Fate of products of degradation processes: consequences for climatic change

The end products of atmospheric degradation are not only CO2 and H2O but also sulfate and nitrate depending on the chemical composition of the substances which are subject to degradation processes. Atmospheric degradation has thus a direct influence on the radiative balance of the earth not only due to formation of greenhouse gases but also of aerosols. Aerosols of a diameter of 0.1 to 2 micrometer, reflect short wave sunlight very efficiently leading to a radiative forcing which is estimated to be about -0.8 watt per m2 by IPCC. Aerosols also influence the radiative balance by way of cloud formation. If more aerosols are present, clouds are formed with more and smaller droplets and these clouds have a higher albedo and are more stable compared to clouds with larger droplets. Not only sulfate, but also nitrate and polar organic compounds, formed as intermediates in degradation processes, contribute to this direct and indirect aerosol effect. Estimates for the Netherlands indicate a direct effect of -4 watt m-2 and an indirect effect of as large as -5 watt m-2. About one third is caused by sulfates, one third by nitrates and last third by polar organic compounds. This large radiative forcing is obviously non-uniform and depends on local conditions.     

The effect of elevated UV-B (280-320 nm) radiation levels on Silene vulgaris: a comparison between a highland and a lowland population

Highland (altitude 1600 m above sea level) and lowland (altitude -2 m below sea level) populations of the perennial herb Silene vulgaris (Moench) Garcke, were tested on their response to elevated levels of UV-B radiation. Highland populations typically receive high natural UV-B fluxes, whereas lowland populations receive a lower natural UV-B dose. Adaptation to high UV-B levels of the highland population is to be expected. Experimental comparison of growth rates, gas exchange rates, transpiration and biochemical parameters using adult plants as well as seedlings did not show a difference in the response to elevated UV-B levels between the two populations. Individuals of both populations were relatively insensitive to elevated UV-B radiation. The response of alpine and lowland populations of Silene vulgaris is discussed in relation to the dispersal of this species after the last ice age.     

A simple dermal absorption model: Derivation and application

This paper deals with the derivation of a QSAR for the estimation of:

• the skin permeation coefficient from aqueous solutions in cm h⁻¹,

• the stratum corneum/water partition coefficient.

These QSARs enable the estimation of:

• the aqueous permeation coefficient in cm h⁻¹,

• the maximum dermal absorption in mg cm⁻² h⁻¹ from a saturated aqueous solution at steady state,

• the lag time in hours (h),

• the diffusivity of a substance in the stratum corneum in cm² h⁻¹

By using the independent variables:

• the log(octanol/water partition coefficient),

• the molecular weight,

• the water solubility.

The estimated maximum dermal absorption and the lag time were compared with some recent measured data of substances, which were not used for developing the QSARs. The estimates were generally in the same order of magnitude as the measured absorption and lag time. These QSARs are recommended for risk assessment of chemicals in the scope of the European REACH legislation.     

Designing a multifunctional artificial reef: studies on the influence of parameters with most influence in the vertical plane

Multifunctional artificial reefs are submerged breakwaters that serve several purposes. As well as protecting the local coastline, they enhance surfing possibilities and/or increase the environmental value of the area where they are situated. Multifunctional artificial reefs (MFARs) have some promising new aspects, too: first, they provide an unimpaired visual amenity, and second, they can offer tourist and economic benefits by improving the surfing conditions. Regarding the functionality of an MFAR, much research has been carried out on surfability, i.e. whether a wave is good for surfers. However, no research has yet been done on the influence of the submergence and the length of the reef slope on the breaker type, even though this is important for the design of the reef in terms of surfability. A preliminary design was achieved step by step, making use of the theory and state of the art of multifunctional artificial reefs (Voorde et al. 2009a, 2009b). This reef geometry was then used as an initial design in physical and numerical tests. These were performed to ascertain the capacity of a multifunctional reef to serve as a submerged breakwater and so protect the local coastline of Leirosa, Portugal, and improve the local surfing possibilities. This paper describes the numerical study conducted to analyze the influences of the main relevant parameters in the vertical plane, namely: the height, the submergence, and the length and slope of the reef. The investigation was conducted using the COBRAS-UC numerical model in the vertical plane and the main results and conclusions are described and presented; a brief discussion and some recommendations for future work are also included.     

A quantitative global review of species population monitoring

Species monitoring, defined here as the repeated, systematic collection of data to detect long-term changes in the populations of wild species, is a vital component of conservation practice and policy. We created a database of nearly 1200 schemes, ranging in start date from 1800 to 2018, to review spatial, temporal, taxonomic, and methodological patterns in global species monitoring. We identified monitoring schemes through standardized web searches, an online survey of stakeholders, in-depth national searches in a sample of countries, and a review of global biodiversity databases. We estimated the total global number of monitoring schemes operating at 3300–15,000. Since 2000, there has been a sharp increase in the number of new schemes being initiated in lower- and middle-income countries and in megadiverse countries, but a decrease in high-income countries. The total number of monitoring schemes in a country and its per capita gross domestic product were strongly, positively correlated. Schemes that were active in 2018 had been running for an average of 21 years in high-income countries, compared with 13 years in middle-income countries and 10 years in low-income countries. In high-income countries, over one-half of monitoring schemes received government funding, but this was less than one-quarter in low-income countries. Data collection was undertaken partly or wholly by volunteers in 37% of schemes, and such schemes covered significantly more sites and species than those undertaken by professionals alone. Birds were by far the most widely monitored taxonomic group, accounting for around half of all schemes, but this bias declined over time. Monitoring in most taxonomic groups remains sparse and uncoordinated, and most of the data generated are elusive and unlikely to feed into wider biodiversity conservation processes. These shortcomings could be addressed by, for example, creating an open global meta-database of biodiversity monitoring schemes and enhancing capacity for species monitoring in countries with high biodiversity. Article impact statement: Species population monitoring for conservation purposes remains strongly biased toward a few vertebrate taxa in wealthier countries.