Project for Integration of Life and Environment
Japan International Volunteer Centre (JVC), Thailand
Reforestation in Thailand is a requirement to repair forest destruction. Eucalypt is the most common species favoured for its fast growth, adaptability to soil and climate types, and use for pulp raw material. Adverse side effects noted include ecological, social and cultural impacts. The NGO has an interest in reconstructing the rural environment in these areas. Tree species used in reforestation should be multipurpose, plantings be of mixed species with tiered canopy levels and the components add to ecological improvement, e.g. to improve soil, diversify habitat, moderate temperatures and improve water release capacity. They should also be fast growing, drought tolerant and culturally harmonising. Eucalypt is seen as demanding of soil nutrients and water, and its best economic returns are from monoculture. In this particular project (Conservation and Watershed area), eucalypt is not favoured, and species with less negative effect are desired; a mixed forest cover is recommended, including local species and taking into account the ecological balance.
Key words: Eucalyptus, Thailand, NGO, ecological impact, multipurpose plantations, agroforestry.
The impact of forest destruction is obvious in Thailand. There are many efforts to re-afforest in different ways and from different points of view.
Eucalyptus is the most famous, among various tree species, chosen for this because of its eminent specific characteristics: fast growth, high adaptability to any condition of soil and rain-fall, low maintenance, best for pulp, etc. The Government has decided to expand Eucalyptus throughout the country. There were different ways of adopting eucalypts depending on ones own background such as: large scale private plantation; small scale private plantation and/or mixed planting; and the Governmental plantations.
Nothing is perfect, and to date there are reactions from those studying the side effects of eucalypt. The arguments mainly mention the impact on ecological, social, cultural aspects and long term economics, which may look either reasonable or terrible. As NGOs which have an overall target to reconstruct the rural area physically, socially, economically and ecologically, to achieve sufficiency and balance, we would like to present an opinions on the eucalypt issue from our own vision.
Agroforestry is a system which is expected to play an important role in rural develop-ment and environment balancing. Agroforestry is also a component of the Project, besides community forest and creating the consciousness and movement in peoples' organizations. In our project, however, Eucalyptus has never been adopted since start up. We have our own reasons for this and these are based on criteria as follows:
Global needs priorities;
Role of agroforestry and companion activities; and
Eucalypt (or other species) impact on the whole system.
What is the global need?
In this level, we urgently need to stop the green house effect and create ecological balance. Every activity of all human beings has to go in the same direction to achieve this goal and we must not undertake any activity which creates a worse environment condition. To adopt eucalypts in Thailand, one must carefully consider whether they create positive or negative reactions to environmental reconstruction.
Specific characteristics of agroforestry and its roles; agroforestry defined
In the broadest sense, the term "agroforestry" encompasses any land use and includes both forest tree and agricultural production on the same piece of land. A more precise definition of agroforestry is: "Agroforestry is a land use that involves deliberate retention, introduction or mixture of trees or other woody perennials in crop/animal production fields to benefit from the resultant ecological and economic interactions. The science and practice of agroforestry aims to produce and maximize positive interactions between trees and crops." In Thailand, agroforestry has long been practiced in forms of indigenous multipurpose plant cultivation. These are food, medicinal, fiber, timber species and many multipurpose species. This practice changed after the introduction of commercial crops produced by the (large scale) monoculture system leading to the decline of the (natural & agro) forest area.
Suitable tree/plant species characteristics for agroforestry
The Project site is on a degraded forest area. To achieve self sufficiency of people and ecological balance, agroforestry will play the most significant role. In choosing tree species and cropping systems, we consider the following proprieties:
A. Multipurpose: In economic value term, those tree species and cropping systems should give multiple products, such as fruits, flowers and leaves (as food); fuelwood; wax; timber; fodder; medicinal extracts and other uses.
B. Companion growing: The multistory cropping system is the most effective use of resources. Those species used should support the harmony of various plants in the whole system.
C. Ecological improvement: Those tree species and cropping systems should enrich soil and improve soil balance; provide habitat and food for various animals; diversify ecosystems which can support and maintain healthy food chains; decrease temperature and increase moisture; improve water supply and recycle capacity.
D. Special advantages: Those tree species should be fast growing, drought tolerant, and require less maintenance, etc.
E. Culturally harmonising with the local society: There are many species from abroad able to grow harmoniously in Thailand plant combinations.
Eucalyptus (or other plant) impact to the whole system
If we accept the above guidelines and assess eucalypts impartially, we can see some characteristics of eucalypts create different effects, both positive and negative to the whole system.
Adaptability: The most prominent characteristic of eucalypts is strong adaptability in any soil and water condition. This is because of its long and deep root system, so it grows very fast, even during the dry season, when other plants die or their leaves fall. Both positive and negative characteristics of eucalypts that we have assessed are summarized in Figure 1. As obviously seen, the positive side is mainly related with economic aspects, while the negative side is with ecological ones.
Figure 1. Assessment of eucalypt tree characteristics
Positive (economic term)
Negative (ecological term)
1. Long, deep roots
Takes a lot of nutrient and water
2. Adaptable in any soil and water condition
High competition to companion plants, desertification of the area, less biodiversity
3. Hard leaf
Longer decomposing period
4. Small crown
This is a factor with good and bad results.
Monoculture is a very good system in economic terms because of convenience in management; the negative effect to the ecosystem is conversely more severe.
Mixed cropping: Some research from the RFD's Silviculture Division shows satisfactory results of eucalypts with agroforestry systems, but this still needs specific management. However, it is possible to avoid negative effects. The research covers the growth of Eucalyptus camaldulensis with five other tree species, indigenous and exotic in the same row, with annual crops in the interval; all plants are harvested from the plot. Even then, though there is still the choice for adopting eucalypts, the problem still goes on because:
The farming system with the most negative effect is monoculture.
The main stream of farming system is monoculture.
We have to accept that we expect to get economic benefit, mainly from eucalypts. So far, the farming system which returns the best economic result (in terms of money), must be monoculture.
To promote eucalypts in agroforestry to farmers is still in risk of causing mistakes in field practice and it needs some special techniques. It takes time for farmers to adopt new practices which differ from traditional conditions.
Our Project site is a former watershed area, and is near the "conserved zone" at present. For such an area, after careful consideration, we consider desirable practices are:
Large scale monocultures of eucalypt plantations be excluded from watershed and conservation zones.
Mixed tree cropping for commercial purpose plantations include at least 10 species, including indigenous species, and strong consideration be given to the inclusion of principles of ecological balance as the pre-eminent guideline of management.
Reafforestation projects of the Government on the so called "Reserved Forest" should avoid monocultures and the use of eucalypts.
The only way to include eucalypt is to adopt it in agroforestry systems, but to be careful of the proportion of each species.
We have made our own decision on the eucalypt issue and we have never adopted its use to date, as we prefer other tree species, which have fewer negative effects and are more appropriate to ecosystems than eucalypt. Eucalypts will still be attractive to the investor who seeks mainly an economic output and neglects its negative effect to the globe and all creatures.
Eucalyptus is not wrong but humans are often wrong.
Pitaya Petmak. 1991. Agroforestry in Asia and the Pacific. FAO/RAPA, Bangkok. pp. 301-304.
Rao, Y.S., MacDicken, K.G. 1991. Agroforestry in Asia and the Pacific. FAO/RAPA, Bangkok.