Anamalai Rainforest Restoration Program

Alternative Native Shade Trees

Monoculture plantations of tea and coffee can improve their ecological value by using a diversity of native shade trees. In the past, most estates primarily used one or a few alien (exotic) species, such as the ubiquitous silver oak (Grevillea robusta) for tea plantations, Eucalyptus, and Maesopsis eminii. Besides being ecologically more sterile, this reliance on a single alien species also leads to greater incidence of pest problems such as red spider mite and fungal rot.

Hundreds of native tree species are found in our forests, a large number of which may be suitable as shade for different plantation crops. In an effort to evaluate a wider variety of native trees as alternative shade for crops, we have partnered with a leading plantation research institute, United Planters Association of South India (UPASI), at Valparai, besides other partner companies. Trials of five species are currently being conducted by UPASI using seedlings provided by NCF (Toona ciliata, Filicium decipiens, Dimocarpus longan, Trichilia connaroides, Ormosia travancorica ). In an effort to initiate the use of native rainforest tree species as shade tree species for shade-requiring crops such as cardamom, coffee, and vanilla, NCF provided a number of saplings of selected species to local companies for planting in estates. Around 50 native rainforest tree species from our nursery have been utilised across these plantations over the last few years.

Red cedar Toona ciliata as shade for tea Litsea oleoides in vanilla plantation

Native trees for plantations may be chosen from indigenous species found in the immediate region within the same plantation district. Indigenous species from other plantation districts, other parts of India, and exotic (alien) species may be avoided. Similarly, it is not a good idea to tissue-culture large numbers of a chosen shade tree, native or exotic, as genetic diversity is reduced by use of clones. It is best to raise plants from seed of diverse native shade trees. That this is possible is evident from the experience with over 120 species in our nursery itself.

Around the world, research is continuing to highlight the benefits of such species to plantations such as
  • better shade,
  • pest control,
  • conservation and augmentation of soil properties and water,
  • additional income from non-timber forest produce, and
  • increased crop yields.

    Ultimately, these native species are likely to grow to eventually provide an ecologically better environment for the crop and wildlife in the area.