Socio-ecological implications of modifying rotation lengths in forestry

The rotation length is a key component of even-aged forest management systems. Using Fennoscandian forestry as a case, we review the socio-ecological implications of modifying rotation lengths relative to current practice by evaluating effects on a range of ecosystem services and on biodiversity conservation. The effects of shortening rotations on provisioning services are expected to be mostly negative to neutral (e.g. production of wood, bilberries, reindeer forage), while those of extending rotations would be more varied. Shortening rotations may help limit damage by some of today’s major damaging agents (e.g. root rot, cambium-feeding insects), but may also increase other damage types (e.g. regeneration pests) and impede climate mitigation. Supporting (water, soil nutrients) and cultural (aesthetics, cultural heritage) ecosystem services would generally be affected negatively by shortened rotations and positively by extended rotations, as would most biodiversity indicators. Several effect modifiers, such as changes to thinning regimes, could alter these patterns.     

Replacing monocultures with mixed-species stands: Ecosystem service implications of two production forest alternatives in Sweden

Whereas there is evidence that mixed-species approaches to production forestry in general can provide positive outcomes relative to monocultures, it is less clear to what extent multiple benefits can be derived from specific mixed-species alternatives. To provide such insights requires evaluations of an encompassing suite of ecosystem services, biodiversity, and forest management considerations provided by specific mixtures and monocultures within a region. Here, we conduct such an assessment in Sweden by contrasting even-aged Norway spruce (Picea abies)-dominated stands, with mixed-species stands of spruce and birch (Betula pendula or B. pubescens), or spruce and Scots pine (Pinus sylvestris). By synthesizing the available evidence, we identify positive outcomes from mixtures including increased biodiversity, water quality, esthetic and recreational values, as well as reduced stand vulnerability to pest and pathogen damage. However, some uncertainties and risks were projected to increase, highlighting the importance of conducting comprehensive interdisciplinary evaluations when assessing the pros and cons of mixtures.     

Agricultural vulnerability over the Chinese Loess Plateau in response to climate change: Exposure,sensitivity, and adaptive capacity

Understanding how the vulnerability of agricultural production to climate change can differ spatially has practical significance to sustainable management of agricultural systems worldwide. Accordingly, this study developed a conceptual framework to assess the agricultural vulnerability of 243 rural counties on the Chinese Loess Plateau. Indicators representing the climate/agriculture interface were selected to describe exposure and sensitivity, while stocks of certain capitals were used to describe adaptive capacity. A vulnerability index for each county was calculated and the spatial distribution was mapped. Results showed that exposure, sensitivity, and adaptive capacity occur independently, with most contributing indicator values concentrated in a narrow range after normalization. Within the 49 most vulnerable counties, which together encompass 81 % of the vulnerability index range, 42 were characterized by high exposure and sensitivity but low adaptive capacity. The most vulnerable area was found to be located in the central northeast–southwest belt of Loess Plateau. Adaptation measures for both ecological restoration and economic development are needed and potential adaptation options need further investigation.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-015-0727-8) contains supplementary material, which is available to authorized users.     

Mutagenic properties of linuron and chlorbromuron evaluated by means of cytogenetic biomarkers in mammalian cell lines

Agricultural practices are usually supported by several chemical substances, such as herbicides. Linuron and chlorbromuron are phenylurea herbicides largely used to protect crops from weeds, blocking photosynthesis by inhibition of the photosystem II complex. The former, also commercially known as lorox or afalon, is selectively used to protect bean and French bean plants, fennels, and celeriacs; the second, commercially known as maloran, is selectively used for carrots, peas, potatoes, soy sprouts, and sunflowers. Considering the widespread use of herbicides and, more generally, pesticides, it is important to clarify their involvement on human health, one of them concerning the possible direct or indirect effect on the genome of exposed populations. Here, we show that these herbicides are endowed by mutagenic properties, as demonstrated by an increased number of chromosomal aberrations (CAs) in two exposed Chinese hamster cell lines derived from ovary and epithelial liver, respectively. This was also confirmed by sister chromatid exchange (SCE) and micronucleus (MN) assays. Our present and previously obtained data clearly indicate that phenylurea herbicides must be used with great caution, especially for agricultural workers who use large amounts of herbicides during their work, and particular attention should be given to residues of these herbicides and their involvement in environmental pollution.     

Comparison of different modifications on QuEChERS sample preparation method for PAHs determination in black, green, red and white tea

The aim of this work was the evaluation of QuEChERS extraction method for polycyclic aromatic hydrocarbon (PAH) determination in various types of tea. In the experiment, different kinds of extraction solvents, sorbents and a final method of sample preparation were compared. The final extracts were analysed by gas chromatography-selected ion monitoring-mass spectrometry. The results suggest that acetonitrile extraction, clean up with SAX and final liquid–liquid extraction was the best combination giving the most purified extracts and acceptable compound recoveries for different types of teas. In the study of real samples, compounds belonging to light PAHs were mostly detected, and heavy polycyclic aromatic hydrocarbons, including benzo[a]pyrene, were not identified in any of samples.     

Cargo-specific accidental release impact zones for hazardous materials: risk and consequence comparison for ammonia and hydrogen fluoride

Impacts of hazardous material releases during transport depend on the characteristics of the cargo, incident location and time, weather conditions (i.e., wind direction and speed), and land use. The objectives of this research were to characterize the dispersion characteristics of two hazardous materials (ammonia and hydrogen fluoride) in relation to meteorological parameters, land use, and cargo characteristics; and evaluate the health risks associated with the exposure after accidental releases. The magnitudes of the impact zones were compared in relation to atmospheric stability and exposure levels. Impact zones were estimated by areal locations of hazardous atmospheres software and imported to ArcGIS. For ammonia, the areas impacted by exposure levels over 1100 ppm Acute Exposure Guideline Level 3 (AEGL-3) were limited to less than 0.3 miles downwind from the incident location under unstable atmospheric conditions, which favor high vertical mixing and rapid dilution, and extended further downwind to distances between 0.5 and 0.7 miles under stable atmospheric conditions. For hydrogen fluoride, the AEGL-3 impact zone (exposure levels over 44 ppm) extended between 0.6 and 0.9 miles directly downwind from the incident location under unstable conditions, and reached approximately 2.0 miles directly downwind from the incident location under stable atmospheric conditions. The results were compared with the Emergency Response Guideline (ERG 2012) and showed agreement. The multilevel analysis of impacts after hazardous material releases during transport (i.e., type of material, geographical data, dispersion profile, meteorological information) can be used for implementing appropriate response and mitigation measures for accidental releases of hazardous cargo.     

In Vitro effects of various xenobiotics on Azotobacter chroococcum strains isolated from soils of southern Poland

Fourteen Azotobacter chroococcum strains isolated from soils of Southern Poland were studied concerning resistance to various xenobiotics: heavy metal ions: Cd(2+,) Cu(2+), Fe(3+), Mn(2+), Pb(2+), Zn(2+), pesticides: herbicides linuron (3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea) and combination of mecoprop ((RS)-2-(4-chloro-2-methylphenoxy)propanoic acid), dicamba (3,6-dichloro-2-methoxybenzoic acid) and MCPA (2-methyl-4-chlorophenoxyacetic acid), fungicide copper oxychloride, insecticide fenitrothion (O,O-Dimethyl O-(3-methyl-4-nitrophenyl) phosphorothioate) and eight antibiotics commonly used against Gram-negative bacteria. The tested soils were divided into seven groups of land use: forest, field crop, park, urban lawn, industrial area, garden and fallow land, and were analyzed for the following heavy metal ion concentrations using the atomic absorption spectrometry (AAS) technique: Cd(2+,) Cu(2+), Fe(3+), Mn(2+), Pb(2+), Zn(2+). All strains were resistant to Pb(2+), whereas other metals caused the growth inhibition of the analyzed strains. There was no significant relationship between metal concentrations in the analyzed soils and metal resistance of the isolates. Herbicide linuron did not inhibit the growth of A. chroococcum in any of the concentrations. All other pesticides caused the growth inhibition only in the concentrate forms. All isolates were sensitive to β-lactam antibiotic Meropenem, however high intraspecies differentiation was observed concerning resistance to other antibiotics. The obtained results require further study regarding resistance mechanisms and possible use of the xenobiotic-resistant strains in land rehabilitation.     

Photocatalytic decomposition of methanol over La/TiO<Subscript>2</Subscript> materials

Lanthanum-modified TiO₂ photocatalysts (0.2–1.5 wt% La) were investigated in the methanol decomposition in an aqueous solution. The photocatalysts were prepared by the common sol-gel method followed by calcination. The structural (X-ray diffraction, Raman, X-ray photoelectron spectroscopy), textural (N₂ physisorption), and optical properties (diffuse reflectance spectroscopy, photoelectrochemical measurements) of all synthetized nanomaterials were correlated with photocatalytic activity. Both pure TiO₂ and La-doped TiO₂ photocatalysts proved higher yields of hydrogen in comparison to photolysis. The photocatalyst with optimal amount of lanthanum (0.2 wt% La) showed almost two times higher amount of hydrogen produced at the same time as in the presence of pure TiO₂. The photocatalytic activity increased with both increasing photocurrent response and decreasing amount of lattice and surface O species. It has been shown that both direct and indirect mechanisms of methanol photocatalytic oxidation participate in the production of hydrogen. Both direct and indirect mechanisms take part in the formation of hydrogen.