UBC Farm Hedgerow Directed Study 2008-2010
Introduction to Portfolio
The UBC Farm hedgerow directed study is a constantly evolving and maturingproject. It is a project that will perhaps never “end,” orbe truly finished. The very nature of hedgerows is successional. And this is the way it should be.
Since 2005, severalfunding and academic interests have focused on establishing hedgerows at the UBC Farm. These include several directed study projects, an undergraduate thesis,[1] and multiple grant-funded projects. After two years of my own study and establishment of hedgerows at the farm, I am only now beginning to understand the full scope of what they have to offer managed landscapes. As a result of my learning process - and many other factors - there are many aspects of my project that I would change if I could, or at least approach differently if I were to start anew. That said, my “mistakes” and struggles with self-directed learning gave me an invaluable opportunity for experiential learning and reflection. This has instilled in me adeep respect for the complexities and unknowns of hedgerow ecology.
I decided to create a mostly practical guide for the hedgerows I worked on (and continue to work on), because the critical basic theory and research is adequately presented in papers preceding my project. I have compiled easily accessible information[2]that is useful as a foundation, recorded history, and reference for management and initiation of hedgerows at the farm. This information includes: four useful hedgerow papers written by my peers; a number of resources and guides that are regionally significant; and, my own documents relevant to the hedgerows I partially and fully established at the farm. It can be fully assumed in reviewing this portfolio that I acutely followed Dianne Favley’s step-by-step methodology for establishing hedgerows insofar as landscape ecology is concerned. Although my species selection process and design differs substantially from Favley’s, the theory and mechanics behind the overall project are generally the same.Because my project is yet to be completed in its materialization, this portfolio is intended to serve as a comprehensive and historical reference for myself and others, and will be updated accordingly as long as it is possible to do so.
Explaining the Hedgerows: Rationalebehind the Four Strips
This project focuses on approximately one-quarter hectare of land, distributed in linear strips in a perpendicular configuration. These are located at the edges of cultivated fields and join small tree stands with the larger forest buffer surrounding the farm. For my own organization, I split the hedgerow strips into four separate areas of roughly equal area; labeled H1, H2, H3 and H4 (see maps). The four hedgerow strips combined meet my proposal’s objectives,although each strip has aunique speciesthemefor both practical and experimental reasons. Therefore, some of the hedgerow strips will meet certain objectives more than others. Especially in the case of more experimental strips (namely H3), I have accepted that my rationale and the hedgerow itself may “fail” to meet my original intensions. On the contrary, such a design for a hedgerow might prove to be enormously interesting and beneficial to the ecological and cultural systems in which it is embedded.
The following is a briefsummary of each strip using key examples to discuss each hedgerow’s site characteristics, species composition, andgeneral rationale for my design in terms of meeting my objectives (please also see corresponding maps and species documentation chart, which will likely be updated more frequently than this document).
H1: The Forest Edge Hedge
In 2005 and 2006, Antonin van der Lelybegan the establishment of H1 and H2 as a directed study (see resources). Antonin only established four species in the H1 strip: one paper birch (Betula papyrifera); two red alders(Alnus rubra); one unhealthy, stunted noble fir (Abies procera); and continual clusters of unidentified non-native raspberries. This strip is closest to the forest edge and is also the lowest lying of all four strips. It is by far the wettest and most shaded area, creating a “cold pocket” where frost can remain for hours after the sun has risen. Of the four strips, the O and A soil horizons in H1 are the deepest, richest in humus, and least rocky. The strip is situated in a north-south orientation and is a considerable distance (approximately 15 feet) away from both adjacent cultivated field edges. These basic characteristics, coupled with my selected objectives, led me to choose the species indicated on the H1 base map.
The forest shade as well as Antonin’s already established(and by now, large) trees allowed me to plant many shade-loving species I could not plant elsewhere, or have planted knowing they will not thrive or grow to their maximum capacity (i.e. Vaccinium ovatum – evergreen huckleberry & Vaccinium membranaceum–black huckleberry). Similarly, the comparatively humus-rich soil and moisture levels allowed me to plant willow and hardhack, which are both excellent regenerative wildlife habitat species that demand constant moisture and substantial organic matter to do well.
H1’s north-south orientation gave me height flexibility that I did not have with H3 and H4. I chose to plant a linden and vine maple, both of which are fantastic bee forage, knowing that neither would reach full height before needing to be cut down (or topped) once they begin to shade out fields. However, the heights at which these trees will remain for a decade or more will not be so high that they cause problems, but rather, will serve as windbreaks, bird travel corridors, bee forage and a number of other beneficial functions.Such is the logic with most of the larger species I chose to plant: although they will eventually come down (hopefully as a useful product: i.e. alder firewood for fish smokes), the services they will provide in the interim, are largely worth it. This holds especially true if successional planting can be pre-planned for, which is something farm management would have to employ.
H1 can be summarized as focusing heavily on wildlife and ecological capacity building with special attention paid to bee forage, bird travel corridors and soil quality building (mainly through nitrogen fixing alders). Additionally, H1 and H2 are very much intended to create a windbreak between fields D7 and D4. There are only a few species in H1 that produce readily edible crops for humans (huckleberry and raspberry) and the focus on medicinal and other non-timber products is minimal. Potential for such objectives could be enhanced easily in the near future, such as oyster mushroom cultivation from red alder cuttings. Lastly, H1 would greatly benefit from the establishment of more coniferous and broadleaf evergreens, which provide beneficial features in a hedgerow that will be discussed later. Ample room has been left for such plantings and will likely be done within the next year as my grant extends into 2011.
H2: Tall Trees and Lots of Breeze Hedgerow
Again, H2 had some interesting features to work with due to Antonin’s previous plantings. This hedgerow became a challenge for me mostly because parts of Antonin’s establishment are incongruous with my particular vision for the hedgerow. Although I never found documentation of what he actually established and the reasoning behind it, I tried to rationalize his choice of species and layout, and generally acceptedmost of it. I had to work around the spotty areas of established species, attempting to fill in the “gaps” in a way that made sense spatially and met my desired objectives. I did end up removing some of the plants from his project mostly based on their poor health, or for spatial reasons. I have enjoyed watching the past three springs as the Scouler’s willow, mountain ash and densely planted cluster of elderberry, snowberry and salmonberry fill in to create what is looking more like a matured hedgerow every year. Witnessing Antonin’s plantings becoming a bona fide hedgerow gave me a refreshed enthusiasm and new perspective on what to plant and where.
Along with creating the aforementioned windbreak, I focused H2 heavily on trees and shrubs with medicinal, culinary and First Nations cultural significance (i.e. crafting materials, medicines, tools, etc.). Species such as cascara, red-flowering currant, tall Oregon grape, mock orange and oceansprayexemplify this focus and can be found interspersed throughout H2. I also continued much same species makeup that Antonin began, many of which conveniently fall within the same three areas of focus listed above. Thus, additional plantings of snowberry, elderberry and paper birch are woven throughout the formerly and newly planted areas of H2. All of the species mentioned thus far are indigenous to the Vancouver area and therefore also service important native insects, birds, small mammals and other biota crucial to creating maintaining an effective and healthy hedgerow (see Antonin’s species analyses and charts in his paper).
Several gooseberry bushes of unknown cultivars (established by Mark Bomford) as well as some native red huckleberries, trailing blackberries and more unidentified raspberries were also present in H2 when I began planting. These are likely all meant to be food crops for humans and can potentially be sold at farm markets. Now mixed in with some of the indigenous species I planted, this demonstrates an interesting mixture of “wild”and cultivated species within a single hedge. It will be interesting to watch as competition for space and other resources affects these two “categories” of plants. My informal hypothesis is that the non-native species which have been bred to thrive and produce copious fruits in highly managed systems will eventually die back or struggle once other plants better adapted to the site’s conditions fill in, mature and gain vigour.
I also planted a few non-native, but hardy species I think will nicely compliment the hedgerow strip and add to its overall capacity and function. I have been prudent to give these plants ample space and adequate positioning with regards to light exposure to ensure their successful growth. These species include another linden, a Viburnum pilacticum cultivar and forsythia. The beautiful, semi-evergreen Viburnum was bred and released by the UBC Botanical Gardens and can be used as cut flowers for market sales while providing excellent aesthetic appeal. If signage is ever a funding priority, it will be nice to credit the Botanical Gardens with the creation of this cultivar and hopefully be acknowledged as a gesture of relationship building between the Gardens and the Farm.
Like H1, this strip will need to be enhanced with more evergreens, especially low-growing coniferous species. More evergreens will greatly increase thermal protection during winters and increase the diversity of wildlife attracted. This will hopefully materialize during fall of 2010.
H3: The Experimental Hedgerow
H3 is a mix of both native and non-native species, with the most emphasis on food and ornamental crops of the four strips. It is also by far the most unconventional and experimental strip. This is partially because I began planting the strip before I had even a fraction of the knowledge I have now about hedgerows. At the time, I was unsure of how much funding I would have for the project and the timeline. When the opportunity arose to use $500 from another farm grant, I had to make some quick species decisions. Luckily, I still feel that most of the species I chose to plant (black and red currants, abelia, barberry and non-native blueberry) will fit in nicely with this hedgerow. I am not so sure the fig trees I planted in this first round will do so well, as they are much less protected from wind and cold temperatures than they should be. Also, in this first round of planting, I decided to plant several peony varieties for cut flower sales and aesthetics, but that decision may prove to be impractical as the hedgerow matures and the peony plants may struggle to persist.
The site conditions in H3 (and H4) are not exactly optimal for establishing a high density strip of perennials. The width of the strip is by far too narrow (12-15 feet is optimal) and there is no room for an “emergent zone” of perennial grasses and a water ditch (see DF&WT reference). In the case of the UBC Farm however, lacking these features is not necessarily a detriment: perennial grasses may encourage wireworm/click beetle populations and unlike the low-lying, shallow water table lands of the Fraser Valley, the UBC peninsula is relatively elevated and the sandy soils are well drained, negating the need for water ditch drainage.
The soil in H3 is quite variable throughout the strip, although several years of sheet mulching has added a significant amount of organic matter to the A horizon. Sheet-mulching however, has added an over-abundance of woodchipsand cardboard to the topsoilthat has the potential to tie up what little nitrogen is presently there. I am not convinced that everything I’ve planted will grow well and maintain vigour without regular amendments and care, or strategic planting of low-lying nitrogen fixers.
This site is also quite exposed to strong winds and full sun for up to 10 hours during the middle summer months. I avoided planting anything that requires full shade to thrive, although once the southern edge of the hedgerow fills in, the plants on the northern edge will be in partial shade. I therefore planted species on the northern edge that are somewhere in the middle between full sun and full shade requirements. I also intentionally planted some species in full sun that need at least partial shade to grow to their maximum height and spread. In doing this, I am hoping to stunt their growth just enough to fill in small spaces where those plants would otherwise become too large. It is important to note that because both H3 and H4 are oriented in an east – west direction and are roughly 10 feet south of a production field, the maximum height these hedgerows can grow is quite limited. I placed a roughly 15 foot maximum height restriction on the species I chose for both strips, knowing that anything larger would have to be pruned or removed in a short period of time. Consequently, most of the species in H3 are shrubs, herbaceous woodies and ground covers.
The species schema for H3 is the most diverse of all strips. In general, the mix between native and non-native plants is fairly diffuse. Similarly, there is a decent amount of evergreen and deciduous shrubsand species continuity, despite the wide variety. Most of the food producing plants (notably berries) are on the southern edge of the strip and have been given ample room to grow, where they will receive full sunlight and enough air circulation to produce abundant yields. These plants should be monitored as potential “you-pick” or market producers given their relatively unmanaged environment. There are also several food producing native species in H3 that continue through H4 and should be monitored and used for similar purposes as the non-native food producers. These include: tall and creeping Oregon grape, service/Saskatoon berry, hazelnut and crabapple. Such species are planted much more sparsely in H3 than in H4 and are intended to give some continuity between the strips. More importantly however, they have been planted experimentally to see how well untraditional combinations of plants will survive and meet my overall objectives for the hedgerows.
It is unclear to me what H3 will look like in a few years. It is hard to say if I have spread myself too thin with all of the objectives I am trying to meet in H3, or if I will be able to demonstrate that hedgerows can be much more diversified and complex than is traditional. Either H3 will provide many services at once, or certain species will die back; leaving holesor being filled in by volunteers/neighbouring plants. The only additional planting H3 needs is nitrogen fixing species (possibly lupins) and a diverse under story of herbs, flowers and cover crops that should be implementedin the next few years.
H4: The Regionally Significant Hedgerow
The H4 hedgerow is the most regionally significant and mimics the species makeup of a typical hedgerow in British Columbia’s lower-mainland. Mostly adopted from Delta Farmland and Wildlife Trust documents, interviews and fieldtrips, this hedgerow is meant to mirror the hedgerows one sees driving pastFraser Valley farmland. 95% of the species found in H4 are native and recommended specifically for hedgerow establishment by Delta Farmland & Wildlife Trust’s responsible land stewardship initiative. Some of the more prominent species include, but are not limited to: beaked hazelnut, black hawthorn, Pacific crabapple, serviceberry, thimbleberry, mock orange and red-osier dogwood. This is the only strip that was fully examined and consulted with Markus Merkins, who is widely regarded as a hedgerow expert in the region. The few species that have been mixed in and are non-native (‘Center Glow’ ninebark cultivar and fig) were planted mostly to fill up space after some nursery ordering trouble, or were part of my first planting which I described under H3.