Biodiversity and Conservation

, Volume 27, Issue 2, pp 273–285 | Cite as

A review of ecological gradient research in the Tropics: identifying research gaps, future directions, and conservation priorities

  • Jannes Muenchow
  • Petra Dieker
  • Jürgen Kluge
  • Michael Kessler
  • Henrik von Wehrden
Review Paper


The Tropics are global centers of biodiversity. Ecological and land use gradients play a major role in the origin and maintenance of this diversity, yet a comprehensive synthesis of the corresponding large body of literature is still missing. We searched all ISI-listed journals for tropical gradient studies. From the resulting 1023 studies, we extracted study-specific information, and analyzed it using descriptive analytical tools and GLMs. Our results reveal that dry tropical areas are vastly understudied compared to their humid counterparts. The same holds true for large parts of Africa, but also the Philippines and the South Asian region. However, we also found that (applied) research output of developing tropical countries is nowadays on par with the output of developed countries. Vegetation and elevation were the most studied response variable and gradient, respectively. By contrast, inconspicous organisms such as oribatid mites and edaphic gradients were largely missing in the literature. Regarding biodiversity, tropical gradient studies dealt extensively with species richness and ecosystem diversity, but much less with genetic diversity. We encourage a wider use of modern statistical learning tools such as non-linear (spatio-temporal) regression and classification techniques, and simulations. Finally, we would embrace an even further development of synergies between applied and basic research and between researchers based in developed and in tropical countries.


Synthesis Tropical ecology Environmental gradient relationships Biodiversity 



We would like to thank all tropical gradient reseachers whose work provided the basis of the present work. Furthermore, we are most grateful to the Deutsche Forschungsgemeinschaft (Project Ri 370/19-1) for partly funding this work.

Supplementary material

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Supplementary material 1 (DOCX 119 kb)
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Supplementary material 2 (DOCX 35 kb)
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Supplementary material 3 (DOCX 150 kb)


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© Springer Science+Business Media B.V., part of Springer Nature 2017

Authors and Affiliations

  1. 1.Institute of Geography, Friedrich Schiller University JenaJenaGermany
  2. 2.Institute of Ecology, Friedrich Schiller University JenaJenaGermany
  3. 3.Institute of GeographyPhilipps-Universität MarburgMarburgGermany
  4. 4.Institute of Systematic and Evolutionary BotanyUniversity of ZurichZurichSwitzerland
  5. 5.Institute of Ecology, Faculty of Sustainability and Center for MethodsLeuphana UniversityLüneburgGermany

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