Where are We Going, Where Have We Been?

Tiger Lily (Lilium columbianum) at Aprovecho

When you look around at the world, what do you see? Trees, shrubs, flowers, buildings, grass, farms, forests, roads, people. Each and every element in a landscape tells a story, and has a history that is entwined with the ecological and social processes at work over time. Understanding a few basic principles of ecology helps to provide context to these elements, so that rather than seeing them as isolated in space and time, we can start to look at them as part of a larger web of stories the world offers us. These stories provide a foundation for making good land management decisions in the future, so we can learn to work with and enhance the natural processes at work all around us. So whether you’re puzzling over a problem with your garden or striving to wrap your mind around a particularly vexing invasive species, start with the long term perspective.

Geology

Developing your sense of history in a place starts with geology. What are the long term processes at work that have shaped the soils you are working with and the topography you feel under your feet? Did ancient volcanoes provide a basis of mineral-rich basalt to your soil? Does an ancient seafloor provide calcium from long-expired molluscs? Did mile-high blocks of ice grind stones into dust as they headed back toward the poles?

Mt. Hood (Wy’East) in Oregon

Getting to know the geologic history of your area is an important first step. In Oregon, we’re lucky to have some fine written resources on the subject. Roadside Geology of Oregon is a fun guide, and books from this series are also available for almost all of the 50 states in the US. I also love In Search of Ancient Oregon by Ellen Morris Bishop. Its a great resource full of pictures from this diverse and beautiful state.

A great guide to understanding local geological history in Oregon

Whatever resource you choose, finding out some basic information about the deep time history of your area is key to developing the first layer of your historic land sense.

Climate

The next influence to consider is how climate has affected the plant and animal communities you see around you. Most plant species are adapted to relatively narrow spectrum of inputs including temperature, moisture, fire, and sunlight. Many plants that we know and love today have evolved in the places where they are over the course of the last 10,000 years or so ~ since the end of the last Ice Age.

Extent of ice sheets (white) and sea level (brown) at the peak of the last Ice Age

However, the changing climate is also changing up these millennia-old relationships. Signs of species decline are showing up all over the world in the form of mass die-offs and lack of reproductive success. On the other side of this troubling trend toward declining biodiversity, there are some species that are doing very well. Some of them, like the Mountain Pine Beetle, take advantage of trees stressed by climate-change induced drought.

Overhead view of lodgepole pine forest with pine beetle damage

These beetles have killed over 1.5 million acres of lodgepole pines in the Intermountain Western US and Canada, with no signs of stopping. Although they’re often seen as the cause of death for the pine trees, they actually represent the endpoint in a long history of ecosystem change that started with warmer winters and drier summers.

And its not just the lodgepole pines – signs of climate change-induced stress in ecosystems are showing up everywhere if you know what to look for. A few points to consider when assessing how climate change may be affecting your local ecosystem include:

– Are there species or groups of species that are experiencing die-off or “attacks” from “pests?” Keep in mind that so-called pests are filling a role in the ecosystem as well, and are usually proliferating in response to changes (such as climate change-induced stressors) that are already present.

– Are there particular invasive species that seem to be running rampant in your area? Recent research suggests that many invasive species have just the right traits to survive and thrive in a changing climate.

– Species are on the move both upwards in elevation and towards the poles to find the temperature regimes that they prefer. Some – like animals and insects – can do this more easily than others – like plants and trees.

Succession

Understanding the ecological phenomenon of succession is key to reading the landscape and interpreting its stories. A working knowledge of what the various stages of succession look like in your area can provide a basis for understanding the stories that the plant and animal communities you observe can tell.

Ecological succession (Source: www.wikipedia.org)

The image above shows succession as a cycle that moves from a mature (or climax) ecosystem through to a disturbance like a fire or landslide, which creates space for pioneer plants like annual and short-lived grasses and forbs (flowering plants). Over time, longer-lived perennials like shrubs and small trees take root, grow, and form a canopy that excludes the early successional species. A disturbance comes, and the cycle begins again, and again, inexorably.

So when you look at a landscape through the lens of succession, you can place what you’re seeing in the following categories: the disturbance, its immediate aftermath, more established vegetation, or plant communities that have been there for a very long time. In most ecosystems, the timeframe through which an ecosystem moves from bare ground to climax forest takes place over the course of a few hundred years, so keep this in mind as well. Even if an area doesn’t look like its changed over the course of a few years, you can be sure that the plant communities you see are part of this successional story.

Water

Water is another factor that shapes landscape, by its patterns of both presence and absence. Its influence can be seen everywhere if you know what to look for. Today, most waterways have been confined to singular channels, but familiarizing yourself with historic floodplain areas is a great way to start thinking about water’s influence on the landscape.

Historic flow channels of the Mississippi River

This map of the historic reach of all the meanders of the lower Mississippi River illustrates just how much water can shape a landscape. Each and every one of those colorful strands represents a river channel where silt and nutrients were deposited, where riparian vegetation grew, where frogs and herons found refuge. As the Mississippi River became more and more important for burgeoning shipping and manufacturing industries, confining it to one major channel became a national priority. Without the meandering river, the ecosystem elements and the relationships they embodied that once flourished in the area are also lost.

Busy beavers ~ the greatest ecosystem engineers

Another huge factor in shaping aquatic landscapes in North America at least is the beaver. These ecosystem engineers are responsible for creating the character of streams and rivers by their dam building activities, which slow down water and allow it to be used by surrounding vegetation. Beaver ponds also change the channel structure by encouraging flooding and creating nutrient-rich floodplains.

Over the course of the last few centuries, beavers have been trapped out of almost every major waterway in North America. Their dam building and floodplain making activities are not generally welcome where people like to build and farm (on those flat lands near waterways that were probably made that way at least in part by, well, beavers). Their extirpation from riparian areas has changed the character and quality of many a stream, making them flow faster and dirtier, and in many cases impairing their year-round nature making them flow seasonally. This in turn affects fish populations, streamside vegetation, and populations of amphibians, birds, insects, and mammals that make use of the riparian ecosystems. Beavers change rivers and rivers change with (and without) beavers.

Culture

Once you’ve got a good sense of the geology, climate, plant ecology, and hydrological dynamics, the next layer to add is the influence of human cultural management of land. Understanding the influence of people on the landscape over time is a huge factor to consider and familiarize yourself with in order to get a sense of what you’re seeing on the ground today. Its critical to acknowledge first and foremost the widespread influence that indigenous people had in managing landscapes prior to European contact. The belief that the US, Canada, Australia, Africa, and other colonized landscapes were mostly uninhabited “wilderness” is quite simply wrong, and it perpetuates the mistaken concept that the land European travelers encountered 500-odd years ago was there for the taking. It wasn’t.

Some of the major Tribal groups of Turtle Island (Source: www.trinityhistory.org)

There’s so much more to this story that can’t be covered here, but I encourage you to look into resources like An Indigenous People’s History of the United States by Roxanne Dunbar-Ortiz and Braiding Sweetgrass by Robin Wall Kimmerer.

What’s important to relate when you’re learning to read landscapes is that all landscapes have been managed by people for a long time. Wherever people have been, they’ve been altering ecosystems – lighting fires, managing herds, tilling the soil, tending crops, diverting water, planting trees. All ecosystems bear the marks of human management over the course of thousands of years. How can you tell?

Well, this goes back to succession. Whether we’re talking about plowing the soil with oxen to plant lentils and barley in Jordan, driving massive herds of buffalo across tallgrass prairies in the US, or planting peach palms and Brazil nuts to alter the rainforest canopy in Brazil, people have always worked with (or against) the forces of succession to get their needs met. Although food production isn’t commonly associated with ecological succession, in reality every action farmers and food producers take is rooted in this basic ecological premise.

For example, modern conventional agriculture is basically a study in working against succession, with tilling the soil setting the stage for primary successional species (including both most annual crops and weeds) growing rapidly. Of course, farmers prefer the crop plants to the weeds, so weed management using mechanical or chemical means becomes necessary. Pioneer species with their short life spans are also prone to diseases and “pests” – the name often given to organisms that eat the things we also want to eat. Hence the apparent need to apply pesticides in the conventional model. The cycle continues year after year as the soil is continually disturbed and the same types of plants are planted.

Other food production systems work more closely with succession, such as the traditional Mayan milpa cycle shown below. In this system, the older forest is cleared to make room for annuals like corn and beans and short-lived perennials like sweet potatoes and papayas. Longer-lived fruit, nut, and fiber-bearing trees like citrus and cherimoya are planted within these first crops, mimicking the shrub and small tree stage of natural succession. Longer lived and slower growing trees like avocado and mango are also planted at this time, which eventually form the canopy of the food forest.

  Milpa Cycle (Source: www.alma-mexico.info)

This type of successional management was (and still is in some places) practiced throughout the world by peoples not considered “agricultural.” These systems are more productive and ecologically beneficial than agriculture as it is currently practiced, so it stands to reason that land managers should be learning from the people still practicing these techniques and adopting them within the context of current agricultural practices.

There’s also plenty of evidence on the ground of these systems that have been lost and abandoned over the course of the last few centuries of indigenous displacement and forced assimilation.

Roasted camas bulbs

In my area, there are still some areas where camas (Camassia quamash) a perennial lily with an edible bulb that was one of the main food crops of the Kalapuya people. Researchers estimate that a family of 5 required approximately 6 acres of camas for their yearly supply. With an estimated 100,000 people living in the Willamette Valley prior to European contact, that comes to around 120,000 acres of camas planted in the region.

And camas is just one of the crops that were grown. Tarweed (Madia spp.), wapato (Sagittaria latifolia), mariposa lily (Calachortus tolmeii), and many others were intentionally cultivated as food crops. So anywhere you see them today, you know that you are standing in what used to be someone’s garden.

 Mariposa lily (Calochortus tolmeii)

Then we come to understanding how the land management decisions made after colonization have affected what we see today. Dramatic changes to landscape form, function, and process followed in the wake of introduced species like cattle, pigs, and sheep, as well as the agricultural practices they are entwined with. Today most of the landscapes we interact with on a daily basis are highly altered from what they once were.

Plastic trash island (Photo by Caroline Power)

However, this doesn’t make them any less natural. Every part of the living ecosystems on Earth are connected and responding to the each and every change that we and other species make. And, humans have been modifying their home environments for as long as they’ve been around. So its natural…but, the type and scale of landscape changes we’ve wrought over the past few hundred years, and especially since the Industrial Revolution are unprecedented in the history of our species. We don’t know whether we’ll be able to survive and thrive in the ecosystems that result from the choices that have been made in our recent history.

But this sobering reality is part of the story as well ~ it is certainly possible to maintain a thriving landscape while meeting our own needs. We just have to dig a little, think broadly, remembering the past and projecting forward into an abundant future.

Putting it All Together

So when you’re looking at a landscape, you’re seeing a multilayered story – one that is affected by geology, climate, ecological succession, water dynamics, and human management and mismanagement. Any one element that you’re looking at, whether an old growth oak tree to a thistle on the planting bed of the Costco parking lot, contains every element of these stories. Taking the time to unpeel these layers and delve into how they intersect to form the tapestry of landscapes we see from moment to moment helps us to understand how we can best begin to steward these powerful yet tenuous relationships.

We’re in a moment of our history where the trajectory that we decide to take as a species has enormous ramifications for both future generations and the rest of life on the planet. Its up to us to endeavor to learn as much as we can about the living systems that surround us so that we can know how to best interact with to enhance, rather than detract from them as we pursue our livelihood needs.