Reforestation Isn’t Just Planting Trees
Planting trees is great, but when it comes to reforestation, we should take into account the complexities of forest ecosystems.
This year, we decided it was time to do some major work on the roof of our little house, after spending way too much time watching sawdust come out of our beams, from whatever civilization of bugs that was building their cities within the wood. Having the bad habit of turning a pretty big project into something closer to daunting, I decided that if we had to replace much of the roof anyway, we might as well just build an entire second story. And having the anti-serendipitous timing that I seem to so often, I chose a dry season that happened to be substantially wetter than the last two rainy seasons!
This blog entry was inspired by the days that I’ve been up in the many hectares of pine that cover the top of the Sacred Sueños eco-Sanctuary, felling, peeling, cutting, and assembling the many pieces of wood that will be necessary to complete this project. I’ve got to admit that it’s beautiful up there, not only for the view that just keeps getting more magical the higher one goes. The fresh and grounding smell, the cushion of needles, the calming sound of the wind through the tree tops, so many large (and extremely useful) trunks shooting up like pillars holding up the sky, all of it consistently brings me a sense of peace and contentment. I think some of my delight must come from my childhood among the forests of Northern Canada.
Yet even as I’m relishing in all that beauty and peace, I look around and take note that there is one significant feature that is almost completely missing: substantial biodiversity. After more than two decades since these pines were planted, there are very few plants that have survived the steady rain of acidic needles that now cover most of the floor between pine trees. Rarely have I heard birdsong. I see no trace of mammals. I realize that I am surrounded by hundreds of trees, yet I’m not in much of a forest.
During much of the 90’s, Ecuador had the sad reputation of being near, if not at, the top of the list of countries that had been destroying the most forest/area in the world. Most of that appeared to be on the coast, destroying dry forest for cattle, and mangroves for beachfront properties and shrimp farming. The sierra, however, also took a big hit, most of it burned for cattle. I’ve noticed that very few farmers around here are stupid enough to burn their riparian zones, so as not to destroy their springs, but deforesting their ridges and hillsides inevitably had a negative affect on the land’s ability to absorb rainfall and distribute water in a way that regulates a springs flow through the seasons. Something had to be done, and so the UN sent money for Ecuador to reforest.
Every time I visit the Podocarpus National Park, I am reminded about all the majestic and gorgeous trees that are native to the Andes. Not just the only native conifer of Ecuador, which the park is named after, but dozens of other species thrive just hours hiking from my home. Some of these even produce fruits, nuts, and absolutely gorgeous wood for building and crafting. The only problem is that they grow slowly, and some don’t grow at all unless they spend a good portion of their youth already within a functioning forest ecosystem.
The Ecuadorians now had money to plant trees, but they needed some way to convince the poor farmers (they were substantially more impoverished then than they still are today) to dedicate their land to trees rather than the crops and livestock of which they were dependent on for survival. If they only had access to my superpower of retrospective idealism, perhaps they would have taught the farmers about all the non-timber forest products that could be harvested through the planting and management of successive ecologies within an analog forest. As it was, they chose a simpler option: focus on extremely fast growing and easily harvestable and millable species. In the end, they chose only two, none of which were native to South America: Eucalyptus and Pine. My predecessor here accepted a good amount of money to plant Pinus radiata.
Lying on that cozy cushion of needles, looking up at the emerald glitter as the trees swayed in the wind, I time-travelled to my youth so immersed within coniferous forest. As a boy scout, I always loved the time of year where we raised money and planted hundreds of trees within the desolation of a recent clear cut. I hadn’t considered that we were usually only planting one or two trees. It wasn’t until much later, in my late teens, picking blueberries in a newly planted clear-cut, that I came upon a sign warning that during certain dates it was not advisable to be in the area. The reason was for aerial herbicide spraying. Memory is a fuzzy thing, but I think it was at that moment that I realized those boy scout planting days had very little to do with reforesting, and more to do with replanting a future clear-cut. I may as well have been planting corn or any other farm crop, just with a much longer timeline between harvests.
At least those plantings were of trees that had historic synergies with the natural ecosystems. Regardless of herbicide spraying, nature would inevitably reintroduce the many shrubs and groundcovers, as well as the insects, birds, and mammals that entertained and nourished the communities of my youth. The pine plantation within Sacred Sueños offered no such synergies, no such habitat. From the satellites above, the UN may have thought their mission accomplished, seeing the browns of deforestation turn lush green. But from my perspective under that canopy, I could see that there weren’t any more forests than before, at least in the short term. A study at the Universidad Nacional de Loja did reveal that there is some ecological succession within the understory of a pine plantation, as long as the trees are separated far enough, and the plantation is over 30 years old (by which time, most are harvested, or been burned for more immediately productive projects). Even though there was a good amount of diversity in their study, it’s nothing compared to what a native-dominated forest contains. There’s no doubt that Pine inhibits healthy forest succession.
Please don’t get me wrong: Whether or not they are part of a forest ecosystem, I do love trees. There’s a lot to appreciate them for, on their own. They are gorgeous. They often serve as habitats for other species, to the point of being an micro-ecosystem on their own. Some provide us with food, fuel, lumber, and other products. Their leaf litter can mulch the soil, increasing tilth and regulating temperature and humidity. Their roots often procure minerals that are missing in the top soil, in effect mining nutrients. They protect the area around them from the harshness of a beating sun and strong winds. They also pump water from the depths, transpiring it through their leaves, so as to increase the humidity around them. This not only assists in regulating the humidity in areas (like here) that have excessively dry seasons, but is actually essential in the generation of clouds. The little rains from the East that serve as a gentle respite during our dry season, is actually Atlantic water that has fallen and been transpired through trees to form rainclouds once again, probably a dozen times before landing on my forehead. If it weren’t for all those trees covering the Amazon, that raindrop on my forehead wouldn’t have made it very far at all.
I love trees, but I would be missing so much if I reduced all the other flora and fauna of the Amazon, and only thought about those water-cycling trees. I would lose tens of thousands of species, many of which offer known and unknown gifts to us, in the form of foods, medicines, erosion protection, flood regulation, and so on, and so on. It is that plethora of interacting species that make the forest what it is, and trees are but one humble yet majestic component.
That canopy of trees alone, devoid of the multitudinous species below them, interacting in so many ways, would be but a thin shell of the rainforest that it once was. In actuality, those trees wouldn’t last long. They depend on the vegetation below them to hold the soil and direct the rivers. They depend on the insects and animals to fertilize their flowers and disseminate their seeds, and to bring nutrients and organic matter from afar. Take away most of the life below them, and soon those majestic trees, themselves, will perish.
Of course, just as many of those trees couldn’t survive without the ecosystems of which they are but a component, they also couldn’t have germinated and grown in the first place, were it not the ecosystems that planted and nurtured them. Even these pines are an example of that.
When Pinus radiata was first introduced to South America, it was an abject failure. They grew slowly, if at all, and most could not survive the dry season. The only difference between those pathetic first trees, and the ones that now thrive so easily throughout the Andes, has nothing to do with the trees themselves. It has to do with what else is living in the soil, another ecosystem that is often neglected when thinking about forests. Once another attempt at introducing Pinus radiata was made, this time also introducing some of the soil from where it grew wild (now central California/northern Mexico) , the trees took off, easily coping with the often poor soil and extremely dry conditions. In this case, it was as simple a component as a symbiotic relationship with a bolete mushroom, that extended the reach of the tree’s roots substantially, and chelated minerals that the roots couldn’t access. This is but a simple example, but in natural ecosystems, all the inter-relationships are so wonderfully complex, that we can only pretend to grasp a little of it.
What we can observe easily, even with the most complex ecological dynamics, is that an old growth forest does not sprout from an empty field. Rather, it comes at the tail end of a long line of other ecosystems that replace on another over long periods of time. This is called ecological succession. That field will have it’s own ecosystem, made of herbs and then shrubs, which eventually change the environment enough to bring in other species, both above and below the ground. We would observe the odd pioneer trees finally sprout and grow out of that shrub land, and then below them come different trees, waiting for the pioneers to die before taking their place as the prominent species. All the while, the other flora and fauna are also changing, each succession generally getting more biodiverse and complex. This process can take decades, sometimes centuries, before we end up with the glory of an old growth system.
I would be a conceited fool if I pretended to know even a fraction of the necessary species and interactions that it would take to get such a forest established. But I can say for sure how it most often doesn’t work: just plant the tree on it’s own. Perhaps, if the soil is already extremely similar to that forest floor, and if many of the species that this tree needs to protect, nourish, etc., are already nearby, then there could be a chance of success. But if you’re taking a degraded area, or a very distinct ecology such as grassland, I’d recommend a strategy that honors ecological succession towards reforestation.
My current advice is the result of doing the conventional opposite, and watching many do the same in my area. As Ecuador slowly rose out of abject poverty, their reforestation policies began to reflect that, paying more attention to native trees over the quick return of Pine and Eucalyptus plantations. I joined the hundreds who were picking up free trees of Andean Walnuts, Podocarpous, and the like, to plant. Many were even paid to clear the land and plant. I don’t know anyone who had a tree survival rate over a small percentage. Thinking about it, I observed that we were trying to create a forest the same way those pines were planted: with the paradigm of a farmer, not a forest.
I was already experimenting with the forest paradigm on large parts of the Sacred Sueños Sanctuary, mostly because it was too big for one kid, and I couldn’t work intensively everywhere. At the time, with the paradigm of a farmer, I thought I was cheating. Now, I’ll stroke my ego a bit, and say that it was the intelligent approach. Here are some of the things I did:
1. Observation and Seed Gathering. This was my excuse to go for hikes around these beautiful mountains, often into the Podocarpous Park itself. I was looking for areas that had also once been cleared, often in places that predated and are now encompassed by the park. This not only gave me the opportunity to see how ecologies naturally succeed, and what the main species are within each stage of ecological succession. I also had the opportunity to learn that, even without the destructive habits of humans, nature has it’s own way of hitting the reset button and starting from scratch. In this bioregion, that reset button is the landslide. Having old forest, recent landslide, and all the stages in between, facilitates a phenomenal amount of biodiversity. I tried to categorize the different stages of succession, and did my best to collect seeds from each. To be honest, I’m not sure if I needed those seeds. My proximity to the park, and all the birds and mammals within it, meant that I had an army of seed planters that I didn’t know about. All I had to do was not disturb them, to let them do the job themselves. For most of the Sanctuary, through most stages of succession, that is exactly what is happening.
2. Prune, Prune, Prune. Reforestation using the paradigm of a forest is time consuming enough, but letting ecological succession take it’s natural course can take even longer, centuries even. That is because the main species at each stage of succession, upon reaching maturity, will try to inhibit the upstarts from overtaking them. It makes sense that these plants want as much time as possible to be the dominant species, spreading as many seeds as possible before they are overwhelmed. This is called allelopathy. In many cases, it can be decades before those dominant species finally get to old, or are disrupted, and a burst of new growth brings forth the next stage of ecological succession. In some areas (not all, because I just don’t have the time and energy), I reduce allelopathy, and speed up the successions, with the help of the trusty machete. Not only do all those cuttings add large quantities of organic matter to the soil, preparing it for the next succession, but the heavy pruning initiates a period of vigorous growth, which stops or slows allepathy. I sometimes wish I had more time for this, but I’ve got other priorities, like sustaining my family. Besides, I’m patient. I’m regenerating the land for the sake of regeneration, and not because I want the instant gratification that seems so common in society.
I think that last point probably sums up why people are so eager to plant trees that are supposed to be at the end of ecological succession, before anything else. We all want to see that Nogal (Andean Walnut) in a forest, and say that we planted it. I’m no exception. I have planted a few as a farmer. But it will be a while before I plant them as a reforestor. And that’s OK, as long as I remind myself what the reasons for reforestation are:
-The soil, and springs are as protected and regenerated by the bushes, shrubs, and pioneer trees as they are by old trees. (more so, if you consider how many people actually clear and burn before planting trees).
-There are plenty of products that can be gleaned through each stage of succession, compared to those that come from the trees planted.
-Ecological succession provides habitat for so many other species than just young trees would.
-I have seen no proof that planting trees sequesters any more carbon than any other developing stages of succession would, whether managed or not. It’s important to think of the carbon being sequestered into soil, not just wood.
Let’s keep planting trees, and supporting others who do the same. But it’s time to support those who approach reforestation with a forest paradigm. I see lots of people and organizations paid to plant trees, but perhaps now’s the time to incentivize folk to nurture developing forest ecologies, as well. Of course, you could start with us…