PALMS Pintaud: Rio Napo Journey Vol. 49(2) 2005

A Journey JEAN-CHRISTOPHE PINTAUD IRD Whimper 442 y Coruña Along the A.P. 17.12.857 Rio Napo Quito, Ecuador

1. gasipaes in a pasture on alluvial terrace of Rio Napo. This species has been domesticated by Amerindians and is still widely cultivated in the Amazon, especially for its edible fruits. An expedition along the Rio Napo, a tributary of the Amazon that flows through Peru and Ecuador, revealed some of the area’s palms, their specific habitats and their importance in the lives of the local people.

PALMS 49(2): 85–91 85 PALMS Pintaud: Rio Napo Journey Vol. 49(2) 2005

In October–November 2004, IRD (Institut de Everything began well; we took off from Quito Recherche pour le Développement, France) airport and soon had magnificent views of the organized an international, multidisciplinary Andes, including the deep blue Mojanda Lake expedition on Rio Napo, a major tributary of above Otavalo and various ice-capped the Upper Amazon River. Rio Napo originates volcanoes. Most spectacular was Cayambe from the northern Andes in Ecuador. In its (5790 m), of which we had a very close view. upper valley, located some 25 km to the SE of Then, as we descended toward the Amazon volcano Cotopaxi (5897 m) it is no more than plain, the sky became more and more cloudy a tumultuous stream. It quickly enlarges and and when we reached the lowlands, we could become navigable from Puerto Napo, some 70 hardly see more than tall yellow flames km to the east of its source. In its lower course, emerging from scattered oil fields, and the in Peru, it reaches nearly 5 km wide in some meanders of Rio Napo, in the middle of the points, and finally merges with the Amazon, mist and rain. 75 km downstream from Iquitos. The Approaching Tiputini, the rain became so expedition included more than 20 scientists heavy that water entered the plane from from five nationalities, with research programs everywhere, and the only thing we could see in hydrology, geology, palaeontology and was the lightning illuminating briefly the . Many new discoveries were made, dense clouds all around the plane. It wasn’t including spectacular macrofossils such as the safe enough to spend more time in this area, teeth of a 15 m long crocodile. A complete and we had to go back to Coca airport, further topography of the river as well as a continuous up the Rio Napo. We waited desperately for stratigraphic sequence of the past 20 million several hours for better weather conditions, years was achieved. which never appeared on this unfortunate day. I happily participated in the Peruvian part of Since the plane had to go back to its base, I the expedition, although joining it in the took my wet equipment and began to search middle of the trip was not so easy. I was for transportation to go down the Rio Napo supposed to come with a small plane taking and meet the expedition at Nuevo Rocafuerte, three passengers from Quito to Tiputini in the the last village before entering Peru. far eastern Ecuadorean Amazon, and meet Unfortunately, it was a Saturday and there is there with a TV team who had to make aerial little activity during the weekend in Coca. The views of the expedition and landscape. next boat to Nuevo Rocafuerte was on Monday

2. A traditional house made of palm material at Campo Serio, Rio Napo.

86 PALMS Pintaud: Rio Napo Journey Vol. 49(2) 2005

3. A swamp forest dominated by tall Attalea butyracea, also with Euterpe precatoria and . and takes 12 hours to reach this village. By fog persisted. It took us two hours to reach that time, the expedition would have been too Nuevo Rocafuerte without major difficulty, far away downstream in Peru to be met. The despite the low visibility. There, an annex of only remaining option was to rent for myself the Peruvian boat on which the expedition alone a 20-seat powerful boat, which is embarked was waiting for me, and after a half- normally contracted by oil companies. After hour trip, I finally met the expedition in having loaded nearly half a ton of fuel in tanks Pantoja, on the Peruvian side, and at last I on the back seats, we departed late in the could begin thinking about palms! afternoon (me, my backpack and the three The main focus of the palm work was to crew members) for a race down the river. We understand where and how changes in palm passed Pompeya after 34 minutes, while species composition between Ecuador and Peru regular transport takes three hours to get there. occurred. The palm flora is significantly As the day finished, it was more and more different in northeastern Ecuador and in the difficult to see the obstacles in the river, and region of Iquitos, while the distance between after some slaloming among dead trunks at 70 the two areas is not so great on the scale of the km/h, the pilot decided it was safer to stay at Amazon basin (500 km). For example, the most night in the small village of Bañacocha. There abundant palm species in the Iquitos-Pebas we met a military hydrologist (unmistakable region of Peru, Lepidocaryum tenue (Vormisto et with his orange uniform) who was coming al. 2004) is totally absent (or at least back from the Ecuadorean part of the unrecorded) from Ecuador (Borchsenius et al. expedition. He informed us that some 1998). Two other genera fairly abundant in members of the expedition were still in Nuevo the Iquitos region, Iriartella and Wendlandiella, Rocafuerte and that I was still in time to meet are also absent from Ecuador, as well as a them early the next morning. We thus decided number of other interesting species such as to depart as soon as daylight appeared. Chelyocarpus repens, Attalea ferruginea, Bactris We woke up at 4:45 a.m. and looked outside halmoorei and Bactris killipii. An especially at the weather conditions. There was no longer interesting distribution pattern to study was rain but a fog so dense that we could hardly that of Astrocaryum urostachys, which has been see anything 5 m away. By 6:00 a.m. the pilot considered as endemic to Ecuador (Borchsenius decided it was possible to go on, although the et al. 1998) and A. macrocalyx, known only

87 PALMS Pintaud: Rio Napo Journey Vol. 49(2) 2005

88 PALMS Pintaud: Rio Napo Journey Vol. 49(2) 2005

Opposite page: soils, the structure and floral composition of which depends on the frequency of flooding 4. Attalea butyracea and Euterpe precatoria at sunset. and quality of drainage. Palm composition is highly characteristic of each habitat . In from the area of Iquitos (Kahn & Millán, 1992). areas almost constantly inundated on river The two species arose from a common ancestor shores, only Bactris riparia is found. In slightly (Pintaud & Kahn 2002) and are immediately higher terraces, frequently flooded forests are distinguished by their habit. Astrocaryum rich in spiny palms (Bactridinae), the most urostachys is densely clustering while A. characteristic of them being , macrocalyx is always solitary. As these species associated with Bactris concinna, B. bidentula, B. occur in abundance in alluvial terraces, their brongniartii, B. bifida and the climbing species distribution would be easy to trace during our orthacanthos, which forms dense trip. Are they meeting and mixing in some thickets. Higher terraces, seldom reached by part or are their ranges totally separated? What, the water, are the typical habitat of Astrocaryum in fact, promoted their morphological urostachys, associated with Attalea butyracea, differentiation? These were some of the Geonoma deversa and G. brongniartii. questions I was eager to answer. On the second day of our descent from The Peruvian course of the Napo is still a very Pantoja, in the vicinity of Campo Serio, we isolated region. It is mostly inhabited by encountered vast areas of swamp dominated Indian communities who cultivate a few crops by Attalea butyracea, a kind of vegetation I had for their subsistence, including the Peach never previously seen in such extensive stands palm, Bactris gasipaes (Fig. 1). Their houses (Fig. 3). I decided to investigate the forest, are made entirely of palm material (Fig. 2). accompanied by Emerson, a crew member who Walls are made with species of Iriarteeae (pona), was to help me with most of the field work I mainly Iriartea deltoidea or Wettinia maynensis, made during the trip. The forest floor was depending on local availability, and roofs are damp and muddy, but many trails crossed the thatched preferentially with Lepidocaryum tenue forest, paved with Attalea leaves. A surprising and Attalea butyracea. fact of the Peruvian Amazon is that there is Natural vegetation along Rio Napo is mostly human presence everywhere. Even in places composed of forests on Quaternary alluvial such as these swamps, not very appealing nor

5. Astrocarym jauari in periodically flooded forest along lower Curaray River.

89 PALMS Pintaud: Rio Napo Journey Vol. 49(2) 2005 close to any settlement, people come and document what species grew in these hills. We gather some products of the forest. stopped at the small settlement of Copal Urco, Extractivism is indeed a very important aspect a toponym meaning “hill of the copal tree” of Amazon life, and palms in particular provide (copal is a name applied to various resiniferous many products, including palm-hearts, fruits, Burseraceae species). There we looked for seeds, building material, fibers etc. I noticed an someone who could guide us in the forested Astrocaryum off the trail and tried to approach hills. Local people in the Amazon are always it, but it was impossible to walk in the deep happy to help visitors. We just asked if mud. Following the example of local people, someone could show us some huicungos (the we cut and put large Attalea leaves on the vernacular name of Astrocaryum species with ground in order to reach the palm and make leaflets arranged in one plane) and a man a herbarium collection. It proved to be immediately volunteered to accompany us. Astrocaryum urostachys. This species was We soon found the palms, which turned out abundant in the swamp, but it had a somewhat to be Astrocaryum macrocalyx. We asked our different morphology from the populations I guide if these palms were always solitary, and knew from Ecuador, with slender stems and he confirmed this important point. So the narrow leaflets, probably because of the boundary between the two Astrocaryum species unusual habitat in which it was growing. Other was clear. Astrocaryum urostachys grows in the common palms were Socratea exorrhiza, with its alluvial plain and A. macrocalyx in the hills of prominent stilt roots, Euterpe precatoria and the Iquitos arch. Where these geomorpho- Geonoma brongniartii, a set of species generally logical structures meet, as here near the mouth abundant in swamps. Mauritia flexuosa, the of Rio Curaray, there is a contact between the most typical swamp palm in the Amazon, was two species. There is thus a sharp boundary on the other hand scarce and basically replaced between a species previously known from by Attalea butyracea, which reached unusual Ecuador and another described from Iquitos, densities in this place. When we went back to exactly what we were looking for. the river, we discovered a breathtaking scenery But what happened with the other species – there was a sunset and moonrise at the same having a similar distribution pattern? So far time. The palms were glowing in the orange we had not seen any of them. Interestingly light of the sun and the moon appeared however, the house of our guide had a roof behind them (Fig. 4). This was really an thatched with Lepidocaryum tenue leaves, one unforgettable sight. of the species abundant in the Iquitos arch. We The third day I explored a hill above the lower asked the man where he gathered these leaves Aushiri river, a tributary of Rio Napo. Many and he said the palm grew rather far away from emerging crowns of and the river, three hours walk from Copal Urco. Iriartea deltoidea caught my attention, but the Then we realized that the areas we were understory proved to be very poor in palms, visiting in the immediate vicinity of Rio Napo with only Hyospathe elegans, Chamaedorea did not represent all the diversity of habitats pauciflora and a couple of Geonoma and Bactris. found in the region and that we were missing some important palm communities. The fourth day we awoke at the mouth of Rio Unfortunately, there was no time to conduct Curaray, the largest tributary of Rio Napo. field study away from the river and we had Again the light was very special, and we not the opportunity to document other species decided to explore the lower course of the limits during that trip. It took three more days Curaray in the morning, taking many to reach Iquitos. All along the lower Napo, we photographs. Astrocaryum jauari was abundant saw Astrocaryum macrocalyx abundantly on along the river, on the lower terraces (Fig. 5). alluvial terraces, just as A. urostachys grew in In some places, the shores were lined with the upper Napo, but we no longer saw the clumps of Bactris riparia, which was also a latter. This gave us further information: there spectacular sight (Fig. 6). Astrocaryum urostachys is no ecological differentiation between the was still abundant in these forests, now far two species, and the contact encountered at from the Ecuadorean border (200 km). Just 5 the base of Iquitos arch may represent the km downstream of its confluence with Rio point were the colonization fronts of the two Curaray, Rio Napo makes a curve at 90° to the species meet. east as it follows the northeastern limit of a major hill system, the Iquitos arch. Since This expedition was therefore very Astrocaryum macrocalyx is known from other informative, as it contributed towards bridging sectors of the arch, it was important to the gap in our knowledge between areas of

90 PALMS Pintaud: Rio Napo Journey Vol. 49(2) 2005

6. Bactris riparia on the banks of a small tributary of Rio Curaray. palm inventories showing different species KAHN F. AND B. MILLAN. 1992. Astrocaryum composition. However, much more remains (Palmae) in Amazonia. A preliminary to be learned before we can fully understand treatment. Bulletin de l’Institut Français the distribution patterns of palms in the d’Etudes Andines 21: 459–531. western Amazon. PINTAUD J.-C. AND F. K AHN 2002. Endémisme et Acknowledgments spéciation radiative chez les palmiers de forêt dense humide: les Iguanurinae de Nouvelle- I am grateful to Jean-Loup Guyot, who led the Calédonie et le genre Astrocaryum en Napo expedition for inviting me to participate, Amazonie. Biosystema 20: 81–87. and to Patrice Baby for his information on the geology of the western Amazon basin. VORMISTO, J., J.-C. SVENNING, P. HALL AND H. BALSLEV. 2004. Diversity and dominance in LITERATURE CITED palm () communities in terra firme BORCHSENIUS F., H. BORGTOFT PEDERSEN AND H. forests in the western Amazon basin. J. Ecol. BALSLEV 1998. Manual to the Palms of 92: 577–588. Ecuador. AAU Reports 37. Aarhus University and PUCE. 217 p.

91