Information about Yasuni National Park
The Amazon River basin is primarily made up of large areas of land with an altitude less than 600 m occupied by tropical rainforest. The basin is crossed by meandering rivers during the rainy season can flood large areas. In the Amazon, the regions closest to the Andes and the equator have low seasonality and high rainfall (6000-4000 mm). To the east and at higher latitudes, decreasing precipitation (2000 mm) and is very seasonal.
Location and hydrography of Yasuni National Park (YNP)
The PNY is located in the provinces of Pastaza and Orellana, in the Ecuadorian Amazon. Its altitudinal range is 600-230 m above sea level. The PNY comprises several river systems belonging to the Napo River basin. The most important are the Tiputini River, Yasuni Nashiño and Cononaco.
According to the composition of its waters, PNY rivers can be classified into whitewater rivers and black water rivers. The first, from which all the rivers PNY large, are characterized by high turbidity, contain a large amount of sediment and a neutral pH. Blackwater rivers typically have little sediment in suspension, a pH ranging between 4.7 and 5.8 and large amount of polyphenols and tannins which allow them a dark brown coloration ( Asanza 1985 ).
Climate information from the Ecuadorian Amazon and PNY
The Ecuadorian Amazon climate is very humid megathermic Uniform characterized by average temperatures near 25 ° C and total annual rainfall almost always higher than 3000 mm (annual rainfall can reach 6000 mm in some regions; Pourrut et al. 1995 ). The distribution of rainfall is remarkably uniform throughout the year despite a relative decline between December and February ( Pourrut et al. 1995 ). The relative humidity is above 90%. The sky is covered by clouds usually so insolation is low (about 1000 hours / year) ( Pourrut et al. 1995 ).
According to information gathered in the Yasuni Research Station of the Pontifical Catholic University of Ecuador (76 ° 24 ’19 “W, 0 ° 40′ 32” S), during the period 1995-2000 the average annual rainfall was 2826.3 mm and average temperature of 25.2 ° C ( Herbarium QCA 2001 ).
In the four types vegetation YNP (according to the classification of Palacios et al.1999 ):
Lowland evergreen forest (Bosque de Tierra Firme): characterized by having well-drained soils with a canopy reaches 30 m and emergent trees reaching 40 m. It has a high heterogeneity and diversity. In a quadrant of 25 ha in the Yasuni Research Station Catholic University found 1104 morphospecies tree trunk with a diameter> 10 cm. The total number of individuals sampled was 152 353 ( Valencia et al. 2004 ). In the same quadrant, the most abundant species are small trees and Rinorea Matisia genres. Among the canopy species, the most abundant are the deltoid and Eschweilera Iriartea palm coriacea ( Valencia et al. 2004 ).
Lowland evergreen forest floodplain by Aguas Blancas (Várzea) are with white water rivers. In times of high rainfall, the forest is flooded for several days as a result of the flooding rivers. The sediments carried by water enrich the soil. The vegetation reaches 35 m in height and depending on the magnitude and frequency of floods in various states of succession (Palacios et al. 1999) .
Lowland evergreen forest floodplain by Aguas Negras (Igapó): located along rivers or sewage lake systems. The forest is periodically flooded waters but generally do not provide a significant amount of soil nutrients (Palacios et al. 1999) . The forest may remain flooded for periods exceeding one year. Canopy height and diversity are low compared to mainland forest.
Floodplain of Lowland Palmas (Moretal) soils are poorly drained and remain flooded most of the year. Mauritia flexuosa palm tree is the most abundant species. The forest canopy reaches 30 m in height and is relatively dense understory (Palacios et al. 1999)