Fernando Reboredo

How differences in the field influence Cu, Fe and Zn uptake by Halimione portulacoides and Spartina maritima

The highest metal levels of Cu, Fe and Zn were always found in Spartina maritima roots; for Halimione portulacoides the highest Cu and Fe levels were also observed in the roots although mean Cu and Zn values in the roots and leaves were not significantly different at the 0.05 significance level. Lower metal and biomass values were found in Spartina collected in soils where continuous waterlogging occurs, which also limits the height of this plant. Nevertheless, these soils contained high metal levels. Iron accumulates in standing dead leaves and culms of Spartina while for Cu and Zn no significant differences were observed between dead and living organs. Generally the top layer of the soils (0–5 cm depth), contains higher Cu and Zn levels. For Halimione bearing soils Fe slightly increases with depth while for Spartina no variation with depth was observed (P < 0.05); mean Fe values at the different stations were not significantly different (P < 0.05). For both species, the interactions between sampling site and substratum were not significant for Fe (P < 0.05), although for Halimione factors can act independently which is not the case for Spartina. The percentages of the total Cu, Fe and Zn in the soils bearing Halimione, extracted by bidistilled water (minimum available for root uptake), were approximately constant and independent of the concentration and nature of the matrix. The availability of Cu is very weak contrasting with that of Zn, Fe presents an intermediate behaviour. However, roots of H. portulacoides and S. maritima contained, Cu levels higher than the bidistilled water extractable soil levels, as seen by the ratio soil level/root level, indicating that roots constitute an important vector for Cu recycling and mobilization.

Protective Response Mechanisms to Heat Stress in Interaction with High [CO2] Conditions in Coffea spp.

Modeling studies have predicted that coffee crop will be endangered by future global warming, but recent reports highlighted that high [CO2] can mitigate heat impacts on coffee. This work aimed at identifying heat protective mechanisms promoted by CO2 in Coffea arabica (cv. Icatu and IPR108) and Coffea canephora cv. Conilon CL153. Plants were grown at 25/20°C (day/night), under 380 or 700 μL CO2 L−1, and then gradually submitted to 31/25, 37/30, and 42/34°C. Relevant heat tolerance up to 37/30°C for both [CO2] and all coffee genotypes was observed, likely supported by the maintenance or increase of the pools of several protective molecules (neoxanthin, lutein, carotenes, α-tocopherol, HSP70, raffinose), activities of antioxidant enzymes, such as superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), catalase (CAT), and the upregulated expression of some genes (ELIP, Chaperonin 20). However, at 42/34°C a tolerance threshold was reached, mostly in the 380-plants and Icatu. Adjustments in raffinose, lutein, β-carotene, α-tocopherol and HSP70 pools, and the upregulated expression of genes related to protective (ELIPS, HSP70, Chape 20, and 60) and antioxidant (CAT, CuSOD2, APX Cyt, APX Chl) proteins were largely driven by temperature. However, enhanced [CO2] maintained higher activities of GR (Icatu) and CAT (Icatu and IPR108), kept (or even increased) the Cu,Zn-SOD, APX, and CAT activities, and promoted a greater upregulation of those enzyme genes, as well as those related to HSP70, ELIPs, Chaperonins in CL153, and Icatu. These changes likely favored the maintenance of reactive oxygen species (ROS) at controlled levels and contributed to mitigate of photosystem II photoinhibition at the highest temperature. Overall, our results highlighted the important role of enhanced [CO2] on the coffee crop acclimation and sustainability under predicted future global warming scenarios.

Cu and Zn uptake by Halimione portulacoides (L.) Aellen. A long-term accumulation experiment.

Coastal areas and plant species colonizing salt-marshes are often exposed to a large diversity of pollutants, with emphasis on heavy metals. The important role of marsh vegetation in the accumulation of metals has been shown. Halimione portulacoides is one of the most representative halophytes of the salt-marshes of the river Sado estuary. In order to study the uptake and pattern of accumulation of Cu and Zn by the roots, stems and leaves of Halimione, plants were cultivated in vitro and treated daily with solutions containing 5, 25 and 50ppm Cu (as CuCl{sub 2}) and 50, 100 and 150ppm Zn (as ZnCl{sub 2}).

Some Observations on the Leaf Ultrastructure of Halimione Portulacoides (L.) Aellen Grown in a Medium Containing Copper

Summary The effects of copper (5 ppm) on the leaf ultrastructure as well as on chlorophyll and protein content of Halimione plants grown in hydroponic cultures were studied in vitro . No morphological changes were detected at the 15th day of treatment with Cu. Chlorophyll a and b and total protein contents were not affected by the treatment, compared with control values. Ultrathin sections of control and Cu-treated plant leaves exhibit regular fine structure of mitochondria, chloroplasts, nucleus and rough endoplasmic reticulum, indicating the absence of cellular damage. However, the presence of starch grains in the chloroplasts of some phloem cells of the Cu-treated plants was noted, generally, contrasting with the absence in chloroplasts of control cells.

The Fall of Oil Prices and the Effects on Biofuels

This analysis is focused on the effect of the abrupt decline of oil prices on biofuels, particularly second-generation ethanol. The efforts to decrease the production costs of biofuels, especially cellulosic ethanol (CE), will be greatly threatened if current oil prices remain low, especially since production is not slowing. Only huge state subsidies could alleviate this threat, but the challenge is to persuade citizens that this sacrifice is worthwhile.

CADMIUM ACCUMULATION BY HALIMIONE PORTULACOIDES (L.) AELLEN : A SEASONAL STUDY

The analysis of Cadmium in soils and vegetation samples collected in several sampling sites in north and south banks of the River Sado estuary was carried out over the course of a year. The results confirm that Cd is easily taken up by H. portulacoides roots and translocated to the leaves. In 75% of the cases the Cd content of leaves was higher than the root content, enhancing the great mobility of this element. A well defined Cd accumulation pattern was observed, the maximum values being obtained in July and October for roots and leaves, respectively. The accumulation of Cd in soil-marshes varies according to the nature of the matrix. The levels in sandy soils are lower than those observed in silty-loam soils; however, neither the organic matter nor the finest fraction of the soil ( < 63 μm) constituted important binding sites, since r values were not significant at the 0·05 significance level. The highest Cd levels in soils were generally found in two distinct sampling sites, one located in the south bank, far from the major pollution sources, and the other in the north bank, next to several industrial plants and very close to a densely populated area, indicating that the sources of contamination are different.

Socio-economic, environmental, and governance impacts of illegal logging

This article examines the main impacts of the illegal logging activities with emphasis on the most important timber production regions. Although the discussion is focused on the environmental, socio-economic and governance impacts, it must be stressed that the term forest governance is the umbrella where the economy, the environmental values, and welfare of forest-dependent communities are sheltered. Considering the effects/impacts of the illegal logging as a whole, we can summarize the following negative key points: (1) Degradation of the most valuable forest stands threatening biodiversity, including rare and endangered species. (2) Increase in soil erosion and landslides. Increase in CO2 release and climatic changes. (3) Human rights abuses and disrespect of the basic needs of local communities and their culture. (4) Corruption, crime, coercion, and money laundering. (5) Reduction of royalties, taxes, and other charges paid by logging companies to the producer States. (6) Depreciation of legal activities due to the unfair concurrence. Despite multiple efforts, the results in the combat of illegal logging are far from satisfactory. Increase the certification area in parallel with an accurate control, devolve the state land to the ancient local owners, increase the cooperation between civil society and forest authorities, and finally strongly improve forest governance, particularly anti-money laundering laws, are crucial aspects in the combat of illegal logging. Furthermore, governments and businesses must implement the triple bottom line concept in order to reach sustainability.

Analysis of sediments for heavy metals by a rapid electrothermal atomic-absorption procedure

A rapid electrothermal atomic-absorption spectrophotometric procedure with homogenization as the only pretreatment is compared with two wet pretreatment methods followed by flame atomic-absorption, in a statistically designed experiment. Samples from the top 5 cm of sediments at three different points of the Tejo estuary were used for the tests. The results show that the electrothermal procedure performed as well as whichever was the better of the flame methods for the determination of cadmium and nickel, irrespective of the sand content of the samples; although not statistically significant, there was apparently a decrease in recovery for chromium, copper and lead by the electrothermal method as the sand content of the sample increased. For zinc the electrothermal method gave results statistically different from those of the flame procedures when the sand content was high but not when the organic content of the sample was high. Because of the limited degree of replication (5 variates) the relative differences between the average values obtained by the three methods were significant only if they exceeded 15%. The electrothermal method has the advantage of substantially greater speed.

Vertical distribution of Al, Cu, Fe and Zn in the soil salt marshes of the SADO estuary, Portugal

The vertical distribution of Al, Cu, Fe and Zn in the soil salt marsh of the river Sado estuary was studied. The results obtained by an acid digestion procedure, indicate that the mean values at the first sampling point (near the Atlantic Ocean and very close to a populous city) are lower when compared with those found at the other Stations (approximately 8.0 and 20.0 km upstream), where they are very similar. These findings are related to the different nature of the soil matrix (essentially sand at Station 1 and silt‐clay at Station 2 and 3), and the reduced availability of the sandy fraction to bind trace metals. A correlation analysis for all the metals in different soil cores indicate that the correlation values at Station 1 are, generally, not significant at a 0.05 significance level.

Evolution of forest cover in Portugal: A review of the 12th–20th centuries

Portugal’s forests in the 12th century were dominated by the Fagaceae represented by Quercus and Castanea, and several pine species. From the 12th century onwards, forests underwent changes in their management starting with protection and ultimately leading to intense exploitation. The massive naval construction during the maritime expansion (mainly in the 15th–16th centuries) involved felling of approximately 5 million trees mainly Quercus suber, Pinus pinea and other Quercus species. Cumulative fuel-wood consumption of 959 Mm3 during 1300–1854 was attributed to demographic expansion while the deforestation rate during 1636–1854 accounted for a minimum of 72.6% and a maximum of 96% of total forest cover. The volume of timber used in railway sleepers from 1856 onwards might have reached 0.5 Mm3. The last quarter of the 20th century increased the forest cover of Portugal through the World Bank program of Eucalyptus globulus reforestation.