Summary, Introduction, Methods, Analysis, Results, Discussion, References, Acknowledgements, Photos, Links

Bamboos of the genus Guadua (Kunth) are important landscape features in the lowland rainforests of the Neotropics where they dominate an estimated 180 000 km² of western Amazonia, including the Department of Madre de Dios in South-eastern Peru (Nelson 1994, Judziewicz et al. 1999). Bamboos can grow in such abundance when conditions are favourable that they are clearly identifiable from satellite imagery, a fact that has been utilised to assess distribution at both the local and landscape level (Menon 1988, Nelson 1994, Judziewicz et al. 1999). Of the 27 Guadua species Worldwide, only 6 have been described from Peru, although it is expected that with more intensive research, particularly in Madre de Dios, others will be found (Londoño pers. com.). The 3 most abundant species in the region are G. weberbaueri, G. sarcocarpa and G. cf. angustifolia. The first two are aggressive, running species, which frequently form monodominant stands (Tupayachi 1989). The latter is the largest and one of the few clump-forming members of the genus, and is locally known as Marona.

Ecologically speaking, Guadua stands support an important and unique community of invertebrates (Izawa 1978, Tupayachi 1989, Conover 1994, Louton, Gelhaus & Bouchard 1996), amphibians (Izawa 1978, Louton, Gelhaus & Bouchard 1996, A. Salas & R. von May pers. com.), birds (Tupayachi 1989, Fitzpatrick & Willard 1990, Kratter 1993, 1997, 1998, Parker, Stotz & Fitzpatrick 1997) and mammals (Emmons 1981, 1990, Olmos et al. 1993, Kirkby et al. 2000). Furthermore, because of the aggressive growth strategy of particularly G. weberbaueri and G. sarcocarpa, normal forest successional processes following small or large-scale forest disturbance can be altered and even arrested for long periods of time (Stern 1985, Silveira & Klink unpubl., B. Griscom pers. com.). These facts are thought to contribute to the high levels of endemism and species diversity evident in the region and to all intents and purposes Guadua can be regarded as a key-stone plant type in Madre de Dios.

Economically, the potential of Guadua as a non-wood forest product (NWFP) in Madre de Dios is enormous, although much work is still required in the fields of market research, product development, supply chain and cost benefit analysis, not to mention forest management before the value of Guadua can be calculated and fully realised (Godoy, Lubowski & Markandya 1993, FAO 2000). Countries such as Colombia, Ecuador and Costa Rica have been successfully managing wild stands or plantations of G. angustifolia for a number of years now (Farrelly 1984, Villegas 1989, Cusack 1997, Londoño 1998, Janssen 2000, Londoño, Marón & Stern pers. com.), although rarely in humid lowland tropical forest. Both government and non-governmental organisations (NGOs) in Madre de Dios are encouraging development projects based on bamboo as an alternative and fast-growing resource for the benefit of the local population (Jeri & Flores pers. com.). To date the species showing most promise is G. cf. angustifolia (hereafter Marona). However, very little is known about its distribution and ecology, indeed its precise taxonomic classification is still uncertain. One NGO interested in filling this knowledge gap is the Madre de Dios-based Amazon Conservation Association (ACA), which manages the Los Amigos Conservation Concession (LACC)(Forsyth 2000, Fig. 1) and provides technical assistance to local people in the Los Amigos area involved in natural resource extraction.

Bamboo specialists consider Marona to be part of the G. angustifolia – G. chacoensis complex, a morphologically highly variable group (Young & Judd 1992, Londoño & Peterson 1992, Stern pers. com.). Like many bamboos its reproductive ecology is characterised by periodic synchronous (semelparous) flowering events followed by senescence of stands (Janzen 1976, Keeley & Bond 1999). The flowering cycle of the species is believed to be around 30 years (Londoño pers. com.), although this has yet to be confirmed. The repercussions of this issue for the future management of Marona should be one of the factors evaluated before a decision is taken on whether to bring the species under management. Due to the general lack of seed for many semelparous species efforts are underway across the World to develop appropriate vegetative propagation techniques (Banik 1987, Seethalakshmi, Surendran & Somen 1988, Sulthoni 1988, Villegas 1989, Cusack 1997, Longhi 1998). Evaluation of such techniques for use with Marona are required for possible future reforest enrichment or plantation development purposes.

Physically, Marona is characterised by large, erect, green, cylindrical, hollow, thorny culms, which may reach a height of 30 m and 20 cm in diameter (Cusack 1994, Renvoize 1998, Judziewicz et al. 1999, Plates 1-3). In addition culms have a band of small white trichomes above and below the nodal line. Culm sheaths are large (50 x 75 cm) and covered in urticating trichomes. Branches are grouped at internodes, and may or may not have trichomes or spines, though only one can be considered as primary. Mature plants can forms dense clumps up to 30 m in diameter.

A plethora of different techniques exist for curing, chemically treating, drying, and otherwise managing recently harvested bamboo culms in order to prevent splitting, insect infestations, particularly with respect to the bamboo powder post beetle (Dinoderus sp.), fungal growth, and to generally improve quality prior to transformation. These techniques are rigorously reviewed in Farrelly (1984), Dunkelberg (1985), Kumar & Dobriyal (1988), Cusack (1997) and Janssen (2000). No one technique seems to be better than any other, it is largely factors such as the type of bamboo, the environment in which it grows, cost and final use which determines the most appropriate technique. As there is not a history of Marona utilisation amongst the local population in Madre de Dios, it is difficult to know which of the many techniques available would be appropriate given the humid tropical environment in which it grows and the logistics of transporting and eventually transforming this resource into economic goods. Suffice to say that it is very likely that culms will have to endure extended periods near the place of harvest before they reach the market. A means of assessing the effectiveness of different post-harvest treatment techniques on Marona culms is therefore required.

This study, which was undertaken from June to September 2001, set out to: 1 map the distribution and abundance of Marona in and around the LACC, using satellite imagery and Geographic Information System (GIS) based spatial analysis techniques, as well as conventional survey methods; 2 determine if Marona is associated with particular forest types, and/or natural or anthropogenic disturbance; 3 assess the characteristics of clumps in terms of number and diameter at breast height (dbh) of live culms, number of dead or dying culms, number of recently germinated culms, degree of illumination, and edaphic properties (soil texture and colour); 4 determine the growth rate and above-ground biomass of culms; 5 assess various techniques for artificial propagation of the species; and 6 determine the most appropriate post-harvest treatment and seasoning techniques for culms.

Summary, Introduction, Methods, Analysis, Results, Discussion, References, Acknowledgements, Photos, Links