Leaf litter traits of invasive alien species slow down decomposition compared to Spanish natives: a broad phylogenetic comparison.

Leaf traits related to the performance of invasive alien species can influence nutrient cycling through litter decomposition. However, there is no consensus yet about whether there are consistent differences in functional leaf traits between invasive and native species that also manifest themselves through their "after life" effects on litter decomposition. When addressing this question it is important to avoid confounding effects of other plant traits related to early phylogenetic divergences and to understand the mechanism underlying the observed results to predict which invasive species will exert larger effects on nutrient cycling. We compared initial leaf litter traits, and their effect on decomposability as tested in standardized incubations, in 19 invasive-native pairs of co-familial species from Spain. They included 12 woody and seven herbaceous alien species representative of the Spanish invasive flora. The predictive power of leaf litter decomposition rates followed the order: growth form > family > status (invasive vs. native) > leaf type. Within species pairs litter decomposition tended to be slower and more dependent on N and P in invaders than in natives. This difference was likely driven by the higher lignin content of invader leaves. Although our study has the limitation of not representing the natural conditions from each invaded community, it suggests a potential slowing down of the nutrient cycle at ecosystem scale upon invasion. © Springer-Verlag 2009

Maximaal toelaatbare risiconiveaus en verwaarloosbare risiconiveaus voor zeldzame aardmetalen (ZAMs)

In this report maximum permissible concentrations (MPCs) and negligible concentrations (NCs) are derived for Rare Earth Elements (REEs), which are also known as lanthanides. The REEs selected for derivation of environmental risk limits in this report are Yttrium (Y), Lanthanum (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Samarium (Sm), Gadolinium (Gd), and Dysprosium (Dy). Since REEs are natural compounds, the added risk approach is used to derive MPC values. The total amount of toxicity studies for freshwater and saltwater organisms to base the MPA upon is limited, often an assessment factor of 1000 had to be used. For fresh surface water, the derived MPCs range from 1.8 ug/L for Nd to 22.1 ug/L for Ce. For salt surface water the derived MPCs are much lower, from 0.28 ug/L for Ce to 3.8 ug/L for Dy. MPC values for fresh water sediments are also higher than those for salt water sediments. Dutch water and sediment concentrations do not exceed the MPCs of the different REEs. Occasionally, environmental concentrations of REEs exceed the NC-levels.In dit rapport worden maximaal toelaatbare risiconiveaus (MTR) en verwaarloosbare risiconiveaus (VR) afgeleid voor zeldzame aardmetalen (ZAM). De geselecteerde ZAMs zijn Yttrium (Y), Lanthanum (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Samarium (Sm), Gadolinium (Gd), en Dysprosium (Dy). Omdat ZAMs van nature voorkomen, is de toegevoegd-risico benadering gebruikt om MTRs af te leiden. Het aantal beschikbare toxiciteitstudies om een MTR op te baseren is beperkt, vaak is daarom een factor 1000 gebruikt om tot een normwaarde te komen. Voor zoet oppervlaktewater ligt de MTR tussen 1,8 ug/l voor Nd en 22,1 ug/l voor Ce. Voor zout oppervlaktewater zijn de afgeleide MTRs veel lager, varierend van 0,28 ug/l voor Ce tot 3,8 ug/l voor Dy. MTRs voor zoete sedimenten liggen eveneens hoger dan voor zoute sedimenten. Nederlandse water- en sedimentconcentraties overschrijden niet de MTRs voor de verschillende ZAMs. Af en toe overschrijden de milieuconcentraties het VR

Maximaal toelaatbare risiconiveaus en verwaarloosbare risiconiveaus voor zeldzame aardmetalen (ZAMs)

In dit rapport worden maximaal toelaatbare risiconiveaus (MTR) en verwaarloosbare risiconiveaus (VR) afgeleid voor zeldzame aardmetalen (ZAM). De geselecteerde ZAMs zijn Yttrium (Y), Lanthanum (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Samarium (Sm), Gadolinium (Gd), en Dysprosium (Dy). Omdat ZAMs van nature voorkomen, is de toegevoegd-risico benadering gebruikt om MTRs af te leiden. Het aantal beschikbare toxiciteitstudies om een MTR op te baseren is beperkt, vaak is daarom een factor 1000 gebruikt om tot een normwaarde te komen. Voor zoet oppervlaktewater ligt de MTR tussen 1,8 ug/l voor Nd en 22,1 ug/l voor Ce. Voor zout oppervlaktewater zijn de afgeleide MTRs veel lager, varierend van 0,28 ug/l voor Ce tot 3,8 ug/l voor Dy. MTRs voor zoete sedimenten liggen eveneens hoger dan voor zoute sedimenten. Nederlandse water- en sedimentconcentraties overschrijden niet de MTRs voor de verschillende ZAMs. Af en toe overschrijden de milieuconcentraties het VR.In this report maximum permissible concentrations (MPCs) and negligible concentrations (NCs) are derived for Rare Earth Elements (REEs), which are also known as lanthanides. The REEs selected for derivation of environmental risk limits in this report are Yttrium (Y), Lanthanum (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Samarium (Sm), Gadolinium (Gd), and Dysprosium (Dy). Since REEs are natural compounds, the added risk approach is used to derive MPC values. The total amount of toxicity studies for freshwater and saltwater organisms to base the MPA upon is limited, often an assessment factor of 1000 had to be used. For fresh surface water, the derived MPCs range from 1.8 ug/L for Nd to 22.1 ug/L for Ce. For salt surface water the derived MPCs are much lower, from 0.28 ug/L for Ce to 3.8 ug/L for Dy. MPC values for fresh water sediments are also higher than those for salt water sediments. Dutch water and sediment concentrations do not exceed the MPCs of the different REEs. Occasionally, environmental concentrations of REEs exceed the NC-levels.DGM-SV

Derivation of Ecologically Based Soil Standards for Trace Elements

A comprehensive and practical overview of the state of the science, Soil Quality Standards for Trace Elements: Derivation, Implementation, and Interpretation addresses the derivation of soil quality standards for trace elements and the implementation of these standards within regulatory and risk assessment frameworks. Forty experts from 11 countries across Europe, Asia, and North America—a multidisciplinary group of government policy makers and regulators, academics, industry representatives, and consultants—provide a focused discussion on the science and methods underpinning the derivation of soil quality standards for trace elements. Outlines the supporting science for setting environmental and human health standards Covers the application and practical use of soil quality standards for trace elements Contains recommendations on the development and use of soil quality standards for trace elements Identifies best practices in accounting for (bio)availability and exposure modelling in standard setting for soils The book provides a clear description of how to derive and implement soil quality standards for trace elements in order to assess human and environmental risks. It covers scientific developments useful for resolving discrepancies in the setting and implementation of soil quality standards. It provides useful tips, including do's, and don'ts on how to deal with issues such as variation of the natural background and soil type dependent toxicity