Rainforestation farming: concept and history (Part I)

by Victor B. Asio, Dept of Soil Science, VSU

a) The concept

Rainforestation or Rainforestation farming is a concept of rehabilitating degraded lands or restoring forests using native forest tree species. It is based on the hypothesis that an ecosystem is more sustainable when its physical structure and species composition are closer to the local rainforest. The Rainforestation farming concept was first presented in seminars by the authors in 1992 and was first published in the peer-reviewed journal Annals of Tropical Research in 1994 (Milan and Margraf, 1994). Two years later a chapter on the Rainforestation concept appeared in the international book Dipterocarp Forest Ecosystems: Towards Sustainable Management by World Scientific (Margraf and Milan, 1996).

 

An idealized sketch of rainforestation about 15 years after its establishment (sketch by R. Dumalag)

The first demonstration sites in Baybay, Leyte were established in 1992. During the early iteration of the concept, spacing and line planting of the trees were considered which were then abandoned by Dr. Margraf because as he always stressed, “nature does not plant trees in straight lines”. Thus, he strongly advocated the random planting of the native trees to simulate a real rainforest. This random planting has thus become a fundamental principle behind the Rainforestation concept. According to the entropy law, the random distribution of tree species should mean more ecosystem stability.

In recent years, the concept has been promoted as a strategy to rehabilitate degraded lands in order to restore the tropical rainforests. In 2004, it was adopted as a national strategy when the Philippine Department of Environment and Natural Resources (DENR) Secretary Elisea G. Gozun through a Memorandum Circular 2004-06 ordered the integration of Rainforestation farming strategy in the development of open areas and denuded forests to promote biodiversity conservation and sustainable development in protected areas and other appropriate forest lands.

 

Photo of the first demonstration site in Mt Pangasugan about 10 years after the establishment

In 2006, the follow-up and monitoring research project funded by GTZ entitled “Rainforestation Farming: Alternative for Biodiversity Conservation and Forest Restoration” (P.P. Milan, M.J. Ceniza, V.B. Asio, S.B.Bulayog, and M. Napiza) was recognized by the Commission on Higher Education (CHED) as the Best Higher Education Institutes (HEI) Research Program. The project provided the needed scientific evidence that the concept was ecologically and economically feasible and now ready for wide-scale dissemination. 

b) Criticisms

From day 1, the concept has met severe and oftentimes unfair criticisms. The earliest criticism that hurt Dr. Margraf was the contention by critics including the ViSCA forestry professors that the originators (Dr. Margraf and Dr. Milan) were neither forest scientists nor vegetation scientists and thus they did not have the expertise to conceptualize a forest restoration strategy. Although valid to some extent, Dr. Margraf was aware of his knowledge limitations so he sought the advice of some of the most brilliant forest science experts in Germany and other countries. 

Another criticism from the agronomists was the use of crops under the “close canopy” demonstration site in that crops require full sunlight to produce yield. As a result, the field staff tried to use fruit trees but this was not very successful as well since the forest trees have the natural tendency to grow tall and cover the fruit trees below. Agroforestry specialists that visited the demonstration sites also consider the planting of crops and fruit trees in between forest trees as “just another variant of agroforestry”. 

Our CHED-PHERNET project site in Inopacan, Leyte, showing the successful 
establishment of the Rainforestation site although at a very high cost

Some forest science experts generally consider the assisted natural regeneration (ANR) as a better strategy to rehabilitate degraded lands because of its greater potential to rehabilitate vast areas of lands at a minimal cost. 

The project site shown in the previous photo in Inopacan, Leyte, appears just a tiny dot in the middle of the large degraded lands (above photo). The other large green patches are actually revegetated through the natural growth of shrubs and trees implying the potential of ANR. 

Lastly, there is a widespread notion that many landowners are only interested to adopt Rainforestation in order to plant hardwood native trees that they could harvest and earn high profits in the future. The fact that a few of the original demonstration sites for the concept established in 1994 have already been harvested by the landowners supports this apprehension. Thus, some people doubt whether this will eventually lead to long-term forest rehabilitation in the country. This should be a big challenge to the Institute of Tropical Ecology and Environmental Management (ITEEM) and other institutions promoting the concept.

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To cite this article: Asio, V.B. 2019. Rainforestation farming: concept and history. http: soil-environment blogspot.com. 

A peer-reviewed article on the history of Rainforestation can be downloaded from the Annals of Tropical Research

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The author (V.B. Asio) has been actively involved in the development and evaluation of the Rainforestation concept from the 1990s until the present. He was a member of the Project Management Core Group of the ViSCA-GTZ Applied Tropical Ecology Project, and later was the first Head of the Terrestrial Ecosystems Division of the Institute of Tropical Ecology. The Core Group members were Dr. M.J.C. Ceniza, Dr. B.B. Dargantes, Dr. R.C. Guarte, Dr. J.M. Quimio, Dr. B.P. Germano & Dr. V.B. Asio.

Soil degradation in the Philippines

Soil degradation is a severe global problem of modern times. About six (6) million hectares of agricultural land worldwide become unproductive every year due to the various soil degradation processes. The problem is much more serious in tropical than in temperate areas since tropical soils are generally more prone to degradation because of the nature of their properties (e.g. they are more weathered) and the prevalent climatic conditions. Countries in Asia and Africa that depend upon agriculture as the engine of economic growth are believed to suffer the greatest impact of soil degradation. In the Philippines, soil degradation is one of the most serious ecological problems today. The National Action Plan (NAP) for 2004 to 2010 identified soil degradation as a major threat to food security in the country. NAP reported that about 5.2 million hectares are seriously degraded resulting in a 30 to 50% reduction in soil productivity.

A degraded upland in Leyte

Soil degradation is defined as the process which lowers the current or future capacity of the soil to produce goods or services. It implies a long-term decline in soil productivity and its environment-moderating capacity. The concept of soil degradation was first used by Kostychiev and Korchinski in 1888 to describe a natural soil change. Since natural degradation is slow, the present concept of soil degradation according to the Global Assessment of Soil Degradation (GLASOD) focuses on a human-induced process. Soil degradation occurs because of drastic changes or disruption in the normal processes of soil formation due to human activities.

A degraded upland covered with Imperata (cogon) grass in Samar

In a review paper on the problem of soil degradation in the Philippines published in the Annals of Tropical Research vol. 31, we (Asio et al. 2009) revealed that soil erosion is the most widespread process of soil degradation and is also the most studied in the country. Other important but less studied soil degradation processes include loss of nutrients and organic matter, salinization, acidification, pollution, compaction, and subsidence. 

A degraded upland in Bukidnon

Studies reviewed have shown that the widespread degraded upland soils possess chemical and physical constraints for crop growth like acidic or calcareous pH, low organic matter and nutrient contents, shallow solum, presence of toxic substances, and compaction. The major factors that cause soil degradation include deforestation, overgrazing, agricultural practices, industrial activities, mining, and waste disposal. Deforestation is the main cause of soil degradation in Asia and South America while overgrazing is the main factor in the dryland areas of Australia, Africa, Europe, and Asia.

The typical degraded land in Cagayan Valley due to deforestation & overgrazing 

There is a need for more data on the physical and socio-economic characteristics of degraded lands to aid in the formulation of appropriate soil management strategies to support biodiesel production in these unproductive lands which are now being promoted by the Philippine government. Also, there is the danger that the use of the degraded lands for intensive and long-term biodiesel production without the appropriate soil management would cause further soil deterioration and thus aggravate the ecological problems that are now occurring.

Reference

Asio VB, Jahn R, Perez FO, Navarrete IA, and Abit SM Jr. 2009. A review of soil degradation in the Philippines. Annals of Tropical Research 31: 69-94

Note: All photos are owned by the author.