Riparian Best Management Practices - Phinney Hill 2013

Riparian Best Management Practices - Phinney Hill Stream Evaluation of the survival and cost-effectiveness of several tree planting treatments in the re-establishment of riparian vegetative cover adjacent to a small man-made stream

Tim Vickers Graeme Stewart-Robertson ACAP Saint John (2013)

Acknowledgements

The Development of a Riparian Best Management Practices (BMP) guide was made possible in large part through an Atlantic Ecosystem Initiative grant provided by Environment Canada. Environment Canada has provided annual financial, logistical and intellectual support of ACAP Saint John since this community group was founded in 1992, and EC’s investment in this BMP re-affirms their commitment to enabling the Saint John community to take a leadership role in the management of its regional environment.

ACAP Saint John would also like to thank volunteers who contributed to the development of this BMP through their tree planting efforts from 2010 through 2012.

Background The City of Saint John (CoSJ) replaced a section of the municipal water main along Pipeline Road at Phinney Hill Stream (PHS) in the Little River watershed of east Saint John in 2010 (Figure 1). Replacing the water main eliminated excessive water leakage from the system and the accompanying release of chlorinated water into the environment. The construction activities resulted in the destruction and subsequent recreation of approximately 1000m of a tributary, that was originally heavily braided and, in places, running down the center of the Pipeline Road (Figure 2), which resulted in degrading fish habitat and increased water temperatures during the summer (ACAP; Phinney Hill Report 2010).

Figure 1.

Location of the man-made Phinney Hill Stream in east Saint John, New Brunswick.

Figure 2: Pipeline Road before re-construction of Phinney Hill Stream (left) showing the stream winding down the middle of the road for several hundred meters. Construction of the new man-made channel was well under way by September 1, 2010 (right).

The newly constructed stream banks were re-vegetated using Hydroseed as mandated by their operating license (Figure 3); however, it was recognized that the addition of larger trees would increase canopy cover and improve fish and wildlife habitat. ACAP Saint John recognised the unprecedented opportunity to assist in the establishment of a newly created man-made watercourse, and acquired stakeholder approval to conduct an field trials on sevarl different treatments of native tree plantings. Specifcially, the objective of this project was to: 1) Conduct numerous treatments (different planting regiments) of native tree species within the riparian zone of Phinney Hill Stream; 2) Determine which planting treatment (species / method / time) provided the greatest survival rates; 3) Re-establish overhanging vegetation along the eastern (non-road) bank of Phinney Hill Stream; and, 4) Produce a Best management Practices report for planting trees within Hydroseeded riparian areas in southern New Brunswick.

Figure 3: Phinney Hill Stream showing the initiation (left) and establishment (right) of Hydroseed following the completion of construction activities.

Methods Planting Treatments A variety of planting treatments using native trees were conducted in 2011 and 2012. In 2011, six treatments were conducted involving the use of three different species; alder, willow and white spruce. Five different treatments involving the willow and alder were conducted on May 13th, 2011 using three planting techniques: live stakes; fascines and pull downs. The five trials consisted of alder live stakes (ALS), willow live stakes (WLS), alder fascines (AF), willow fascines (WF) and alder pull downs (APD). Willow pull downs could not be used due to their lack of availability immediately adjacent to Phinney Hill Stream. Trees were planted solely along the eastern bank of the stream as they could not be planted along the road due to access concerns. The trees were planted along the entire 1000m length of the eastern bank of the Phinney Hill stream, with approximately 10m of distance between each planting. Color coded flagging tape was used for each trial to help monitor the growth and development of each respective treatment (technique + species).

Sixty volunteers assisted in the planting of 125 potted white spruce (~30cm in height) along Phinney Hill Stream on September 25th, 2011. It took them three hours to complete the planting. The trees were planted 8 meters apart along the same 1000 meters of the stream with an additional 100 meters added (equaling 1.1km). Volunteers were given instruction by ACAP staff to ensure proper technique. Holes were dug eight meters apart for the potted plants to be placed in. Once trees were in place any remaining space was covered with the soil dug from the hole.

On September 12, 2012, twelve volunteers from Xerox assisted in the planting of 96 potted white cedar, 80 white spruce seedlings and 23 alder pull downs. The plantings were conducted so as to be spaced equally amongst the previous (2011) treatments) with care being taken not to disturb or damage any other planted trees. Again, the treatments were given a unique colour coding to foster improved assessments in in the future.

Planting Techniques Live Stakes Branches of approximately one meter in length were cut from nearby willow and alder bushes within the watershed, but outside of the 30m buffer zone of any watercourse. The stakes were driven into the ground approximately 75 cm from the stream, to a depth of approximately 30 cm (Figure 4). Two live stakes of the same species were planted side by side and considered a single trial. Each willow and alder stake were planted thirty meters apart.

Figure 4: Alder and willow live stakes are driven into the ground approximately 0.75m from the edge of Phinney hill stream.

Fascines Branches of approximately one meter in length were bunched together in groups of six or seven with foliated ends alternated to face in both directions (Figure 5). These branches were then tied together with jute string at the middle of the cluster, and colour coded flagging tape was applied. A trench was dug perpendicular to the stream channel, approximately 75 cm wide and 75 cm deep and the fascine was placed into the hole such that both ends were exposed (Figure 6). Large rocks were used to hold them in place while soil was shoveled over the branches leaving foliated ends exposed (Figure 7). Lastly, hay was put over top of the covered hole to prevent erosion.

Figure 5: Willows and alders were cut by hand, sorted, grouped and tied into fascine bundles.

Figure 6: A trench was dug perpendicular to the Phinney hill Steam channel (left) to allow for the planting of alder and willow fascines by ACAP staff. At least one large rock was placed on top of each fascine (right) to maintain their depth in the channel.

Figure 7: A completed fascine planting that has been covered with hay to prevent erosion.

Pull Downs

This technique, as the name implies, involves utilising an existing tree in close proximity to the stream and bending it downward such that its upper most branches provide immediate riparian cover. In this case, a trench (~ 1m long x 0.5m deep) was dug in a position perpendicular to the stream in which the tree could be pulled down with the center buried in soil leaving ends of the branches exposed (Figure 8). The branches were pulled down as far as possible, slowly and carefully to prevent breakage, especially of the main trunk. Large rocks were placed on the middle of the tree to keep it in place. Soil was shoveled back into the hole and over the middle of the tree. Hay was placed over the soil and middle of branches to prevent erosion. Upon completion, branches were facing the stream in a perpendicular direction, with expectation its foliage would eventually grow over the stream to provide shelter for fish and wildlife, decrease erosion along stream banks and reduce water temperature during the summer months (Figure 8).

Figure 8: A trench has been dug (top left) in preparation for an alder pull-down. The alder is then slowly and carefully bent downward (top right) and placed in the trench and held in position until it can be weighed down with heavy rocks (bottom left). The trench is filled in with soil, covered in hay and weighed down with additional heavy rocks (bottom right).

For this type of planting, it was necessary to have the desired type of tree in close proximity to the planting area. Due to this constraint, it was only possible to use this technique for alders on the lower section of the stream. Willows were not found in close enough proximity to the stream.

Potted Evergreens Potted white spruce and white cedar were planted approximately 1m from the edge of the stream by simply digging a hole large enough to accept the entire root mass and carefully placing the root mass into the hole.

The original earth was then placed around the roots and gently compacted by foot until the soil was firm and the tree was stable.

Planting Assessments The initial assessment of survival of the willow and alder treatments occurred on August 10, 2011, 89 days after the initial planting session. The trees were assessed and new flagging tape applied to facilitate identification the following spring. An additional assessment of willow, alder and white spruce was conducted on September 12, 2012, and a final assessment of potted evergreens (white spruce and white cedar) on March 9, 2013.

Survival of willow and alders was based on any single branch showing foliage, while evergreen survival was based on the physical appearance of the needles (green and not red) as well as structural integrity (i.e. browsed by deer).

Results Year 1 Alder Live Stakes Of the 18 alder live stakes planted, only one survived, equaling a 6% survival rate (Figures 9 (left) and 10).

This could indicate live stakes do not work well for alders or that the environmental conditions at this location were not suitable. They will be assessed again in 2012 to see how they progressed.

Willow Live Stakes Of the 18 willows planted in May 2011 using the live stake technique, 14 or 78% appeared to survive (Figures 9 (right) and 10). This could indicate willow take well to this environment or the live stake planting technique, or both. Further observation will provide longer term results.

Figure 9: Alder live stake showing no sign of growth (left). Willow live stake with new growth (right).

Alder Fascines Only 12% of the alder fascines survived (Figure 10), which could indicate that the alder cuttings weren’t able to adapt well to this environment with the facine planting technique. Two of the 17 planted (and found) on May 10, 2011, survived. The two that survived were not growing strong during the August 10th observation. They will be assessed again in 2012 to give a better estimation of survival rate over a longer period of time.

Willow Fascines With 71% surviving (Figure 10) , the willow fascines grew well in this area with this planting technique.

Twelve of the 17 planted (and found) appeared to be growing well on August 10, 2011 with signs of new growth. Some willow fascines grew almost two times their initial length, since they were first planted in May. Alder Pull Downs All eight alders (100%) planted using the pull down method survived as of August 10, 2011 (Figure 10).

Potted White Spruce Observations conducted throughout the winter months and into spring of 2012 found 100% of the potted White spruce had survived.

Figure 10: Comparison of five planting methods of alder and willow plantings used on May 13th, 2011.

Percent survival was based on observation of the plantings on August 10th, 2011. ALS – Alder live stakes, WLS – Willow live stakes, AF – Alder fascines, WF – Willow fascines, APD – Alder pull downs

Year 2 Assessments of survival were conducted for a second time on September 12, 2012. These assessments included the potted White spruce that were not available during year 1.

Alder Live Stakes The one alder live stake that had previously survived as of August 10, 2011 was no longer viable as of September 12, 2012, resulting in a 0.0% survival rate (Figure 11).

Willow Live Stakes All fourteen of the previously surviving willow live staked=s were still viable as of September 12, 2012, maintaining the survival rate of this treatment at 77.8% (Figure 11).

Alder Fascines The eighteenth alder fascine, which had not been found during the last assessment, was discovered with growth (foliage) along with another that had been presumed to have been non-viable. As such, the survival rate of this treatment was more accurately determined to be 22.2% (Figure 11), and not the 12% previously recorded.

Willow Fascines This treatment had a survival rate of 83.3% (Figure 11), with 15 of 18 treatments showing foliage. As with the alder fascines, two additional fascines were found to have new growth that had previously thought to have been non-viable.

Alder Pull Downs Only 7 of the eight alder pull downs were found to be intact as one (which had previously been a survivor) was found disrupted possibly by an ATV. This treatment was removed from the trial. Six of the seven were found to have new growth, resulting in a survival rate of 85.7% (Figure 11).

Potted White Spruce All 125 potted white spruce were found to have survived and to be in very good condition, resulting in a 100% survival rate (Figure 11).

Figure 11: Comparison of five planting methods of alder and willow plantings used on May 13th, 2011, along with potted White spruce on September 25, 2011. Percent survival was based on observation of the plantings on September 12, 2012. ALS – Alder live stakes, WLS – Willow live stakes, AF – Alder fascines, WF – Willow fascines, APD – Alder pull downs, PS – Potted White spruce.

Potted White cedar Preliminary assessments of the white cedars conducted during the winter of 2013 also suggest very high survival rates, with no discolouration or browsing by wildlife.

Conclusions The results of this study find that the use of alders through live staking or fascines is not an effective method by which to re-establish riparian vegetation. However, given that alders were the dominant flora in much of the riparian area of Phinney Hill Stream (like many low lying steams in this part of New Brunswick) the use of alder pull-downs does appear to provide the highest survival rates next to potted evergreens. Pull downs also have the added advantage of provide virtually instantaneous canopy cover as they can be directed such that the tips of the trees overhang the watercourse. Furthermore, pull downs require minimal investments in materials or tools and can be taught to volunteers within minutes. As such, where alders are a viable and preferred riparian foliate, it is recommended that alder pull downs be the treatment of choice.

Willows, which are a time-tested favourite of fish habitat managers, provided high survival rates for both live stakes and fascines. Willows are hereby also recommended due to their high survival rates, low costs and minimal technical requirements; however, given their propensity for invasive roots they should not be utilised in close proximity to valued infrastructure such as foundations or drainage tiles.

Potted White spruce and potted White cedars both had exceptionally high survival rates, suggesting these are also good choices riparian cover; however, these treatments carried substantially higher initial costs (~ $10-$15 / tree) without any offsetting lower planting effort. Furthermore, the slow growth rate of these species suggests canopy cover would not be realised for at least a decade after planting, versus alder and willows which can be re-established in a few years. As such, these treatments are only recommended where a mix of species is desired, aesthetics are a primary requirement (private or commercial property), where highly hydrated soils are absent, or where a funding agency requires them to be utilised.

ACAP Saint John is a non-profit charitable environmental organisation that was founded in 1992. Our Mission is to engage the multi-sectorial community of Greater Saint John in the collaborative management and restoration of our watersheds. ACAP Saint John works with those stakeholders in the community who share a common belief that an industrialised urban center can support an abundance of functional natural capital. ACAP Saint John envisions a sustainable community that embraces the interdependence of the unique social, economic and environmental characteristics of the region’s watersheds.

Contact

ACAP Saint John 76 Germain Street, PO Box 6878 Stn ‘A’ Saint John, New Brunswick, E2L 4S3 Ph: 652-2227 fax: 633-2184 e-mail: acapsj@rogers.com Website: www.acapsj.com Facebook.com/acapsj