Volume 9, Part 4, November 1995

THE BMS EXPEDITION TO CUYABENO,ECUADOR: AN INTRODUCTION

J. HEDGER!, D. JEAN LODGE2, G. DICKSON3, H. GITAY4,T. LAESS0E5 & R. WATLING6

1 Department ofBiological Sciences, University College of Wales, Aberystwyth,Dyfed, Wales

2 Center for Forest Mycology Research, USDA-Forest Service, PO Box 1377,Luquillo, PR 00773-1377, USA

3 Flagstones, 72 Catisfield Lane, Fareham, Hants, P015 5NS, UK4 Research School ofBiological Sciences, Institute of Advanced Studies, Australian

National University, Canberra, ACT 0200, Australia5 Botanical Institute, Department ofPhycology & Mycology, Oster Farimagsgade 2D,

DK-1353 Copenhagen K, Denmark6 Royal Botanic Gardens, Inverleith Row, Edinburgh EH3 5LR, UK

In 1989 the Council of the BMS respondedfavourably to a suggestion that, in view of the lackof mycological expertise in most officialbiologicalexpeditions, the Society itself should organise anexpedition to a tropical rainforest. It was to be ascientific expedition and a sub-committee ofCouncil was set up consisting of Harry Evans,David Pegler, Thomas Laessee, Jean Lodge, JohnHedger and Roy Watling with Gordon Dickson asChairman. After several meetings, correspon-dence and consideration of sites in several tropicalcountries Cuyabeno in Ecuador was decided uponas the venue. This was largely because JohnHedger had visited it regularly and had contactwith people who could act as local organisers, afactor which turned out to be ofmajor importance.The headquarters was to be at the field station ofthe Catholic University of Quito which is situatedbeside a temporary lake, dotted with the crowns ofthe trees above the water, laden with Bromeliadsand Orchids - a wonderful sight.

Whilst BMS Council agreed a sum for organisa-tional expenses and a subsidy to three students,each individual was responsible for their ownexpenses. In the end thirty applications wereapproved of which half were from UK and othersfrom countries including Switzerland, Germany,Belgium, Hong Kong and the United States. AnItalian group was obliged to cancel due to with-drawal of funding. Arrangements in Ecuadorwere handled by a team led by John Hedger and

consisted of Titti de Vries, Walter Penelosa,Mauricio Gavillanes and Ricardo Viteri. Theparty was divided into three groups, each to spendtwo weeks on site and to carry their own foodsupply. Members had to take the usual rainforestprecautions of carrying compass, whistle andwater, travel in pairs, and specify theirdestination.

Travel to the site consisted of a journey bymilitary transport aircraft or hired bus to LagoAgrio, a three hour trip by coach and a down-riverjourney by two outboard powered dugouts.

Once there we had quite comfortable beds withmosquito-nets. A large open room was used as adining room and another was set up as a labora-tory where culture techniques and microscopicexaminations could be made. Thanks to the skillofRicardo we even had light for an hour or so mostevenings. A drying rack had been built byVittoriano which used bottled gas; it worked hardall the time. It had been agreed that all duplicatematerial should be deposited with the Universityand with the Department of Agriculture.

Our diet of rice was leavened by being mixedwith an occasional tin of tuna or even by pirhanawhen Vittoriano or one of the members couldcatch one. We drank boiled water and surpris-ingly few people developed gastroenteritis.

Participants developed many projects rangingfrom ecological studies of wood and litter decom-poser fungi, through culturing of aquatic Hypho-

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mycetes and wood decomposers to surveys ofpalmicolous ascomycetes and entomoparasitic,xylariaceous, and phycomycetous fungi. The firstgroup was led by John Hedger (expedition coordi-nator) and Gordon Dickson, the organizer for theexpedition. The second group was led by HarryEvans , assisted at the beginning by John Hedger,and the third by Jean Lodge and later by JohnHedger. All three groups were aided in manyways by the indigenous Siona and Secoyaand twoEcuadorian graduate students, Ricardo Viteri andPablo Yepez.

Our plans to stay at the PUCE field station(research station of Pontifica Universidad Cato-lica del Ecuador, expanded with money donatedby Xenova and Sandoz for the BMS expedition)literally went up in smoke when the stationburned to the ground three weeks before the firstgroup was due to arrive. We were kindly accomo-dated by Cecilia DeVries at the Neotropic TurisLodge, located across the lake from the fieldstation. Each morning, we travelled to theopposite side of the lake by motorised dugoutcanoe, and returned to the 'laboratory' at middayor in the afternoon. This occupied a large, open,palm thatched building (see Figs 4 & 5 on page153) and was supplied with two isolationchambers for culture work. Electricity for micros-copeswas supplied for several hours each day by agas powered generator and car batteries.

Ecology and Management of the Reserve

The Cuyabeno Faunistic Reserve (Reserva deProduccion Faunistica Cuyabeno) is on the equa-tor near the border with Colombia (00° OO'N, 76°10'W), and is about 254,000 hectares in extent. Itis under the jurisdiction of the indigenous people,the Siona-Secoya and is managed by the Ministryof Agriculture Department of Conservation and

. Natural Resources. The elevation at Cuyabeno isabout 250 m.

The region has a mean annual rainfall of 3300mm with some seasonality; April-November tendto be the wettest months and December-Januarythe driest. The mean annual temperature for theregion is 24 °Cwith a seasonal range of20 to 32 °Cleading to high evapotranspiration rates. Usingthe Holdridge classification, the region is on theborder between the Tropical and the SubtropicalMoist and Wet life zones (Holdridge et al., 1971)with a cover of evergreen tropical lowland forest.

Volume 9, Part 4, November 1995

The forest has three distinctive subtypes in thearea, determined by the periods of waterlogging.Rio Cuyabeno, with its headwaters in the Andes,is the main river that flows through the area anddrains into Rio Agua Rico; it joins Rio Napo at thePeruvian boundary and eventually flows into theAmazon River . Within the Cuyabeno Reserve , RioCuyabeno forms a series of 14 shallow lakescaused by slow drainage in the river systemleading to the water being backed up in theselakes. The biggest of these, Lagunda Grande(about 1 km wide), is where the PUCE station andthe Neotropic Turis Lodge are located. The lakelevel fluctuates by up to 4 m, depending on therainfall in the Andes, often being dry in the lowrainfall season , but can get floodedto 1 m depth in24-48 hours.

Igapo Forest. The dominant plant of the season-ally floodedIgapo forest is an ectomycorrhizal treein the Leguminosae (Mimosoideae), Macrolobiumacacifolium (Bentham) Bentham. Some of thetrees grow well out into the lake, standing in 3-4metres of water. Such trees probably establishduring dry years, but must grow sufficientlyduring their first year so as to reach the photiczone of the lake (the upper half metre, because ofhigh tannic acid levels) before the next rainyseason. Smaller trees, such as Genepa sp. (Rubia-ceae) which form the understorey at the lakemargins, are also completely submerged when thewater levels are high. In a very unusual event, thelakes failed to drain during the dry seasonpreceding our expedition. It was therefore unbe-lievable that one was canoeing over the tops ofsaplings which seemed completely healthy intheir aquatic environment.

Camangucho Forest. Camangucho forests arealmost permanently flooded palm swamps occur-ring along depressions and stream valleys. Themost characteristic tree of the camangucho forestis a huge fan palm, Mauritia flexuosa LJ. Theseswamps became infamous during the expeditionfor their boot-sucking mud.

Tierra firme . The best developed and diverseforests occur on low ridge slopes and crests thatare never flooded, known as tierra firme (i.e., firmground). In 1994, Valencia et al. reported as manyas 473 tree species greater than 10 cm diameter atbreast height in a one hectare plot of tierra firmeforest at Cuyabeno, making it the most diverselowland tropical forest so far measured. Valencia

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Volume 9, Part 4, November 1995

et al. had permanently numbered the trees intheir study plot, facilitating our identification ofhost plants based on their list. The forest canopy isstratified, with a scattering of very large emer-gents above a canopy oflower trees, a series of ill-defined understoreys, and a shrub/sapling/palmifern ground-layer. The emergent canopy treesinclude species of figs (Ficus spp.), laurels iOcoteaspp.) and members of the Sapotaceae (e.g., Pou-teria spp.).

Fungi at Cuyabeno

John Hedger and Habiba Gitay conducted twoecological surveys of fungi in Cuyabeno in 1988and 1991. Their (unpublished) results indicatedthat disruption of the canopy, and rainfall duringthe two days preceding each survey, stronglyaffected the abundance offruiting bodies ofagariclitter decomposers, which are numerically domi-nated by small species such as Mycena spp. inSect. Sacchariferae. The previous data of Hedgerand Gitay were useful in analysing agaric litterfungal diversity at Cuyabeno (Lodge & Cantrell,this issue). Maria Nunez (in press) found thatsome of the aphyllophoraceous fungi growing onsmall woody litter suspended above the forestfloor were likewise ephemeral with the rains,while other species formed structures that pro-tected them from desiccation. Hedger and Gitay(unpub.) had previously suggested that woodcolonised by xylariaceous fungi and discomyceteswas drier than uncolonized wood, perhaps fromfungal activity. The results of Schoeman's study(during this expedition), however, did not indicatea strong difference in moisture between woodwithand without ascomycetes overall, although woodcolonised by certain species of Xylaria might besignificantly drier. Hedger and Gitay had found ahigh degree of resource partitioning amongdecomposer fungi at Cuyabeno, such that differ-ent fungal species assemblages occurred on sub-strates ofdifferent sizes and types; they also founddifferent assemblages on the same substratesdepending on whether they were suspended aboveground or lying on the forest floor. Analogously,Richardson, Moller and Dreyfuss based on obser-vations made (during the expedition), found signi-ficant differences among assemblages of fungiisolated from aquatic habitats depending onwhere they collected their samples.

The uplifting ofthe Andes is thought to have ledto many speciation events among plants, animals,and possibly fungi. In addition, the Amazonianbasin may have retained many ancestral species,thus contributing to the high diversity of themycota. Indeed, many of the agarics (e.g., Lodge,this issue) and some of the xylariaceous fungi (T.Laessee, pers. obs.) were undescribed species. Theabundance ofentomopathic fungi on arthropods atCuyabeno was previously noted by Hedger andGitay, and proved to be a source ofinteresting andpotentially useful biocontrol species for CarolEllison and Harry Evans. A list of 1639 fungicollectedduring the BMS expedition was compiledby Gordon Dickson and is available on request.Duplicate material from the expedition is beingdeposited at the Catholic University in Quito(PUCE) and with the Ministry of Agriculture.

List of participants (from UK except whereindicated);Thomas Laessoe, Denmark*; Jean D. Lodge,Puerto Rico*; Paul Lunt; Kurt Mendgen, Kon-stanz; Ernesto Morales, Georgia, ?USA, MariaNunez, Norway; Christine Schaeffer, Berlin,Magnus Schoeman, Ulrich Strahm, Switzerland;Margaret A. Whalley; Ricardo Puce Viteri,Florida, USA; Martyn A. Ainsworth; SharonCantrell, Georgia, USA; James Chapman;Michael D. Coffey; California, USA*; Ciara M.Clarke; Cony A. Decock, Belgium; Gordon Dick-son; Michael M. Dreyfuss, Switzerland*; Carol A.Ellison; Harry Evans; Jane Frohlich, Hong Kong;John Hedger; (Coordinator); Susan C. Hines;Gregoire Hennebert, Belgium*; Kevin Hyde,Hong Kong; Gordon Rutter*.* Participants at the Tropical RainforestSymposium held at Kew, 18 November 1994.

ReferencesHedger, J.N. & Gitay, H. Fungal assemblages, their

resource utilisation and response to climaticfactors in tropical rainforest ofCuyabeno Reserve.- unpublished manuscript.

Holdridge, L.R., Grenke, W.C., Hatheway, W.H.,Liang, T. and Tosi, J.A. Jr. (1971) Forest environ-ments in tropical life zones: a pilot study. NY 747pp.Pergamon Press,

Valencia, R., Balslev, H. & Pax Y. Mino, G. (1994)High tree alpha-diversity in Amazonian Ecuador.Biodiversity and Conservation 3: 21-28.

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