TL;DR; In order to build a usable biodiversity knowledge graph we should adopt JSON-LD for biodiversity data, develop reconciliation services to match entities to identifiers, and a use a mixture of document and graph databases to store and query the data. To bootstrap this project we can create wrappers around each biodiversity data provider, and a central cache that is both a document store and a simple graph database. This power of this approach should be showcased by applications that use the central cache to tackle specific problems, such as augmenting existing data.
I’ve thrown together some notes on building a biodiversity knowledge graph, and in the interests of making it interactive it's in the form of a web page: http://bionames.org/~rpage/towards-knowledge-graph/. There are buttons to click that display live data, and I hope to dd more examples as I flesh out the ideas. I'm hoping to have a fully-functioning live demo that can be used to explore the notion of a knowledge graph and demonstrate what we can do with it. It will be pretty obvious that this is all a bit crude, but my goal is to try and sketch out a fully-functioning system that can create and query the graph, and support interesting applications.