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Planting prescriptions must be developed in a timely manner. Lead time must be allowed for the collection, if required, and processing of seed, completion of any prescribed site preparation, for nurseries to grow the seedlings, planting contracts to be advertized and issued, and for delivery of stock to the planting site. Initial planting prescriptions are developed along with the SP. Prescription information and sample forms are located in Appendix 1, Forms Management.
An essential factor in any successful planting program is the determination of an appropriate planting microsite a microsite that will address the limiting factors of the site, factors that may otherwise negatively affect seedling establishment and performance. Determination of the appropriate planting microsite must be considered during the SP.
This decision on microsite requirements is tied directly to the selection of species and stock type, and to the decision about site preparation requirements. The development of the planting prescription is only one part of the larger overall reforestation plan for the site.
What constitutes an appropriate microsite is dependent on several factors:
These factors and the impacts that they may have on the success of a plantation are outlined in the video Planting spot selection: Matching seedlings with microsite, B.C. Min. For., (1992).
It is critical that the microsite requirements are carried from the prescription stage to the appropriate schedule of the planting contract and into the field as well.
Prompt planting, immediately following harvesting or site preparation, is one of the most successful and cost effective methods of reforestation. Planting prescriptions are the foundation on which planting projects are formulated and planned, and as such are key to the success of the reforestation effort. The key elements in the timing of planting prescriptions are as follows:
In general, ideal planting dates occur when all factors indicate that the potential of the seedlings to survive is at a maximum. The start date of a planting window should not be an administrative decision, as it depends on any combination of the following factors:
The majority of planting in British Columbia is carried out in spring. Site conditions such as soil temperatures and rate of snow melt must be closely monitored in the early spring to determine the planting start date. Spring planting can begin once the following three conditions have been met:
Spring planting may be best suited for sites with a combination of the following characteristics:
The success of a spring (or any) planting program depends mainly on three points:
Start up and completion dates of planting have been established following years of survival and growth performance results and extensive local experience. The dates are not arbitrary, rather the recommended time frames are based on sound biological and physiological principles. Planting seasons for biogeoclimatic zones by regions are outlined in the Provincial Seedling Stock Type Selection and Ordering Guidelines, Table 6 in the chapter Choosing a Stock Type.
Spring planting, usually with fully dormant seedlings, should begin as soon as the weather and soil conditions permit and be completed as quickly as possible to allow the seedlings to adjust and fit into their natural biological cycle.
Sites that have become free of snow may still have access problems due to late snow melt on roads. Blocks should be checked for access, and planning should consider access problems due to snow.
The latest completion date for spring planting is June 20. Dormant spring planted seedlings must be given sufficient time to break bud, flush, and elongate before summer drought conditions occur and have time to set buds and harden off prior to heavy late summer or fall frosts. By mid-June seedlings may have been in storage for six months. Carbohydrate reserves may be at critical levels, impairing field survival and growth.
Prescribe sites that predictably will not be available for planting before mid-June for summer planting in the interior and fall planting on the coast.
Seedlings for spring planting are generally lifted at the nurseries when they are nearing maximum dormancy and have achieved a specified frost hardiness. The lift period for interior nurseries is generally late October to early December, while coastal nurseries complete their lift from late November to early February.
Planting stock that will be stored more than 23 months is usually stored frozen at minus 12°C. This is a common practice for all species. These storage conditions minimize seedling respiration, maintain dormancy, and inhibit the growth of moulds. Adequate time prior to the start-up of planting season must be allowed so the thawing process can be initiated. A variety of thawing regimes are now being used. Contact a Nursery Administration Officer for specific thawing guidelines and time lines.
Seedlings that will be stored for less than 2-3 months, a common occurrence on the coast, may be cold stored and kept at 1-2oC above freezing.
Dormant Versus Hot-lifted Spring Stock
While spring stock is dormant-lifted and frozen stored for over winter storage, there is the option to use hot-lifted spring stock. Stock scheduled for planting prior to March 15 (mostly coastal stock) is usually spring lifted and stored at temperatures above freezing. Some other hot-lifted spring stock can be ordered. Consider spring hot-lifted stock only for sites where the nursery is close by and the nursery has a proven ability to successfully lift stock in early spring. The same guidelines for stock use that are applied for summer-lifted hot stock must be followed.
Hot-lifted spring planting generally applies to bareroot and transplants for some coastal projects.
Summer planting in B.C. is one other planting option being used, especially in the interior. This is due to a proportion of logging taking place in high-elevation ecosystems. Summer planting may begin as early as mid-June and extend to the end of August, depending on site conditions and the availability of suitably conditioned seedlings. Refer to the Provincial Seedling Stock Type Selection and Ordering Guidelines for planting windows for summer planting by region and biogeoclimatic zone. Areas best prescribed for summer planting, are those with any of the following conditions:
Summer planting stock experiences its spring flush, shoot elongation, and bud set while still in the nursery. Lifting of summer stock is done in co-operation with nursery specialists who ensure that stock is ready for outplanting. (Refer to the Provincial Seedling Stock Type Selection and Ordering Guidelines, Receiving and Handling Stock.) Seedlings are generally lifted when the following conditions have been met:
Summer planting of hot-lifted seedlings requires careful co-ordination of the lifting, packaging, shipping, and planting of the seedlings since all of these steps must be completed within a few days.
Summer stock requires special onsite care, including:
These factors must be taken into account when developing a planting prescription. Greater care and administration of stock is usually required for a summer plant.
The success of a summer planting program depends on the timely availability of the planting stock and the manpower to handle and plant it.
Few operational summer planting programs are presently carried out on the coast due to the length of the spring season. This long season usually provides ample time to complete planting. However, the Vancouver and Prince Rupert regions are implementing summer planting programs, most often on their coast/interior transition sites.
Late Summer (Fall) Planting
Fall planting in British Columbia is currently restricted to the coastal and coast/interior transition regions of the province where the options for spring planting are limited by late melting of winter snow packs and where summer moisture deficits cause stressful drought conditions. No operational fall planting occurs in most of the interior primarily due to the shorter growing season, cold soils, and the ever present risk of damaging frost.
If the decision is made to fall plant, plant as early as possible. Have stock hardened off in the nursery as early as possible, providing the flexibility to plant early if field conditions permit.
The commencement of any fall planting program depends on stock conditions and soil moisture. It is very important that the soil be sufficiently warm and moist to stimulate some root development. Sites with fine-textured soils and large expanses of exposed mineral soil may be at risk to frost heaving. Avoid planting these areas late in the season.
Fall planting generally begins in the first week of September. The season generally extends through late September or mid-October. The chapter on Choosing a Stock Type in the Provincial Seedling Stock Type Selection and Ordering Guidelines, outlines planting windows available for fall planting by region and biogeoclimatic zone.
Correct species selection is one of the primary and most important steps in the reforestation process. When selecting the species for a specific site, one must keep in mind the future goals of the forest and the projected end product. In most cases, the species will be specified in the SP. However, the planting prescription should confirm the correct species selection. When selecting a species, consider the following:
Species selection is a critical component of biodiversity. The SP should tie in with upper-level plans to ensure the maintenance or enhancement of biodiversity. Planting by itself, or in combination with natural regeneration, can create a highly successful (in terms of economics and aesthetics) and biologically diverse forest. Special consideration may need to be given to ensure success of some species. For example, western redcedar must be protected (refer to Protection of Planted Seedlings) in some coastal ecosystems where deer browsing can severely affect survival and growth. Recommendations regarding biodiversity requirements under the Forest Practices Code can be found in the Biodiversity Guidebook, 1995.
The objective of stock type selection is to decide, based on site conditions and experience, what seedling morphological characteristics (e.g., height, root collar diameter) will best suit the site. The selection of stock type is an important element in the regeneration process.
Stock type selection has its greatest influence on the initial survival and early growth rate of a plantation. With time, however, site conditions will usually assume a more important role in determining stand performance. Selection of an appropriate stock type can help to overcome the establishment and early growth limiting factors on the site. In addition, choices made at this stage can affect future stand management decisions.
For more information, refer to the Provincial Seedling Stock Type Selection and Ordering Guidelines, 1998.
Planting density should ensure that there is a sufficient number of well-spaced acceptable trees per hectare to produce target stocking levels at free growing. The appropriate planting density can be determined by working backwards from the desired stocking at free growing and considering those factors that will affect final stocking (i.e., planting density equals target stocking at free growing plus expected mortality, minus expected well-spaced natural fill-in).
The choice of planting density depends on the following factors:
The appropriate planting density is developed at the time of the plantability survey. A guide for target stocking is provided on an ecosystem basis in the Establishment to Free Growing Guidebook. Details on plantability surveys are covered in the chapter on Silviculture Surveys, Section 3, Survey Procedures.
Inter-tree spacing is the distance specified, in metres, between planted trees, when determining the planting contract specifications. Based on the desired planting density, the contract inter-tree spacing is determined from Table 1.
Table 1. Inter-tree spacing based on planting density
based on 3.99 m plot radius (1/200 ha)
Planting densities are generally rounded to the even number to facilitate the use of the 3.99 m plot and its multiplier factor of 200. If planting densities of 900 or 1100 were desired, then the larger plot size of 5.64 m with a multiplier factor of 100 should be used to ensure an adequate sample of trees are measured (see 7.7, Intensity in Project Management).
Minimum Inter-tree Spacing
The minimum inter-tree spacing is established at the SP stage and forms the legal basis for a free growing assessment. It is critical that it matches with the plantability survey criteria and the final planting prescription requirements. Trees planted at less than the minimum inter-tree spacing (specified in the SP) can not be tallied as acceptable at free growing.
The planting or spacing latitude is set in order to achieve a desired planting density within the constraints or variation given by the site conditions. Spacing latitude can be characterized by the following three points:
The planter is expected to use this spacing latitude to make use of the most appropriate planting microsite. In order to maintain the overall density at prescribed levels, the planter should compensate for the tighter spacing of one tree by planting the next tree at greater than the contract spacing.
As the availability of plantable microsites decreases due to the presence of acceptable natural regeneration or poor site conditions (thick duff, heavy slash, or standing water), the planting or spacing latitude should be increased. Guidelines for determining spacing latitude are summarized in Table 2.
Spacing Latitude - Mounded Site Preparation
When prescribing for planting on areas of mounded site preparation, the spacing latitude provisions will not apply. However, as stated previously, trees planted at less than the minimum inter-tree spacing can not be tallied as acceptable, well-spaced trees at free growing. For mounded ground, the description of what is an acceptable mound is critical. The planting contract should stipulate that every mound that has the acceptable characteristics (e.g., size, amount of soil capping) will be planted.
Note: Other spacing provisions in the planting contract should be deleted or referenced as they will not apply in such an area.
Table 2. Spacing latitudes and guidelines for their application
The most commonly used planting tool in British Columbia is the planting shovel. Other tools include the planting spear, and the cottonwood planting tool.
While many styles and types of shovels exist, the most critical requirement is the length of the blade. The blade must be as long or longer than the root system on the stock type being planted. The site conditions such as depth of duff, depth of mineral soil capping on site prepared areas, and depth to bed rock also dictate the size of shovel required for the task. This is usually determined at the prescription stage and should be included in viewing and contract tendering specifications and re-iterated at the pre-work conference.
The four most common spade types are described below and illustrated in Figure 1.
A. The Tree Planter Spade is the most popular shovel available for planting plugs, 1-, 2-, and 3-year-old bareroot seedlings with roots up to 25 cm long. The minimum blade length is 27 cm.
B. The Speed Spade is strictly used to plant plug stock seedlings. The minimum blade length is 24 cm.
C. The Spear is used to plant seedlings in rocky ground enabling planters to locate more plantable spots per hectare. The minimum blade length is 21 cm.
D. The Cottonwood Planting Tool is designed to plant cottonwood whips. It is constructed of 190 mm diameter round steel rod. Total length of 160 cm with a foot step at 72 cm and a top T bar of 30 cm. The tool is inserted to varying depths depending on whip stock size.
Figure 1. The common spade types and an example of the cottonwood whip planting tool (not to scale).
Proper planting microsite selection is critical to ensure seedling survival and growth. A lot of time and money goes into the production of high quality seedlings and into the preparation of the planting site. All of these efforts can be wasted if the seedlings are not planted on the proper microsites.
Stipulations in the contract regarding spacing tolerances allow the planter and planting administrator the flexibility to allow for optimum microsite selection.
The person preparing the planting contract must ensure that the microsite requirements are incorporated into the contract specifications and are communicated to the planting contractor and planters.
More information on planting spot selection can be found in the video Planting spot selection: Matching seedlings with microsites. As well, a detailed description of preparing microsites and the different microsite options available through site preparation techniques can be found in the chapter on Site Preparation.
A workshop entitled Microsite Selection and the Informed Tree Planter A Critical Step is available. This course is designed to provide the planter with basic information on the importance of microsite selection and the impact it can have on the success of a plantation. The training can form the basis for the achievement of the prescribed microsite requirements outlined in the SP and ensure the communication between the contract officer and the planters regarding microsite selection for the specific site being planted.
For more information on the workshop, contact the Regional Reforestation Forester or the Regeneration Specialist, Resource Practices Branch.
The microclimatic conditions around a seedling are very important in spot selection. The assessment of these conditions can be critical to plantation success.
For more information on microsite conditions, refer to:
Many planting sites require special techniques to enhance survival and growth of the seedlings. These should be determined at the time of the original prescription and included in the contract package and discussed at the pre-work conference. New requirements should not be added, without a contract amendment or Change of Work Order. Remember that each additional requirement will increase the cost of the project. Ensure that each requirement is necessary for that particular site and then enforce it during the planting.
Screefing is a technique that removes loose debris, needles, and sticks that cover the acceptable well decomposed humus or mineral soil growing medium. In most cases screefing is accomplished by the kicking action of the planters boot, or the scraping action of the planter´s shovel. (Refer to the safety discussion related to screefing on the Workers Compensation Board Worksafe Online web site.) Screefing in wet areas should be done with caution as too much screefing can result in water ponding and the creation of a cold rooting zone for the seedling. In some soil and moisture conditions, screefing to mineral soil may also increase the potential for frost heaving.
When screefing, removal of all the humus layer is not always desirable or warranted. Well-decomposed humus layers are often rich in nutrients and capable of supporting excellent root growth. Site- and species-specific requirements for screefing should be made at the prescription stage. Some species such as western hemlock root extensively in the lower humus layers of the forest floor.
Where manual screefing is expected to substantially increase the planting costs, alternative site treatment should be considered prior to planting. Site treatment can provide improved microsites, more plantable spots, greater planter productivity, and improved planting quality-all potential benefits in terms of survival and growth performance of the planted seedlings. See the chapter on Site Preparation for details.
For more information, refer to:
On some south-facing exposures, the potential for high surface temperatures and solar radiation damage to seedlings can cause damage to newly planted seedlings. Consider shading tender, nursery grown seedlings from excessive radiation and heat. The root collar of the seedlings is very vulnerable during the first season on the planting site. To minimize stress on the seedling, plant trees in shaded microsites to accomplish the following:
The best solution for areas experiencing high radiation problems is to prescribe the use of natural shading on the northeasterly side of logs, stumps, and any other debris, and to order short, stocky seedlings grown at the nursery in outside compound conditions already acclimatized to high light and radiation levels. Artificial shading with shade cards or similar objects will also protect the seedlings from the sun and reduce evapotranspiration. However, this method of shading has not proven to be operationally feasible in most areas due to a variety of reasons (e.g., high cost of installation and maintenance, improper positioning of cards).
Obstacle planting, which involves planting in the shelter of stumps, coarse woody debris, or other natural features, may reduce wind-related damage, damage from snow creep, snow press, and cattle as well as reducing the incidence of damage caused by radiation frost.
Note: Care must be taken when making a prescription to assess any forest health concerns, such as root rot, that may preclude planting close to stumps.
For more information on obstacle planting with regards to cattle and range situations, see Protection of Planted Seedlings, 2.9, Special Requirements, Project Planning and Prescription Development.
In general, the practice of planting slightly deeper than the root collar is preferred over planting too shallow. Using this technique will ensure correct positioning of the seedling after the soil settles, especially on mechanically site prepared ground. In addition, it ensures there are no exposed roots, which would otherwise be subject to severe sun scald and desiccation.
One apparent disadvantage of deep planting seedlings is the increased chance of `J' or `L' roots, observed when long-rooted trees are planted in shallow holes. As well, deep planting is not recommended on cold wet soils.
The effect of deep planting varies by species, site, and treatment. One situation where deep planting has proven to be particularly effective is on sites that have been mounded. On mounded sites, deep planting has the following advantages:
When planting mounds, care must be taken not to J the plug at the interface between the mineral soil cap and the resistant inverted humus.
Fertilization at Time of Planting
Fertilization at the time of planting is generally not recommended. Operational trials have shown that results are extremely variable and net benefits may be low, non-existent, or negative. However, one example where benefits have consistently occurred is on sites having chlorotic, slow-growing Sitka spruce, western hemlock, and western redcedar regeneration on salal-dominated sites (refer to SCHIRP Research Update #1, Chapter 1 Influence of Density, Scarification and Fertilization at Planting on Growth of Cedar and Hemlock on CH and HA Sites). Seedlings planted on rehabilitated sites may also show a positive response. Fertilization at time of planting on these sites may provide an immediate but temporary release of growth check.
An analysis of the effects of fertilization at time of planting is available as Regeneration Note #7, Gromax and Fertilization at Time of Planting: A Provincial Summary of Operational and Research Experience, 1995.
For more information see:
Animal damage to planted seedlings can greatly reduce survival and growth, particularly during the first years after planting.
The animals most responsible for heavy damage are deer, elk, moose, snowshoe hare, and voles. Others of lesser importance include pikes, mountain beaver, and pocket gophers.
Areas susceptible to animal damage can be identified by considering the following points:
Some animal damage can be controlled through identification of population buildups and identifying high hazard areas prior to logging. Outbreaks of small mammal damage may be predicted on the basis of population cycles. Snowshoe hare, for example, has predictable 9- to 10-year cycle fluctuations. The next outbreak will start in about 2009. If planting is completed during the periods of low population, seedlings will be able to achieve higher survival and growth rates prior to a population outbreak. Other plans, such as Landscape Management Plans or Management and Working Plans should consider animal damage issues. The adjustment of harvesting schedules may be an option in some situations.
There are various methods that can be prescribed to successfully reduce animal damage:
The most effective method of animal damage control used in a specific area will depend on the extent of animal damage and the type of animal responsible for the damage. When identified, population cycles and peak periods will be useful for developing planting and other treatment schedules for animal damage reduction.
For more information on animal damage and management to reduce damage, refer to:
Identification of present or potential cattle use areas can be critical in planning your planting program.
Grazing Management: Cattle can be compatible with forest regeneration, provided good grazing management practices are employed. To maintain seedling damage at a minimum the cattle must be efficiently herded and transferred to other sites throughout the growing season. Cattle movement should be frequent and the number of cows per site should be minimized. Clearcuts should be intensively grazed for only brief periods of time, particularly in the first year of seedling establishment, and grazing should be on a rotational basis. Seedling damage usually does not occur until forage is reduced and cattle begin to move around in search of better grazing. However, decisions must be made on a site-specific basis due to many plantation variables. It is difficult to rigidly define the optimum number of cattle and a regular movement schedule for all plantations because of cutblock, time of year, quality, quantity and type of forage, weather, number of cattle, presence of water and other factors all vary between plantations. For good cattle management a comprehensive monitoring program must be established and implemented.
Communication with the Range Section and ranchers in the area is important so that the objectives and needs of each other are well understood.
Cattle will generally walk or graze along the path of least resistance; for example they will follow a disc trench as if it is a trail. Seedling injury along V-plow trenches can be reduced by more than half when a winged ripper tooth is run down the middle of the V-plow path, therefore discouraging cattle from using the path. In grazing areas, prescribe planting up from the bottom of the trench, closer to the hinge, or on the berm position. Planting close to obstacles such as slash or stumps is also a good strategy. Also, prescribing larger, well-branched stock types may be of benefit as they may be able to withstand a higher level of damage and still survive. Techniques to increase even use of forested range include construction of drift fences and fencing problem plantations, problem cattle concentration points and waterholes. Careful location of waterholes and salt blocks may prevent plantation degradation. The removal and/or planned orientation of slash within plantations may be used to permit, prohibit or direct cattle access and movement.
For further information, refer to Land Management Report 32, A bibliography on range, forages, and livestock management in British Columbia, 1985.
For surveys associated with apparent seedling damage, contact the Kamloops Forest Region Range staff.
Insects and Disease
An assessment of potential risk to insects and disease is an integral part of the SP and should be re-evaluated when finalizing the planting prescription.
Problems with insects and disease can be traced to two origins, those associated with the site and those originating in the nursery and being found on the planting stock after transporting to the planting site.
For more information on site assessments of pests and diseases, refer to:
To identify potentially high hazard forest ecosystems refer to the regional forest health charts or contact regional forest health staff. Stand susceptibility maps relevant to the forest health factors should also be consulted. These information sources must be considered together as there is no single reference listing forest health hazard levels for all forest ecosystems. Forest health charts available from regions are as follows:
Forest health charts are not published for the Cariboo and Prince George Forest Regions. For these regions, please contact local forest health staff for assistance.
The effects of a single or repeated frost event during the growing season can cause serious regeneration problems. On many site types studies have shown that frost can occur at any time during the growing season.
Factors such as wind, relative humidity, and long wave radiation can affect the potential for frost damage. As well, site factors such as elevation, slope and topography, aspect, and vegetation cover will affect frost damage.
During the establishment phase, some tree species are highly susceptible to growing-season frosts, resulting in damage and mortality. On site series where growing-season frosts are common, the use of species more tolerant to frost is recommended. Possible remedies when using frost-susceptible species include maintaining protective cover, reducing frost ponding by improved air drainage, or mounding. Table 3 summarizes the relative frost tolerance to growing-season frosts of the tree species of British Columbia, and can aid in matching frost-tolerant species with the expected frost on these sites.
Table 3. Relative tolerance to growing-season frost by tree species (Establishment to Free Growing Guidebook, 1995, Appendix 4)
Symptoms of frost damage typically occur on the current year's foliage, particularly on the terminal leader and on laterals directly exposed to the cold night sky. After a frost, symptoms usually begin to appear within a few days and are fully evident within 1-2 weeks. Damage is evident as the browning, yellowing, or death of new growth. Seedlings that have repeatedly suffered frost damage develop a bushy growth form.
One publication that reviews the causes of summer frosts, the identification of frost prone sites, and the effects of frost on conifer seedlings is entitled The causes of summer frost and its effects on conifer seedlings, FRDA Project 3.65.
For more information on frost and frost damage, refer to:
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