This paper is largely reproduced from a chapter previously published as R. Rollenbeck, J. Bendix and P. Fabian (2010). Spatial and temporal dynamics of atmospheric water and nutrient inputs in tropical mountain forests of southern Ecuador. In Tropical Montane Cloud Forests. Science for Conservation and Management, eds. L.A. Bruijnzeel, F.N. Scatena and L.S. Hamilton. Cambridge: Cambridge University Press, pp. 367-377. www.cambridge.org/9780521760355.
Special Issue Article
Spatial and temporal dynamics of atmospheric water inputs in tropical mountain forests of South Ecuador†
Article first published online: 23 DEC 2010
Copyright © 2010 John Wiley & Sons, Ltd.
Special Issue: Hydrometeorology of tropical montane cloud forests
Volume 25, Issue 3, pages 344–352, 30 January 2011
How to Cite
Rollenbeck, R., Bendix, J. and Fabian, P. (2011), Spatial and temporal dynamics of atmospheric water inputs in tropical mountain forests of South Ecuador. Hydrol. Process., 25: 344–352. doi: 10.1002/hyp.7799
- Issue published online: 20 JAN 2011
- Article first published online: 23 DEC 2010
- Manuscript Accepted: 18 MAY 2010
- Manuscript Received: 15 SEP 2009
- tropical mountain forest;
As part of an interdisciplinary research programme, the spatial and temporal variability of precipitation in southern Ecuador has been investigated since January 2002. The study site is located at the northern margin of the Podocarpus National Park in the vicinity of Loja, about 500 km south of Quito, at altitudes ranging from 1800 to 3200 m.a.s.l. Due to its low density, the conventional rainfall station network fails to register the highly variable spatial distribution of rain, whereas contributions by fog are not accounted at all. Hence, for the first time in a tropical montane forest setting, a weather radar was used, covering a radius of 60 km and reaching from the Amazon Basin to the coastal plains of the region. Furthermore, a network of sampling stations supplies data about the altitudinal gradient of fog and rainwater inputs. The precipitation distribution in the study area proves to be far more variable than previously thought and is strongly coupled to the orographic characteristics and the special topographical setting of the landscape. Maxima in precipitation occur especially in the eastern parts of the radar range on slopes exposed to advected moisture from the Amazon Basin, whereas the highest crests of the Andes receive less precipitation. The study area has two cloud condensation levels, occurring at 1500–2000 and 2500–3500 m.a.s.l., respectively. At 1800–2000 m.a.s.l., fog is estimated to contribute an additional input of 5% of conventionally measured rainfall, increasing to about 35% at the highest measurement station (3200 m.a.s.l.). In contrast to some other tropical mountains, there seems to be no maximum zone of water input, although the gradient remains positive up to the highest altitudes. The unusual precipitation distribution is thought to reflect the contrasting climatological influences operating in the study area. Copyright © 2010 John Wiley & Sons, Ltd.