Designing Tree Plantings for Wildlife
Food, water, cover and space are the essential elements of wildlife habitat. All species of wildlife require good quality habitat on a year-round basis. Properly designed wildlife plantings can improve the habitat for many wildlife species.
Destruction of valuable habitat (i.e. clearing bluffs, draining sloughs and cultivating native grasslands) is the main cause of declining wildlife populations today. This document outlines a variety of methods for improving or creating wildlife habitat through the planting of trees and shrubs.
Planning your Habitat Enhancement Project
Like any project, the secret to success is planning. The first step in planning the project is to determine where it will be located. Once that is completed produce a scale drawing of the area where the tree planting will take place. Include on the map existing bluffs, rock piles, water-bodies, buildings, roads and power lines. Examine the drawing and try to determine how these natural features can be incorporated into the planting. Keep in mind that the rows in wildlife plantings need not necessarily be straight. In fact, wildlife will have a greater attraction to the planting if the rows are curved. Be sure to allow for room at the ends of the rows to turn with maintenance equipment. Design the tree rows using a multi-row approach, allowing at least 10 feet between rows. Connect and incorporate natural features of the landscape into the planting. For example, a multi-row wildlife field shelterbelt which curves around a rock pile could also function as a travel corridor.
There is some evidence to suggest that creating habitat in isolation from natural areas can lead to a predator trap. These small linear habitat areas can be worked very effectively by foraging predators. In some instances, entire local populations of the prey species have been destroyed after being attracted to the habitat, through predation. Therefore, it is recommended that the wildlife planting be located in areas which have some natural habitat associated with it. As a general rule, most wildlife plantings should be no smaller than 3 acres in size.
Important Components of Wildlife Habitat
When designing a planting for wildlife, there are many elements which should be considered. The main elements of wildlife habitat are food, water, shelter and space. All wildlife species need these to live. When designing the planting it is very important that these needs are considered for the species that the habitat is designed for.
Availability of food and cover are critical in the winter months when the energy needs of wildlife are greatest. Trees and shrubs which retain their fruit above the snowline throughout the winter provide an important source of high quality winter food. Dense shrubs and trees such as conifers provide important thermal cover for wildlife by protecting them from cold temperatures. In addition, trees and shrubs provide refuge from predators and during the summer furnish cover for nesting and raising young.
Trees and shrubs provide fruits, nuts, seeds, foliage and insects as food for wildlife. The availability of this food is most important during the winter when energy needs of the wildlife are the greatest and other food sources are scarce. Trees and shrubs which retain their fruit above the snowline throughout the winter can be an important source of food for wildlife.
Insects are an important food for many birds during the breeding season. For instance, young sharptail grouse and Hungarian partridge feed almost exclusively on insects. As well, chickadees feed on insects which dwell in the crevices of tree bark. Most migrating birds are insectivorous and use tree plantings for cover, nesting and feeding areas. Those shelterbelts which attract insects will also attract songbirds.
Ensuring that alternative food sources are available near the wildlife planting is also important. Some species such as pheasant, will only make effective use of tree cover if there is a food source nearby. Leaving small plots of standing grain near the planting site will improve the overall habitat of the area.
Shelter is the most important component trees and shrubs contribute to wildlife habitat. Wildlife plantings can provide excellent refuge from predators, protection from inclement weather, and travel corridors to move safely between habitat areas.
Planting shrubs such as hawthorn and buffaloberry will form an almost impenetrable barrier to large predators because of their thorny structure. Shrubs which have a high stem density, such as sea-buckthorn or choke cherry will form dense canopies which will provide additional hiding cover. Dense trees such as conifers provide important thermal cover for wildlife by protecting them from cold temperatures. In open areas with no other trees or perches, tall trees such as poplar may attract avian predators. For most wildlife enthusiasts owls and hawks are welcome, however if you are enhancing an area for use by upland game birds, shorter trees and shrubs would be more suitable.
Trees and shrubs provide nesting habitat for a wide variety of birds. Planting a high diversity of species will satisfy the different nesting and perching height requirements of various bird species, thereby attracting a greater diversity of wildlife to the planting. In addition, other species including squirrels, rabbits and deer will use these areas for cover.
Wildlife must move about to find food, water, and escape predators. Planting travel corridors provide wildlife with the cover they require as they move from one area to another. These corridors can be designed to connect a feeding area with a bedding area. Wildlife utilize the available habitat more freely if they travel under the protection of trees and shrubs. In many cases, these corridors can be designed to also function as field shelterbelts.
Wildlife Habitat Planting Designs
To be maximally effective, wildlife plantings should consist of multiple-rows. Multiple row plantings provide additional food, protective cover, nesting and bedding areas.
Ideally the planting should be at least nine rows wide (see figure 1). Plantings with a smaller number of rows could also be designed by eliminating some of the deciduous tree rows. Wider plantings with a larger number of rows can be created by doubling or tripling the rows recommended. It is important to keep in mind that not all species suggested below are adapted to all regions and soil types.
Plantings should be designed with taller trees, usually conifers in the centre, with progressively shorter deciduous trees and shrubs on either side. The outside rows (rows 1 and 9) should be composed of short shrubs such as snowberry, rose or wolf-willow. The next rows (rows 2 and 8) should be made up of choke cherry, buffaloberry, caragana, sea buckthorn, dogwood or red elder. As we progress through the rows we select increasingly taller trees and shrubs. In rows 3 and 7, hawthorn, Siberian crab, ussurian pear, and Russian olive are planted. In rows 4 and 6, the tallest deciduous trees such as poplar, Manitoba maple, bur oak, willow and green ash are used. The centre row is reserved for conifers. Scots pine, white or Colorado spruce are planted in this row.
"triangular" cross section increases the vertical stratification which helps to accommodate the diversity of nesting, foraging and perching height requirements of a variety of song birds. In addition this design also helps to ensure that at least one side of the planting will not be covered by snow during years of heavy snowfall and therefore ensure that the fruit and browse is available for wildlife.
Figure 1: Multi-row tree planting sketch
Multi-row Multi Use Shelterbelts
Multi-row multi use shelterbelts can be established to provide superior wind protection for the crop and to create better habitat for wildlife. Since these belts are a minimum of three rows wide we can incorporate many wildlife habitat components within the belt by selecting the proper species. Conifers planted in one row will provide winter thermal cover. Planting a variety of deciduous trees and shrubs such as; green ash, Manitoba maple and poplar, can ensure a diversity of nesting heights. Including fruit bearing shrubs such as chokecherry, buffaloberry or dogwood in the outside row(s) will contribute to a diverse food source for wildlife.
In addition to providing good soil erosion control and augmenting existing wildlife habitat, multi-row shelterbelts can also contribute to economic diversification. Opportunities for fruit harvest, Maple syrup production and specialty wood products exist. Please see Forest Belts for more information.
Figure 2: Block planting
Block Plantings consist of several rows of trees planted parallel to each other. They usually incorporate natural features of the landscape such as stream edges, sloughs, or existing bluffs. The rows are gently curved to follow the natural contours of the land and include shrubs and trees which will provide year-round food and cover for wildlife. Many prairie wildlife species prefer to feed and nest along the edge of a shelterbelt. By gently curving the tree rows, more edge is created and therefore more wildlife is attracted to the planting. Curving the rows also creates sheltered bays where wildlife can move out of the trees and still feel protected. Block plantings are most beneficial when planted near, or in conjunction with, a water body.
Figure 3: Bluff extensions
Bluff extensions are usually developed to enhance existing bluffs with some habitat elements which are lacking. Fruit bearing trees and shrubs are planted to increase the diversity of food available. In some cases conifers are planted to provide improved winter thermal cover. Bluff extensions can also be designed to function as travel corridors between two bluffs. The travel corridor can be composed of conifers, which increase thermal cover or fruit bearing trees and shrubs, which add variety to the food source.
Riparian areas are the lushly vegetated areas in coulees, alongside rivers, creeks, lakes and sloughs. Although these areas only make up a small percentage of the prairies, they are very important because of the diversity of plants and animals they support.
Figure 4: Riparian ecosystem
Riparian ecosystems are considered to be one of the most productive ecosystems in the world. Some evidence suggests that a large percentage of all prairie wildlife species, spends at least one portion of its life cycle in a riparian area.
Degraded riparian areas can be improved through various management techniques such as tree and shrub plantings. Re-establishing vegetation will stabilize banks and reduce further erosion.
Planting low growing shrubs such as snowberry and rose near sloughs will help to provide improved nesting cover for water fowl and other ground nesting birds. Planting taller trees and shrubs such as green ash, Manitoba maple, dogwood, choke cherry and poplar will shade the water surface reducing evaporation. Shade also helps to keep water temperatures low, which in turn allows for a greater concentration of dissolved oxygen. In areas where salinity exists species such as buffaloberry, Russian olive and choke cherry are better adapted. In moist, non-saline areas red elder, hawthorn, dogwood and hedge rose are preferred.
Densely vegetated riparian areas provide essential habitat for many wildlife species including deer, songbirds, insects and many aquatic species. However, these benefits are not limited to wildlife alone. Agriculture is benefited through increased ground water reserves, improved water quality and better quality of life for rural residents.
Abandoned Farmyard Enhancement
Abandoned farmyards are extremely important to wildlife since they are often the only patches of woody habitat in the extensively cultivated regions of the prairies. Many of these old yards have shelterbelts composed of caragana, Manitoba maple and some scots pine and spruce. While these trees and shrubs provide good cover and nesting sites they are not very effective in supplying food or winter thermal cover. Additional rows containing fruit bearing shrubs could be planted around the perimeter of the farmyard. Also, planting a clump or a few short rows of white or Colorado spruce on the north or west sides of the yard will provide good winter thermal cover.
Figure 5: Abandoned farmyard
Planting tree and shrub rows around the outside will maintain the centre of the yard in grass to provide bedding, nesting and feeding areas for wildlife. In addition, it will further isolate the habitat area from agricultural activity and add to the seclusion valued by wildlife. Maintaining the open area in the centre will allow access to the farmyard for equipment and grain storage.
Enhanced Single-row Wildlife Field Shelterbelt
Field shelterbelts reduce wind erosion, distribute snow and increase crop yields. The main shelterbelt species; caragana, green ash and willow, offer wildlife good cover and protection from the wind but provide little food. An enhanced field shelterbelt is created by planting a variety of fruit-bearing shrubs such as choke cherry, hedge rose, sea-buckthorn, buffaloberry and Siberian crabapple in with the main shelterbelt species such as ash or caragana. Single-row wildlife shelterbelts will both protect the soil and provide valuable food and cover for many prairie wildlife species.
Selection of appropriate tree and shrub species is very important. Each species has its own characteristic height, longevity, growth rate, soil adaptability and value to wildlife. Please refer to Table 1 for more information.
|40||Low||Moderate||Medium-High||Good winter food for wildife|
|Bur Oak||12.0m||40ft - 65ft||Medium||Slow||Low||Good cover, perching site, acorn valued by Jays and deer|
|Caragena||4.5 m - 15 ft||80||Low||Moderate||Medium||excellent cover and nesting sites, drought resistant|
|Choke Cherry||7.0 m - 22 ft||40||Medium||Moderate||Medium-Low||Shade intolerant, good fall food, suckers|
|Dogwood||2m||6ft - 25||Medium-High||Moderate||Medium-Low||Good browse, fruit is eaten by fall migrants|
|Medium||Moderate||Medium||Slow-moderate growth in dry conditions or in sandy soils|
|Medium||Moderate||Medium||Excellent food source, excellent cover|
|Low-Medium||Fast||Medium||Excellent cover, excellent food source|
|Manitoba maple||14.0 m - 45 ft||45||Medium||Fast||Medium||Good canopy cover and nesting sites|
|High||Fast||Low||Good nesting and perching sites|
|High||Fast||Low||Excellent cover, fruit is eaten by fall migrants|
|Low||Moderate||Medium-High||Good cover and emergency food source, drought tolerant|
|Sea Buckthorn||4.5 m - 15 ft||40||Low||Moderate||Medium-High||Good over for wildlife, suckers heavily in light soil|
|Medium||Moderate||Medium-Low||Excellent winter food source for birds and deer|
|Low||Moderate to fast||Medium||Excellent food and nesting cover for ground nesting birds|
|Medium||Moderate||Medium-Low||Good perching sites, food for deer and racoons|
|Low-Medium||Moderate to fast||Medium||Good nesting cover and some food value|
|High||Fast||Low||Good nesting and perching sites, browse for deer|
|White spruce||18.0 m
|70||Medium||Slow||Low||Requires protection during establishment|
|Colorado spruce||18.0 m
|80||Medium||Slow||Medium-Low||Requires protection during establishment|
|Scots pine||18.0 m - 60 ft||70||Medium||Moderate||Low||Faster growth rate than spruce,
Requires protection during establishment
The spacing recommendations within and between rows is very important (see table 2 below). Remember that the seedlings you are planting will eventually develop into large mature trees/shrubs. Therefore, allow enough room between the rows to reduce competition and to allow maintenance equipment to pass through during the first five years. For wildlife plantings a minimum distance of 10 ft. between rows should be used. This spacing will permit room for maintenance and will provide dense wildlife habitat with good canopy cover at maturity.