Conserving germplasms of Indonesia’s native tree species

A number of programs including large tree planting components have been implemented since then, including forest restoration programs using reforestation fund delivered to regional government through special allocation funds (DAK-DR) and national campaigns on forest and land rehabilitation (GNRHL, 2003-2009). Many of these programs have not been very successful and according to CIFOR (2008) about 85% of the forestry development budget, from 1976 to 2008, was spent on ineffective and low ecological impacts land rehabilitation and reforestation activities.

Many evaluation studies on the performance of land rehabilitation and reforestation programs in Indonesia have been made by experts and research organizations. Most of these evaluations focused on the weakness of the government system and some looked into the general technical implementation, achieved results and impact, but hardly any evaluation included considerations and assessment of the germplasm or genetic material (normally seed) used for producing the seedlings being used in the land rehabilitation and reforestation programs.

Reforestation requires more than just planting the right species on the right places. The genetic composition of the reproductive material significantly affects the success of reforestation. This has been realized by most forestry experts, but the issue has always been taken for granted by the program planners and implementers and consequently the genetic aspects of tree planting have in most situations not been directly addressed. The negative effects of not using the best possible genetic material, when producing seedlings in the nurseries and planting trees in the field are, in most situations, not immediately evident, but accumulate over time.

Tree communities, established in the field, need particularly adaptive genetic composition and variation to succeed over time; such composition and variation promote survival and good growth, while at the same time enhancing resilience and resistance to biotic and abiotic stress factors such as environmental variations or pests and pathogens. In the long term, adaptive genetic diversity will promote successful reproduction; reduce the risk of inbreeding and genetic impoverishment, which can result from genetic drift, and increase population’s ability to adapt to future site conditions.

Establishing tree seedlings in nurseries from seed is by far the most common strategy used to propagate trees for rehabilitation/restoration programs.

It is a widespread practice to procure tree planting materials through seed collections from trees of unknown genetic quality. Often seed are collected from trees in remaining forest patches near restoration sites, but often these forests have too few trees or are too fragmented to ensure a sufficient large genetic variation to sustain future viable tree populations. When tree populations are small, mating among relatives increases, resulting in elevated inbreeding rates. Inbred seed tends to produce seedlings, and ultimately trees, that have reduced vigour and are vulnerable to pest and diseases and less able to survive to climate changes etc.

Considering the above, the seed sources for re-establishing forest cover should be established from high quality mother trees holding sufficient genetic diversity.

To do so, Ministry of Forestry and Environment (MoEF) should develop seed sources, which are areas planted with carefully selected germplasm of high quality. Seed sources are managed to maintain and improve genetic variation and to produce frequent, abundant and easily collected high quality seeds. Trees are generally more than 7 years old before producing seeds, and therefore it will take at least 7 years before the next generation of seed can be collected and used for reforestation and restoration programs.,. For slow growing native species this process will take at least 40 years.

At present, MoEF mostly manage seed sources of fast growing exotic species, while seed sources of native tree species living in the threatened natural forest such as Ulin (Eusideroxy lonzwagery), Meranti Merah (Shorea leprosula, Shorea parvifolia, etc.), Tengkawang (Shorea pinanga, Shorea stenoptera etc.), Merbau (Intsiabijuga), Eboni (Diospyroscelebica) are still absent. This despite the fact, that exploration, conservation and improvement of native tree germplasms are most urgent, given the high rate of natural forest depletion.

Apart from the genetic aspect, the physical and the physiological aspects of germplasm are equally important. This can be enhanced by improving techniques of seeds collection, processing and storing. Eventhough collecting seeds of native tree species from diverse high quality forested areas are expensive in the short-term, it is cheap in the long-term, as the invested capital will return many times due to higher survival of the trees in the field and the higher delivery of services from the plantings, as trees are long living organisms.

Given the big number of native tree species germplasms needed to be explored, conserved and improved, MoEF will certainly be unable to work alone. Big hands of government institutions, universities, research organization and private sectors at regional level are urgently needed.

Ideally each forested district should establish seed sources of key native trees species of the area, they should also protect the selected areas of the remaining intact natural forest as a kind of natural ‘germplasm bank’.

National campaigns and actions for saving and using the germplasm of Indonesia’s native tree species are urgently needed, before losing the most valuable part of the biodiversity of the rich natural forest.

Our grandchildren will enjoy the revenues we are investing now, as ‘using quality tree seed doesn’t cost, it pays!

Edi Purwanto (TBI Indonesia Programme Director) and Soren Moestrup (senior adviser at department of geosciences and natural resource management, forest, nature and biomass at the University of Copenhagen)