There are elements of Arthur Machen's work throughout the novel, as one reviewer points out in a blurb on the back cover. Of course, Lebbon has a character talk about an Arthur Machen story early in the text, so there's a signpost here, brightly illuminated. It's Machen's "The Terror," in which animals launch an attack on humanity, that's referenced in the novel.
However, there are other Machanesque touches as well that recall other works, especially a discussion of what true natural evil would look like ("The White People") and Machen's ideas of reality being perhaps too horrible to contemplate without some mediation ("The White People" and "The Great God Pan," among others).
Lebbon doesn't attempt to write like Machen. The Nature of Balance is more like SplatterMachen, with all the explicit blood and guts and gore and sexual ramifications shown where they were only (strongly) implied in Machen's early 20th-century work. It works because of Lebbon's strong hand at characterization more than anything else.
The litany of horrors can get a bit repetitive after awhile (never have so many things smelled so "rich" and "meaty" -- the line between gross-out and dog-food commercial can be a thin one). But Lebbon also exhibits a great deal of creativity in depicting Nature gone mad at warp-speed. There's actually something Miltonic in some of the descriptions of what is, I suppose, a post-post-lapsarian landscape, a world in which once again everything has changed, changed utterly. But there's also hope, and hopeful characters amidst the rubble and the crawling tentacles of malevolent trees. Recommended.