• KiLi Sub Project 7:
  Effects of climate und land use change on biodiversity and ecosystem functioning   of pollinators and decomposers

From 03/2010 to 07/2016

Project leader:  Ingolf Steffan-Dewenter, Roland Brandl
PhD student:  Alice Claßen, Juliane Röder,William Joseph Kindeketa, Antonia Mayr, Sara Frederiksen, Henry Njovu
Counterpart:  Mary Gikungu, Paul J. Msemwa

Arthropods are the most diverse group of terrestrial animals with fundamental importance for the functioning of ecosystems as pollinators, decomposers, herbivores and predators. During the first phase we established the sampling design and collected data on diversity patterns of bees and soil animals as well as plant-pollinator interactions and decomposition along the elevational and land use gradients of the Kilimanjaro. In the next project phase we plan to continue and extent this research:

(I) One focus will be on the functional and phylogenetic diversity of selected arthropod lineages. This focus is based on the hypothesis that the importance of biotic interactions decreases whereas the importance of habitat filtering increases with elevation.

(II) We will furthermore focus on multitrophic interaction networks as well as key processes triggered by arthropods to understand the variation of density and diversity of pollinators, soil animals and herbivores. For pollinators this work is based on the hypotheses that plant-pollinator networks are more specialised in natural systems than in disturbed or managed systems and that pollination limitation is most pronounced in natural systems at high altitudes and in disturbed or managed systems. Further, we test the hypotheses that rates of herbivory and decomposition increase with decreasing elevation, increasing mean temperature and nutrient level and, for herbivory (decomposition), are higher (lower) in disturbed or managed compared to natural ecosystems.

(III) We will perform an experiment of the combined effects of biotic interactions on ecosystem functioning.

(IV) Finally we will start to develop an area-wide indicator system using up-to-date developments in remote sensing.

Data on diversity, traits, phylogenetic and biotic interaction for arthropod pollinators, herbivores and soil animals will be sampled on all 60 study sites. Labour-intensive exclosure and translocation experiments to quantify diversity-functioning relationships and adaptation mechanism can be only performed on a subset of sites including the 12 intensive study sites or in the three experimental gardens (880 m, 1440 m and 2200 m a.s.l.).