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  • Libary: Conservation of forests needed to protect biodiversity

    Project Staff
    A study prepared for Sierra Club BC and the Wilderness Committee by Jared Hobbs, director of J Hobbs Ecological Consulting Ltd.
    Forward
    Rare and at-risk species have always engendered empathy within our society. Perhaps it’s because the suggestion of rarity implies value but, in a biological context, there is often an additional and far more insightful consideration. Many threatened and endangered wildlife species in Canada were, in fact, once quite common; the factors that have negatively influenced their previous abundance have often been brought about by a litany of human-wrought changes to the environment. In BC, many of these changes are relatively recent or still underway. Rare and at-risk species convey a message of a dysfunctional ecosystem that needs immediate attention to arrest or reverse species’ declines; through their own demise these species are signaling that they need our help. 
    Within BC’s borders commercial forestry, agriculture, mining, urban settlement, and road-development have all left a troubling legacy on the landscape. Before European influence, the BC coastline supported a rich temperate rainforest ecosystem: rivers teemed with salmon and in the upper headwaters of the rivers that carve their way through rugged coast mountains tailed frogs were once common in clear, cool fast-flowing streams. The ancient forests that once lined the valley slopes supported many ancient-growth forest inhabitants including marbled murrelets, spotted owls, coastal giant salamanders, and grizzly bears. As you moved inland, you would have encountered a rich grassland ecosystem, with tall prairie grasses swaying in the wind along the benches of the Thompson and Fraser Rivers. Further east, along the Okanagan and Similkameen valleys, pocket-desert ecosystems once supported pygmy short-horned lizard, burrowing owls, white-tailed jackrabbits, and greater sage grouse; today these species have all been extirpated from BC, their habitat plowed under for the sake of development — in many cases simply to grow grapes for our dining pleasure. Some species, such as the western rattlesnake, American badgers, white-headed woodpecker, and bighorn sheep still maintain a tenuous and diminishing presence in the Interior of BC as they bear witness to the loss of their habitat. Moving further inland, and northwards, you would have encountered mountains and valleys that supported grizzly bear, caribou, and wood bison; today these species all have much smaller ranges in North America, and their numbers continue to dwindle. 
    This report on recovery actions provides a review of policy and policy implementation by both the federal and BC provincial governments. Specifically, the content of this report focuses on recovery management and planning, and profiles some of the inherent challenges experienced by both levels of government in the implementation of actions that have been advanced in the interest of recovery of species-at-risk.
    (2022) Species-at-risk Recovery in BC—An Audit of Federal and Provincial Actions.pdf
    David Broadland
    By Solomon Z. Dobrowski et al
    Expanding the global protected area network is critical for addressing biodiversity declines and the climate crisis. However, how climate change will affect ecosystem representation within the protected area network remains unclear. Here we use spatial climate analogs to examine potential climate-driven shifts in terrestrial ecoregions and biomes under a +2 °C warming scenario and associated implications for achieving 30% area-based protection targets. We find that roughly half of land area will experience climate conditions that correspond with different ecoregions and nearly a quarter will experience climates from a different biome. Of the area projected to remain climatically stable, 46% is currently intact (low human modification). The area required to achieve protection targets in 87% of ecoregions exceeds the area that is intact, not protected, and projected to remain climatically stable within those ecoregions. Therefore, we propose that prioritization schemes will need to explicitly consider climate-driven changes in patterns of biodiversity.
    (2021) Protected-area targets could be undermined by climate change-driven shifts in ecoregions and biomes.pdf
    Project Staff
    By Mathew G. E. Mitchell et al
    Effectively conserving ecosystem services in order to maintain human wellbeing is a global need that requires an understanding of where ecosystem services are produced by ecosystems and where people benefit from these services. However, approaches to effectively identify key locations that have the capacity to supply ecosystem services and actually contribute to meeting human demand for those services are lacking at broad spatial scales. We developed new methods that integrate measures of the capacity of ecosystems to provide services with indicators of human demand and ability to access these services. We then identified important areas for three ecosystem services currently central to protected area management in Canada—carbon storage, freshwater, and nature-based recreation—and evaluated how these hotspots align with Canada’s current protected areas and resource development tenures. We find that locations of ecosystem service capacity overlap only weakly (27–36%) with actual service providing areas (incorporating human access and demand). Overlapping hotspots of provision for multiple ecosystem services are also extremely limited across Canada; only 1.2% (∼56 000 km2) of the total ecosystem service hotspot area in Canada consists of overlap between all three ecosystem services. Canada’s current protected area network also targets service capacity to a greater degree than provision. Finally, one-half to two-thirds of current ecosystem service hotspots (54–66%) overlap with current and planned resource extraction activities. Our analysis demonstrates how to identify areas where conservation and ecosystem service management actions should be focused to more effectively target ecosystem services to ensure that critical areas for ecosystem services that directly benefit people are conserved. Further development of these methods at national scales to assess ecosystem service capacity and demand and integrate this with conventional biodiversity and conservation planning information will help ensure that both biodiversity and ecosystem services are effectively safeguarded.
    (2020) Identifying key ecosystem service providing areas to inform national-scale conservation planning.pdf
    David Broadland
    By Karen Price, Rachel Holt, and Dave Daust
    The Province has appointed a task force to investigate the state of BC’s old growth forest. The panel will report to government in April 2020.
    The old growth task force website1 shows a map of the old growth forest in BC — and says “Based on government’s working definition, old-growth forests comprise about 23% of forested areas, or about 13.2 million hectares”.
    We have written this report because old growth cannot be portrayed by a single number or map. Old forest comes in many forms.
    We have used publicly available provincial data and definitions to examine the status of different types of old forest found across the province in different ecosystems (biogeoclimatic variants) and productivity classes. These distinctions matter because while all forms of old growth have inherent value, different types provide tremendously different habitat, functional, cultural, spiritual and timber values. BC’s globally rare high productivity forests have particular value for their high biomass, structural complexity and stable carbon storage.
    Our analysis concludes the following:
    The provincial total area of old forest (~13.2 million hectares) matches our total.
    The vast majority of this forest (80%) consists of small trees:
    ›  ~5.3 million hectares have site index2 5–10m; another ~5.3 million hectares have a site index 10–15m.
    ›  Small trees characterize many of BC’s natural old forest types, including black spruce bog forests in the northeast, subalpine forests at high elevation, and low productivity western redcedar forests on the outer coast.
    ›  Large areas of this old forest type remain because the trees are too small to be worth harvesting (under today’s prices).
    In contrast, only a tiny proportion of BC’s remaining old forest (3%) supports large trees:
    › ~380,000 hectares have a site index 20–25m, and only ~35,000 hectares of old forest have a site index greater than 25m.
    › These types of forests match most people’s vision of old growth. They provide unique habitats, structures, and spiritual values associated with large trees.
    › Productive old forests are naturally rare in BC. Sites with the potential to grow very large trees cover less than 3% of the province. Old forests on these sites have dwindled considerably due to intense harvest so that only 2.7% of this 3% is currently old (see pie chart). These ecosystems are effectively the white rhino of old growth forests. They are almost extinguished and will not recover from logging.
    › Over 85% of productive forest sites have less than 30% of the amount of old expected naturally, and nearly half of these ecosystems have less than 1% of the old forest expected naturally. This current status puts biodiversity, ecological integrity and resilience at high risk today.
    A Last Stand For Biodiversity (2020).pdf
    David Broadland
    The 2019 the provincial government asked foresters Gary Merkel and Al Gorley to undertake a strategic review of the state of BC’s old-growth forests. Their report led the BC government to seek First Nations’ approval for temporary logging deferrals on 2.6 million hectares of forest that government databases have identified as old forest.
    (2020) A New Future For Old Forests-Gorley-Merkel.pdf
     
    One page of this report that is particularly relevant to the Discovery Islands Forest Conservation Project is the description of the risk to biodiversity in areas that now have low levels of old forest compared to their original state, and the list of biogeoclimatic zones where that risk is high. The list includes the three main biogeoclimatic zone variants that occur in the Discovery Islands. Below is the text from page 31 of the report:
    "Knowing how much to maintain as forest with old trees is guided by the notion that mimicking nature is the approach that presents the least risk to biodiversity. The concept used to measure this is called 'natural range of variability' (NRV). This is typically based on a description of ecosystems as they existed before major changes brought about by extensive industrial or agricultural activity. Conservation science provides us with a general risk rating, telling us that if we retain 70% or more of the natural abundance of forest with old trees the risk of species loss, compromised ecosystem services, and losing ecosystem resilience is low. If we retain below 30%, the risk is high. At between 30% and 70%, the risk varies by ecosystem.
    "Consistent with what we heard from several provincial government staff, a recent report submitted to the panel by a group of independent scientists illustrates that we are in situations of high risk to biodiversity in many areas in the province, particularly in high-productivity, low elevation ecosystems. More troubling is the future projection where almost all of the province will be in high biodiversity risk once our current management approach harvests most of the available old forest. The time to complete this transition depends on the available old forest and various industry and economic factors in each region.
    "Their research also provided the following list of BEC zones that contain less than 10% of their original old forests:
    CDFmm (all CDF),
    CWHxm1,2, dm,
    CHxw, mk3,4, mw1,2,3,4,
    IDFxc, xh1,2,4, xk, xm, xs, xx2, dc, dk1,2,3,4,5, dm1,2, mw1,2,
    PPxh1,2,3 (all PP),
    SBPSmk,
    SBSwk1,2,3a,
    and possibly: ESSFxv2, dc1, mh, mv1,2,3,4, wc3,4, wh3, wk1 and wm1,2,3,4.
    "They note that there is some uncertainty because of potential misclassification of age in some of these units, and also recommend that these areas be deferred from further development until we have brought them back enough to meet current legislated targets.
    "Several practitioners also raised the issue of our current management system combining old forests and using their aggregated data when making assessments for managing biodiversity risk and planning for old forest retention. One example was parks and protected areas, where an initial net down estimate is removed at the landscape level and then netted out again at the detailed operations level, resulting in double counting. A related concern is that many parks and protected areas contain low-productivity old forests, which are deducted from total old growth aggregate targets without identifying which ecosystem they represent. These types of aggregation calculations overlook distribution and spatial considerations that are crucial in managing for effective ecosystem health."
    The main biogeoclimatic zone variants in the Discovery Islands are CWHxm1, CWHxm2, and CWHdm, all estimated to have less than 10 percent of the natural level of old forest remaining, thus putting each of these variants at high risk of biodiversity loss.
    David Broadland
    By Alana R. Westwood et al
    British Columbia has the greatest biological diversity of any province or territory in Canada. Yet increasing numbers of species in British Columbia are threatened with extinction. The current patchwork of provincial laws and regulations has not effectively prevented species declines. Recently, the Provincial Government has committed to enacting an endangered species law. Drawing upon our scientific and legal expertise, we offer recommendations for key features of endangered species legislation that build upon strengths and avoid weaknesses observed elsewhere. We recommend striking an independent Oversight Committee to provide recommendations about listing species, organize Recovery Teams, and monitor the efficacy of actions taken. Recovery Teams would evaluate and prioritize potential actions for individual species or groups of species that face common threats or live in a common area, based on best available evidence (including natural and social science and Indigenous Knowledge). Our recommendations focus on implementing an adaptive approach, with ongoing and transparent monitoring and reporting, to reduce delays between determining when a species is at risk and taking effective actions to save it. We urge lawmakers to include this strong evidentiary basis for species recovery as they tackle the scientific and socioeconomic challenges of building an effective species at risk Act.
    (2018) Protecting biodiversity in British Columbia- Recommendations for developing species at risk legislation.pdf
    David Broadland
    By Julia R. Chandler, Sybille Haeussler, Evelyn H. Hamilton, Michael Feller, Gary Bradfield, Suzanne W. Simard
    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. We created a plant-trait dataset for the 181 recorded species to define plant functional types representing groups of plants that behave in similar ways and/or produce similar ecological outcomes. These plant functional types, along with taxonomic analysis of diagnostic and indicator species, were then used to evaluate plant community response to disturbance. Twenty years post-treatment, species diversity increased in all zones and plant abundance was greatest in the Interior Cedar-Hemlock. Cover of understory plant functional types associated with mature conifer forests increased in all zones, constituting a significant proportion (> 40%) of the vegetation community by year 20. Response patterns varied by zone and with time. Understory species diagnostic of mature forests were present in all zones by year 20, but we identified indicator species sensitive to slashburning or requiring more time for recovery, including white-flowered rhododendron (Rhododendron albiflorum) and devil’s club (Oplopanax horridus). Overall, loss of compositional or functional diversity following harvest and site remediation was not detected, suggesting that montane and subalpine forests in British Columbia are resilient to this treatment. However, because these forests can be slow to recover from disturbance, the post-disturbance assessment window of this study may not have been long enough to detect diminishment of ecosystem resilience.
    (2017) Twenty years of ecosystem response after clearcutting and slashburning in conifer forests of central British Columbia, Canada (2017).pdf
    David Broadland
    By Nick M. Haddad et al
    We conducted an analysis of global forest cover to reveal that 70% of remaining forest is within 1 km of the forest’s edge, subject to the degrading effects of fragmentation. A synthesis of fragmentation experiments spanning multiple biomes and scales, five continents, and 35 years demonstrates that habitat fragmentation reduces biodiversity by 13 to 75% and impairs key ecosystem functions by decreasing biomass and altering nutrient cycles. Effects are greatest in the smallest and most isolated fragments, and they magnify with the passage of time. These findings indicate an urgent need for conservation and restoration measures to improve landscape connectivity, which will reduce extinction rates and help maintain ecosystem services.
    (2015) Habitat fragmentation and its lasting impact on Earth’s ecosystems.pdf
    Project Staff
    By Alan E. Burger et al
    We recorded the occurrence and relative abundance of potential predators of the threatened marbled murrelet (Brachyramphus marmoratus) in the Carmanah, Walbran, and Klanawa Valleys on southwest Vancouver Island, British Columbia. Data covering multiple years (1994–2000) came from two series of dawn surveys used to monitor murrelet activities (45 stations in total), and two series of point counts (190 stations). Steller's jays (Cyanocitta stelleri) were consistently the most common potential predator. Common ravens (Corvus corax) and red squirrels (Tamiasciurus hudsonicus) were also frequently encountered, but owls, accipiters, and falcons were rare. Northwestern crows (Corvus caurinus) and bald eagles (Haliaeetus leucocephalus) were rare at our inland stations, but other studies showed that they were common at the coast. The survey and point count data showed that the percent occurrence and relative abundance (individuals per survey) of Steller’s jays, common ravens, and all predators combined were higher at stations bordering clearcuts and roads than at stations within interior forest or bordering streams. Highest counts were usually at sites frequently used by people. Predators were more abundant in the fragmented forests of the Klanawa Valley than in the less disturbed Carmanah-Walbran Valleys. In particular, counts of Steller’s jays at road and clearcut edges were significantly higher in Klanawa than in Carmanah-Walbran. A pilot experiment using 40 artificial nest sites on tree boughs in old-growth patches in the Klanawa Valley revealed that eggs disappeared more rapidly near clearcut edges than in the interior forest. We conclude that predation risk at nests of marbled murrelets is likely to be higher near clearcuts and roads than in interior forest, and higher in fragmented landscapes than in relatively undisturbed old-growth forests.
    (2004) Effects of Habitat Fragmentation and Forest Edges on Predators of Marbled Murrelets and Other Forest Birds on Southwest Vancouver Island.pdf
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