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Numerous recent studies have argued that moisture limitation is leading to growth declines and mortality of black spruce (Picea mariana) and white spruce (Picea glauca) in the North American boreal forest. A parallel line of research suggests that increasingly common severe wildfires are altering successional pathways and leading to long‐term replacement of spruce forests with those dominated by paper birch (Betula papyrifera, Betula neoalaskana) and trembling aspen (Populus tremuloides). When both conifers and deciduous trees establish after fire, this biome shift hypothesis implicitly assumes that deciduous species will outcompete the conifers, owing to their more rapid vertical growth and because they might be less sensitive to warm and dry conditions.We established a research site in a white spruce‐paper birch forest on an east‐facing slope in interior Alaska and tested the hypothesis that Alaska paper birch are better adapted to warm and dry conditions than white spruce. Over 6 years (2013–2018), we made hourly measurements of microclimate and xylem sap flux of both species. We also collected increment cores and conducted climate‐growth analyses for both species.During our 6‐year study, growing seasons with low volumetric soil water content (SWC) were those that followed shallow winter snowpacks and had limited summer rainfall, not necessarily those with warm air temperature. Both species were sensitive to moisture limitation. The tree‐ring data revealed significant positive effects of cumulative water year precipitation on radial growth, with a steeper slope for paper birch than for white spruce. Radial growth of both species was also positively related to mean water year air temperature. Sap flux density declined progressively for white spruce over the range of observed SWC and abruptly for paper birch when SWC fell below ~15%.Synthesis. Our results show that, while paper birch might be less sensitive to mild drought than white spruce, it may be more sensitive to severe drought, raising questions about the ability of paper birch to outcompete co‐occurring white spruce in a drier climate. [ABSTRACT FROM AUTHOR]

Many nature‐based solutions (NBS), including urban greenspaces, urban agriculture and agroforestry, depend upon animal‐pollinated plants to sequester carbon or to provide other ecosystem services. Thus, long‐term success of these solutions also depends upon resilient pollinator communities. Despite their importance to functioning communities, a literature search revealed that 0%–3% of papers on NBS and related topics considered pollinators or pollination. Pollinators were more likely to be considered in the subgroup of papers on NBS related to agricultural production, where 12.5% considered pollination. Conservation of species interactions is essential to conservation of biodiversity and the sustained benefits of NBS. By applying our understanding of the ecology of plant‐pollinator mutualisms to the implementation of NBS, we can promote their functioning under future climatic conditions. In particular, we point to the need to identify keystone plants and pollinators, those species that contribute most to biodiversity maintenance, community stability and ecosystem function, and to leverage these species and their interactions in NBS and conservation efforts. We further advocate for the use of phylogenetic trait‐based analyses to understand the characteristics associated with keystoneness. Synthesis: Resilience of pollination services rests upon the responses of keystone species and their partners, and the likelihood that they continue to express traits that confer mutual benefit under future climates. By understanding the traits of species of outsized importance to their communities, we gain insight into the mechanisms underlying the resilience of pollination services and the NBS that rely on those services in a changing world. [ABSTRACT FROM AUTHOR]

1. Boreal forest soils contain large stocks of soil carbon (C) that may be sensitive to changes in climate and disturbance. Destablization of boreal forest soil C through changes in C inputs, belowground C pools and/or wildfire could feedback to accelerate rising atmospheric CO2 concentration. Additionally, increasing frequency of severe fires may be changing the dominant forest types and reshaping aboveground C stocks. 2. Although controls on ecosystem C pools have received considerable attention, many studies have been limited to locations near the road system, leading to uncertainty in current and future C stocks across boreal Alaska. Here, we leveraged 545 randomly selected and spatially balanced Forest Inventory and Analysis (FIA) plots across ~13.5 million hectares in interior Alaska to examine the factors governing soil and live tree C pools. 3. Forest type mediated the effects of mean summer air temperature and the probability of near-surface permafrost on soil C. Meanwhile, forest type, stand age and aspect were the primary drivers of live tree C. Overall, plots with a known history of wildfire during the past 70 years did not have significantly different soil C stocks than plots without a known history of fire, likely due to the historical predominance of low severity fires. 4. Where wildfire likely initiated a transition to deciduous trees (19% of plots), live tree and soil C pools were reduced by 16% and 20%, respectively. Ecosystem C likely recovered over time, as maturing deciduous stands rapidly gained C in live trees. Deciduous stands without a known fire had comparatively very large live tree C stocks, suggesting a significant change in the distribution of ecosystem C following severe fire. 5. Synthesis. Our results highlight the nuanced interactions among wildfire, landscape position and forest type that will play important roles in shaping future boreal ecosystem C stocks. [ABSTRACT FROM AUTHOR]

(1) The Betula papyrifera (paper birch) forest of the wilderness of south eastern Labrador is described. (2) B. papyrifera forests range in size from less than 1 ha to several km², display sharp borders with the adjoining conifer forests and are restricted to steep slopes that have burned in the previous 110 years. (3) Floristically, the B. papyrifera community is distinguished from conifer forests by the presence of fourteen differential species, by the scarcity of terrestrial cryptogams and by the development of a diverse understorey of vascular plants. (4) Three minimum conditions are necessary for B. papyrifera forest development: (i) moist and well drained soils, (ii) a nearby seed source, and (iii) an open site. (5) The nearly exclusive restriction of B. papyrifera forest to areas that have burned in the last 110 years indicates that the open site conditions necessary for stand initiation are largely created by lightning fires. (6) Age structure analysis demonstrates that, following fire, regeneration by B. papyrifera is rapid and results in the formation of an even aged overstory. Gradual invasion of canopy openings by Picea mariana and Abies balsamea results in the progressive conversion to conifer forest. (7) Fire maintains B. papyrifera and other early post-fire communities in a mosaic pattern and increases regional vegetation diversity. The pattern is not random, but is controlled by species autecologies, the pattern of fires and physiography. The vegetation of south eastern Labrador is in a state of dynamic equilibrium. [ABSTRACT FROM AUTHOR]

This article discusses the transition phase of the "Journal of Ecology." With the implementation of Web-based submission and review and the hard work being put in by authors, referees and associate editors, the year 2003 saw a lot of changes. Submissions were over 10% higher than in 2002, enabling the journal, to an even greater extent than in the past, to accept only the best papers. The journal's aim is to publish excellent work in any aspect of plant ecology and paper hopes that readers will appreciate seeing new topics being covered, as well as those that have traditionally appeared in "Journal of Ecology."

The article presents abstracts on algal ecology which include the systematic study of the forms encountered in diverse terrestrial habitats in Denmark, the morphology and ecology of an extreme terrestrial form of Zygnema ericetorum, and plankton from several pools in the Kidderminster district.

The article offers a reaction to the paper "Some observations on the relations between H-ion concentration of the soil and plant succession," by Emmett and Ashby wherein these two authors proposed a sampling method for segregating the frequency distribution of a species over an area from that of soil acidity over the same location. It is posed that the statistical test employed by these authors in the analysis of their data was incorrect and consequently the hypothesis that the two species Pteridium aquilinum (L.) Kuhn and Vaccinium myrtillus L. transpired with the same frequency at every pH value within their pH ranges was affirmed when in reality there is observable evidence to the contrary.

An introduction is presented in which the editors move forward with new initiatives to celebrate the journal's centenary, explain the different metrics of the journal impact, and clarify the review process and submission of articles.

The article outlines recommendations relating to the accurate use of the taxonomic aspects of ecological investigations, which are approved by the Council of the British Ecological Society. The Council hopes that the Flora and Edition which has been used in determining the taxonomic concepts and nomenclature followed in the paper should be stated by contributors to the "Journal of Ecology." The Council also encourages the preservation of material of all the taxonomic units, from each plant community described. Finally, the Council calls on contributors to state the herbarium or herbaria in which his specimens have been deposited.

1. This study assessed the effects of resource (i.e. nutrients) and non-resource (i.e. interference for space) competition from fine roots of competing grasses on the growth, morphology and architecture of fine roots of four tree species of varying successional status: Populus deltoides ¥ P. balsamifera (a hybrid), Betula papyrifera, Acer saccharum and Fraxinus americana. We tested the general hypothesis that tree fine-roots are affected by both below-ground resource and non-resource competition from non-self plants, and the more specific hypothesis that this effect is stronger in early-successional tree species. 2. The experiment was conducted in split-containers where half of the roots of tree seedlings experienced either below-ground resource competition or non-resource competition, or both, by grasses while the other half experienced no competition. 3. The late-successional tree species A. saccharum and F. americana were mostly affected by resource competition, whereas the early-successional P. deltoides¥ balsamifera and B. papyrifera were strongly affected by both resource and non-resource competition. Non-resource competition reduced fine-root growth, root branching over root length (a measure of root architecture) and specific root length (a measure of root morphology) of both early-successional species. 4. Synthesis. This study suggests that early-successional tree species have been selected for root avoidance or segregation and late-successional tree species for root tolerance of competition as mechanisms to improve below-ground resource uptake in their particular environments. It also contradicts recent studies showing perennial and annual grasses tend to overproduce roots in the presence of non-self conspecific plants. Woody plants, required to grow and develop for long periods in the presence of other plants, may react differently to non-self root competition than perennial or annual grasses that have much shorter lives. [ABSTRACT FROM AUTHOR]

The article reports developments on the success of the "Journal of Ecology," the official publication of the British Ecological Society in Great Britain. The Impact Factor of the "Journal of Ecology" has increased by about 26 percent between 2004 and 2005. Jian-Ming Deng has awarded the 2006 John L. Harper Young Investigator's Prize for his paper about the relationship of plant mass-density and moisture gradient that was published in the journal. Meran Owen has been appointed as managing editor for the journal.

CONCLUDING REMARKS This new paper by Fong et al. makes an exciting and relevant contribution to the emerging field of trait-based seaweed ecology, leading to new opportunities in trait-based seaweed research. In this issue, Fong et al. show how the use of categorical traits can greatly accelerate progress in the emerging field of seaweed trait-based ecology (Fong et al., [3]). Keywords: aquatic plant ecology; categorical traits; determinants of plant community diversity and structure; functional traits; Macroalgae; plant development and life-history traits; trait-based ecology EN aquatic plant ecology categorical traits determinants of plant community diversity and structure functional traits Macroalgae plant development and life-history traits trait-based ecology 1844 1847 4 09/07/23 20230901 NES 230901 In this issue, Fong et al. show how the use of categorical traits can greatly accelerate progress in seaweed trait-based ecology. [Extracted from the article]

While trait‐based approaches have been effectively leveraged by plant ecologists to advance our understanding of community responses to major global challenges, such as climate change and invasive species, the study of marine macroalgae is still mired in a functional group (FG) framework developed in the 1980s.In this paper, we used predominantly categorical data for 18 macroalgal traits that were accessible in public databases and/or the literature to explore their usefulness in a trait‐based framework for marine macroalgae. Species were clustered into emergent, data‐driven groups using a Gower dissimilarity matrix, then a k‐medoid clustering approach called partitioning around the medoids.We identified 14 emergent groups (EGs) that captured a spectrum of strategies used by different macroalgal species. However, significant 'gaps' in trait space may identify evolutionary constraints to algal adaptive strategies. Multivariate analysis showed how the 18 traits created trait space and drove the clustering. A spectrum of strategies and the influence of multiple traits imply that algal strategies are likely governed by complex multivariate, not bivariate, trade‐offs. Finally, we found that our EGs appeared to reflect multivariate trade‐offs and diverse ecological strategies more than the traditional FG model for macroalgae. We tested the usefulness of our EGs by comparing real‐world spatial distributions of species across habitats with known strong environmental filters to their area occupied in trait space. We found significant separation in trait space and divergent occupancy patterns across global distributions, attachment substrates and elevational zones. These results support the use of categorical data accessible in the literature as a useful step towards developing trait‐based ecology for marine macroalgae.Synthesis. Our findings indicate that readily accessible categorical traits produce emergent FGs that reflect environmental filtering and therefore demonstrate the power of trait‐based approaches over the current FG framework. Furthermore, we posit that categorical traits are a valuable and potentially complementary addition to a newly developing database of continuous traits because they encompass a broader, more globally accessible set of traits. [ABSTRACT FROM AUTHOR]

Common garden experiments are indoor or outdoor plantings of species or populations collected from multiple distinct geographic locations, grown together under shared conditions. These experiments examine a range of questions for theory and application using a variety of methods for analysis. The eight papers of this special feature comprise a cross section of contemporary approaches, summarized and synthesized here by what they tell us about the relationships between climate‐related trait spectra and fitness optima.Four of the eight papers are based on field experiments in prairie, desert, Mediterranean and boreal biomes. Representative of many common garden experiments, these experiments reveal consistent evidence of traits varying with population climate provenance, but evidence of a tradeoff between growth and tolerance traits or of consistent fitness optimization at home is scant, in contrast to trait theory. Two synthesis papers highlight dominant patterns of trait divergence, including for an exotic invasive species. One theoretical paper warned that unknown kinship relationships between populations can result in the misidentification of adaptive trait divergence. A third synthesis paper formulated novel and ambitious goals for common‐garden studies through including measurement of response variables at multiple levels of biological organization.The featured papers discuss multiple avenues for improving common garden studies. Genomic analysis, together with the quantification of kinship relationships, will continue to reveal the influence of environmental drivers on gene selection. Measuring a more complete set of fitness traits, especially for traits related to regeneration, will permit the development of projection models to explicitly link trait spectra, climate patterns and fitness consequences. More standardized data reporting will additionally improve abilities to synthesize findings across experiments. Testing population performance in competition with other species will produce more robust fitness comparisons between genotypes, especially for slower‐growing genotypes in higher‐resource environments. Adding gardens in and beyond climatic edge locations will furthermore strengthen the understanding of population failure and species exclusion. Finally, there is unrealized potential in adding ecosystem‐level observations to common‐garden studies that will enhance integrative analysis across scales of biological organization and scientific domains.Synthesis. With novel, creative designs, data integration and synthesis, common garden experiments will continue to advance the understanding of trait ensembles interacting with climate across scales of biological organization, provide pivotal data for global change models and guide ecological applications such as restoration of habitats for rare and climate sensitive species. [ABSTRACT FROM AUTHOR]