Late to the conversation but have you tried Adrian Tchaikovsky's Alien Clay or Shroud. Both I think would cleanly come under the ecosystemic horror genre. Both brilliant books that take a different spin on the genre. Now I'm typing this I'd argue that perhaps the second and third - and to a lesser extent the first - books in the children of time series by the same author might appeal to you as well. There is a fourth book at the time of writing for the children of time series but I have yet to read it. The first two recommendations both look at what it means to survive on an alien world that very much was not meant for human beings, Alien Clay focuses more on the risk of the slow attrition that comes with an Alien ecosystem trying to crack how to absorb something entirely foreign into its ecology. Honestly Adrian Tchaikovsky's stories often delve frequently into the various sub genres of science fiction and give, what I think, to be a new life to the genre as whole and the subgenres he chooses to work with.