The presence of resident communities reduced disease spread and this effect varied considerably between different communities.
During each crisis, Christian Aid has worked through both secular and faith-based local partners, representative of resident communities.
Most have gone home but the combined strength of the two resident communities has grown to about 140,000.
We then used these single-species and one-resource interactions to determine resource consumption patterns (1) between the different members of resident communities and (2) between different resident communities and the invading pathogen.
We used bacterial resource consumption patterns to determine indirect resource competition networks (1) between different members of resident communities and (2) between different resident communities and the invading pathogen.
We found that highly connected resident communities decreased the probability of pathogen invasion success in microcosm experiments.
(a) Spread of bacterial wilt plant disease in the absence and presence of resident communities (control denotes for treatment without any bacteria).
Competition-mediated extinctions within the resident community22 could thus lead to less efficient utilization of resource niche space and expose resident communities to invasions.
(c) Pathogen growth in successfully invaded communities was constrained most when the resident communities had high niche overlap with the pathogen.
Mechanistically, this could have been due to more efficient consumption of resources by highly connected resident communities, which could have prevented pathogen establishment and subsequent growth.
We then assembled resident communities in all possible species combinations (b), and defined resource competition networks characteristics (connectance, nestedness and niche overlap) for all assembled communities.
