What is included in the term ‘biological diversity’ or ‘biodiversity’ (3 main points)?
- Genetic diversity: genetic variation amongst individuals of the same species (white moose vs. black moose)
- Species diversity: Number and relative abundance of species in an area. Generally, the more diverse the habitat, the more species diversity
- Ecosystem diversity: Variety of unique or distinguishable habitats within an area
Diversity of wildlife = …?
Diversity of wildlife = diversity of habitats
Provide some examples of economic importance of biodiversity
o Consumptive uses of natural products such as timber, fish, game, berries and mushrooms, firewood, and medicinal plants
o Non-consumptive uses, such as guiding, viewing, recreation, education, science, and natural control of pests
o Future options-products or use not realized today, but which may become important in the future
Provide some examples of ecological importance of biodiversity
o We depend on the environment for our own health and existence
o Biodiversity is a cornerstone to the health of the environment
Describe the three ethical values of biodiversity
o Existence value
o Option value
o Bequest value
Define “Existence Value”
where people conserve an element of biodiversity for its own sake, without an intention of using it (non-consumption).
Describe the three types of values associated with existence values
Aesthetic enjoyment;
• natural beauty of old-growth forests (Cathedral Groove), or
• landscapes teaming with wildlife (Lamar Valley)
Intrinsic rights; where the mere existence of something gives it a right to continue, and to be protected
Spiritual health; where people receive inspirational, religious, or cultural benefit from nature. For some, this can only be found in natural, old-forest settings.
Why do we have species and habitats ‘at risk’ in BC? (4 main points)
Biodiversity in BC is threatened because not all species can adapt to the unnatural pressures of:
o Invasion by exotic plants and animals (broom, knotweed, & starlings)
o Access
o Urban & resource development (forestry, mining, grazing, or hydro)
o Pollution
o Loss or fragmentation, and unnatural changes (fire prevention) of habitat
What is meant by biodiversity provides ‘resiliency’ to ecosystems?
- capabilities to adapt to change in the environment without significant loss
in ecosystem functions
What is the ‘umbrella’ or ‘coarse-filter’ approach to managing landscapes?
- Attempts to manage a broad range of habitats that maintain natural diversity within them.
- CFA focuses on managing ecosystems and their natural processes
What 2 assumptions is the Coarse Filter Approach based upon?
o Management disturbances should mimic conditions under which natural
systems evolved
o More closely managed disturbances emulate natural disturbances, the lower
the risk of losing natural biodiversity
In general, what does the CF approach involve?
This approach involves maintaining:
o The essential structural attributes of each type of habitat
o Full range of types of habitats and seral stages within a particular ecosystem o Ecosystem processes
Why should the CF approach mimic natural patterns?
More closely managed disturbances emulate natural disturbances, the lower
the risk of losing natural biodiversity
What are the three principles that the CFA is based upon?
- Forest habitats can be grouped into 3 categories at the landscape level (early-seral stage, mid-seral stage, and late-seral stage (old-growth))
- Vertebrates tend to be associated with the structural attributes rather than with stand age per se.
- Some old-growth dependent species may require microclimate conditions of late-seral forests
Example of a stand-level disturbance type?
Windthrow may affect large areas, but more usually impacts smaller, stand size areas (typically <100 ha)
Are stand-level disturbances more prevalent in coastal or interior habitats?
Coastal - windthrow is the dominant natural disturbance force (less wildfires etc.)
Define ‘species-specific’ or ‘fine-filter (FFA)’ management
- Needed to meet the needs of a particular species or a unique vegetation community
- The fine filter approach protects the critical habitat for specific species’ needs
What are some characteristics of FFA?
o Are well suited to endangered or rare species
o Are suitable for species with special values
o Do not address ecosystem function of a species
Examples of fine filter approaches (4):
o Protecting key natal ponds for tiger salamander
o Managing large-diameter ponderosa pine for white-headed woodpecker
o Managing coastal old-growth reserves for marbled murrelet
o Managing old-growth, closed-canopy forests for northern goshawks
How does the ‘biodiversity guidebook’, ‘riparian guidebook; and ‘identified
wildlife guidebook’ relate to each other?
- The practices in the Biodiversity and Riparian Management Area guidebooks act as the coarse filter, protecting most species
- The practices in the General Wildlife Measures for Identified Wildlife Guidebook act as the fine filter, protecting those species whose habitat requirements are not adequately covered by the coarse filter guidelines
What are ‘ecotones” and how does the abiotic and biotic features vary in
ecotones relative to the contributing habitats?
Ecotone: Forest edge where one ecosystem type meets another
Microclimate conditions (such as temperature, humidity, light, snow/moisture accumulation, and wind) change from an edge into the intact forest
Biotic effect = occurs when plant and animal species associated with 1 habitat move into the other – could extend > 400m
Forest interior is the area of the forest not influenced by microclimate or biotic edge effect.
Distinguish between ‘hard edges’ and ‘soft edges’
Hard edge: the edge between patches may be highly contrasting (e.g., trees next to lakeshore, or tall older trees next to regenerating seedlings)
Soft edge: along lesser contrasting habitats such as riparian/hardwood interfaces.
- In managed forests, generally, as opening sizes decrease the proportion of edge increases.
How can the shape of disturbances influence the proportion of interior habitat?
What determines the range of sizes and age classes of cutblocks?
