Unravelling stability‐complexity relationships
2012
Hastings, Alan
[Formula: see text] [ The consumer Ceriodaphnia reticulata. This experiment used a very similar species to the one shown here, namely Ceriodaphnia reticulata. This freshwater cladoceran grazer can consume phytoplankton species that have a maximal axial dimension of upto ∼35 μm. As a result, Pediastrum simplex (CPCC 431), Fragilaria crotonensis (CPCC 269), Asterionella formosa (CPCC 605), and Staurastrum pingue (UTEX1606) would have inedible for Ceriodaphnia dubia. Ankistrodesmus falcatus (UTEX 101) may also have been selected against in some instances due to its large size. Neither C. dubia density nor stability were affected by resource species diversity, although resource community composition did matter. ] Narwani, A. & Mazumder, A. (2012) Bottom‐up effects of species diversity on the functioning and stability of food webs. Journal of Animal Ecology, 81, 702–714. Defining the characteristics of persistent species assemblages is a major focus in ecology. A key set of questions is: how to scale up from interactions between two species to multiple species, what is the role of species characteristics in coexistence and what are the ecosystem level consequences of the characteristics of coexistence. Narwani & Mazumder use meticulous experimental work to look at these three questions simultaneously using carefully controlled microcosms. A key finding is that the relationships between stability and diversity as measured by effects on different trophic levels and different aspects of ecosystem function depend critically on the community composition. The particular species involved are more important than the overall diversity.
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