Biodiversity Guidebook Table of Contents]


biodiversity: the diversity of plants, animals and other living organisms in all their forms and levels of organization, and includes the diversity of genes, species and ecosystems, as well as the evolutionary and functional processes that link them.

biogeoclimatic zone: a geographic area having similar patterns of energy flow, vegetation, and soils as a result of a broadly homogenous macro-climate.

clearcutting: The process of removing all trees, large and small, in a stand in one cutting operation. The previous stand is replaced with an even-aged crop of new trees through planting and/or natural regeneration (including advance regeneration).

coarse woody debris: sound and rotting logs and stumps that provide habitat for plants, animals, and insects and a source of nutrients for soil development. Material generally greater than 8–10 cm in diameter.

connectivity: a qualitative term describing the degree to which late successional ecosystems are linked to one another to form an interconnected network. The degree of interconnectedness and the characteristics of the linkages vary in natural landscapes based on topography and natural disturbance regime. Breaking of these linkages results in forest fragmentation. Fragmentation due to forest harvesting should be viewed and managed to mimic fragmentation resulting from natural disturbance. The degree and characteristics of this “natural fragmentation” vary with differences in landscape type. Specific types of connectivity are defined below:

endangered species: see “threatened or endangered species”.

even-aged management: a silvicultural system that is designed to regenerate and maintain an even-aged stand. Clearcutting, seed tree and shelterwood are even-aged systems.

forest ecosystem network: a planned landscape zone that serves to maintain or restore the natural connectivity within a landscape unit. A forest ecosystem network (or FEN) consists of a variety of fully protected areas, sensitive areas, and old-growth management areas.

forest interior: see Appendix 1 “Edge effects and forest interior.”

landscape: a watershed or series of similar and interacting watersheds, usually between 10 000 and 100 000 ha in size.

landscape unit: a planning area, generally up to about 100 000 ha in size, delineated according to topographic or geographic features such as a watershed or series of watersheds. It is established by the district manager.

managed forest: that portion of the landscape outside forest ecosystem networks in which forestry operations occur.

mature seral: forests composed primarily of co-dominant trees, with canopies that vary vertically, horizontally, or both. Generally refers to trees 80 to 120 years old or greater, depending on species and site conditions. The age and structure of mature seral vary significantly by forest type and from one biogeoclimatic zone to another.

natural disturbance type: an area that is characterized by a natural disturbance regime. See the section “Establishing seral stage objectives for natural disturbance types.”

old-growth management areas: areas that contain or are managed to replace specific structural old-growth attributes, and that are mapped out and treated as special management areas.

old seral: old seral is a forest that contains live and dead trees of various sizes, species, composition, and age class structure Old seral forests, as part of a slowly changing but dynamic ecosystem, include climax forests but not sub-climax or mid-seral forests. The age and structure of old seral varies significantly by forest type and from one biogeoclimatic zone to another.

patch: a stand of similar-aged forest that differs in age from adjacent patches by more that 20 years. When used in the design of landscape patterns, the term refers to the size of either a natural disturbance opening that led to even-aged forests or an opening created by cutblocks.

planning unit: a sub-unit of the landscape planning unit; a biogeoclimatic subzone within a drainage, for example.

potential natural community: the plant community that would be established if succession were allowed to be completed without further human interference.

protected area: An area that has protected designation according to provincial or federal statute. Protected areas are land and freshwater or marine areas set aside to protect the province’s diverse natural and cultural heritage.

rare ecosystem: an ecosystem (site series or surrogate) that makes up less than 2% of a landscape unit and is not common in adjacent landscape units.

reserve: an area of forest land that, by law or policy, is not available for timber harvesting or production.

residual cover: living and dead vegetation that persists over-winter and provides protective and breeding cover during critical periods in the following spring before new growth takes over this function.

seed tree system: an even-aged silvicultural system in which selected trees (seed trees) are left standing after the initial harvest to provide a seed source for natural regeneration. Seed trees can be left uniformly distributed or in small groups. Although regeneration is generally secured naturally, it may be augmented by planting. Seed trees are often removed once regeneration is established, or may be left as reserves.

seral stages: the stages of ecological succession of a plant community, for example, from young stage to old stage; the characteristic sequence of biotic communities that successively occupy and replace each other, altering in the process some components of the physical environment over time.

silvicultural systems: a planned cycle of activities by which a forest stand, or group of trees, is harvested, regenerated, and tended over time. Silvicultural systems used in British Columbia include clearcutting, seed tree, shelterwood, and selection. Each name reflects the type of stand structure created by harvesting.

site series: sites capable of producing the same late seral or climax plant communities within a biogeoclimatic subzone or variant.

stand attributes: the components of a forest stand. See Appendix 5.

stand level: the level of forest management at which a relatively homogeneous land unit can be managed under a single prescription, or set of treatments, to meet well-defined objectives.

stand-initiating events: occur when natural disturbances such as wildfire, wind, landslides, and avalanches significantly alter an ecosystem. In most cases there is considerable mortality of plant species, some degree of site disturbance and the initiation of successional processes that will form a new plant community with a different structure and likely a different composition than its predecessor.

stand-maintaining events: the fairly frequent occurrence of wildfires, either as surface or surface and crown fires, which serve to maintain an ecosystem at a particular successional stage. This may result in a “fire climax,” such as is found in the Ponderosa pine or interior Douglas-fir types, or in a coastal forest of mid-seral tree species in relatively even-aged stands.

structural attributes: components of a forest stand (including living and dead standing trees, canopy architecture, and fallen dead trees) which together determine stand structure.

threatened or endangered species: indigenous species that are either threatened or endangered, and identified as “red listed” by the Ministry of Environment, Lands and Parks.

uneven-aged management: a silvicultural system designed to create or maintain and regenerate an uneven-aged stand structure. Single tree and group selection are uneven-aged silvicultural systems.

viable population: a self-sustaining population with a high probability of survival despite the foreseeable effects of demographic, environmental and genetic stochasticity and of natural catastrophes.

wildlife tree: a standing live or dead tree with special characteristics that provide valuable habitat for the conservation or enhancement of wildlife. Characteristics include large diameter and height for the site, current use by wildlife, declining or dead condition, value as a species, valuable location, and relative scarcity.

wildlife tree patch: an area specifically identified for the retention and recruitment of suitable wildlife trees. It can contain a single wildlife tree or many. A wildlife tree patch is synonymous with a group reserve.

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