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Date: August 12, 2014.
Subject: Natural Resource Conservation Values Associated with the Crown
Land portion of WL 1475, near Upper Lantzville.
Thank-you for providing a tour of the above site on the afternoon of August 6th. Since that tour, I have conducted a desktop review of standard information sources relating to this Crown Forest parcel. I present the findings of that review below, along with my preliminary assessment of the conservation values associated with this site. I have also included a brief discussion of potentially important gaps in the existing information, should a more thorough assessment be desired.
- Environmental Setting
The subject property encompasses approximately 244 ha of Crown Forest within Area L of the Regional District of Nanaimo (RDN). It extends from approximately 0.7 km to 2.0 km south of the Island Highway. Neighbouring properties to the south and west of the site are privately owned and managed forest land, while areas to the east are a mix of rural residences and private forest land. A utility corridor and rural residential properties occur near the northern margins of the site.
The subject property extends across parts of two streams and one small wetland. The headwaters and middle reaches of Knarsten Creek, a relatively small permanent drainage with a mainstem length of roughly 3.5 km, are captured within the site. Roughly half of this watercourse is within WL 1475. According to a government-maintained database (i.e. FLMNO’s Fish Habitat Wizard), Knarsten Creek supports native salmonids. Coho Salmon and Coastal Cutthroat Trout are found along the middle reaches of the creek, while Chum Salmon are reported to use the lowest reaches of Knarsten Creek (north of WL 1475). There appears to be a barrier to fish migration in Knarsten Creek, within the central part of WL 1475. In the western part of WL 1475, a second creek occurs, termed Hardy Creek. The latter flows to the northeast for about 1 km before draining into a small wetland, and then apparently flows north for another km before emptying into Nanoose Harbour.
The subject property possesses a varied topography, capturing areas of coastal plain, moderate-sloped hillsides, wet depressions, well-incised creek beds, and dry ridge crests. In general, terrain is steepest in the south, becoming more gentle as one moves north across the site. Elevations within the site range from approximately 100 m in the north to 320 m in the south, placing it in the transition zone between the Moist Maritime Subzone of the Coastal Douglas Fir Biogeoclimatic Zone (or CDFmm Subzone) and the Very Dry Maritime Subzone of the Coastal Western Hemlock Biogeoclimatic Zone (or CWHxm Subzone). The general upper elevational limit for the CDFmm Subzone is 150 m (Green and Klinka 1994), and the site tour suggests that the CDFmm persists until at least 150 m, probably higher. The CDFmm is differentiated from the adjacent CWHxm Subzone by its higher cover of Grand Fir in the canopy and greater abundance of Ocean-spray in the understory.
The subject property is not immediately adjacent to any large protected areas in the region. The site is located about 1 km south of Arbutus Grove Provincial Park and 4.5 km north of the RDN’s Benson Creek Falls Regional Park, both of which protect about 22 ha of forest within the transition zone between the two Subzones.
- Documented Elements of Conservation Interest Within and Near WL 1475
Endangered Forest Ecosystems
Review of online databases covering this site indicate a number of sensitive ecosystems occur within WL 1475. A search of the Provincial Conservation Data Centre’s (CDC) Rare Element database found a large polygon representing the Red-listed (or Endangered) Douglas-fir / Dull Oregon Grape forest ecosystem type (CDC Element No. 52631) running the length of the site, covering its northern part. According to a summary report for this polygon, the patch measures about 103 ha within the CDFmm Subzone, is relatively intact, and contains a mix of young and mature forest (70% young; 30 % mature). This polygon was ranked by the CDC as having fairly high ecological integrity, although shortcomings were noted with respect to its size and connection to other forest parcels. However, this is often the case within the CDFmm Subzone, and given the threats from development, it is my opinion that one would be hard-pressed to find another unprotected site more deserving of protection in the current context.
Other Ecologically Sensitive Ecosystems
In addition to endangered forest ecosystems, the Crown Forest portion of WL 1475 includes two types of Sensitive Ecosystem Inventory (SEI) polygons: Riparian Forest and Wetland. SEI Map Sheet No. 92F.030 shows a large linear Riparian Forest polygon running through the centre of the site (SEI Polygon No. N0526C), associated with the upper reaches of Knarsten Creek. A smaller Riparian Forest polygon to the north (No. N0526A) is associated with the middle reaches of Knarsten Creek, while SEI polygons in the western part of the woodlot (No. N0539 and N0568) are associated with Hardy Creek. Polygon N0539 is of special conservation interest, as it provides a habitat linkage between the small wetland occurring on the site and Dumont Marsh, located a short distance to the east.
It should be noted that during the August site inspection, riparian areas within WL 1475 supported a number of veteran Douglas-fir trees, as well as mature Western Redcedar and Grand Fir specimens.
The small wetland along Hardy Creek in the northwestern part of WL 1475 has been designated as Sensitive Wetland No. N0541on SEI Map Sheet No. 92F.030. It measures about 1.4 ha in total area, and has been classified as a “swamp”, or shrub-dominated, type of wetland. The dominant shrub in this wetland appears to be Hardhack. A number of emergent aquatic plants, particularly Slough Sedge, are usually found in this type of wetland.
Sensitive Wildlife Species / Habitat Elements
A record of the Blue-listed (or threatened) Northern Red-legged Frog was found in the CDC Rare Element database in close proximity to WL 1475. The record (No. 55667) dating from the spring of 2004, describes two adult frogs found on private properties within 100 m of the Hardy Creek wetland (SEI Polygon N0541) in the western end of WL1475. Although this frog can move several hundred metres from breeding areas, the timing of the record suggests that SEI Polygon N0541 may serve as a breeding habitat for this species. It is also noteworthy that adult Red-legged Frogs are highly dependent on forest cover for their “core” (or non-breeding habitat) for most of their annual cycle.
Review of the Wildlife Tree Stewardship (WITS) nest database covering WL 1475 indicates that two Bald Eagle nests representing a main nest and alternate occur within 500 m of the woodlot. These nests, No. 105-043 and 105-044 in the WITS database, are located adjacent to Hardy Creek just south of the E & N Railway tracks. While eagles in the region are generally habituated to human activities, noisy activities associated with forest harvesting (e.g. chainsaws, drilling, and blasting) can negatively impact eagle breeding success, particularly if carried out during the early part of the breeding season.
- Potential Elements of Conservation Interest Within WL 1475
Based on the August site inspection, there is some potential for other elements of conservation value to be found at this site. Foremost among these is the very likely presence of “at-risk” ecological communities in the southern part of the site. The probability of finding threatened or endangered plant communities is considered high here because many forest types within the CWHxm Subzone are either Red- or Blue-listed ecosystems, possessing the second-highest priority under the Province’s Conservation Framework. This includes the “zonal,” or most common, Western Hemlock – Douglas-fir – Kindbergia plant community. If it has not already been done, ecosystem classification across the southern part of the site, covering the CWHxm Subzone, is recommended to identify the locations of other under-represented plant communities.
Since most rare plants are typically found in habitats that are themselves somewhat uncommon (e.g. rock bluffs, seepage zones, wetlands), the potential for rare species to occur on this site is considered to be fairly low. Nevertheless, springtime rare plant searches within wetlands and riparian areas may be useful in documenting additional plant species of conservation interest.
Habitat conditions across the site appear superficially suitable to support the Blue-listed Wandering Salamander. This is an entirely terrestrial salamander associated with low-elevation Douglas-fir and Western Hemlock stands (Matsuda et al. 2006). As this species is most active during warm and wet periods, it is recommended that several time-constrained surveys be conducted for this species in mid-spring. The surveys should focus on parts of the site with sizeable downed logs and a humid micro-climate (e.g. riparian stands).
Given the presence of mature trees and cavity-bearing snags, there is some potential for two “at-risk” owl species to breed within WL 1475. The Blue-listed Western Screech owl appears to have broad dietary requirements and could hunt in a variety of habitats, wherever rodents, small fish, and/or insects are abundant. It requires require sizeable tree or artificial cavities for nesting. The Vancouver Island subspecies of the Northern Pygmy-owl is also Blue-listed, being broadly but sparsely distributed across the island. The standard approach to inventory for these owls is the call-playback survey, which uses recorded calls to elicit alarm or territorial responses from owls in the vicinity of the surveyor. The preferred window for call-playback surveys for these species would extend from early to late April. Two rounds of surveys are recommended.
As mentioned in the previous section, there is some potential for the small wetland in the northwestern part of the site to support breeding by the Blue-listed Red-legged Frog. The preferred method to document breeding by this species is through searches for their distinctive egg masses, which typically appear in late March or early April.
It is my opinion that this site possess a number of characteristics which, taken together, form a compelling argument for its conservation, or at least more sensitive management than is generally required for timbering areas. The site supports sizeable patches of rare and under-represented forest types, captures an interesting mosaic of ecologically sensitive ecosystems, and contains many veteran and mature trees with high habitat values. In addition to these attributes, stands on this site provide important core habitat for the Blue-listed Red-legged Frog, and other native pond-breeding amphibians.
Ideally, this site would form part of a large contiguous forest running from tidewater to the insular mountains of Vancouver Island. However, historical patterns of land use have largely precluded the creation of such a complex involving this site, and most others across southern Vancouver Island. Considering the recent focus by Provincial government agencies on stewardship of the Coastal Douglas Fir Zone, this site should be considered a high priority for protection and/or special management.
It has been a pleasure to conduct this work on your behalf. Feel free to contact me at 250-248-1918 if you have any queries or require additional input.
Joe Materi, R.P.Bio.
Green, R.N. and K. Klinka. 1994. A Field Guide to Site Identification and Interpretation for the Vancouver Forest Region, B.C. Ministry of Forests, Burnaby. 285pp.
Matsuda, B., D.M. Green, and R.W. Campbell. 2006. Amphibians and Reptiles of British Columbia. Royal B.C. Museum, Victoria, B.C. 266pp.
Appendix A – Conservation Data Centre Rare Element Database search results.
Appendix B – Sensitive Ecosystem Inventory mapping covering the site.