When I think of the landscapes which raised me, I see a colour palette. The road from Santa Fe to Albuquerque, lined with red and yellow sand, dotted with green juniper trees, purple mountains rising in the distance. It’s a slow, quiet type of beauty that feels reassuringly constant. As a child, I could easily define what I thought a landscape was: a flat plain and a broad horizon, a big blue sky in a beautifully open space.

A few years ago, I moved to Puerto Rico. The first thing I noticed was the vibrancy of the earth, bright greens and orange clay, turquoise waters. The second thing I noticed was the rapid speed of life. Vines seem to dominate houses and telephone poles overnight; fruit explodes from the limbs of trees in a matter of days. Tree roots overtake sidewalks in rapid flourishes of destruction and creation. Feeling claustrophobic in the steep dips and curves of tropical topography, the third realisation was an epiphany. What we call a landscape can be so many different things: a place, a perspective, and as I was coming to realise, a complex self-organising system that can know, and remember.

My childhood love of nature drove me to study ecology, eventually specialising in landslides in tropical mountains. The science behind ecological landscapes is defined by a series of generalisations about their dynamics, sourced from physics and mathematics. One of the first scientific definitions of ‘landscape’ that stuck with me focused on a coming together of different things: ‘[an] area that is spatially heterogeneous in at least one factor of interest’.[1] In other words, landscapes are made up of different smaller components. In this vein, ecological landscapes fall into the broad category of ‘complex systems which self-organise’ – order arises from interactions on small scales rather than top-down construction. The interactions of these innumerable components, of slow and fast processes mingling together at various scales, determines a landscape and its dynamics.

As I shifted to this more scientific perspective, I was struck by something. My personal interest in landscapes stemmed from their comparative distinctiveness. However, even distinct landscapes are guided by similar patterns of internal heterogeneity; it’s the diversity within a landscape that makes it what it is. This diversity of components within landscapes contains a kind of knowledge distinct from that gained through human experience. These components and their interactions constitute a landscape’s pool of experience, refined by environmental pressures over time. Ecologists call this landscape memory.

Landscape memory arose from that vibrant branch of ecological science concerning resilience.[2] A basic definition might be ‘the influence of past landscape states on future landscape states.’[3] Landscape memory is seen in the behaviour of black tailed deer in a recently burned forest, who come to prefer habitat less prone to high severity burns,[4] the response of coral reef communities after period of heat stress,[5] and pine seeds which have evolved dependency on fire to germinate[6]. This memory includes patches of land which have recently experienced landslides, or forest fires, and so lack the fuel to support similar events in the immediate future (this pattern is sometimes described as landscape immunity).[7] Together, landscape memory encompasses a sprawling array of processes, from large scale evolution to behaviours formed within single lifespans.

Under this definition, landscape memory is a presence: a series of processes that come to resemble knowledge, retained in a wide array of forms to guide future development. It is also useful to think of memory as an absence: that which is not useful is forgotten. If landscape memory is a landscape’s knowledge, the adaptive cycle is how a landscape learns and forgets. The adaptive cycle maps a buildup and breakdown in four stages.

We might enter this cycle at the stage of ‘exploitation’, where a relatively clean slate leaves room for growth. To use the example of a forest, young trees would sprout from seeds and propagules, building small communities. Competition intensifies during the following stage, ‘conservation’, and established residents block the growth of other trees and vegetation. ‘Release’brings a disturbance, like a forest fire or a landslide, signalling a breakdown. Disturbances have a bad reputation, but defined simply, they are a release of built-up energy. After disturbance comes ‘reorganisation’, a period during which a landscape fosters new growth. Surviving aspects are central to regrowth, while that which does not survive is removed, or transformed into something useful. Familiar plants and animals return to a disrupted landscape, rebuilding as they have for millennia. When the cycle starts over again, it builds on a similar trajectory to the last. However, everything is slightly different: experience guides the way towards more resilient strategies.

The adaptive cycle is a powerful generalisation. In viewing landscapes in parallel, with seemingly different events representing similar stages, something can be learned without directly experiencing it. For landscapes, there is some evidence that the memory of a specific disturbance carries over to others.[8] This may be helpful as global heating drives novel weather patterns, conditions, and disturbances, of which landscapes lack adaptive experience and so do not ‘remember’.[9]

After years of study, I’ve realised how difficult it can be to define a landscape. In ecology, a landscape is a set of patterns and processes that propagate through space and time. An artistic landscape refers to a perspective. A body is a landscape, with microbial communities which have their own dynamics, and an immune system constantly battling for equilibrium. We speak of political landscapes, where standards of order set from above are challenged from below. Exploring landscape memory reveals much beauty and many lessons, especially as it draws our attention to small scale, self-organising change, interrelation, and the way that the natural world remembers and adapts. Perhaps these lessons could help us locate beauty as we navigate the chaos of the other many overlapping, interwoven landscapes we find ourselves in today.