The Interactive Role of Climatic Transfer Distance and Overstory Retention on Douglas-Fir Seedling Survival and Height Growth in Interior British Columbia.

The future climatic niche of interior Douglas-fir (Pseudotsuga menziesii var. glauca [Mirb.] Franco) is expected to have little spatial overlap with its current range due to climate change.

Soil microbial legacies influence plant survival and growth in mine reclamation.

Plants alter soil biological communities, generating ecosystem legacies that affect the performance of successive plants, influencing plant community assembly and successional trajectories. Yet, our understanding of how microbe-mediated soil legacies influence plant establishment is limited for primary successional systems and forest ecosystems, particularly for ectomycorrhizal plants. In a two-phase greenhouse experiment using primary successional mine reclamation materials with or without forest soil additions, we conditioned soil with an early successional shrub with low mycorrhizal dependence (willow, ) and a later-successional ectomycorrhizal conifer (spruce,  × ).

Stump removal and tree species composition promote a bacterial microbiome that may be beneficial in the suppression of root disease.

Stumping is an effective forest management practice for reducing the incidence of Armillaria root-rot in regenerating trees, but its impact on the soil bacterial community has not been ascertained. This study investigated the long-term impact of stumping and tree species composition in a 48-year-old trial at Skimikin, British Columbia, on the relative abundance, diversity and taxonomic composition of bacterial communities by sequencing the v4 region of 16S rRNA gene using the Illumina Miseq platform. A total of 108 samples were collected from the forest floor (fermented (F) and humus (H) layers) and mineral soil (A (0-10 cm) and B (10-20 cm) horizons) of 36 plots (half each stumped or unstumped) that were planted with pure stands and admixtures of Douglas-fir, western redcedar and paper birch.

Resilience of Rhizopogon-Douglas-fir mycorrhizal networks 25 years after selective logging.

Rhizopogon vesiculosus and R. vinicolor are sister fungal species; they form ectomycorrhizas exclusively with Douglas-fir roots, and they are important in forming relatively large mycorrhizal networks, but they may be vulnerable to disturbance caused by logging practices. The main objective was to determine the resilience of mycorrhizal networks 25 years following removal of large hub trees.

Long-term effects of stump removal and tree species composition on the diversity and structure of soil fungal communities.

Stump removal is a common forest management practice used to reduce the mortality of trees affected by the fungal pathogen-mediated root disease, Armillaria root rot, but the impact of stumping on soil fungal community structure is not well understood. This study analyzed the long-term impact of stumping and tree species composition on the abundance, diversity and taxonomic composition of soil fungal communities using internal transcribed spacer (ITS) marker-based DNA metabarcoding in a 48-year-old trial at Skimikin, British Columbia. A total of 108 samples were collected from FH (fermented and humus layers), and soil mineral horizons (A and B) from stumped and unstumped plots of six tree species treatments (pure stands and admixtures of Douglas-fir, western red-cedar and paper birch).

The effects of ectomycorrhizal fungal networks on seedling establishment are contingent on species and severity of overstorey mortality.

For tree seedlings in boreal forests, ectomycorrhizal (EM) fungal networks may promote, while root competition may impede establishment. Thus, disruption to EM fungal networks may decrease seedling establishment owing to the loss of positive interactions among neighbors. Widespread tree mortality can disrupt EM networks, but it is not clear whether seedling establishment will be limited by the loss of positive interactions or increased by the loss of negative interactions with surrounding roots.

Density-dependent processes fluctuate over 50 years in an ecotone forest.

Spatial patterns can inform us of forest recruitment, mortality, and tree interactions through time and disturbance. Specifically, successional trajectories of self-thinning and heterospecific negative density dependence can be interpreted from the spatial arrangement of forest stems. We conducted a 50-year spatial analysis of a forest undergoing succession at the ecotone of the southwestern Canadian boreal forest.

Intraspecific Fine-Root Trait-Environment Relationships across Interior Douglas-Fir Forests of Western Canada.

Variation in resource acquisition strategies enables plants to adapt to different environments and may partly determine their responses to climate change. However, little is known about how belowground plant traits vary across climate and soil gradients. Focusing on interior Douglas-fir ( var.

Shifts in Ectomycorrhizal Fungal Communities and Exploration Types Relate to the Environment and Fine-Root Traits Across Interior Douglas-Fir Forests of Western Canada.

Large-scale studies that examine the responses of ectomycorrhizal fungi across biogeographic gradients are necessary to assess their role in mediating current and predicted future alterations in forest ecosystem processes. We assessed the extent of environmental filtering on interior Douglas-fir ( var. (Beissn.

Below-ground biotic interactions moderated the postglacial range dynamics of trees.

Tree range shifts during geohistorical global change events provide a useful real-world model for how future changes in forest biomes may proceed. In North America, during the last deglaciation, the distributions of tree taxa varied significantly as regards the rate and direction of their responses for reasons that remain unclear. Local-scale processes such as establishment, growth, and resilience to environmental stress ultimately influence range dynamics.

Twenty years of ecosystem response after clearcutting and slashburning in conifer forests of central British Columbia, Canada.

Forests are being clearcut over extensive areas of western North America, but plant community response to harvesting and slashburning under varying climatic conditions in central British Columbia, Canada is still largely unknown. Evaluation of resilience is hampered by the short history of logging, lack of long-term experiments and methodological limitations. To test the effect of clearcut logging, prescribed burning and reforestation on forest resilience, we recorded vascular plant cover repeatedly after treatment between 1981 and 2008 in 16 permanent research installations in three biogeoclimatic zones: Engelmann Spruce-Subalpine Fir, Interior Cedar-Hemlock and Sub-Boreal Spruce.

Transfer of C between paired Douglas-fir seedlings reveals plant kinship effects and uptake of exudates by ectomycorrhizas.

Processes governing the fixation, partitioning, and mineralization of carbon in soils are under increasing scrutiny as we develop a more comprehensive understanding of global carbon cycling. Here we examined fixation by Douglas-fir seedlings and transfer to associated ectomycorrhizal fungi, soil microbes, and full-sibling or nonsibling neighbouring seedlings. Stable isotope probing with 99% C-CO was applied to trace C-labelled photosynthate throughout plants, fungi, and soil microbes in an experiment designed to assess the effect of relatedness on C transfer between plant pairs.

Change in soil fungal community structure driven by a decline in ectomycorrhizal fungi following a mountain pine beetle (Dendroctonus ponderosae) outbreak.

Western North American landscapes are rapidly being transformed by forest die-off caused by mountain pine beetle (Dendroctonus ponderosae), with implications for plant and soil communities. The mechanisms that drive changes in soil community structure, particularly for the highly prevalent ectomycorrhizal fungi in pine forests, are complex and intertwined. Critical to enhancing understanding will be disentangling the relative importance of host tree mortality from changes in soil chemistry following tree death.

MycoDB, a global database of plant response to mycorrhizal fungi.

Plants form belowground associations with mycorrhizal fungi in one of the most common symbioses on Earth. However, few large-scale generalizations exist for the structure and function of mycorrhizal symbioses, as the nature of this relationship varies from mutualistic to parasitic and is largely context-dependent. We announce the public release of MycoDB, a database of 4,010 studies (from 438 unique publications) to aid in multi-factor meta-analyses elucidating the ecological and evolutionary context in which mycorrhizal fungi alter plant productivity.

Ectomycorrhizal fungi mediate indirect effects of a bark beetle outbreak on secondary chemistry and establishment of pine seedlings.

Dendroctonus ponderosae has killed millions of Pinus contorta in western North America with subsequent effects on stand conditions, including changes in light intensity, needle deposition, and the composition of fungal community mutualists, namely ectomycorrhizal fungi. It is unknown whether these changes in stand conditions will have cascading consequences for the next generation of pine seedlings. To test for transgenerational cascades on pine seedlings, we tested the effects of fungal inoculum origin (beetle-killed or undisturbed stands), light intensity and litter (origin and presence) on seedling secondary chemistry and growth in a glasshouse.

Inter-plant communication through mycorrhizal networks mediates complex adaptive behaviour in plant communities.

Adaptive behaviour of plants, including rapid changes in physiology, gene regulation and defence response, can be altered when linked to neighbouring plants by a mycorrhizal network (MN). Mechanisms underlying the behavioural changes include mycorrhizal fungal colonization by the MN or interplant communication via transfer of nutrients, defence signals or allelochemicals. We focus this review on our new findings in ectomycorrhizal ecosystems, and also review recent advances in arbuscular mycorrhizal systems.

Rapid Increases in forest understory diversity and productivity following a mountain pine beetle (Dendroctonus ponderosae) outbreak in pine forests.

The current unprecedented outbreak of mountain pine beetle (Dendroctonus ponderosae) in lodgepole pine (Pinus contorta) forests of western Canada has resulted in a landscape consisting of a mosaic of forest stands at different stages of mortality. Within forest stands, understory communities are the reservoir of the majority of plant species diversity and influence the composition of future forests in response to disturbance. Although changes to stand composition following beetle outbreaks are well documented, information on immediate responses of forest understory plant communities is limited.

Local adaptation in migrated interior Douglas-fir seedlings is mediated by ectomycorrhizas and other soil factors.

Separating edaphic impacts on tree distributions from those of climate and geography is notoriously difficult. Aboveground and belowground factors play important roles, and determining their relative contribution to tree success will greatly assist in refining predictive models and forestry strategies in a changing climate. In a common glasshouse, seedlings of interior Douglas-fir (Pseudotsuga menziesii var.

Defoliation of interior Douglas-fir elicits carbon transfer and stress signalling to ponderosa pine neighbors through ectomycorrhizal networks.

Extensive regions of interior Douglas-fir (Pseudotsuga menziesii var. glauca, IDF) forests in North America are being damaged by drought and western spruce budworm (Choristoneura occidentalis). This damage is resulting from warmer and drier summers associated with climate change.

Decline of ectomycorrhizal fungi following a mountain pine beetle epidemic.

Forest die-off caused by mountain pine beetle (MPB; Dendroctonus ponderosa) is rapidly transforming western North American landscapes. The rapid and widespread death of lodgepole pine (Pinus contorta) will likely have cascading effects on biodiversity. One group particularly prone to such declines associated with MPB are ectomycorrhizal fungi, symbiotic organisms that can depend on pine for their survival, and are critical for stand regeneration.

Ectomycorrhizal fungal community assembly on regenerating Douglas-fir after wildfire and clearcut harvesting.

Wildfire severity in forests is projected to increase with warming and drying conditions associated with climate change. Our objective was to determine the impact of wildfire and clearcutting severity on the ectomycorrhizal fungal (EMF) community of Douglas-fir seedlings in the dry forests of interior British Columbia, Canada. We located our study within and surrounding the area of the McLure fire (August 2003).

Vertical partitioning between sister species of Rhizopogon fungi on mesic and xeric sites in an interior Douglas-fir forest.

Understanding ectomycorrhizal fungal (EMF) community structure is limited by a lack of taxonomic resolution and autecological information. Rhizopogon vesiculosus and Rhizopogon vinicolor (Basidiomycota) are morphologically and genetically related species. They are dominant members of interior Douglas-fir (Pseudotsuga menziesii var.

Long-term warming alters the composition of Arctic soil microbial communities.

Despite the importance of Arctic soils in the global carbon cycle, we know very little of the impacts of warming on the soil microbial communities that drive carbon and nutrient cycling in these ecosystems. Over a 2-year period, we monitored the structure of soil fungal and bacterial communities in organic and mineral soil horizons in plots warmed by greenhouses for 18 years and in control plots. We found that microbial communities were stable over time but strongly structured by warming.