[Spoiler warning to end all spoiler warnings. You will find out about just about everything that happens in these books.]

I have, as I’ve said before, a considerable taste for dystopian and apocalyptic fiction, moreso in recent years than previously; and according to actual published scientific research (!!!) it is not just me. Apparently, the future disappeared as a place people could fathom and predict about thirty years ago, and it has not come back. (But more about that when I review the book I read this in. I’ll have to finish it first, which is going to take a while, because I can only read it in thirty minute increments on the elliptical machine. Any more than that and I find myself clutching my head and wondering what my daughter’s life will be like.)
But when I hear the Southern Reach books described as horror, I can’t agree. The Southern Reach trilogy is only a horror series if you see Nature as other. If you like boundaries between Human and Nature, you will find these books horrifying, because they erase those boundaries. But nothing dies in these books–at least, nothing that people don’t kill. Any damage done by Area X to human beings is either to our artefacts (and big deal) or to the specific shapes of our bodies. Humans become Other in Area X: first utterly entranced by the cornucopia of wilderness on every side, then changed, then something else entirely. It’s hard for me to see becoming a bird, or a marmot, as a terrifying fate. Particularly when through this process the rest of nature is saved.
Southern Reach inspired the kind of detailed, nerdy, reference-saturated book reviews typically reserved for english theses, and for good reason: a reader could spend a good long time peeling back the layers without hitting the core. Widely agreed on is that they are densely atmospheric, eerie, concerned with our environmental plight, filled with alienated characters whose human identities are slowly stripped away, and not the least bit concerned with your personal need for closure. The books rate a bunch of 5-star ratings and a bunch of 2-star ratings on Goodreads: people either loved it, or complained bitterly about how odd it was and how they wanted it all tied up with a nice neat bow. (Hint: if you like your bows nice and neat, pass this series by and pick something more traditional up.)

So you may (almost certainly in absolutely no way whatsoever) be interested in the main themes of the novels, expressed as a collection of analogies and metaphors:
1. Decay. Things rot, fall apart, rust, are covered in lichen, are soggy, soft, falling down, skeletons are bleaching, floors ripped out by seedlings, and so on–a few times on every page.
2. Light. Specifically, from Area X. Area X is jam-packed full of light references. Stars. Sun. The moon, sometimes with a halo. Area X infections described as an internal brightness. Things glow that shouldn’t. From other geographies and locations, no light. Lots of darkness.
3. Birds. In a larger respect flying things in general, such as insects and bats, but mostly birds. Birds everywhere. Birds all over the damned place, including one small bird in the Southern Reach cafeteria who took up a fair bit of page space in volume 2.
4. Sea monsters. Sometimes just fish and other watery critters, but sea monsters mostly. The word “leviathan” comes up an awful lot.
5. Unhappy marriages. Spouses either die or get divorced. All of them. Or people stay single and are never married. There is no one in these books who has a happy marriage. Relationships in general are fraught. Some friendships are close, but the characters are in general people with few connections to the people around them. Parents are abusive or at least not affectionate or die or abandon children or are otherwise lost. Friends lie to each other and keep secrets. People fall in love with people who don’t love them back.
6. Alienation, particularly with the Biologist. I’ll come back to that.
7. Religion, but no faith. Preachers, sermons, gods, shrines, temples, etc., all over the place. No prayers. A very odd, central piece of religious writing apparently conceived by Area X, without any reference to any deity.
8. Nature vs. civilization. The human destruction of the environment is a constant drumbeat under the story. Pollution, toxic waste, illegal dumping, extinctions, and so on, are constantly discussed, and constantly contrasted with the “pristine wildnerness” of Area X: “The air was so clean, so fresh, while the world back beyond the border was what it had always been during the modern era: dirty, tired, imperfect, winding down, at war with itself. Back there I had always felt as if my work amounted to a futile attempt to save us from who we are.” (p. 30, book 1) (I hear you, B.)

9. Transformation, succession and transition. Things are constantly changing from one thing into something else. Most notably (and I venture to guess for most people most frighteningly), people become something else: animals, monsters. A lighthouse doubles itself and becomes a tunnel (that the biologist insists on calling a tower, and which seems to have a lot of light in it for something underground).
First Digression: Succession ecology:
One of the things I loved about this series is that Vandermeer so clearly did his homework. The biologist is a succession ecologist, and it is a perfect fit for the themes of the books, so it’s worth exploring what that is a bit more.
Succession ecology is the discipline that studies the transformation of one kind of environment into another kind of environment. When a forest grows in an old meadow, for example. Different communities of plants and animals succeed each other in more or less predictable ways in a journey to what’s called a “climax ecosystem.”

Now.
The first and most major caveat of succession ecology is that there are no value judgments.
Forests are not “better” than meadows. The various successional habitats that will grow and change on that landscape on the way to the forest are not “improvements” or “progress.” It’s just a description of what is, what it becomes, and why. As a professor of mine put it, a trucker drives by the same forest every few months and throws his cigarrette out the truck window. Sometimes it starts a fire. The first three times, the forest grows back. The fourth time, it becomes a blueberry patch. The forest is not better than the blueberry patch. The blueberry patch is not better than the forest.
But the progression of the burnt patch of ground (it could be caused by people; alternatively, by a natural process such as a storm or disease) towards something stable and long-term follows a fairly well-known progression. You start with the opportunists, the pioneering plants who like lots of space, sunlight and nutrients, all of which you get in the newly disturbed ecosystem. We like to call these plants weeds, and indeed weeds do love human habitats because human habitats are constantly disturbed. Lawns are little more than intentional high-maintenance disturbed habitats which, if left to their own devices, would become climax ecosystems. In my part of the world, if you leave your lawn alone for ten years, it becomes a young forest (probably maple/ash/beech). But we don’t leave them to their own devices; we interfere constantly with succession, and then complain when the opportunists love all the light, space and nutrients we so thoughtfully give them.

In a non-human environment, what happens is that the pioneers (weeds) start to crowd each other out: there is less light, fewer nutrients, and the plants start to cast shade on the ground, making it difficult for their own seeds to grow. A new community of plants and animals adapted to conditions of greater scarcity starts to take root. This process then repeats itself until a plant and animal community that is compatible with the conditions it creates–that can grow and flourish within the nutrient, sunlight and space it itself makes–establishes itself. These may oscillate over time (for instance, maple trees make conditions that are hard for maple seedlings but great for ash/beech seedlings; ash/beech trees make conditions that are hard for ash/beech seedlings but great for maple seedlings; so over time you see them shift back and forth along a continuum that is more or less stable overall). These tend to be diverse, complex, and dominated by species that conserve resources within their own biomass. Forests with big trees in them, for instance. Weeds no longer flourish there.
Succession ecology, both mentioned explicitly and implied as part of the Regular Planet-to-Area X transformation, is referenced constantly. What impresses me about this is Vandermeer’s ability to remain consistent with the value-neutrality of succession ecology when used to discuss what is happening in Area X. Part of Florida coastline becoming a segment of weird-ass alien ecology? Just part of the circle of life, friend.
Second Digression: Invasive Species:
The thing to remember about climax ecosystems is that they’re not permanent. They are very stable, more stable than the various stages that lead to them, but plants and animals are more or less mobile and they like to move around, expand their territory, and find new niches to exploit.
It is perfectly natural for living things to move about. Ecosystems are not museum displays. They change, constantly.
What happens when a species arrives in a new habitat can follow a number of different trajectories, broadly divided into failure, naturalization, and invasion.
A failed species is one that tried a new habitat and did not survive.
A naturalized species is one that tried a new habitat and found a good niche, something that it could use without negative impacts to existing plant and animal communities. It fits in. Queen Anne’s Lace here in Canada is an example. Most of the plants we in Ontario are familiar with are actually not native.
An invasive species is one that tries a new habitat and is able to successfully compete with the existing native species, to the point where it damages the local environment.
Invasive species come up a lot–as examples and as metaphors–in the Area X series.
Is Area X or its originating agent an invasive species, destructive of the environment it found? Or is it an opportunist, exploiting an ecological niche and creating a new climax ecosystem? Or is it a saviour of the existing environment, containing the true destructive agent (humanity) on behalf of the rest of creation? No answer to these questions is ever provided, but they are asked–more or less explicitly–all the time, in all three books.
End digressions
10. Thistles. These books are obsessed with thistles. I don’t blame Vandermeer–I love thistles too. I don’t love pulling them out of rose gardens (don’t ask), but as wildflowers, I can totally understood a good non-tactile love affair with thistles. But these three books talk about thistles to the exclusion of almost any other wildflower that may be present in Area X.

11. Control, and the lack thereof. One of the characters is named Control; he keeps trying to exert influence on the situation and is thwarted at absolutely every turn. But it’s not just him. The Southern Reach agency–an offshoot of Central, which is only two letters off from Control–as a whole is trying to control Area X–contain it, understand it, influence it, and failing for decades. Ultimately every human attempt to understand and prevent what is happening in Area X is an utter failure; the only remotely successful human interaction with it takes place in a context of acceptance (also the title of the third book). As one of the incarnations of the Biologist says, “I’m not an answer. I’m a question.”
At the very end, Control (the character) manages to affect Area X is some unexplained way, but mostly by giving up control, or any attempt at it. He’s just going to throw himself into the mystery and see what happens.
Third Digression: The Biologist & Alienation:
I LOVE THE BIOLOGIST.
What a great character. But so odd (which, to be honest, is why I love her so much). She just hates everyone, doesn’t she? Even the man she married she seems kind of iffy about (at least until the end of the first book).
The Biologist, in both incarnations, is a person who values nature over other people. She can’t keep a job; she doesn’t really have any friends; her marriage is on the rocks; she’s surly, argumentative, obstinate, prickly, and fiercely protective of non-human nature. SHE IS AWESOME.
She’d hate me–I’m human, after all–but I do adore her.
Random selection of quotes from/about the Biologist:
“when you see beauty in desolation it changes something inside you. Desolation tries to colonize you.”
“All three stared at me then, as if I were the strange cry at dusk.”
“I made no friends there, and I wasn’t sure that even long-standing neighbors were friends, either. … I wasn’t looking for much of anything from anyone.”
“I would not become that person the locals saw out on the rocks and still thought of as an outsider.” (but only because she left before they could.)
“At some point during our relationship, my husband began to call me the ghost bird, which was his way of teasing me for not being present enough in his life. … If we went to bars with his friends, one of his favorite things to do, I would volunteer only what a prisoner might during an interrogation. They weren’t my friends, not really…”
“But fun for me was sneaking off to peer into a tidal pool, to grasp the intricacies of the creatures that lived there.”

And at this point, Dear Readers, I have chosen only a handful of relevant quotes from just the first half of the first book.
It’s relentless. Reminders of the Biologist’s alienation from humanity and civilization and her preference for non-human nature aren’t just constant, they’re celebrated. She is the only character who really adapts well to Area X, who copes with it, and can establish herself there. Her alienation ultimately leads to her transformation, not into a fuzzy earth-mammal or -bird, but into an alien, capable of travelling between worlds.
The biologist is not the only alienated character, but she is the only character who appears in all three books and never gets a name. Control has a name–John. The psychologist has two names–Cynthia and Gloria.
In one of the reviews I linked to up-page, the reviewer suggests that Vandermeer is claiming our identities are the source of our misery. Enh. I’m not sure about that. If so, the Biologist would surely be brimming over with joy, but she never is. Her lack of human-identity makes her uniquely suited to long-term adaptation within Area X, but it doesn’t ease her misery. Ultimately, if the books are about anything, I think they’re about our limitations: Area X utterly confounds us and we never are able to solve the mystery. It is alien, truly alien rather than big-bug-eyed-monsters. In her own way, the Biologist is also alien, which may be why she gets along so well there–and why less alienated folks find Area X to be so very frightening.