a recent occurrence in African grassland ecosystems. This study assessed the distribution of Euryops floribundus (a native shrub species) along an elevation and invasion intensity gradients, and its relationship with soil and herbaceous vegetation in a South African grassland. Shrub density increased (p < 0.05) from the uplands (2,301 plants/ha) to the bottomlands (4,888 plants/ha). Themeda triandra (a highly palatable grass) was dominant at the uplands and sloping sites, whereas Eragrostis plana and Sporobolus africanus (poorly palatable grasses) dominated the bottomlands. Upland soils had the highest organic carbon (OC), phosphorous (P), calcium and nitrogen (N) contents, but the lowest shrub density and herbaceous biomass. Canonical correspondence analysis indicated that elevation, soil OC and N contents determine important vegetation variables along the elevation gradient. In the shrub density gradient, soil P, OC and N responded positively to E. floribundus density. Grass biomass in the moderate and heavily invaded sites was high, but the abundance of palatable grasses declined, suggesting that E. floribundus invasion may be concomitant with a decrease in rangeland condition in terms of quality forage provision.