Description
Exclosures or, enclosures, refer to the practice of fencing-off an area in order to protect it from human use and animal intrusion. The main goal of enclosures through fencing is to allow natural regeneration and rehabilitation of degraded lands within the enclosed space. This intervention fosters natural regeneration and helps to restore organic matter and a healthy soil structure. Exclosures can also be used to change the cover of the land to allow time for new land coverage (vegetation) to be established. Exclosures can be applied in a variety of different landscapes and environmental conditions. This technique is a relatively cheap type of intervention if the materials are available on site but can be somewhat more expensive where materials need to be acquired or where more sophisticated enclosures are built.
PRE-CONDITIONS FOR IMPLEMENTATION
- You should first ensure that user and land rights are in place before laying down fences. There may be costly legal implications for building fences on other’s lands.
- Exclosures are most beneficial when implemented as part of a system of sustainable land management and when they are well designed to fit within the context of implementation.
- The choice of an appropriate fencing type as well as a fitting method of installation should be based on knowledge of the local territory as possible. For example, certain types of wood used for fence posts may be more prone to rotting quickly under certain climatic conditions, thus implementors should be wary when selecting fencing materials.
- Ensure that posts are placed deep enough in the soil to stop them from becoming loose or needing frequent maintenance. In the case of wooden posts in clayey soils, posts should be placed at a depth around ten times the diameter of the post. When using stems for live fencing, pushing these deep in the soil will give the stems better access to water.
METHOD OF APPLICATION: PERMANENT & TEMPORARY FENCING
Materials required for Permanent Fencing:
- Fencing material (such as fence posts of wood, and wire or mesh).
- Hardware including hinges, screws, and nails to assemble the exlosure.
- Heavy-duty gloves for protection and ease of handling of equipment and fencing materials.
- Tools such as an a-level, tape measure, drill, hammer, shovel, fence pliers, saw, etc.
- A post hole digger/post-stomper.
- Wire strainers for tightening the fence.
- A crowbar or another tamping tool for breaking up soil when digging.
Materials required for Temporary Fencing:
- Temporary fencing wire (usually electric polywire or polytape).
- Fence posts (plastic or fiberglass step-in post; metal ‘t’ posts).
- Reel for creating temporary fence wire.
- Electric fence charger.
Additional optional:
- Electric fence tester.
- Quad/Tractor.
Steps of Implementation:
- Plan the fence layout for the exclosure.
Consider the area that is to be enclosed. How large will this area be? Where will gates and corner posts be placed? Try to avoid hard, rocky soils and slopes as these can make installation difficult and threaten the long-term structure of the fence line. It is also advisable to mark out the line of the fence with a piece of wire, string, or paint before installation. Keep in mind that straight lines are most cost-efficient as every corner requires corner-posts. The most important elements to map out are fence lines, corners, and gates. - Choose the fencing material.
Fence material and fencing types vary in terms of their durability, ease of installation, and costs. Different types of fencing are thus fit for different purposes and objectives. Keep in mind that the specifications of the fencing you will implement will vary based on the objective of the exclosure being constructed. For example, fencing aimed at enclosing cattle to prevent them from grazing on a recovering area of land will require a taller fence with fewer horizontal lines than a fence aimed at restricting the movement of sheep. For an overview of the different types of fencing and a comparison between them, you can check out this website.Different fence materials and fencing types are suitable based on the objectives you want to achieve through using exclosures. - Installation of the fence.
This process will vary based on the type of fencing chosen and the resources available. In the case of wooden posts in clayey soils, posts should be placed at a depth around ten times the diameter of the posts. The basic steps for installing a woven-wire permanent fence are the following:
- Start by installing corner posts. These posts should be set securely into the ground and should be braced with wooden supports. Braces ensure that tension can be absorbed by the fence. You can read more about different types of bracing for corner posts here. For temporary fencing, plastic step-in posts are most commonly used and make for easier installation/retrieval.
- Install the line posts. These posts should be placed every 8-12 feet along the fence line. Make sure they are set securely and that they are straight by using an a-level.
- Unroll the woven wire fence (or other fencing material) along the side of the fence against which you want to secure it. Stand the fencing material up and attach it to one of the corner posts, using fencing pliers and/or staples. Make sure the fence is taut and straight. For temporary fencing, a reel is needed to unravel the fencing material. Stapling the fencing material onto the posts and tightening the wire is usually not necessary with temporary fencing as posts come with slots where the fence wire can be attached or threaded through.
- Attach the fence to each line post, pulling it tight with fencing pliers or a come-along tool.
- Staple the fence to the line posts using fencing staples. Make sure to staple the fence securely to each post.
- Install any gates or other features you need. Make sure to install these securely.
- Walk the line of the fence and double-check that your fence is properly installed. If installing electrified temporary fencing, a fence charger should be bought and installed, too.
METHOD OF APPLICATION: LIVING FENCES
Materials required:
- Barbed wire.
- Seeds.
- Hardware such as hinges and nails.
- Tools such as a level, a tape measure, a drill, hammer, shovel, fence pliers, saw, etc.
- Electric fence charger.
Additional optional:
- Electric fence tester.
- Quad/Tractor.
Stages of implementation:
There are several ways of building a living (or ‘live’) fence, depending on what vegetation is available as well as on the local environmental context. The basic methodology is the following:
- Choose the right species for your living fence.
Select plants that are native to your area and are suitable for the growing conditions and fencing needs on your land. Some popular species for living fences include holly, boxwood, willow, and bamboo. Consider the size of the fence you want to build (width of posts, height of fence, etc.) as well as the growth time of different species. Using crop trees for live fencing can be effective for this kind of fence construction, too.
2. Prepare the soil.
Clear the area of any debris and weeds. If necessary, loosen the soil along the line of the soon-to-be-built fence and mix in compost/fertilizer if you believe the soil might not be nutrient-rich enough.
3. Plant the shrubs/Sow the seeds.
Follow the instructions for tree planting and plant the seeds or stems at an appropriate distance from each other (this will vary depending on the selected species and size of the tree at full maturity, as well as the technical considerations for the fence).
Note: As long as a minimum spacing between stems/seeds is observed, the next biggest consideration for spacing is likely to be the length of the materials used for the horizontal reinforcement (see step 6).
4. Apply water and mulch.
Water the shrubs regularly during the first year to help them establish their roots. Spread a layer of mulch around the base of the plants to retain moisture and suppress weed growth.
5. Prune and maintain the shrubs and trees.
Trim the shrubs as needed to maintain their shape and size. Remove any dead or diseased branches promptly.
6. Create horizontal reinforcements.
Once the planted trees have reached a good height (usually between 1 and 2 years after sowing), use materials such as tree cuttings, bamboo, and barbed wire to form the horizontal layers of the fence. Fix the bamboo and/or wire to the trees - the fence posts - using vines or cloth. This case study uses an arrangement of 1 strand of barbed wire with 2 bamboo sticks above and below it.
COSTS
Estimated costs and benefits of different variations of this intervention:
Category | Permanent fencing
(¼ mile or 402m) |
Flexible fencing
(¼ mile or 402m) |
Live fencing
(¼ mile or 402m) |
Location | Iowa, US | Iowa, US | Khmer, Cambodia |
Type | High-tensile electrified wire fence | Electrified polywire fence | Cashew living fence |
Labor time | 18 hours | 2 hours | 17.5 hours |
Purchasing costs | USD 1,172 | USD 315 | USD 206 |
Source | ISU, 2022 | ISU, 2022 | WOCAT, 2019 |
CASE STUDIES
- Cashew fences in Cambodia, WOCAT, 2019.
- Live fences for protecting crops and plants in Burkina Faso, HDL, N.d.
- Electric fence for degraded pastureland in Georgia, WOCAT, 2018.
- Portable fencing for rotational grazing in Texas, Thomas, 2018.
- Rehabilitation of pasture land through fencing in Tajikistan, WOCAT, 2018b.
FIND OUT MORE
- Literature review of environmental and socio-economic impacts of exclosures (Nyberg et al., 2019).
- Guidebook for live fences in resource-poor lands (Kuchelmeister, 1989).
- Temporary fencing for rotational grazing (Buschermohle, 2020).
- Price of various fencing equipment in Saskachuwan, Canada (Saskatchewan, 2022).
- A video guide on ‘How to build a woven wire fence’, by Just a Few Acres Farm.