HM227 How do dragonfly communities change over an elevation gradient?
Dr. Merlijn Jocque
The introduction to this project is based on the chapter of Samways (2008) on Dragonflies as
focal organisms in contemporary conservation biology and Oertli (2008) on the use of
dragonflies in the assessment and monitoring of aquatic habitats. Aquatic resources are under
particular threat today and, therefore, the management of aquatic habitats and of their
watersheds requires the development of comprehensive assessment and monitoring methods.
Biological methods are now widely used, and many include Odonata. Odonata constitute a
valuable tool for various types of assessment and monitoring, such as the measure of
biodiversity, the appraisal of water-body health or integrity (including water quality and
ecosystem function), the monitoring of management or restoration practices, and the detection
and prediction of the biological impact of climate warming. Furthermore, sampled through
standardized methodologies, they have already provided excellent data-sets for hypothesis
testing in ecology or evolution. In applied issues, the adult stages of Odonata are surveyed at a
low cost, and are therefore useful for rapid assessments; they can be used for preliminary
screening, for example when identifying local hotspots of diversity or, on the contrary, of
degraded sites.
Despite the wide spread use of Odonata for conservation and in research, little is known about
dragonflies in Honduras and in Cusuco National Park. Preliminary surveys conducted since
2010 have revealed about 40 dragonfly species in CNP, with a wide range of interesting
findings, including some new country records, undescribed species to science and new
records of rare species. We have a fairly good idea of what is available now in the park, and
this is the moment to move forward and start with distributional patterns and community
structure. A biotic index to monitor river water health in CNP is in progress at the moment of
writing, and as a side project it would be interesting to see to what extent dragonflies can be
used as an easy to observe group to preliminary monitor the status of the rivers. Before
dragonflies could be used for such a purpose, more insight is needed in the natural variation in
dragonfly communities. This project aims at setting the first steps towards understanding
natural community structuring factors in cloud forest dragonfly communities. Besides
distribution patterns associated with environmental characteristics such as climate
(temperature, precipitation) or larval habitat features (river type), this project aims to assess
niche optima. Niche optima will be assessed making use of niche distribution modelling and
the student will also collect size data of the dragonflies to identify the optimal climatic
conditions and habitat types.
Little is known on the ecology of Central American dragonflies, and in particular on the
change of dragonfly communities along an elevational gradient. Von Ellenrieder 2009,
Campbell et al. 2010 and Gomez-Anaya et al. 2011 are some of the more recent case studies
that have looked into the elevational distribution of species. All these studies observed a
decrease of species richness with elevation. Besides this general observation little was
recorded.
References
Campbell, W. B., R. Novelo-Gutierrez, and J. A. Gomez-Anaya. 2010. Distributions of
odonate richness and diversity with elevation depend on windward or leeward aspect:
implications for research and conservation planning. Insect Conservation and
Diversity 3:302-312.
Gomez-Anaya, J. A., R. Novelo-Gutierrez, and W. B. Campbell. 2011. Diversity and
distribution of Odonata (Insecta) larvae along an altitudinal gradient in Coalcoman
mountains, Michoacan, Mexico. Revista De Biologia Tropical 59:1559-1577.
Von Ellenrieder, N. 2009. Odonata of the Argentine Yungas Cloud Forest: Distribution
Patterns and Conservation Status. Odonatologica 38:39-53.
Oertli B. 2008. Chapter 7. The use of dragonflies in the assessment and monitoring of aquatic
habitats. In: Córdoba-Aguilar, A. Dragonflies and Damselflies : Model Organisms for
Ecological and Evolutionary Research. Oxford University Press.
Samways M.J. 2008. Chapter 8. Dragonflies as focal organisms in contemporary conservation
biology. In: Córdoba-Aguilar, A. Dragonflies and Damselflies : Model Organisms for
Ecological and Evolutionary Research. Oxford University Press.