Using clear plastic CD cases as low‐cost mini‐rhizotrons to phenotype root traits
Cassidy et al. developed a novel low‐cost method to visually phenotype belowground structures in the plant rhizosphere. Their method combines the benefits of pots and germination pouches. In CD mini‐rhizotrons, plants grew significantly larger than in germination pouches, and unlike pots, it is possible to measure roots without destructive sampling.
Applications in Plant Sciences
GlobalFungi: Global database of fungal records from high-throughput-sequencing metabarcoding studies
Fungi are key players in vital ecosystem services, spanning carbon cycling, decomposition, symbiotic associations with cultural and wild plants and pathogenicity. The high importance of fungi in the ecosystem processes contrasts with the incompleteness of understanding of the patterns of fungal biogeography and the environmental factors that drive it. To close this gap of knowledge, Větrovský et al. have collected and validated data published on the composition of soil fungal communities in terrestrial environments including soil and plant-associated habitats and made them publicly accessible through a user interface at http://globalfungi.com.
Diminishing CO2-driven gains in water-use efficiency of global forests
There is broad consensus that, via changes in stomatal conductance, plants moderate the exchanges of water and carbon between the biosphere and atmosphere, playing a major role in global hydroclimate. Tree rings record atmospheric CO2 concentration (ca) and its isotopic composition (13C/12C)—mediated by stomatal and photosynthetic influences—that can be expressed in terms of intrinsic water-use efficiency (W). Adams et al. compile a global W dataset based on 422 tree-ring isotope series and report that W increased with ca over the twentieth century, but the rates of increase (dW/dca) declined by half.
Nature Climate Change
Taxonomic similarity does not predict necessary sample size for ex situ conservation: a comparison among five genera
Effectively conserving biodiversity with limited resources requires scientifically informed and efficient strategies. Guidance is particularly needed on how many living plants are necessary to conserve a threshold level of genetic diversity in ex situ collections. Hoban et al. investigated this question for 11 taxa across five genera. In this first study analysing and optimizing ex situ genetic diversity across multiple genera, they found that the percentage of extant genetic diversity currently conserved varies among taxa from 40% to 95%. Most taxa are well below genetic conservation targets. Resampling datasets showed that ideal collection sizes vary widely even within a genus: one taxon typically required at least 50% more individuals than another
Local conditions and policy design determine whether ecological compensation can achieve No Net Loss goals
Sonter et al. use spatial simulation models to quantify potential net impacts of alternative compensation policies on biodiversity (indicated by native vegetation) and two ecosystem services (carbon storage, sediment retention) across four case studies (in Australia, Brazil, Indonesia, Mozambique). No policy achieves No Net Loss of biodiversity in any case study. Two factors limit their potential success: the land available for compensation (existing vegetation to protect or cleared land to restore), and expected counterfactual biodiversity losses (unregulated vegetation clearing). Compensation also fails to slow regional biodiversity declines because policies regulate only a subset of sectors, and expanding policy scope requires more land than is available for compensation activities.
A consensus phylogenomic approach highlights paleopolyploid and rapid radiation in the history of Ericales
Large genomic data sets offer the promise of resolving historically recalcitrant species relationships. However, different methodologies can yield conflicting results, especially when clades have experienced ancient, rapid diversification. Larson et al. analyzed the ancient radiation of Ericales and explored sources of uncertainty related to species tree inference, conflicting gene tree signal, and the inferred placement of gene and genome duplications.
Effects of amusing memes on concern for unappealing species
There is limited knowledge of the mechanisms that can inspire people's concern and engagement in the protection of unpopular and unappealing species. Lenda et al. analyzed Polish people's interest in themed internet memes featuring the proboscis monkey (Nasalis larvatus) and the consequences of this interest for conservation marketing We examined Google Trends data, used Google Search, and searched popular media materials to estimate interest in the proboscis monkey in Poland.
The negative regulator SMAX1 controls mycorrhizal symbiosis and strigolactone biosynthesis in rice
Most plants associate with beneficial arbuscular mycorrhizal (AM) fungi that facilitate soil nutrient acquisition. Prior to contact, partner recognition triggers reciprocal genetic remodelling to enable colonisation. The plant Dwarf14-Like (D14L) receptor conditions pre-symbiotic perception of AM fungi, and also detects the smoke constituent karrikin. D14L-dependent signalling mechanisms, underpinning AM symbiosis are unknown. Choi et al. present the identification of a negative regulator from rice, which operates downstream of the D14L receptor, corresponding to the homologue of the Arabidopsis thaliana Suppressor of MAX2-1 (AtSMAX1) that functions in karrikin signalling. They demonstrate that rice SMAX1 is a suppressor of AM symbiosis, negatively regulating fungal colonisation and transcription of crucial signalling components and conserved symbiosis genes.