Mechanistically derived dispersal kernels explain species-level patterns of recruitment and succession.

Species-level dispersal information can give mechanistic insights into how spatial processes impact plant communities. Unfortunately, field-based estimates of the dispersal abilities of multiple members of a community are often lacking for many plant systems. Here, we provide a simple method for measuring dispersal ability for large numbers of grassland plant species based on functional traits.

Stressful life events in childhood and allergic sensitization.

Stressful life events evidently have an impact on development of allergic diseases, but the mechanism linking stress to pathological changes of immune system function is still not fully understood. The aim of our study was to investigate the relationship between stressful life events, neuropeptide and cytokine concentrations in children as well as the association between early stressful life events and atopic eczema (AE). Within the LISA plus (Life style - Immune system - Allergy) study, blood samples from children of 6 years of age were analyzed for concentration of the neuropeptides vasoactive intestinal peptide (VIP), somatostatin (SOM), substance P (SP) and the Th1/Th2 cytokines IFN-γ and IL-4.

Spatial heterogeneity in species composition constrains plant community responses to herbivory and fertilisation.

Environmental change can result in substantial shifts in community composition. The associated immigration and extinction events are likely constrained by the spatial distribution of species. Still, studies on environmental change typically quantify biotic responses at single spatial (time series within a single plot) or temporal (spatial beta diversity at single time points) scales, ignoring their potential interdependence.

1-Aminocyclopropane-1-carboxylate deaminase producers associated to maize and other Poaceae species.

Background: Complex plant-microbe interactions have been established throughout evolutionary time, many of them with beneficial effects on the host in terms of plant growth, nutrition, or health. Some of the corresponding modes of action involve a modulation of plant hormonal balance, such as the deamination of the ethylene precursor 1-aminocyclopropane-1-carboxylate (ACC). Despite its ecological importance, our understanding of ACC deamination is impaired by a lack of direct molecular tools.

Harnessing uncertainty to approximate mechanistic models of interspecific interactions.

Because the Lotka-Volterra competitive equations posit no specific competitive mechanisms, they are exceedingly general, and can theoretically approximate any underlying mechanism of competition near equilibrium. In practice, however, these models rarely generate accurate predictions in diverse communities. We propose that this difference between theory and practice may be caused by how uncertainty propagates through Lotka-Volterra systems.

Multi-element compound specific stable isotope analysis of chlorinated aliphatic contaminants derived from chlorinated pitches.

Tetrachloroethene and trichloroethene are typical by-products of the industrial production of chloromethanes. These by-products are known as "chlorinated pitches" and were often dumped in un-contained waste disposal sites causing groundwater contaminations. Previous research showed that a strongly depleted stable carbon isotope signature characterizes chlorinated compounds associated with chlorinated pitches whereas manufactured commercial compounds have more enriched carbon isotope ratios.

Herbivory and eutrophication mediate grassland plant nutrient responses across a global climatic gradient.

Plant stoichiometry, the relative concentration of elements, is a key regulator of ecosystem functioning and is also being altered by human activities. In this paper we sought to understand the global drivers of plant stoichiometry and compare the relative contribution of climatic vs. anthropogenic effects.

Identifying mechanisms that structure ecological communities by snapping model parameters to empirically observed tradeoffs.

Theory predicts that interspecific tradeoffs are primary determinants of coexistence and community composition. Using information from empirically observed tradeoffs to augment the parametrisation of mechanism-based models should therefore improve model predictions, provided that tradeoffs and mechanisms are chosen correctly. We developed and tested such a model for 35 grassland plant species using monoculture measurements of three species characteristics related to nitrogen uptake and retention, which previous experiments indicate as important at our site.

Identifying taxonomic and functional surrogates for spring biodiversity conservation.

Surrogate approaches are widely used to estimate overall taxonomic diversity for conservation planning. Surrogate taxa are frequently selected based on rarity or charisma, whereas selection through statistical modeling has been applied rarely. We used boosted-regression-tree models (BRT) fitted to biological data from 165 springs to identify bryophyte and invertebrate surrogates for taxonomic and functional diversity of boreal springs.

Aqueous photodegradation of substituted chlorobenzenes: Kinetics, carbon isotope fractionation, and reaction mechanisms.

Substituted chlorobenzenes are the basic substructure of many surface water contaminants. In this study, the isotope fractionation and reaction mechanisms involved during the aqueous direct and indirect photodegradation of CH-, Cl-, and NO- substituted chlorobenzenes were investigated in laboratory experiments. Only 4-nitrochlorobenzene showed slow but isotopically fractionating direct photolysis.

Novel aspects of uptake patterns, metabolite formation and toxicological responses in Salmon exposed to the organophosphate esters-Tris(2-butoxyethyl)- and tris(2-chloroethyl) phosphate.

Given the compound differences between tris(2-butoxyethyl)- and tris(2-cloroethyl) phosphate (TBOEP and TCEP, respectively), we hypothesized that exposure of juvenile salmon to TBOEP and TCEP will produce compound-specific differences in uptake and bioaccumulation patterns, resulting in potential formation of OH-metabolites. Juvenile salmon were exposed to waterborne TCEP or TBOEP (0.04, 0.

Integrating community assembly and biodiversity to better understand ecosystem function: the Community Assembly and the Functioning of Ecosystems (CAFE) approach.

The research of a generation of ecologists was catalysed by the recognition that the number and identity of species in communities influences the functioning of ecosystems. The relationship between biodiversity and ecosystem functioning (BEF) is most often examined by controlling species richness and randomising community composition. In natural systems, biodiversity changes are often part of a bigger community assembly dynamic.

Author Correction: Herbivores rescue diversity in warming tundra by modulating trait-dependent species losses and gains.

The original version of this Article contained errors in Figure 2. The dark green symbols on the scatter plot were light green, and vice versa. These errors have now been corrected in the PDF and HTML versions of the Article.

River water infiltration enhances denitrification efficiency in riparian groundwater.

Nitrate contamination in ground- and surface water is a persistent problem in countries with intense agriculture. The transition zone between rivers and their riparian aquifers, where river water and groundwater interact, may play an important role in mediating nitrate exports, as it can facilitate intensive denitrification, which permanently removes nitrate from the aquatic system. However, the in-situ factors controlling riparian denitrification are not fully understood, as they are often strongly linked and their effects superimpose each other.

Local loss and spatial homogenization of plant diversity reduce ecosystem multifunctionality.

Biodiversity is declining in many local communities while also becoming increasingly homogenized across space. Experiments show that local plant species loss reduces ecosystem functioning and services, but the role of spatial homogenization of community composition and the potential interaction between diversity at different scales in maintaining ecosystem functioning remains unclear, especially when many functions are considered (ecosystem multifunctionality). We present an analysis of eight ecosystem functions measured in 65 grasslands worldwide.

High Resolution Monitoring Above and Below the Groundwater Table Uncovers Small-Scale Hydrochemical Gradients.

Hydrochemical solute concentrations in the shallow subsurface can be spatially highly variable within small scales, particularly at interfaces. However, most monitoring systems fail to capture these small scale variations. Within this study, we developed a high resolution multilevel well (HR-MLW) with which we monitored water across the interface of the unsaturated and saturated zone with a vertical resolution of 0.

Asynchrony among local communities stabilises ecosystem function of metacommunities.

Temporal stability of ecosystem functioning increases the predictability and reliability of ecosystem services, and understanding the drivers of stability across spatial scales is important for land management and policy decisions. We used species-level abundance data from 62 plant communities across five continents to assess mechanisms of temporal stability across spatial scales. We assessed how asynchrony (i.

Herbivores rescue diversity in warming tundra by modulating trait-dependent species losses and gains.

Climate warming is altering the diversity of plant communities but it remains unknown which species will be lost or gained under warming, especially considering interactions with other factors such as herbivory and nutrient availability. Here, we experimentally test effects of warming, mammalian herbivory and fertilization on tundra species richness and investigate how plant functional traits affect losses and gains. We show that herbivory reverses the impact of warming on diversity: in the presence of herbivores warming increases species richness through higher species gains and lower losses, while in the absence of herbivores warming causes higher species losses and thus decreases species richness.

Effect of solution pH on aging dynamics and surface structural evolution of mZVI particles: H production and spectroscopic/microscopic evidence.

A microscale zero-valent iron (mZVI)-based in situ reactive zone is a promising technology for contaminated groundwater remediation. Estimation of mZVI aging behavior after its injection into the subsurface is essential for efficiency and longevity assessments. In this study, batch tests were conducted to investigate the effect of initial pH on mZVI aging dynamics, as well as the formation and evolution of aging products over 112 days.

A decade of insights into grassland ecosystem responses to global environmental change.

Earth's biodiversity and carbon uptake by plants, or primary productivity, are intricately interlinked, underlie many essential ecosystem processes, and depend on the interplay among environmental factors, many of which are being changed by human activities. While ecological theory generalizes across taxa and environments, most empirical tests of factors controlling diversity and productivity have been observational, single-site experiments, or meta-analyses, limiting our understanding of variation among site-level responses and tests of general mechanisms. A synthesis of results from ten years of a globally distributed, coordinated experiment, the Nutrient Network (NutNet), demonstrates that species diversity promotes ecosystem productivity and stability, and that nutrient supply and herbivory control diversity via changes in composition, including invasions of non-native species and extinction of native species.

Integrating chytrid fungal parasites into plankton ecology: research gaps and needs.

Chytridiomycota, often referred to as chytrids, can be virulent parasites with the potential to inflict mass mortalities on hosts, causing e.g. changes in phytoplankton size distributions and succession, and the delay or suppression of bloom events.

Urban heat island (UHI) influence on secondary pollutant formation in a tropical humid environment.

Unlabelled: The combined action of urbanization (change in land use) and increase in vehicular emissions intensifies the urban heat island (UHI) effect in many cities in the developed countries. The urban warming (UHI) enhances heat-stress-related diseases and ozone (O) levels due to a photochemical reaction. Even though UHI intensity depends on wind speed, wind direction, and solar flux, the thermodynamic properties of surface materials can accelerate the temperature profiles at the local scale.