Coastal Forest and Mountains – British Columbia

Sockeye Run, British Columbia. (Photo: Dennis Sizemore)

Sockeye Run, British Columbia. (Photo: Dennis Sizemore)

Coastal temperate rainforest is a globally rare ecosystem type, occurring on less than 1% of the earth’s surface. Many native species have been extirpated from the southern portion of the region, including catastrophic reductions of many salmon stocks and the extermination of top carnivores (grizzly bears and wolves) from the coastal forests of the lower 48 United States. Some of the last remaining large contiguous areas of intact, coastal temperate rainforest are found in British Columbia and Southeast Alaska— forests that still contain a full assemblage of large carnivore species and prolific stocks of pacific salmon. Ecosystem processes in the region are also largely intact; for example, coastal forest in the region supply woody debris and other materials that are vital to river system integrity and ecological functioning and provide storage of massive amounts of carbon. The region houses a number of additional important biodiversity components including unique coastal bog complexes, unregulated river systems, intact estuaries, marine kelp and seagrass beds, seabird colonies, archipelago/fjord terrain, deep fjord and cryptodepression lakes, and intertidal flats with abundant invertebrates and resident and migratory waterbirds.

Nevertheless, despite their biological diversity and global significance, the future of the coastal temperate rainforest is still highly uncertain. The primary threat to the region is unsustainable industrial logging and its associated ecological impacts. The region has a long history of conflicts between environmentalists and the timber industry that have generated both national and international interest in both Alaska and British Columbia. Which areas should receive highest priority for conservation? How much area is enough? What types of human activities are acceptable? How should conservation policies be implemented? We sought to develop science-based tools and to assemble regional data necessary to address these sorts of questions, through the development of a Conservation Area Design (CAD) for the region. Here we present regional spatial datasets that represent a full range of biodiversity values for the coastal temperate rainforest. We also present analyses results that identify high value, irreplaceable conservation areas and identify some of the last remaining, ecologically intact and relatively undisturbed watersheds in the region.

The study area is defined by the ecosections of the Coastal Forest and Mountains ecoregion, plus the adjacent Northern Pacific Ranges and the Outer Fiordlands ecosections. The study area includes much of Southeast Alaska and the adjacent transboundary mountains, the island of Haida Gwaii, the Nass Basin and the Central and North Coast regions of British Columbia. This region has a land area of 21.4 million hectares plus an additional 11 million ha of ocean. Several primary watersheds in the region have headwaters that originate outside of the study area; inclusion of the entire extent of primary watersheds encompasses and additional 15.2 million hectares for a total study are a size of 47.2 million hectares.

This report provides tools and data necessary for science-based conservation planning and a framework of how priority areas can be systematically identified. The objective of this exercise is ultimately to serve four well-accepted goals of conservation: 1) represent ecosystems across their natural range of variation; 2) maintain viable populations of native species; 3) sustain ecological and evolutionary processes within an acceptable range of variability; and 4) build a conservation network that is resilient to environmental change. In pursuit of these goals, the Conservation Area Design for the CFM region incorporates three basic approaches to conservation planning:

• Representation of a broad spectrum of environmental variation (e.g., vegetation, terrestrial abiotic, and freshwater and marine habitat classes).

• Protection of special elements: concentrations of ecological communities; rare or at-risk ecological communities; rare physical habitats; concentrations of species; locations of at risk species; locations of highly valued species or their critical habitats; locations of major genetic variants.

• Conservation of critical habitats of focal species, whose needs help planners address issues of habitat area, configuration, and quality. These are species that (a) need large areas or several well connected areas, or (b) are sensitive to human disturbance, and (c) for which sound habitat-suability models are available or can be constructed.

We attempted to assemble and use the best available information for this assessment. We recognize that new and more comprehensive data will continually become available and finer-scale analyses may provide more detailed information necessary for local planning and management purposes.

For example, much of the data and approach we developed and applied for the entire region was also used to develop a finer-scale land-use plan for the British Columbia portions of the study area in collaboration with the B.C. Coastal Information Team and the Nature Conservancy of Canada. For such cases, finer scale analysis is often more useful for land-use and management decisions. Nevertheless, we suggest that regional analyses are important for several reasons. Regional analysis can place any landscape feature in a local, regional, or global context. A second important advantage is that species, plant communities, and other conservation targets can be considered together within an environmental framework that shaped their evolution and continues to shape their interactions. Finally, regional analysis provides a consistent, standardized framework that encourages cooperation across political boundaries and may promote implementation of conservation strategies that operate at larger geographic scales that could not be addressed at a local level.

We selected a set of conservation targets that represent a wide range of biodiversity values for the region. We included coarse filter terrestrial and freshwater ecosystem targets and a suite of focal species targets. To ensure broad representation of a wide range of these values, we stratified target selection by using the ecoregion / ecosection classification system. This system is in common use in North America (and around the world), and divides terrestrial ecosystem complexity into discrete geographical units. Ecosections describe areas of similar climate, physiography, oceanography, hydrology, vegetation, and wildlife potential (Report Maps 1 & 2).

The spatial distribution and relative amount of each conservation target was summarized using 1000 hectare hexagonal planning units. Representative configurations of planning units were assembled using the software program MARXAN which utilizes an algorithm called “simulated annealing with iterative improvement” as a heuristic method for efficiently selecting regionally representative sets of areas for biodiversity conservation at a minimum of cost. We used MARXAN to run a combination of 5 diff e rent goal settings (30 – 70% representation goals in 10% increments) and 3 boundary length modifiers (which influences the degree of clumping) and each run was repeated 100 times for a total of 1500 possible conservation solutions. The sum total of all runs was integrated into a single final “summed solution” which is a measure of irreplacability or conservation value for each planning unit (Map 26). Conservation value for each watershed (a more practical unit for land use designation) was calculated by taking the area-weighted mean of the planning unit conservation value.

We also assessed the ecological integrity of all watersheds in the study area based on relative levels of human impacts (Map 24). These two streams of information (conservation value and ecological integrity) were used in combination to delineate the Conservation Area Design, which includes 3 Tiers of conservation priority (Map 27). We suggest that this approach can be used to identify the highest level regional priorities, i.e. high value, relatively intact areas that serve as anchors for a comprehensive Conservation Area Design for the Coastal Temperate Rainforest. The design can also be used to identify areas in need of restoration such as watersheds which relatively high value with moderate levels of human impacts.

Although the preponderance of evidence from the scientific literature suggests that there may be no substitute for large, strictly protected areas for meeting conservation objectives, even a designation of a set of new, large protected are as may not be enough for long-term conservation. Species will eventually decline as protected areas begin to resemble habitat islands and surrounding areas become increasingly inhospitable. Thus, identification and protection of large contiguous areas, coupled with the maintenance of favorable conditions in non-protected areas, are both equally important for long-term conservation. Despite these lessons from science, resource managers and decision makers are often tasked with meeting multiple, conflicting demands and are often forced into compromises that result in the incremental degradation of ecosystems. While developing new and innovative solutions for resolving conflicts surrounding conservation is both attractive and pragmatic, we should continue to keep in mind that a comprehensive conservation solution may require conservation of vast, un-fragmented areas, and protection of this scale (no matter how innovative) may be expensive and somewhat unpopular with existing economic interests. Nevertheless, we believe that we have developed a set of usable tools and assembled necessary data for designing a comprehensive set of conservation areas in the Coastal Forest and Mountains region.

Coastal Forest and Mountains – Maps, Publications and Reports