TITLE: Diagrams to summarise Biodiversity - Ecosystem Function 
Research
DATE: 2021-06-01
AUTHOR: John L. Godlee
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I've been writing the background and introduction chapter of my PhD 
thesis. In it, I write about previous research into the 
"Biodiversity - Ecosystem Function Relationship", the idea that 
variation in biodiversity affects the way ecosystems function. To 
visualise some of the breakthroughs over the last 30 or so years I 
decided to make a schematic diagram. The diagram is below, with the 
lengthy caption I included in the chapter.

  ![Schematic diagram visualising some key breakthroughs in 
biodiversity - ecosystem function 
research](https://johngodlee.xyz/img_full/befr/befr_graph.png)

Schematic diagrams illustrating various inferences made on the 
Biodiversity - Ecosystem Function Relationship by previous studies. 
a) The classic BEF relationship found by many small scale 
experiments (Cardinale, Srivastava, et al., 2009). b) As more 
functions are considered simultaneously the minimum species 
richness needed to maintain overall ecosystem functionality 
increases, also showing how the proportion of functionally 
redundant species increases as less functions are considered (i.e. 
the curve reaches asymptote at a lower species richness) (Hector 
and Bagchi, 2007). c) The saturating relationship of the number of 
ecosystem functions considered and the number of species 
influencing ecosystem multifunctionality (Hector and Bagchi, 2007). 
d) As studies progress through time the strength of the BEF 
relationhip increases, the rate of increase in ecosystem function 
increases as species richness (S) grows (Cardinale, J. P. Wright, 
et al., 2007). e) As studies progress through time the shape of the 
relationship becomes more linear, saturating at progressively 
higher species richnesses. Studies averaged over longer periods 
exhibit a greater loss in ecosystem function in response to an 
equivalent species richness reduction (Reich, D. Tilman, et al., 
2012). f) When functional richness is used in place of species 
richness, the relationship reaches asymptote at a higher richness. 
Additionally the relationship becomes more concave as a power 
coefficient representing the strength and number of species 
interactions increases. FR gt1 (interspecific competition greater 
than intraspecific competition (unstable)) results in a convex 
relationship, while FR lt1 results in a concave relationship (Mora, 
Danovaro, and Loreau, 2014).