Shannon M. Berch

A manual of concise descriptions of North American ectomycorrhizae

The CDE manual had its genesis in a workshop on describing ectomycorrhizae at the 9th North American Conference on Mycorrhizae in Guelph, Ontario, in 1993. Following the workshop, a poll by D.M. Durall found extensive international opinion supporting the development of a concise, standard set of ectomycorrhizal characters, and a standard system for storing ectomycorrhizal descriptions. At a May 1995 workshop at Mesachie Lake, B.C., researchers from western North America began to develop an illustrated manual of morphological and molecular descriptions. It was designed to grow by contributions from various researchers and to have a format which is affordable and easy to use in the lab. The first edition and folios 1 and 2 were published in 1996. A third folio, of five descriptions, was published in 1997. Over the next several years, the editors plan to publish five more folios, to reach a total of 40 descriptions. Each description includes a photographic plate of morphology (dissection microscope) presented in colour in the manual, a black and white plate of anatomy (compound microscope), and a two-page written description (see sample description). To date, 15 ectomycorrhizae of mature trees of Douglas-fir, western hemlock and Engelmann spruce have been described by researchers in four laboratories in western North America.

Organic nitrogen use by salal ericoid mycorrhizal fungi from northern Vancouver Island and impacts on growth in vitro of Gaultheria shallon

Abstract Salal (Gaultheria shallon) recovers quickly from rhizomes after clear-cut timber harvesting and dominates clearcuts of Tsuga heterophylla and Thuja plicata forests. Thus it contributes to considerable problems in regeneration of these sites in coastal British Columbia, Canada. Based on what is known about other ericaceous plants, we speculated that mycorrhizal fungi of salal play a vital role in the growth and dominance of salal by providing access to organic nitrogen. In this study, the ability of four species of fungi isolated from salal to use different forms of organic nitrogen was tested in pure culture and in association with salal. The organic forms of nitrogen applied were glutamine (an amino acid), glutathione (a peptide), and bovine serum albumin (BSA, a protein). The fungi tested were Oidiodendron maius, Acremonium strictum, and two nonsporulating fungi. Inoculated plants always grew better than noninoculated plants regardless of nitrogen source. Glutamine was used as readily as ammonium nitrogen by all four fungi and the mycorrhizal plants of salal colonized by those fungi. There was considerable variation between fungus species or the plants inoculated with those fungi in using glutathione and BSA. Salal inoculated with O. maius grew better on glutathione than BSA, while A. strictum and unknown 1 produced significantly greater yields of salal on BSA. Colonization rates of salal by all four fungi was higher on glutathione or BSA than on ammonium or glutamine.

Criteria and guidance considerations for sustainable tree stump harvesting in British Columbia.

Abstract Stump extraction for forest health has been carried out operationally in British Columbia (BC) for many years. Emerging bioenergy opportunities plus the anticipated need for more fibre because of reductions in timber supply may increase interest in stump harvesting, but there are numerous environmental, economic and policy barriers that must be overcome first before industrial-scale stump harvesting can be seriously considered in BC. The potential for a future change in practice provides an opportunity to learn from the existing literature and identify knowledge gaps. In this article we review the available literature on stump harvesting from the European Union within the context of BCs forests, economy, biodiversity, environment and policies. We provide recommendations on how the government of BC could move forward if they decide to enable stump harvesting for fibre and bioenergy, including assessment of net economic and carbon benefits and environmental effects, improvements in inventory and the scientific knowledge base needed to support policy and guidance, and investigation of operational enhancements.

Effects of growth medium, nutrients, water, and aeration on mycorrhization and biomass allocation of greenhouse-grown interior Douglas-fir seedlings

Commercial nursery practices usually fail to promote mycorrhization of interior Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco var. glauca (Beissn.) Franco] seedlings in British Columbia, which may account for their poor performance following planting in the field. We tested the effects of four nursery cultivation factors (nitrogen fertilization, phosphorus fertilization, watering, and soil aeration) and field soil addition on mycorrhization, survival, growth, and biomass allocation of interior Douglas-fir seedlings in a series of greenhouse experiments. Where field soil was added to the growing medium, mycorrhization and root/shoot ratios were maximized at lower levels of mineral nutrient application and aeration. Where field soil was not added, mycorrhization was negligible across all fertilization and aeration treatments, but root/shoot ratio was maximized at lower levels of mineral nutrients and the highest level of aeration. Regardless of whether field soil was added, intermediate levels of soil water resulted in the best mycorrhizal colonization and root/shoot ratios. However, field soil addition reduced seedling mortality at the two lowest water levels. A cluster analysis placed ectomycorrhizal morphotypes into three groups (Mycelium radicis-atrovirens Melin, Wilcoxina, and mixed) based on their treatment response, with all but two morphotypes in the mixed group whose abundance was maximized under conditions common to advanced seedling establishment. For maximal mycorrhization and root development of interior Douglas-fir seedlings, nurseries should minimize addition of nitrogen and phosphorus nutrients, maximize aeration, provide water at moderate rates, and, where possible, add small amounts of field soil to the growing medium.

Truffle diversity (Tuber, Tuberaceae) in British Columbia

To improve baseline data for the developing truffle industry in British Columbia, we compiled existing Tuber species sequences from published and unpublished studies and generated new ITS sequences for truffles belonging to Tuber collected in the province. In doing so, we obtained evidence that 13 species of Tuber occur in the province, including six introduced and seven native species, two of which are putative undescribed species. Of the native species, the Tuber anniae species complex is widely distributed in the province while Tuber beyerlei appears to be much more restricted in distribution. Four of the introduced species have commercial value (Tuber melanosporum, Tuber aestivum, Tuber brumale, and Tuber borchii) as do two of the native species (Tuber gibbosum and Tuber oregonense). Focused sampling on likely tree hosts, both hardwood and Pinaceae species, as well as in currently unexplored parts of the province seems likely to expand our knowledge of the diversity and distribution of Tuber species in British Columbia.

Biogeography and organic matter removal shape long-term effects of timber harvesting on forest soil microbial communities

The growing demand for renewable, carbon-neutral materials and energy is leading to intensified forest land-use. The long-term ecological challenges associated with maintaining soil fertility in managed forests are not yet known, in part due to the complexity of soil microbial communities and the heterogeneity of forest soils. This study determined the long-term effects of timber harvesting, accompanied by varied organic matter (OM) removal, on bacterial and fungal soil populations in 11- to 17-year-old reforested coniferous plantations at 18 sites across North America. Analysis of highly replicated 16 S rRNA gene and ITS region pyrotag libraries and shotgun metagenomes demonstrated consistent changes in microbial communities in harvested plots that included the expansion of desiccation- and heat-tolerant organisms and decline in diversity of ectomycorrhizal fungi. However, the majority of taxa, including the most abundant and cosmopolitan groups, were unaffected by harvesting. Shifts in microbial populations that corresponded to increased temperature and soil dryness were moderated by OM retention, which also selected for sub-populations of fungal decomposers. Biogeographical differences in the distribution of taxa as well as local edaphic and environmental conditions produced substantial variation in the effects of harvesting. This extensive molecular-based investigation of forest soil advances our understanding of forest disturbance and lays the foundation for monitoring long-term impacts of timber harvesting.

Improved Soil Mapping in British Columbia, Canada, with Legacy Soil Data and Random Forest

The need for improved soil inventory information in the province of British Columbia (BC), Canada, was addressed using a random forest (RF) classifier that was informed using legacy soil data. RF models were prepared for 110 ecodistrict subdivisions of BC, and predictions were subsequently assembled into a final soil parent material map mosaic covering the entire province. The ecodistricts are part of a framework for ecosystem classification in BC and in Canada, and delineate areas with relatively homogeneous biophysical and climatic conditions. Training areas for predicting soil parent materials were identified using single-component polygons from legacy terrain, soil, and ecosystem maps. For parent material mapping, we intersected training points amalgamated from all legacy surveys with a suite of 18 topographic covariates derived from a 100-m digital elevation model (DEM). For each ecodistrict, two versions of the resulting training dataset were submitted to the RF classifier. A ‘balanced’ dataset contained equal numbers of training data points for all parent material classes representing all legacy data derived from single-component polygons. A ‘constrained’ dataset was also derived where conditions were imposed on selected topographic attributes of the training points to reflect known geomorphic processes and to ensure consistent mapping criteria were applied across multiple legacy soil survey projects. RF predictions of soil parent material resulted in 100-m gridded class maps for BC that incorporate expert knowledge extracted from legacy soil inventories.

Provincial Government Standards, Criteria, and Indicators for Sustainable Harvest of Forest Biomass in British Columbia: Soil and Biodiversity

Abstract Sustainable forest management (SFM) is a cornerstone of forest management, whether the resulting forest products are destined for the manufacturing sector or for the emerging bioenergy feedstock market. In British Columbia, research on the environmental effects of forest management has generated scientific knowledge that has informed two linked areas of government responsibility: a comprehensive set of science-based regulations and policies to ensure soil and water conservation, and a monitoring program to ensure the effectiveness of these regulations and policies. An increasing amount of biomass is being harvested from British Columbia’s forests as a feedstock for bioenergy, and these removals have the potential to incrementally increase machine traffic and organic matter removals from forest sites, compared to harvesting operations focused solely on roundwood for timber or pulp. To the extent that existing standards support SFM, they may be sufficient for ensuring that biomass harvesting is also sustainable. Regardless of the new challenges created by intensive harvesting practices, the principles of soil and biodiversity conservation remain the same. The current framework for BC’s SFM policy is reviewed to examine whether it addresses the major sustainability issues that are likely to arise in the province if intensive biomass harvesting becomes more prevalent. We conclude that intensification of biomass removals will require us to keep focused on stand and landscape sensitivity to coarse woody debris removals and biodiversity requirements, nutrient removals, and cumulative soil disturbance.

Monitoring soil disturbance on salvaged areas within the mountain pine beetle infestation using digital imagery

Abstract There is a concern that the accelerated timber harvest in the mountain pine beetle epidemic area of British Columbia (BC) could compromise long-term forest productivity if soils are unduly disturbed. Consequently, the Ministry of Forests, Lands and Natural Resources Operations (MFLNRO) developed a protocol using ground- and image-based methods to assess the status of the forest soil resource in part of the BC Forest and Range Evaluation Program (FREP). Although this protocol uses high-resolution aerial imagery, the MFLNRO is also collecting beetle imagery at a smaller scale for detecting and monitoring. For this evaluation, we use a combination of ground- and imagery-based assessments as developed for FREP within the BC Interior Plateau. We determined that low-resolution data are useful and are sufficient for detecting and measuring the extent of roads and landings. Areas occupied by landslides, erosion, drainage diversion, inordinate disturbance, or roadside work areas can be captured on remote-sensed images with spatial resolution greater than 2.5 m. However, based on this review and previous work, aerial photographs in 10-cm pixel size are best suited to reveal less evident harvesting-related soil disturbance.