 |
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||
Figure
The choice of where and what to plant depends on the purpose of the plantation, on who the land and the trees belong to and on other possible uses of the land. The first step is to find out what the needs of the local populations are. What are the benefits they expect? Who in the local community benefits from a plantation and who might not benefit from it? How will the plantation affect other land-uses like food production or grazing? What are the potential conflicts in connection with the plantation? These factors have to be discussed until all concerned reach agreement. These discussions are very important and should start early during the planning of the plantation. Plantation programs which will result in reduced benefits for the population are not likely to succeed. More tree planting projects fail because of problems with the people involved than because of technical mistakes. This manual deals mostly with the work to be done after the basic agreement has been reached. The list of references at the end of this booklet includes useful documents on extension and people's participation in forestry projects.
When you start the technical planning take a close look at the area. Decisions have be made on:
- What regeneration method to use (whether to plant, rely on natural regeneration or seed directly on the site)?- What tree species to establish (matching species to planting purpose and site)?
- Whether to plant a single tree species or a mixture of several?
- What type of planting stock to use (bare rooted, potted seedlings or stumps, small or large seedlings)?
- What planting pattern to use and how many seedlings to plant?
- When to plant?
- How to protect the seedlings?
To make the right decisions you have to get to know the area. Start by drawing a simple map of the plantation site and calculate the area available. One way of doing this is described in Technical Sheet 1. Mark variations in site conditions on the map. Information that can be of importance for further work should be written down.
Planning a plantation
Where and what to plant?
What regeneration method?
What species?
Mixed or single species?
What type of planting stock?
What planting pattern?
When to plant?
How to protect the
seedlings?
You have to decide whether to plant seedlings, to seed directly on the site or to rely on natural regeneration and coppicing.
If natural vegetation exists on the site and the main objective is fuelwood supply or soil conservation, protecting and helping the vegetation to recover might be the cheapest and quickest way to ensure reforestation. This is especially true in dry, hilly and eroded areas. The area should then be closed from grazing and micro-catchments might have to be constructed to ensure that the shoots get enough water. After a cover of bushes and small trees has been established, the less desirable competing plants should be cleared away to promote sprouting in the more valuable species.
This method might be combined with enrichment planting. This means planting seedlings in groups or lines inside a growing stand between existing trees and bushes. Shade-tolerant tree species have to be used. Enrichment planting is not likely to succeed at sites with rich vegetation where the seedlings will not be able to compete with the herb vegetation.
Direct sowing on the site is sometimes used to establish a new stand. This may be a simple way of establishing tree cover but often the increased need for site preparation and weeding make it more expensive than planting. Direct sowing can be used for species with very rapid initial growth when seeds are plentiful and cheap and germination is reliable. Species possible to establish in this way include Acacia Senegal, Acacia nilotica, Acacia mearnsii, Cassia siamea and Neem (Azadirachta indica).
Where natural regeneration is not possible or too unreliable, or where the tree species that are to be established are not found in the natural vegetation on the site, trees have to be planted.
This booklet will mainly focus on the planting of trees.
Regeneration methods
Coppicing
Natural regeneration
Enrichment planting
Direct
sowing
The choice of species is a most important and difficult decision to make. The choice depends primarily on three basic questions, which should be asked in the following order:
- what do the owners/beneficiaries of the project want from the plantation?
- what species are available that will produce what the people want?
- will these species grow on the sites available?
For soil conservation, for example, fast-growing species with an extensive root system are preferable. They quickly cover and bind the soil, protecting it from rain and wind. A plantation aimed primarily at construction poles or timber will require trees with relatively heavy, durable wood and a straight stem. For fodder production, ample leaf and seed production are essential and good regrowth after coppicing and browsing. If you grow trees together with agricultural crops or to rehabilitate wasteland, leguminous varieties (for example, the Acacia family) would be a good choice because of their soil-improving ability. (Most leguminous and some other tree species can extract nitrogen from the air with the help of little nodules on their roots. They then add nitrogen to the soil when the leaves fall off). Multipurpose tree species may combine a variety of different uses.
If local, indigenous, tree species, that you know grow well in the area, are available, it may be safer to use them than to try other, exotic ones. It is essential to select species that will be able to survive the first crucial years, that will withstand the environmental conditions on the specific site and that are easy to handle both in the nursery and in the field. Good coppicing ability (i.e. putting out new shoots from the stump after cutting) may be a special advantage.
What species to establish
What is the purpose of the
plantation?
What species are available that will
produce what people want?
Will these species grown on the site
available?
A plantation may consist of only one species or a mixture of several species.
A single-species plantation is easier to handle during both the planting and the maintenance phase. Planting a mixture of species will reduce the risk of failure if a certain species does not survive or grows badly. Mixing the species may also be desirable because of site conditions or to obtain several products from the same plantation. It all depends on the purpose of the plantation.
If you choose to create a mixed plantation, you have to decide what type of mixture will be most appropriate.
When planting bigger sites, the area should be subdivided into blocks. The different blocks can then be planted with different species. This will reduce the risk of damage caused by pests, insects and fire.
A site with varying soil or moisture conditions can be utilized best if several species that are adapted to the different conditions can be selected. The species should be planted in groups on the portions of the site matching the species' site requirements.
You can also create a mixture with slow-growing, valuable timber trees and faster-growing trees that will be used for fuel wood or fodder. An example is Teak (Tectona grandis) and Leucena (Leucena leucocephala). Leucena will be cut as fuelwood or fodder repeatedly until the Teak crowns form a close canopy and Leucena eventually is shaded out. In these kinds of mixtures two (or more) species are distributed evenly over the area or planted in alternate lines. There should preferably be an even mixture of light-demanding and more shade-tolerant species.
Mixed or single species plantations
Single species plantation
Blocks with different species
Mixed plantation
Mixture with
underplanting
Bare-rooted seedlings are less expensive to grow and to transport. They are however, vulnerable to drying out and mechanical injuries during transport and planting. Any weak point in the chain - nursery work/distribution/planting - can result in severe loss of the plants' availability to survive. They have to be handled with care and should be stored for as short a time possible.
Containerized seedlings are less sensitive, less liable to dry out, or to get injured during transport and easier to plant without damaging the roots. They often have a higher rate of survival than bare-rooted plants. They are, however, more expensive to produce. Handling and transport will also be more expensive because of the considerable weight of the earth in the pots. If no experience or information is available on the survival rate and establishment cost for the two methods, both could be tried experimentally to clarify the choice.
The seedlings should have a root system that is between half the size to the size of the shoot. Big seedlings cost more to produce but are necessary for planting difficult sites. The seedlings may be separated according to quality and the seedlings of better quality used on the most difficult or inaccessible sites. The quality and grading of the seedlings are described in more detail in section 3.3.
Cuttings are sections of roots, stems or branches that will, when placed in moist soil, grow into new plants. Cuttings can be grown into plants in the nursery. For some species they can also be planted directly on the planting site. Stumps are a special type of cutting. They consist of a short, pruned stem and a strong pruned taproot derived from nursery stock.
Planting stock
Bare-rooted seedling
Containerized seedling
Cuttings
branch cutting
stump
The most commonly used planting patterns are square spacing or triangular spacing where the distance between the rows are the same as along the rows. If strip clearing or weeding are used, a rectangular pattern, where trees are closer in the rows, than between the rows might reduce labour input. For very harsh climates and on poor soils, it might be appropriate to plant in clusters.
The appropriate spacing varies with the site, the purpose of the plantation and the species chosen. It is also a compromise between expected yield and the cost of establishing the plantation. Wider spacing (more than 3x3 m) is preferred:
- for fruit trees;- when planting on agricultural or grazing land;
- to reduce the cost of planting;
- in arid areas to avoid competition for water and nutrition;
- to reduce the number of thinnings (if the aim of the plantation is large diameter timber).
Closer spacing (3x3 m or closer) is preferred:
- to avoid expensive replacement planting;- to give early soil cover;
- when weed competition needs to be suppressed by early tree canopy closure;
- for slow-growing species when aiming for good quality sawlogs, i.e. small branches/knots;
- when there is a market for smaller dimension wood from thinnings;
- for fast-growing species such as Willows and Eucalyptus, when using short rotation to produce mostly smaller dimension wood (e.g. for fuel).
On dry sites most trees are now planted with an average of 3 or 4 metres between trees (i.e. 1100 or 625 trees/ha, respectively). On fresh sites in tropical highlands and in temperate climates a spacing of 2 square metres (i.e. 2500 trees/ha) is common. The table on the following page can be used when calculating how many seedlings will be needed for a site.
Spacing
Square spacing
Rectangular spacing
Triangular spacing
Clusters
Calculating the number of seedlings needed
If you know how many plants you want to plant per hectare, you can calculate the square spacing using the formula:
If on the other hand you know what spacing you want, you can calculate the number of seedlings needed using the formula:
10,000/(distance a x distance b) = Number of seedlings per ha
|
Spacing between lines (m) |
Spacing within lines (m) |
Space per seedling (m2) |
Seedlings per hectare |
|
1 |
1 |
1 |
10000 |
|
2 |
2 |
4 |
2500 |
|
2.5 |
1.6 |
4 |
2500 |
|
3 |
3 |
9 |
1111 |
|
4 |
2 |
8 |
1250 |
|
4 |
4 |
16 |
625 |
|
10 |
10 |
100 |
100 |
Planting should be completed early in the rains in as short a time as possible. The trees must be given time to become well established prior to the dry season. A good rule of thumb is to start planting when the soil is moist to a depth of 15-25 cm or to the bottom of the planting hole. Failures because planting is too late are more common than failures because of planting too early. In many tropical sites, the optimum planting time is two to four weeks each year. To obtain good results and avoid labour shortage in these areas considerable preparatory planning is needed. The size of the plantation might have to be adapted to the availability of labour. If dry sites cannot be planted in time, planting should be postponed until the next season.
Tree seedlings may be harmed by browsing, fire, insects and diseases. The risk of damage should be assessed and protection ensured during planning.
In most areas some sort of agreement and protection is needed to keep livestock out of the plantation during the establishment phase. Goats and sheep chew leaves and shoots and tear off the bark. Cattle can quickly destroy a plantation by trampling on the young seedlings.
Forest fires are often man-made. If the plantations benefit all members of the community, prevention of fires is mostly a matter of public relations and information. Sharing the produce of the plantation is one way of increasing the interest of the local population. Permanent guarding, fire breaks and controlled grazing or grass-cutting are also means of preventing fire.
Insects and diseases are often species-specific. Species liable to damage should be avoided. Pesticides or chemically treated plants may also be used.
Protection measures are described further in Chapter 6.
When to plant
Planting should start early in the
rain
How to protect the seedlings
|
|
|
|
|
|
Browsing |
Fire |
Insects |
Diseases |
Figure
When all decisions are made and the basic information collected, a plantation plan should be prepared. It should consist of a plantation record and a map. An example of a form to use for the plantation record is given on the opposite page.
The map is the main tool for planning (guidelines on how to draw a map are given in technical sheet 1).
If you want to create a plantation with different species mixed in groups, you have to decide where to plant the different species to best utilize the varying site conditions within the plantation area. This should be marked on the map.
Mark also access roads, suitable seedling depots (with water and shade) and where to start planting. In dry areas start the annual plantation work at the driest part of the site. This will give the seedlings as long a time as possible before the beginning of the dry season. If you have decided that the best quality seedlings, or larger holes or other special measures are needed in certain areas, this should be clearly indicated on the map.
|
|
Plantation record |
|
Village: Kovali |
District Tiruchirappalli |
|
Site name: |
Area: 35 ha |
|
Batcha plain Owner: |
Kovali village community |
|
Type of plantation: |
Soil conservation/fodder |
|
Previous vegetation: |
Waste land with scattered bushes (Cassia and Prosopis) |
|
Terrain: |
Flat |
|
Main soil type: |
Sandy loam |
|
Method of clearing: |
No clearing needed |
|
Risk/need for protection: |
Grazing, termites |
|
Transport: |
Truck hired from Mr. Schultz |
|
Tools required: |
20 planting hoes (ordered 12.1.93) |
|
Workdays required: |
See attached workplan |
|
Date of planting: |
26 April to 20 May 1993 |
|
Nursery of origin: |
Keela Kolathur village nursery |
|
Spacing: |
4x4 metres |
|
Water conservation measures: |
None |
|
Fertilizer: |
Not applied |
|
Species and number of plants: |
Local name |
Botanical name | |
| |
Velvel |
Acacia leocophloea |
12,000 |
| |
Vagai |
Albizia lebbek |
4,000 |
| |
Usilam |
Albizia amara |
6,000 |
Seed lots No.:
Weeding 1:
Weeding 2:
Weeding 3:
Survival count:
Beating-up:
Average plant
height:
Protection applied:
Area to be planted
Map of the area to be planted
|
Common mistakes when planning Not enough attention to discussions on the needs, benefits and potential conflicts in connection with tree planting project. No agreement on the rights and duties of all involved, particularly concerning protection. As a result, a dissatisfied group sabotages the project (uproots trees, burns plantation or lets cattle destroy the trees, etc.). Species are not well suited for the purpose of plantation. Suitable local species are not utilized because there is no information in books and manuals. Local people's knowledge of sites and trees not used. Lack of coordination between nurseries and the plantation programme. Need for protection is underestimated. |
 |
 |
