Aline Horwath
Canopy access in virgin forest of Cocha Cashu (300 m)
|
Aline.Horwath@plantsci.cam.ac.uk
Education
2007-present - PhD, Physiological Ecology Group, University of Cambridge
2003-2004 - MSc Plant Diversity/Taxonomy, University of Reading
1999-2003 - BSc (Hons) Plant Sciences, University of Edinburgh
Project title: Biodiversity and ecophysiology of epiphytic bryophytes as indicators of a climatic gradient in Peru
Tropical ecosystems and especially montane cloud forests belong to the most species-rich terrestrial habitats and are increasingly threatened by climate change and anthropogenic activities1. The humid cloud forest canopy in particular shows a great abundance of epiphytes, both vascular and non-vascular with many different highly specialised life forms2,3. Although being the most diverse group of land plants, bryophytes remain under-described due to their inconspicuous morphology, and thus challenging identification. Structurally, evolutionary and physiologically however, they represent exceptionally interesting organisms4. The remarkable diversity, simplicity but nevertheless efficiency of bryophyte form and function makes them unique model species for investigations of ecophysiological processes, both at plant and also ecosystem levels5.
While particularly epiphytic bryophytes can serve as sensitive indicators of changing environmental conditions in fragile ecosystems such as the cloud forest canopy6,7, stable isotopes (13C and 18O) can provide markers for the study of complex physiological processes across spatial and temporal scales8. Isotope ratios and discrimination patterns represent powerful tools commonly used in ecology. They allow elucidating the intricate details of plant-environment interactions, as well as the metabolic and atmospheric transformations of water and carbon dioxide, not only at the leaf-level but also on a global scale9.
The main objective of my PhD project is to map the distribution and diversity patterns of epiphytic mosses and liverworts collected along an altitudinal gradient in southeastern Peru, and model their hydrology. The study will test if bryophytes can serve as sensitive indicators of environmental changes and if the isotopic signals of 18O and 13C in organic material reflect the altitudinal transition from dryer to moist habitats, and can thus provide markers for climate change. Additionally, biomass estimates will define the currently unknown contribution of epiphytic biomass to the total carbon budget of tropical montane cloud forests.
My field work is carried out in the Kosñipata Valley, Manu National Park, and Tambopata National Reserve, in collaboration with the 'Andean Biodiversity and Ecosystems Research Group'. The double rope technique (BCAP; GCP) is used for canopy access. Identification of plant material will be carried out at the Smithsonian Tropical Research Institute in Panama and the Royal Botanic Garden Edinburgh.
View of the 'Trocha Union' ridge and the lowlands under cloud cover (from Wayqecha field station, 3000 m). Eight 1 ha plots are located along this ridge.
|
References
1. Foster, P. Earth-Sci Rev 55, 73-106 (2001).
2. Nadkarni, N.M. Amer. Zool. 34, 70-78 (1994).
3. Holz, I. et al. The Bryologist 105(3), 334-348 (2002).
4. Glime, J.M. Bryophyte Ecology, vol. 1 (2007).
5. Wood, A.J. et al. The Bryologist 103(1), 128-133 (2000).
6. Gignac, L.D. The Bryologist 104(3), 410-420 (2001)
7. Benzig, D.H. Climatic Change 39, 519-540 (1998).
8. Dawson, T.E. et al. Annu Rev Ecol Syst 33, 507-559 (2002)
9. Ito, A. Tellus 55B, 596-612 (2003).
Supervisors
Prof Howard Griffiths (Physiological Ecology group, Department of Plant Sciences, University of Cambridge)
Dr David Coomes (Conservation and Community Ecology, Department of Plant Sciences, University of Cambridge)
Funding
Financial support has been received from NERC, Jesus College, Dulverton Canopy Fellowship (GCP) and Frank Smart Studentship.
Publications
Cheek, M., Corcoran, M. and Horwath, A. 2008. Four new submontane species of Psychotria (Rubiaceae) with bacterial nodules from Western Cameroon. Kew Bulletin 63, 405-418.
Horwath, A. B., Grayer, R.J., Keith-Lucas, D.M., Simmonds, M.J. 2008. Chemical characterisation of wild populations of Thymus from different climatic regions in southeast Spain. Biochemical Systematics and Ecology 36(2), 117-33.
Cheek, M., Horwath, A. and Haynes, D. 2008. Psychotria kupensis (Rubiaceae) a new dwarf, litter-gathering species from western Cameroon. Kew Bulletin 63, 243-246.
Cloudforests in the Kosñipata Valley, southeastern Andes of Peru (canopy view from Trocha Union plot II, 3240 m).
|