Ectomycorrhizal Networks in the Anthropocene: From Natural Ecosystems to Urban Planning.

Trees acquire hydric and mineral soil resources through root mutualistic associations. In most boreal, temperate and Mediterranean forests, these functions are realized by a chimeric structure called ectomycorrhizae. Ectomycorrhizal (ECM) fungi are highly diversified and vary widely in their specificity toward plant hosts. Reciprocally, association patterns of ECM plants range from highly specialist to generalist. As a consequence, ECM symbiosis creates interaction networks, which also mediate plant-plant nutrient interactions among different individuals and drive plant community dynamics. Our knowledge of ECM networks essentially relies on a corpus acquired in temperate ecosystems, whereas the below-ground facets of both anthropogenic ECM forests and inter-tropical forests remain poorly investigated. Here, we successively (1) review the current knowledge of ECM networks, (2) examine the content of early literature produced in ECM cultivated forests, (3) analyze the recent progress that has been made in understanding the place of ECM networks in urban soils, and (4) provide directions for future research based on the identification of knowledge gaps. From the examined corpus of knowledge, we reach three main conclusions. First, the emergence of metabarcoding tools has propelled a resurgence of interest in applying network theory to ECM symbiosis. These methods revealed an unexpected interconnection between mutualistic plants with arbuscular mycorrhizal (AM) herbaceous plants, embedding ECM mycelia through root-endophytic interactions. This affinity of ECM fungi to bind VA and ECM plants, raises questions on the nature of the associated functions. Second, despite the central place of ECM trees in cultivated forests, little attention has been paid to these man-made landscapes and in-depth research on this topic is lacking. Third, we report a lag in applying the ECM network theory to urban soils, despite management initiatives striving to interconnect motile organisms through ecological corridors, and the highly challenging task of interconnecting fixed organisms in urban greenspaces is discussed. In particular, we observe a pauperized nature of resident ECM inoculum and a spatial conflict between belowground human pipelines and ECM networks. Finally, we identify the main directions of future research to make the needed link between the current picture of plant functioning and the understanding of belowground ECM networks.

Root anatomy helps to reconcile observed root trait syndromes in tropical tree species.

PREMISE: Studying the organization of functional traits in plant leaves and stems has revealed notable patterns linking function and form; however, evidence of similarly robust organization in root tissues remains controversial. We posit that anatomical traits in roots can provide insight on the overall organization of the root system. We hypothesized that size variation in the tissue outside the stele is related in a nonlinear fashion with functional traits associated with direct resource uptake, including a negative relationship with root architectural traits, and that similar relationships detected in tropical areas also hold true in other biomes. METHODS: We addressed our hypotheses using empirical data from 24 tropical tree species in French Guiana, including anatomical measurements in first order roots and functional trait description for the entire fine root system. In addition, we compiled a global meta-analysis of root traits for 500+ forest species across tropical, subtropical, and temperate forests. RESULTS: Our results supported the expected nonlinear relationships between cortical size and morphological traits and a negative linear trend with architectural traits. We confirmed a global negative relationship among specific root length (SRL), diameter, and tissue density, suggesting similar anatomical constraints in root systems across woody plants. However, the importance of factors varies across biomes, possibly related to the unequal phylogenetic representation across latitudes. CONCLUSIONS: Our findings imply that the rhizocentric hypothesis can be a valuable approach to understand fine root trait syndromes and the evolution of absorptive roots in vascular plants.

Linking drought-induced xylem embolism resistance to wood anatomical traits in Neotropical trees.

Drought-induced xylem embolism is considered to be one of the main factors driving mortality in woody plants worldwide. Although several structure-functional mechanisms have been tested to understand the anatomical determinants of embolism resistance, there is a need to study this topic by integrating anatomical data for many species. We combined optical, laser, and transmission electron microscopy to investigate vessel diameter, vessel grouping, and pit membrane ultrastructure for 26 tropical rainforest tree species across three major clades (magnoliids, rosiids, and asteriids). We then related these anatomical observations to previously published data on drought-induced embolism resistance, with phylogenetic analyses. Vessel diameter, vessel grouping, and pit membrane ultrastructure were all predictive of xylem embolism resistance, but with weak predictive power. While pit membrane thickness was a predictive trait when vestured pits were taken into account, the pit membrane diameter-to-thickness ratio suggests a strong importance of the deflection resistance of the pit membrane. However, phylogenetic analyses weakly support adaptive coevolution. Our results emphasize the functional significance of pit membranes for air-seeding in tropical rainforest trees, highlighting also the need to study their mechanical properties due to the link between embolism resistance and pit membrane diameter-to-thickness ratio. Finding support for adaptive coevolution also remains challenging.

Future practice of comprehensive care: Practice intentions of exiting family medicine residents in Canada.

OBJECTIVE: To describe exiting family medicine (FM) residents' reported practice intentions after completing a Triple C Competency-based Curriculum. DESIGN: The surveys were intended to capture residents' perceptions of FM, their perceptions of their competency-based training, and their intentions to practise FM. Entry (T1) and exit (T2) self-reported survey results were compared considering the influence of the curriculum change. Unmatched aggregate-level data were reviewed. The T1 survey was administered in the summer of 2012 and the T2 survey was administered in the spring of 2014. SETTING: Six Canadian FM residency programs across 4 provinces in Canada (Alberta, Saskatchewan, Ontario, and Quebec). PARTICIPANTS: Overall, 341 entering FM residents in 2012 responded to the T1 survey and 325 exiting FM residents completing their residency programs in spring 2014 responded to the T2 survey. MAIN OUTCOME MEASURES: Self-reported data on FM residents' future practice intentions related to comprehensive care, providing care across clinical domains and settings, and providing comprehensive care individually or in teams. RESULTS: A total of 341 (71.3%) residents responded to the T1 survey and a total of 325 (71.4%) residents responded to the T2 survey. Of these, 78.7% responded that they intended to provide comprehensive FM in multiple clinical settings in their future practices, with 70.8% indicating a comprehensive care practice with a special interest and 36.6% intending to provide care in a focused practice. Overall, 92.9% reported that they intended to work in group practice environments. Ninety percent reported they intended to work in interprofessional team practices. CONCLUSION: While an upward trend toward the practice of comprehensive care was demonstrated, findings also showed an increased trend toward providing care in focused practices. Further research is needed to better determine how FM residents understand the definition of comprehensive FM and its practice models. The survey provides an opportunity to explore questions related to practice intentions that could be helpful in work force planning. As the first study to compare entry and exit data from learners who have been exposed to a Triple C competency-based approach, this survey provides important baseline data for use by many.

Giving curriculum planners an edge: using entrance surveys to design family medicine education.

OBJECTIVE: To pilot a survey of family medicine residents entering residency, describing their exposure to family medicine and their perspectives related to their future intentions to practise family medicine, in order to inform curriculum planners; and to test the methodology, feasibility, and utility of delivering a longitudinal survey to multiple residency programs. DESIGN: Pilot study using surveys. SETTING: Five Canadian residency programs. PARTICIPANTS: A total of 454 first-year family medicine residents were surveyed. MAIN OUTCOME MEASURES: Residents' previous exposure to family medicine, perspectives on family medicine, and future practice intentions. RESULTS: Overall, 70% of first-year residents surveyed responded (n = 317). Although only 5 residency programs participated, respondents included graduates from each of the medical schools in Canada, as well as international medical graduates. Among respondents, 92% felt positive or strongly positive about their choice to be family physicians. Most (73%) indicated they had strong or very strong exposure to family medicine in medical school, yet more than 40% had no or minimal exposure to key clinical domains of family medicine like palliative care, home care, and care of underserved groups. Similar responses were found about residents' lack of intention to practise in these domains. CONCLUSION: Exposure to clinical domains in family medicine could influence future practice intentions. Surveys at entrance to residency can help medical school and family medicine residency planners consider important learning experiences to include in training.

Collaboration between family physicians and nurse clinicians: opinions of graduates in family medicine.

OBJECTIVE: To determine whether graduating family physicians are exposed to collaboration between family physicians and nurse clinicians during their training, as well as their opinions about shared care between doctors and nurse clinicians in the delivery of patient care. DESIGN: Anonymous online survey. SETTING: Two French-Canadian university family medicine residency programs. PARTICIPANTS: The 2010 and 2011 graduating family physicians (N = 343) from the University of Montreal and Laval University in Quebec. MAIN OUTCOME MEASURES: The extent to which nurse clinicians in graduating family physicians' training milieu were involved in preventive and curative patient care activities, and graduates' opinions about nurse clinicians sharing care with physicians. RESULTS: Of 343 graduates, 186 (54.2%) participated in the survey. Although as residents in family medicine their exposure to shared care with nurse clinicians was somewhat limited, respondents indicated that they were generally quite open to the idea of sharing care with nurse clinicians. More than 70% of respondents agreed or strongly agreed that nurse clinicians could adjust, according to protocols of clinical guidelines, the treatment of patients with diabetes, hypertension, and asthma, as well as regulate medication for pain control in terminally ill patients. By contrast, respondents were less favourable to nurse clinicians adjusting the treatment of patients with depression. More than 80% of respondents agreed or strongly agreed that nurse clinicians could initiate treatment via a medical directive for routine hormonal contraception, acne, uncomplicated cystitis, and sexually transmitted infections. Respondents' opinions on nurse clinicians initiating treatment for pharyngitis and otitis were more divided. CONCLUSION: Graduating family physicians are quite open to collaborating with nurse clinicians. Although they have observed some collaboration between physicians and nurses, there are areas of shared clinical activities in which they would benefit from further exposure and training.

Collaboration between family physicians and community pharmacists: opinions of graduates in family medicine.

OBJECTIVE: To ascertain the opinions of graduating family physicians about collaboration between family physicians and community pharmacists. DESIGN: Anonymous online survey. SETTING: Two French-Canadian university family medicine residency programs. PARTICIPANTS: The 2010 and 2011 graduating family physicians (N = 343) from the University of Montreal and Laval University in Quebec. MAIN OUTCOME MEASURES: Content of written prescriptions; frequency of and reasons for consultations with community pharmacists; and graduates' perceptions of sharing professional responsibilities with community pharmacists. RESULTS: The response rate was 54.2%. Overall, graduates were open to collaborating actively with community pharmacists. For example, at least 60% of graduates reported that it was important to write on prescriptions about any changes to patients' medication and creatinine clearance. Most graduates responded positively to sharing responsibility for the adjustment of treatment of patients with certain chronic conditions (88.3% for anticoagulation, 64.7% for hypercholesterolemia, 61.2% for hypertension, and 60.6% for diabetes) and for the initiation of treatment of minor conditions according to a collective prescription (80.6% for traveler's diarrhea, 74.1% for juvenile acne, and 73.6% for allergic rhinitis). However, such interprofessional collaboration requires that each professional group continues to adapt to its roles and responsibilities. CONCLUSION: Family medicine graduates are open to actively collaborating with community pharmacists, but they have some reservations regarding sharing certain responsibilities. As collaborative practices are changing, graduates' opinions should be documented once they are actually practising.