BC Journal of Ecosystems and Management

Rapid climate change is predicted for British Columbia’s Inland Temperate Rainforest (ITR), a globally unique ecosystem. Lichens, which may serve as effective biomonitors of ecosystem health, have been proposed for use as climate change indicators for a variety of ecosystems globally. This research presents a climate biomonitoring protocol using arboreal macrolichen communities in the inland rainforest in British Columbia. We report our initial findings of 39 lichen taxa, including a number of rare species and cyanolichens, which may be especially sensitive to climate. Comparisons of these data with future measurements will provide an indication of how the inland rainforest may be responding to climate change.

The ponderosa pine and Douglas-fir forests in the Interior of British Columbia, Canada, are facing problems such as forest in-growth mainly due to fire suppression, reducing grazing land area. This study focused on the use of thinning to reduce forest stand density and restore understorey species diversity and increase aboveground biomass productivity. Data were collected over a 4-year period. Species richness and diversity were generally lower under the canopy of ponderosa pine and Douglas-fir trees than outside the canopy. Species diversity was reduced by thinning at one site but unaffected by thinning at the other. Total understorey biomass increased up to 80% within 3 to 4 years after thinning. Depending on site and year, biomass production of one or more plant groups, such as forb, shrub, or graminoid, increased. Reduction in litter depth was observed at both sites due to the removal and/or reduction of needle sources. Variations in species composition existed among blocks and between sites, suggesting greater sampling size may be needed in future research to better capture the spatial variability. Thinning reduces stand density and thereby reduces fuel load and enhances understorey species productivity.

Ponderosa pine (Pinus ponderosa) ecosystems in British Columbia have high concentrations of biodiversity and species at risk, and numerous studies suggest frequent, low-intensity fire was a traditional disturbance pattern in this ecosystem type. Fire history was analyzed in the Trout Creek Ecological Reserve near Summerland, BC, a 75 ha parcel in the PPxh1 biogeoclimatic variant.The area’s fire history spans from 1715 to 1952, with a mean area fire interval of 18 years. Fire management options are reviewed.

We examined the development of understorey forage plant communities in relation to tree density in an experimental ponderosa pine (Pinus ponderosa) stand. We used a 45-year-old ponderosa pine spacing trial near Westwold, British Columbia, Canada, with five spacing treatments (1.22, 2.44, 3.66, 4.88, and 6.10 m) to sample understorey biomass and diversity, with a focus on pinegrass (Calamagrostis rubescens) and rough fescue (Festuca campestris)—two regionally important forage grasses. We predicted that there would be a positive correlation between tree spacing and understorey biomass and a compositional shift from pinegrass to rough fescue under increased tree spacing. We found that rough fescue, the preferred forage species, grew only under tree spacings equal to or greater than 3.66 m, with the greatest biomass at 4.88 and 6.10 m spacings, whereas pinegrass was equally abundant under all spacings. We believe that silvopasture principles could be applied to similar ponderosa pine stands to optimize and maintain both timber and forage productivity.

Emerging research has highlighted the significance of ancient western redcedar (Thuja plicata) stands within the upper Fraser River watershed as examples of rare forest types within British Columbia’s inland temperate rainforest (ITR). These stands represent a globally significant repository of canopy lichen biodiversity. Ancient redcedar stands were historically found in greatest abundance in wet “toe-slope” topographic positions, where mountain slopes flatten out as they reach the valley bottom. Abundant groundwater runoff and wet soils in these topographic positions provided protection from fires and sustained trees during dry summer periods. However, the placement of road and rail corridors in these same topographic positions has facilitated the logging of many ancient redcedar stands. The result has been the widespread loss of ancient cedars, which today account for only 3.7% of the 130 571 ha ICHvk2 biogeoclimatic zone east of Prince George. Of the remaining ancient cedar stands found in the ICHvk2 less than 2% (approx. 100 ha) are currently protected within BC provincial parks. Here we outline three scenarios that would increase the proportion of this ecosystem within BC parks and would support landscape-level planning objectives for the upper Fraser River watershed. We suggest that the cultural and biological values represented by these proposed areas would meet criteria for nomination as a UNESCO World Heritage or Biosphere Reserve site, ultimately resulting in widespread positive benefits for diversification of the regional economy, by building on a regional tourist attraction that has already developed at the site of the Ancient Forest Trail.

This research report summarizes findings of an electronic survey designed by FORREX to document the information needs of British Columbia natural resource management professionals in the area of silvicultural systems and stand management techniques, including their ability to use this knowledge to manage for different values on the landscape and the reasons why certain sources of information were not used. Conducted from September to October 2010, the survey was emailed to 561 key silviculture practitioners and researchers in British Columbia. A total of 107 recipients (slightly over 20%) responded to the survey.

The main knowledge gaps identified by survey respondents were related to growth and yield, economic rates of return, treatment response, and effects of treatments on values such as biodiversity, wildlife habitat, and hydrology. Other information needs identified included potential impacts of climate change on forest health, forest fire frequency and severity; and production of biofuels or carbon sequestration, and trade-offs associated with managing for these new products.

These survey results will help extension providers improve future extension programming. They will also prove useful in developing government and academic silviculture research programs and allocating funds for these programs. Survey results related to implementation barriers will also aid government policy-makers.

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Diffuse and spotted knapweed (Centaurea diffusa Lam and C. stoebe L.) are two closely related invasives found in many parts of British Columbia’s Southern Interior, causing substantial economic losses in rangelands. Beginning in 1970, the provincial government initiated a long-term biological control effort against the knapweeds, introducing 10 different insect agents from 1970 to 1987. In an effort to evaluate the efficacy of the program, archival (1983–2008) data was amassed from 19 vegetation monitoring sites that contained knapweed. In 2010, these sites were relocated and re-monitored and cover values were analyzed. Diffuse knapweed showed significant declines at 14 of 15 sites; spotted knapweed declined at three of four sites. Possible alternative explanations for the decline are discussed. Evidence strongly points to a suite of biocontrol agents (seed feeders and root feeders) as the primary drivers of knapweed decline in British Columbia’s Southern Interior.

This literature review summarizes the state of current information on the extraction, synthesis, properties, and potential uses of juglone, a natural product produced by the walnut tree (Juglandacea). Juglone (5-hydroxy-1,4-naphthoquinone) is known primarily for its allelopathic effect against certain plants and toxicity towards marine organisms. It has a wide variety of potential uses in medicine, and as a biocide for organic farming and pest control. This summary also provides historical uses of juglone and the walnut tree, a brief background on the biosynthesis and mode of toxicity of juglone. We further go on to recommend and outline the most common methodologies for extraction of the compound in the academic and small industrial setting.