Summary1. The importance of plant-soil interactions in land reclamation, and the management and restoration of functioning native ecosystems, is becoming widely recognized. However, relatively little is known about broad-scale patterns of genetic variation and adaptation in wild plant-soil symbiotic interactions. 2. The current study is part of a larger project examining patterns of genetic variation and adaptation in host and symbiont populations across their geographical ranges using two widespread native Australian Acacia spp. ( A. salicina , A. stenophylla ) and associated populations of rhizobial bacteria. 3. A total of 58 sites were characterized with regard to symbiont population sizes, soil chemistry and environmental parameters. Rhizobial abundance was negatively correlated with a small number of soil factors, including nitrogen, and positively correlated with organic carbon and cation exchange capacity. 4. There were clear differences between host species in seedling growth responses in glasshouse trials using pots inoculated with native soils. While A. salicina grew equally well with soils from A. stenophylla and A. salicina sites, A. stenophylla grew best when inoculated with its own soils, indicating broad-scale adaptation to its own rhizobia. 5. Rhizobial abundance in these soils was also strongly correlated to variation in nodulation and host growth, indicating that abundance may be a good indicator of the relative effectiveness of rhizobial populations. 6. The clear differences in specificity and effectiveness of host-symbiont associations, even among related species, suggests that better knowledge of these systems at multiple spatial scales is central to understanding the factors that influence the ecology and evolution of plant and soil communities, and has potential to increase the cost-effectiveness of restoration programs.

BACKGROUND: There is considerable uncertainty regarding the acceptability of routine distress screening. METHODS: In an unfunded implementation study, the authors asked 50 clinicians (chemotherapy nurses and treatment radiographers/radiation technologists) to implement a screening program for distress as part of routine care and to record their feedback after each clinical encounter. In total, 379 patients were screened using a simple paper-and-pencil versions of distress thermometer and the emotion thermometer (ET). RESULTS: Across all screening applications, clinicians believed that screening was useful during 43% of assessments and was not useful during 35.9% of assessments, and they were unsure or neutral in 21.1% of assessments. The application of the screening program assisted staff in changing their clinical opinion after 41.9% of assessments, and clinicians believed that the screening program helped with communication in >50% of assessments. However, 37.5% believed that screening was impractical for routine use, and more chemotherapy nurses than radiographers rated the screening program as ''not useful.'' On multivariate analysis, 3 variables were associated with high staff satisfaction with screening, namely, receipt of prior training, talking with the patient about psychosocial issues, and improved detection of psychological problems. A favorable perception of screening also was linked to a change in clinical opinion. CONCLUSIONS: Opinions of cancer clinicians regarding routine distress screening were mixed: Approximately 33% considered screening not useful/impractical, whereas >50%n believed promoted good communication and/or helped with recognition. Clinicians who were more positive about screening gained greater benefits from screening in terms of communication and recognition. Cancer 2012;118:6260-9.

Summary 1.The ecological importance of host-soil symbiont associations for plant community structure and dynamics has been recently highlighted, particularly with regard to ecological and evolutionary responses along environmental gradients. 2. We used a range of native Australian shrubby legumes ( Acacia spp.) and associated root-nodule forming bacteria (rhizobia) in laboratory and glasshouse studies to investigate the ecology of Acaciarhizobial interactions with respect to soil salinity, a major environmental stressor in many parts of the world. 3. Analysis of laboratory growth data provided clear evidence of a trade-off in that growth rate of individual rhizobial isolates was reduced with increasing salt tolerance in culture. 4. A large replicated glasshouse inoculation trial using 40 strains of rhizobia and nine species of Acacia that varied in their ability to grow in saline soils found strong evidence of host specificity, but neither the average growth promotion of host plants nor the specificity of growth promotion was related to salt tolerance of the isolates. 5. In a second glasshouse experiment, we used a subset of salt-sensitive and salt-tolerant rhizobia and six Acacia species to evaluate performance and symbiotic effectiveness across different levels of soil salinity. Overall, we found no evidence of a relationship between rhizobial salt-tolerance (as measured in the laboratory) and impact on host growth performance, either in saline or nonsaline soils, and there was no evidence that salt-tolerant rhizobia perform better in more saline environments. 6. Synthesis . More salt tolerant Acacia spp. were less responsive in growth to rhizobial inoculation than salt sensitive hosts, implying that evolution towards reduced dependence on the symbiosis may facilitate adaptation to salt, raising a general question regarding the extent to which shifts in dependence on microbial symbionts underlies plant adaptation to other environmental gradients.

In this paper we review the influence of various soil factors on the legume–Rhizobium symbiotic relationship. Abiotic factors such as extremes in soil pH (highly acidic or alkaline soils), salinity, tillage, high soil temperature and chemical residues, all of which can occur in crop and pasture systems in southern Australia, generally reduce populations of Rhizobium in the soil. Naturally occurring Rhizobium populations, although often found in high numbers, are generally poor in their ability to fix nitrogen and can compete strongly with introduced Rhizobium inoculant. The introduction of new legume genera as a continuing and essential part of change in farming systems usually requires the need to identify new and specific inoculant Rhizobium strains not found in the soil, but necessary for optimum nitrogen fixation. It is therefore necessary to characterise the specific requirements or limitations in the soil for establishing Rhizobium populations to ensure optimal nitrogen fixation following inoculation of legumes. The ability of the introduced Rhizobium to form effective nodules is rarely linked to a single soil attribute; therefore the study of rhizobial ecology requires an understanding of many soil and environmental factors. This paper reviews current knowledge of the influence of soil factors on rhizobial survival, the nodulation process, and nitrogen fixation by legumes.

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