The influence of balanced and imbalanced resource supply on biodiversity – functioning relationship across ecosystems

Numerous studies show that increasing species richness leads to higher ecosystem productivity. This effect is often attributed to more efficient portioning of multiple resources in communities with higher numbers of competing species, indicating the role of resource supply and stoichiometry for biodiversity-ecosystem functioning relationships. Here, we merged theory on ecological stoichiometry with a framework of biodiversity-ecosystem functioning to understand how resource use transfers into primary production. We applied a structural equation model to define patterns of diversity-productivity relationships with respect to available resources. Meta-analysis was used to summarize the findings across ecosystem types ranging from aquatic ecosystems to grasslands and forests. As hypothesized, resource supply increased realized productivity and richness, but we found significant differences between ecosystems and study types. Increased richness was associated with increased productivity, although this effect was not seen in experiments. More even communities had lower productivity, indicating that biomass production is often maintained by a few dominant species, and reduced dominance generally reduced ecosystem productivity. This synthesis, which integrates observational and experimental studies in a variety of ecosystems and geographical regions, exposes common patterns and differences in biodiversity-functioning relationships, and increases the mechanistic understanding of changes in ecosystems productivity

Interactions between ecosystem properties and land use clarify spatial strategies to optimize trade-offs between agriculture and species conservation

Species conservation and forage production are both important, yet conflicting components of sustainable grassland management. We modeled forage production and conservation value as dependents in a chain of responses and effects, starting with abiotic environmental conditions that affect the spatial distribution of land uses and biotic ecosystem properties. We asked which relationships in this causal chain determine trade-offs between forage production and conservation value. Abiotic and biotic ecosystem properties were recorded on 46 plots in the coastal marshes of Northwest Germany. Plant and bird conservation values were calculated using Red Lists, and sales of forage-based agricultural products were assessed by interviewing farmers. We used a structural equation model to determine responses and effects. Groundwater depth and salinity represent the ultimate causes for the spatial variation in sales and conservation value. The water gradient translated into more proximate causes, such as land-use intensity affecting aboveground net primary productivity, forage quality, and species richness. Plant species conservation and forage production were segregated along the water gradient, and both bird conservation and forage production depended on grassland management, albeit at different fertilization levels. Our study points to segregation and integration as two spatial strategies to react to trade-offs between services.EDITED BY Christine Fürs

PlantTraitDataKleyerEtAl2018JECOL

The data file comprises 23 different traits from 2530 plant individuals of 126 sppecies sampled on 381 plots, established on dry semi-natural grasslands, heaths, mesic and wet pastures and meadows, reeds, and saltmarshes, geographically ranging from Switzerland to Germany, The Netherlands and Denmark. All traits were measured using a common protocol. Find more details including the protocol in the paper "Trait correlation network analysis identifies biomass allocation traits and stem specific length as hub traits in herbaceous perennial plants

Data from: Trait correlation network analysis identifies biomass allocation traits and stem specific length as hub traits in herbaceous perennial plants

Correlations among plant traits often reflect important trade‐offs or allometric relationships in biological functions like carbon gain, support, water uptake, and reproduction that are associated with different plant organs. Whether trait correlations can be aggregated to “spectra” or “leading dimensions,” whether these dimensions are consistent across plant organs, spatial scale, and growth forms are still open questions. To illustrate the current state of knowledge, we constructed a network of published trait correlations associated with the “leaf economics spectrum,” “biomass allocation dimension,” “seed dimension,” and carbon and nitrogen concentrations. This literature‐based network was compared to a network based on a dataset of 23 traits from 2,530 individuals of 126 plant species from 381 plots in Northwest Europe. The observed network comprised more significant correlations than the literature‐based network. Network centrality measures showed that size traits such as the mass of leaf, stem, below‐ground, and reproductive tissues and plant height were the most central traits in the network, confirming the importance of allometric relationships in herbaceous plants. Stem mass and stem‐specific length were “hub” traits correlated with most traits. Environmental selection of hub traits may affect the whole phenotype. In contrast to the literature‐based network, SLA and leaf N were of minor importance. Based on cluster analysis and subsequent PCAs of the resulting trait clusters, we found a “size” module, a “seed” module, two modules representing C and N concentrations in plant organs, and a “partitioning” module representing organ mass fractions. A module representing the plant economics spectrum did not emerge. Synthesis. Although we found support for several trait dimensions, the observed trait network deviated significantly from current knowledge, suggesting that previous studies have overlooked trait coordination at the whole‐plant level. Furthermore, network analysis suggests that stem traits have a stronger regulatory role in herbaceous plants than leaf traits

Integrating Electrical and Mechanical Design and Process Planning

This paper reports on the development of the process-planning module for EDAPS, an integrated system for designing and planning the manufacture of microwave modules. Microwave modules are complex devices having both electrical and mechanical properties, and EDAPS integrates electrical design, mechanical design, and process planning for both the mechanical and electrical domains. EDAPS's process planning module provides an integrated approach to process planning in both the electronic and mechanical domains, specifically in the manufacture of microwave transmit-receive (T/R) modules. It enables EDAPS to generate process plans concurrently with design---and we are developing ways for EDAPS to use the process planning information provide feedback to designers about manufacturability, cost, and lead time for manufacturing their designs. The planning module is based on a modified version of an AI planning methodology called Hierarchical Task Network (HTN) planning. We provide an overview of..

The transition to non-lead rifle ammunition in Denmark: National obligations and policy considerations

The issue of Denmark regulating use of lead-free rifle ammunition because of potential risks of lead exposure in wildlife and humans was examined from a scientific and objective policy perspective. The consequences of adopting or rejecting such regulation were identified. Denmark is obliged to examine this topic because of its national policy on lead reduction, its being a Party to the UN Bonn Convention on Migratory Species, and its role in protecting White-tailed Sea Eagles (Haliaeetus albicilla), a species prone to lead poisoning from lead ingestion. Lead-free bullets suited for deer hunting are available at comparable cost to lead bullets, and have been demonstrated to be as effective. National adoption of lead-free bullets would complete the Danish transition to lead-free ammunition use. It would reduce the risk of lead exposure to scavenging wildlife, and humans who might eat lead-contaminated wild game meat. Opposition from hunting organizations would be expected