Conifer restoration on the Duncan-Lardeau Flats Wildlife Properties. January 2006

Transcription

1 Conifer restoration on the Duncan-Lardeau Flats Wildlife Properties January 2006 Prepared for Columbia Basin Fish and Wildlife Compensation Program 333 Victoria Street Nelson, B.C. Prepared by Brenda Herbison, R.P.Bio. Argenta, B.C. VOG1BO

2 Conifer Restoration on the Duncan-Lardeau Flats Wildlife Properties Introduction The objective of this reconnaissance project has been to identify locations on the Duncan Lardeau (DL) Wildlife Properties where wildlife habitat could potentially be enhanced by planting conifer seedlings. The rationale guiding the assessment has been that conifers may be appropriate where they could enhance habitat structural diversity, and/or where they could provide specific missing habitat elements (such as visual barriers, or snow interception cover), and/or, where they could help to restore more natural conditions although it is recognized that natural is difficult to define on DL Wildlife Properties. The numerous unnatural human influences that have affected vegetation structure since the turn of the last century on these properties include homesteading, logging, livestock grazing, burning, shrub-cutting, mowing, and, most profoundly, the damming of inflows on the Duncan River and Kootenay Lake. (Alexander 1998, Chapman 1982, Silver 1978, Woods 1981, Herbison 1972, 2000, 2003) Project Area The Duncan-Lardeau Wildlife Properties are located on the floodplain of the lower Duncan River, between the north end of Kootenay Lake and Meadow Creek, B.C. The 543 hectare area is owned by the Nature Trust of B.C. (TNT) and the Crown, and is managed jointly by the Columbia Basin Fish and Wildlife Compensation Program (CBFWCP) and B.C. Ministry of Environment (MOE). Methods The approach included pre-field review and interpretation of 1929 to 2000 air photos, recent photos from mid elevation vantage-points, winter aerial photographs, and all literature directly relevant to the DL Wildlife Properties including the references listed above as well as Super 1991, Poole et al. 1998, and Herbison 1982 and This served to identify the existing distribution of conifers on the property and to document the history of conifer establishment and removal. Fieldwork then concentrated in the mid to high-bench floodplain sites potentially suitable for conifer establishment but supporting few to no conifers at present, or where the conifer status was unclear. Low-lying riparian, early seral communities were excluded from consideration. Results Lot 881 Lot 881 has been partially logged a number of times since Stumps and air photos suggest the earliest logging most probably removed large cedar for shake bolts, and that mid-century logging removed cedar poles. The most recent logging, in the mid 1990s, removed a high percentage of the mature conifers (spruce and cedar) just prior to the purchase by the CBFWCP and TNT. Currently there are healthy and abundant ~ 10 m tall cedar and spruce in the understory that are likely to dominate the canopy in approximately years. (These were probably tall seedlings when the canopy was logged.) 1

3 There is no obvious need for coniferous enhancement on this property at this time. It is recommended that the health of the existing young conifers be monitored by occasional reconnaissance over the next few decades. There were 500 spruce seedlings planted by the CBFWCP on Lot 881 in It is recommended that their condition be assessed in 2006 regarding potential need for brushing. Lower Lot 570 and Lot 896 (Figure 1) Polygon 1 is characterized by old cottonwood and birch with bands of old cedar and spruce, interspersed with abandoned channel courses that are occupied by deciduous shrubs of several height classes. It is one area on the DL properties that appears to be in a relatively natural structural state and still relatively free of nonnative weeds. It is suggested that this stand type be used as a structural model for Polygon 2. Polygon 2 is characterized by very dense, 2-4 metre tall shrub thickets of hazelnut, hawthorn, and rose, with occasional mature cottonwood and birch, cascara and alder. Its structure has been influenced by livestock grazing (early 1900s to late 1980 s), logging of shake bolts (early 1900 s to 1979), possibly by homesteading (west side, near highway) and, most recently, by shrub slashing for ungulate habitat enhancement (1980s-1990s). At present, major portions of this polygon give the appearance of being too dense for use by large mammals. Past efforts at habitat enhancement slashing have been aimed in part at reducing stem density, but the result in many cases has been to increase stem density, particularly in lightly utilized locations or when non-preferred browse species were slashed (Herbison 2000). It is suggested by the present report that a patchier, less uniform, structure would be desirable in Polygon 2, with a more open quality in the shrub layer, and that occasional clumps of planted conifers might help to create that condition. As the conifers matured they would contribute significantly to bird and small mammal species diversity. Ungulates would benefit by a better than present distribution of snow interception cover in winter, as well as increased ease of movement year round that would likely develop over time in association with the conifers. It is recommended that a small number of spruce and cedar be planted in Polygon 2, using Polygon 1 as a structural model for the planting design. Suggested are naturallooking clumps to be distributed within somewhat linear (channel-shaped) zones, to occupy ~ 20 % of the polygon area (~ 4 to 5 hectares out of 24 hectares). Shallow old channel courses run through Polygon 2 in which the water table is close to or at the surface. These will need to be considered in the planting design. Polygon 4 is a strip between Highway 31 and the wildlife properties on Lot 570 and Lot 896 that could potentially benefit from a light planting of conifers to provide a visual and 2

4 Cooper Creek 1 Figure 1: Conifer Status for Lower Duncan Wildlife Properties Old cottonwood and birch amidst riparian shrub communities, interspersed with old spruce and cedar. Protect from weed invasions via Polygons 2 and 11. No other action recommended. (32.7ha) 10 Duncan Over-dense tall shrub communities with virtually no conifers. dispersed groups. Model after habitat structure in polygon 1. (24.3ha) Mature cottonwood, aspen, and shrub thickets between meadows. Conifer planting not recommended at this time. (4.8ha) Strip between DL 896 meadows/ DL 570 and Highway 3A. Consider light planting of spruce and cedar as a visual and sound barrier. (8.0ha) DL570 River 5 6 Old, declining cottonwood, younger aspen, tall shrub communities near Highway 3A. Reassess potential benefit from conifers in 5-10 years. (5.1ha) Mature cottonwood and shrub thickets. Look at in 5-10 years re: conifer establishment. (11.3ha) 7 Small area of high, dry ground on DL supporting birch, Douglas-fir. (1.2ha) Area of high ground on DL supporting birch, less cottonwood and approximately 30 mature Douglas-fir. (2.0ha) Significant area of seed-generated cottonwood 5-15 metres tall. Avoid habitat enhancement activities. (43.4ha) W:\SRM\NEL\WORKAREA\CBFWCP\LANDMANAGEMENT\DUNCAN\CONIFER_STATUS_L_DUNCAN_05.MXD $MAPS/CBFWCP_MANAGEMDLANDS/DUNCAN/CONIFER_STATUS_L_DUNCAN_05.PDF metres BC Alber, NAD 83 February 8, 2006 Columbia Basin Fish & Wildlife Compensation Program ³ DL DL16024 Upper and mid DL 570. Dominated by diversity of conifer species. No actions recommended at this time. (80.5ha) Grass/sedge meadows and shrub communities. No conifer planting recommended. (28.9ha) Shrub communities with cedar establishing naturally. No conifer planting recommended. (6.3ha) Deciduous shrubs and cottonwood with very sparsely distributed conifer seedlings that are establishing naturally. (86.3ha) 7 9 Kootenay Lake

5 sound/disturbance barrier for wildlife. There do not appear to be many natural conifers coming into the rather open understory facing the highway. It is recommended that a light planting of conifers be considered in the more open sites along this strip. The location of the highways right-of- way will need to be identified and taken into account; either avoided, or arrangements made with the Ministry of Transport to plant within the right-of-way. Aesthetics should be considered, as well (i.e., no straight lines). Another feature in Polygon 4 that will need to be considered is the linear wetland (standing water) that runs alongside the highway through Polygon 4 and down through Polygon 8. Conifers will need to be planted on the higher ground only. Lot Polygons 7, 8, 9, and 13 Lot has a mixed history of human influences that include grazing, burning, and shrub slashing. It has an active, current flood disturbance history in the low areas around the outer edges of the island. The diversity in elevations and substrate textures creates a wider variety of moisture regimes than exists on most of the adjacent floodplain. Low areas around Lot are occupied by early seral riparian shrub communities (red osier dogwood, willow, cottonwood, and alder). Low spots within the island or around beaver works on old and active channels support sedges and other wetland species. A higher strip along the north side, center, is occupied by mature cottonwood /birch stands and an even higher strip towards the east supports approximately 30 large (30-60 cm dbh) Douglas-fir with a minor component of birch and cottonwood as well as one mature cedar and one white pine. Small conifers (spruce and Douglas-fir, primarily) are slowly colonizing high areas center to and south of the strip of older conifers. These are less than 10 m tall at this time and are very sparsely distributed. No planting is recommended at this time, but the conifer status on Lot should be reassessed again in a few years. Upper Lot 570 Polygon 10 Most of upper Lot 570 is occupied by late mature and old stands of cedar, hemlock, and spruce with late seral Douglas-fir and larch stands at the north end. There is no observable need for coniferous enhancement in Polygon 10. Recommendations/Conclusions There are approximately 32 hectares on the DL Wildlife Properties that appear suitable for a much dispersed planting of conifers for habitat enhancement. These locations are identified in a very general manner on the map (Figure 1). Chronological and other details are outlined in Table 1. It is recommended that detailed maps of the planting design within Polygons 2 and 4 be produced at the layout stage with the aid of a handheld GPS. 4

6 It is recommended that the planted seedlings be propagated from seeds collected close to the place of origin (provenance) that is, on or very near the DL Wildlife Properties - if at all feasible. This would preserve the unique genetic attributes that may have evolved to suit this particular location. 5

7 Table 1. Schedule for Conifer Restoration on the Duncan-Lardeau Wildlife Properties Year Month(s) Activity Polygon(s) Seedlings Details Spruce Cedar Total 2006 August Cone crop reconnaissance Determine availability of spruce and cedar cones on the DL Wildlife Properties 2006 September Cone collection If the cone crop in 2006 is sufficiently prolific to warrant collection, pick cones utilizing non-destructive methods (long pruning tools, ladders, climbing) 2006 October Seeds to nursery If seeds are successfully collected, provide to Harrop nursery immediately after collection so they can be appropriately stratified (chilled) and stored over the winter January Order seedlings to plant in spring These will be planted in January 2007 to grow through the summer to reach 40+ cm in height by fall The seedlings will be stored at the nursery until Spring Winter Detailed site plan and layout January Order seedlings to plant in spring Seeds collected on the DL Wildlife Properties in 2006 can be used if stored correctly 2008 April Planting April Planting Hand-clearing of shrubs and heavy screefing will be required for site preparation. It is recommended that slash be piled to make ungulate access to seedlings difficult. Cedar will likely require additional protection from browsing Early summer Brushing will likely be needed 2 & Early summer Brushing will likely be needed 2 & 4 6

8 References Alexander, E Lardeau Valley Memories. Chapman, P Where the Lardeau River Flows. Herbison, B Ecological Description of the Duncan-Lardeau Delta. Unpublished paper for Selkirk College Winter habitat use by white-tailed deer and Rocky Mountain Elk on the Duncan-Lardeau flats. Unpublished paper for B.C. Ministry of Environment Assessment of shrub enhancement possibilities on the Duncan- Lardeau flats. Unpublished report for the Columbia Basin Fish and Wildlife Compensation Program, Nelson, BC Black Cottonwood along the lower Duncan River: interpretation of current conditions relevant to flow management for riparian diversity. B.C. Hydro Duncan Dam Water Use Planning Project. Poole, K.G., K. Hulburt and B.Park Duncan Properties Wildlife Management Plan. Unpublished report prepared for Columbia Basin Fish and Wildlife Compensation Program, Nelson, BC. Silver, R A wildlife management plan for the Duncan-Lardeau delta. Unpublished report, Fish and Wildlife Branch, B.C. Ministry of Environment, Nelson. Super, M Preliminary management plan for District Lot Unpublished report, Fish and Wildlife Branch, B.C. Ministry of Environment, Nelson. 13 pp. Woods, G Duncan Lardeau management plan. Unpublished report, Fish and Wildlife Branch, B.C. Ministry of Environment, Nelson. 7